Pedigree analysis of eight Spanish beef cattle breeds - Gutierrez, J P; Altarriba, J; Diaz, C; Quintanilla, R; Canon, J; Piedrafita, J (GENETICS SELECTION EVOLUTION, 2003)
The genetic structure of eight Spanish autochthonous populations (breeds) of beef cattle were studied from pedigree records. The populations studied were: Alistana and Sayaguesa (minority breeds), Avilena - Negra Iberica and Morucha ({''}dehesa{''} breeds, with a scarce incidence of artificial insemination), and mountain breeds, including Asturiana de los Valles, Asturiana de la Montana and Pirenaica, with extensive use of AI. The Bruna dels Pirineus breed possesses characteristics which make its classification into one of the former groups difficult. There was a large variation between breeds both in the census and the number of herds. Generation intervals ranged from 3.7 to 5.5 years, tending to be longer as the population size was larger. The effective numbers of herds suggest that a small number of herds behaves as a selection nucleus for the rest of the breed. The complete generation equivalent has also been greatly variable, although in general scarce, with the exception of the Pirenaica breed, with a mean of 3.8. Inbreeding effective population sizes were actually small (21 to 127), especially in the mountain-type breeds. However, the average relatedness computed for these breeds suggests that a slight exchange of animals between herds will lead to a much more favourable evolution of inbreeding. The effective number of founders and ancestors were also variable among breeds, although in general the breeds behaved as if they were founded by a small number of animals (25 to 163).
Keywords: beef breeds; conservation; inbreeding; probability of gene origin

Photoprotection in evergreen Mediterranean plants during sudden periods of intense cold weather - Garcia-Plazaola, J I; OLANO, J M (Trees-Structure and …, 2003)
The photoprotective responses to an abrupt period of exceptional cold weather were studied in several Mediterranean evergreen species with different ecological requirements. The same pattern of response was observed in most of the species with little change in hydrophilic antioxidants (ascorbate and glutathione) and the carotenoid pool, an increase in the content of a -tocopherol, and a night retention of de-epoxidised xanthophylls (antheraxanthin and zeaxanthin). The accumulation of these xanthophylls correlated with a sustained decrease in maximal photochemical efficiency (Fv/Fm). This reduction in the rate of electron transport would reduce the production of superoxide in photosystem I, as well as the subsequent hydrogen peroxide and hydroxyl radical. Thereby if any transitory photooxidative stress is produced under these conditions it should be due mainly to the formation of singlet oxygen by triplet excited chlorophyll within the antenna. Since a-tocopherol is the main scavenger of singlet oxygen and lipid peroxy radicals, the large increase of this antioxidant within the species could be enough to compensate for the higher degree of photooxidative stress, playing an essential role in the survival of vegetation during the incidence of exceptional cold fronts in the Mediterranean region.
Keywords: a-tocopherol; antioxidants; photooxidative stress; xanthophyll cycle

Photoprotection in evergreen Mediterranean plants during sudden periods of intense cold weather - García-Plazaola, J. I.; Olano, J. M. (Trees-Structure and …, 2003)
The photoprotective responses to an abrupt period of exceptional cold weather were studied in several Mediterranean evergreen species with different ecological requirements. The same pattern of response was observed in most of the species with little change in hydrophilic antioxidants (ascorbate and glutathione) and the carotenoid pool, an increase in the content of a -tocopherol, and a night retention of de-epoxidised xanthophylls (antheraxanthin and zeaxanthin). The accumulation of these xanthophylls correlated with a sustained decrease in maximal photochemical efficiency (Fv/Fm). This reduction in the rate of electron transport would reduce the production of superoxide in photosystem I, as well as the subsequent hydrogen peroxide and hydroxyl radical. Thereby if any transitory photooxidative stress is produced under these conditions it should be due mainly to the formation of singlet oxygen by triplet excited chlorophyll within the antenna. Since a-tocopherol is the main scavenger of singlet oxygen and lipid peroxy radicals, the large increase of this antioxidant within the species could be enough to compensate for the higher degree of photooxidative stress, playing an essential role in the survival of vegetation during the incidence of exceptional cold fronts in the Mediterranean region.
Keywords: a-tocopherol; antioxidants; photooxidative stress; xanthophyll cycle

Plant species diversity, plant biomass and responses of the soil community on abandoned land across Europe: idiosyncracy or above belowground time lags - Hedlund, K; Regina, I Santa; der Putten, W H Van (Oikos, 2003)
We examined the relationship between plant species diversity, productivity and the development of the soil community during early secondary succession on former arable land across Europe. We tested the hypothesis that increasing the initial plant species diversity enhances the biomass production and consequently stimulates soil microbial biomass and abundance of soil invertebrates. We performed ﬁve identical ﬁeld experiments on abandoned arable land in ﬁve European countries (CZ, NL, SE, SP and UK) which allowed us to test our hypothesis in a range of climate, soil and other environmental factors that varied between the experimental sites. The initial plant diversity was altered by sowing seed mixtures of mid-successional grassland species with two or ﬁve grass species, one or ﬁve legumes and one or ﬁve forbs. The results of low and high sown diversity treatments were compared with plots that were naturally colonized by species present in the seed bank. In three out of the ﬁve ﬁeld sites, there was no correlation between plant species number and plant biomass production, one site had a positive and the other a negative relation. Treatments with a high diversity seed mixture had a higher biomass than the naturally colonized plots. However, there was no signiﬁcant difference between high and low sown diversity plots at four out of ﬁve sites. The three-year study did not give any evidence of a general bottom-up effect from increased plant biomass on biomass of bacteria, saprophytic fungi or abundance of microarthropods. The biomass of arbuscular mycorrhizal was negatively related to plant biomass. The abundance of nematodes increased after abandonment and was related to plant biomass at four sites. Our results support the hypothesis that plant species diversity may have idiosyncratic effects on soil communities, even though studies on a longer term could reveal time lags in the response to changes in composition and biomass production of plant communities.
Keywords: Microbial biomass; plant biomass; plant diversity; soil community (voyant)

Population structure of the wild boar (Sus scrofa) in two Mediterranean habitats in the western Iberian Peninsula - Fernandez-Llario, P.; Mateos-Quesada, P. (FOLIA ZOOLOGICA, 2003)
Wild boar population structure was studied in two well-preserved forests of western Iberian Peninsula, one located in a typically Mediterranean zone (vegetation mainly holm oak Quercus ilex and various tall-shrubs species), and the other in a more Atlantic area (mainly oak Q. pyrenica but with abundant cork oak Q. suber in some places). Data were colleted during hunts in monterias' area between the 1994/95 and 2000/2001 hunting seasons (October to February). 972 hunted wild boars were sexed and aged in the field, using growth patterns and tooth attrition. The mean age of hunted wild boars differed in the two zones. 2.11 years old in holm oak forest, and 1.78 years old in oak forest. This difference may result from shurb cover density and its effect on hunting dog, efficiency in rooting out wild boar. However, mean age was similar other zones of Europe. Proportionately more females were taken than males demonstrate the usefulness of Mediterranean hunting in contributing to management and conservation.
The following values have no corresponding Zotero field: pub-location: KVETNA 8, BRNO 603 65, CZECH REPUBLIC publisher: INST VERTEBRATE BIOLOGY AS CR
Keywords: age; Holm oak forest; hunting; oak forest; sex-ratio

Population structure of the wild boar (Sus scrofa) in two Mediterranean habitats in the western Iberian Peninsula - Fernández-Llario, P; Mateos-Quesada, P (FOLIA ZOOLOGICA, 2003)
Wild boar population structure was studied in two well-preserved forests of western Iberian Peninsula, one located in a typically Mediterranean zone (vegetation mainly holm oak Quercus ilex and various tall-shrubs species), and the other in a more Atlantic area (mainly oak Q. pyrenica but with abundant cork oak Q. suber in some places). Data were colleted during hunts in monterias' area between the 1994/95 and 2000/2001 hunting seasons (October to February). 972 hunted wild boars were sexed and aged in the field, using growth patterns and tooth attrition. The mean age of hunted wild boars differed in the two zones. 2.11 years old in holm oak forest, and 1.78 years old in oak forest. This difference may result from shurb cover density and its effect on hunting dog, efficiency in rooting out wild boar. However, mean age was similar other zones of Europe. Proportionately more females were taken than males demonstrate the usefulness of Mediterranean hunting in contributing to management and conservation.
Keywords: age; Holm oak forest; hunting; oak forest; sex-ratio

Preferencias de los propietarios e intervención pública: el caso de las dehesas de la comarca de Monfragüe - CAMPOS PALACIN, P; Mariscal Lorente, P J (Investigación Agraria: Sistemas y Recursos Forestales, 2003)
The public have an increasing interest in Dehesa environmental services (recreation, option and existence values). The growing Government incentives on environmental friendly agricultural practices have given a new opportunity for private economics of natural and environmental resources in Dehesa. This work presents the results from a Delphi questionnaire on owners’ preferences and demands of compensations for undertaking environmental conservation and improvement measures in Dehesa of Monfragüe shire. The private owners of Dehesa are investors that have, at the same time, commercial aims and private environmental services autoconsumption preferences. A contingent valuation questionnaire has been applied to a group of Dehesa ’ owners to measure the maximum willingness to pay (WTP) —to accept losses— of commercial capital income against the maintenance of private environmental services autoconsumption. The Delphi results show that owners’attitude is in favour to follow the environmental friendly agricultural practices, when the Government incentives are higher than the losses of commercial capital income plus a risk premium. The value of owners’ autoconsumption measured by the WTP question from the contingent valuation gives an autoconsumption profitability rate from 1% to 5% of the total market value of the Dehesa.
Keywords: Contingent valuation; Dehesa; Delphi technique; environmental and agroforestry practices; environmental autoconsumption services; Hicksian income

Preferencias de los propietarios e intervención pública: el caso de las dehesas de la comarca de Monfragüe - Campos Palacín, P.; Mariscal Lorente, P. J. (Investigación Agraria: Sistemas y Recursos Forestales, 2003)
The public have an increasing interest in Dehesa environmental services (recreation, option and existence values). The growing Government incentives on environmental friendly agricultural practices have given a new opportunity for private economics of natural and environmental resources in Dehesa. This work presents the results from a Delphi questionnaire on owners’ preferences and demands of compensations for undertaking environmental conservation and improvement measures in Dehesa of Monfragüe shire. The private owners of Dehesa are investors that have, at the same time, commercial aims and private environmental services autoconsumption preferences. A contingent valuation questionnaire has been applied to a group of Dehesa ’ owners to measure the maximum willingness to pay (WTP) —to accept losses— of commercial capital income against the maintenance of private environmental services autoconsumption. The Delphi results show that owners’attitude is in favour to follow the environmental friendly agricultural practices, when the Government incentives are higher than the losses of commercial capital income plus a risk premium. The value of owners’ autoconsumption measured by the WTP question from the contingent valuation gives an autoconsumption profitability rate from 1% to 5% of the total market value of the Dehesa.
Keywords: Contingent valuation; Dehesa; Delphi technique; environmental and agroforestry practices; environmental autoconsumption services; Hicksian income

Primo contributo alla definizione tipologica delle sugherete della Calabria - Mercurio, R; Spampinato, G (SISEF Atti 3, 2003)
Recenti indagini sulla distribuzione della sughera in Calabria, sia sulla base dei popolarnenti esistenti che dei fitonimi , mostrano un areale poten ziale molto pill ampio di quello reale. Le cause della rarcfa zione della sughera sono dovute essenzialmenre al fuoco , al pascolo incontrollato calla manean za di interesse selvicolturale e di utilizzo del sughero. Sono rari i popo lamenti accorpati superiori a 10 ettari, mentre preval gono nuclei piu 0 meno ampi di pochi ettari 0 gruppi sparsi di poche piante. La sughera esostanzialrnentc presentc nel versante tirrenico dal livello del marc fino a circa 800 m rna si riscontra, in nuclei di piu limitata estensionc, anche in quello ionico dove in passato veniva ignorata. DOli punto di vista ecologico [a sughera si rinviene principalmente su substrati acid i quali sabbie silicee e prodotti di sfaldamento dei graniti , in aree caratterizzate da un bioclima meso mediterraneo sub umido 0 umido. DOli punta di vista fitosociologico Ie sugherete calabresi sono stale riferite all' Helleboro-Quercetum suberis, fitocenosi inclusa nelle formazioni scmpreverdi dei Quercetea ilicis . Sulla base di queste indagini vengono proposte nuov c linita tipologiche forestali : sugherete mesotile, sugherete mesotermofile c sugheretc tcrrnoxerofile. Per ogni unita tipologica vengono indicate Ie pratiche sclvicolturali piu appropriate per la loro conservazione .
Keywords: calabria; fitosociologia; quercus silber l; tipi forestali

Primo contributo alla definizione tipologica delle sugherete della Calabria - Mercurio, R.; Spampinato, G. (SISEF Atti 3, 2003)
Recenti indagini sulla distribuzione della sughera in Calabria, sia sulla base dei popolarnenti esistenti che dei fitonimi , mostrano un areale poten ziale molto pill ampio di quello reale. Le cause della rarcfa zione della sughera sono dovute essenzialmenre al fuoco , al pascolo incontrollato calla manean za di interesse selvicolturale e di utilizzo del sughero. Sono rari i popo lamenti accorpati superiori a 10 ettari, mentre preval gono nuclei piu 0 meno ampi di pochi ettari 0 gruppi sparsi di poche piante. La sughera esostanzialrnentc presentc nel versante tirrenico dal livello del marc fino a circa 800 m rna si riscontra, in nuclei di piu limitata estensionc, anche in quello ionico dove in passato veniva ignorata. DOli punto di vista ecologico [a sughera si rinviene principalmente su substrati acid i quali sabbie silicee e prodotti di sfaldamento dei graniti , in aree caratterizzate da un bioclima meso mediterraneo sub umido 0 umido. DOli punta di vista fitosociologico Ie sugherete calabresi sono stale riferite all' Helleboro-Quercetum suberis, fitocenosi inclusa nelle formazioni scmpreverdi dei Quercetea ilicis . Sulla base di queste indagini vengono proposte nuov c linita tipologiche forestali : sugherete mesotile, sugherete mesotermofile c sugheretc tcrrnoxerofile. Per ogni unita tipologica vengono indicate Ie pratiche sclvicolturali piu appropriate per la loro conservazione .
The following values have no corresponding Zotero field: periodical: SISEF Atti 3
Keywords: calabria; fitosociologia; quercus silber l; tipi forestali

Regional differences in land use affect population performance of the threatened insectivorous plant Drosophyllum lusitanicum (Droseraceae) - Garrido, B.; Hampe, A.; MARAÑON, T.; Arroyo, J. (Diversity and Distributions, 2003)
We analyse populations of the insectivorous plant Drosophyllum lusitanicum (L.) Link (Droseraceae) and their habitats throughout the species’ distribution range (Portugal, Spain and Morocco), and examine their relations. We have surveyed 32 populations and we analyse their demographic structures, accompanying plant communities (by TWINSPAN analyses), and relationships between population features and several edaphic and nonedaphic environmental variables (by multiple regression analyses). Plant communities, their ﬂoristic richness and degree of endemism change across the geographical range of Drosophyllum. Populations vary strongly in size, density and age structure. Their recruitment seems largely determined by competition with the surrounding vegetation, while only weak relationships were detected between population performance and other environmental factors. The demographic structure of populations exhibits a marked geographical differentiation, with populations becoming older and sparser towards the north-western part of the range. The largest and presumably most stable populations are mostly found in southern Spanish heathlands, which are nowadays scarcely affected by man. Moroccan populations suffer from browsing by cattle and experience an accelerated generation turnover, while most Portuguese populations occur in afforested areas and experience strongly reduced recruitment. The historical distribution range of Drosophyllum within its peculiar habitat has probably been relatively stable, but recent regional differences in human land use have resulted in present-day differences in population performance, as well as in types and degrees of threat across the three countries involved. Conservation strategies should take into account this range-wide variation and combine approaches on different spatial scales.
Keywords: carnivorous plant; conservation; demographic structure; ecogeography; geographical range; mediterranean heathland; range-wide survey; Regeneration

Regional differences in land use affect population performance of the threatened insectivorous plant Drosophyllum lusitanicum (Droseraceae) - Garrido, B; Hampe, A; MARAÑÓN, T; Arroyo, J (Diversity and Distributions, 2003)
We analyse populations of the insectivorous plant Drosophyllum lusitanicum (L.) Link (Droseraceae) and their habitats throughout the species’ distribution range (Portugal, Spain and Morocco), and examine their relations. We have surveyed 32 populations and we analyse their demographic structures, accompanying plant communities (by TWINSPAN analyses), and relationships between population features and several edaphic and nonedaphic environmental variables (by multiple regression analyses). Plant communities, their ﬂoristic richness and degree of endemism change across the geographical range of Drosophyllum. Populations vary strongly in size, density and age structure. Their recruitment seems largely determined by competition with the surrounding vegetation, while only weak relationships were detected between population performance and other environmental factors. The demographic structure of populations exhibits a marked geographical differentiation, with populations becoming older and sparser towards the north-western part of the range. The largest and presumably most stable populations are mostly found in southern Spanish heathlands, which are nowadays scarcely affected by man. Moroccan populations suffer from browsing by cattle and experience an accelerated generation turnover, while most Portuguese populations occur in afforested areas and experience strongly reduced recruitment. The historical distribution range of Drosophyllum within its peculiar habitat has probably been relatively stable, but recent regional differences in human land use have resulted in present-day differences in population performance, as well as in types and degrees of threat across the three countries involved. Conservation strategies should take into account this range-wide variation and combine approaches on different spatial scales.
Keywords: carnivorous plant; conservation; demographic structure; ecogeography; geographical range; mediterranean heathland; range-wide survey; Regeneration

Runoff erosion and nutrient depletion in five Mediterranean soils of NE Spain under different land use. - Pardini, Giovanni; Gispert, Maria; Dunjó, Gemma (The Science of the total environment, 2003)
We investigated the influence of agricultural management and various plant covers related to the period of abandonment on soil properties, erosion and nutrient depletion in a typical Mediterranean area with sandy loam shallow soils. Cultivated soils (CS) with insufficient management, 5 year abandoned soils covered with meadow (A5), 25 year abandoned soils covered with dense scrubs (A25), 50 year abandoned soils covered with cork trees (A50) and soils in a 50 year pine reforested area (P50) were studied over a period of 6 months (May-October 1999). The soils were classified as Lithic Xerorthents. Both the differences in soil properties and response to rainfall events were mainly attributed to the different vegetation types and stages in land management. Principal components analysis (PCA) was performed on the results, by running the overall data determined after five rainfall events. The factors extracted by PCA of the samples by variables matrix represented the response of the environments to different rainfall intensities as a function of management or natural evolution after abandonment. CS environments showed the highest runoff and sediment yield as well as the highest amount of dissolved organic carbon (DOC) and nitrogen in runoff water. The sequence of abandonment (A5, A25 and A50) showed approximately the same runoff production, whereas eroded sediments (ES) and DOC were inversely correlated. Organic carbon in the ES and DOC in runoff water always increased with the period of abandonment, which accounted for consistent nutrient depletion. Nevertheless, the A50 environment (dominated by Quercus suber) showed the best soil properties, whilst the A25 environment with dense cover of Cistus monspeliensis and Calicotome espinosa seemed to cause a worsening effect on the soil's physical and chemical properties. This is probably because these environments are more severely damaged by wild fire occurrence. In terms of sediment yield, the P50 environment followed CS environment, indicating that reforestation followed by insufficient forest management may negatively affect both soil properties and response to the erosive action of rainfall.
Keywords: Abandonment; erosion; land management; nutrient availability; Nutrient losses; runoff; Sediment yield; soil properties; structure; Water retention

Runoff erosion and nutrient depletion in five Mediterranean soils of NE Spain under different land use. - Pardini, Giovanni; Gispert, Maria; Dunjó, Gemma (The Science of the total environment, 2003)
We investigated the influence of agricultural management and various plant covers related to the period of abandonment on soil properties, erosion and nutrient depletion in a typical Mediterranean area with sandy loam shallow soils. Cultivated soils (CS) with insufficient management, 5 year abandoned soils covered with meadow (A5), 25 year abandoned soils covered with dense scrubs (A25), 50 year abandoned soils covered with cork trees (A50) and soils in a 50 year pine reforested area (P50) were studied over a period of 6 months (May-October 1999). The soils were classified as Lithic Xerorthents. Both the differences in soil properties and response to rainfall events were mainly attributed to the different vegetation types and stages in land management. Principal components analysis (PCA) was performed on the results, by running the overall data determined after five rainfall events. The factors extracted by PCA of the samples by variables matrix represented the response of the environments to different rainfall intensities as a function of management or natural evolution after abandonment. CS environments showed the highest runoff and sediment yield as well as the highest amount of dissolved organic carbon (DOC) and nitrogen in runoff water. The sequence of abandonment (A5, A25 and A50) showed approximately the same runoff production, whereas eroded sediments (ES) and DOC were inversely correlated. Organic carbon in the ES and DOC in runoff water always increased with the period of abandonment, which accounted for consistent nutrient depletion. Nevertheless, the A50 environment (dominated by Quercus suber) showed the best soil properties, whilst the A25 environment with dense cover of Cistus monspeliensis and Calicotome espinosa seemed to cause a worsening effect on the soil's physical and chemical properties. This is probably because these environments are more severely damaged by wild fire occurrence. In terms of sediment yield, the P50 environment followed CS environment, indicating that reforestation followed by insufficient forest management may negatively affect both soil properties and response to the erosive action of rainfall.
The following values have no corresponding Zotero field: accession-num: 12798105
Keywords: Abandonment; erosion; land management; nutrient availability; Nutrient losses; runoff; Sediment yield; soil properties; structure; Water retention

A set of primers for the amplification of chloroplast microsatellites in Quercus - Deguilloux, M.-F.; Dumolin-Lapègue, S; Gielly, L; Grivet, D; Petit, R J (Molecular Ecology Notes, 2003)
The increase in demand for the certification of oak seed lots, as well as control of the geographical origin of oak wood, has led us to develop powerful genetic markers permitting us to discriminate among provenance regions. With the aim of detecting new chloroplast variants, we have identified 17 potential cpSSRs motifs from available oak sequences and tested their variability among French oak populations. Six loci were polymorphic at the intraspecific level in Quercus petraea and Q. robur. Moreover, conservation of the primer pairs was checked on a set of 21 forest tree species and they were all shown to work well on several Quercus species, and even within Fagacaea.
Keywords: chloroplast genome; cpSSR; forest tree; oak; population genetic; simple sequence repeat

Silvicultural management in maintaining biodiversity and resistance of forests in Europe—the Mediterranean region - Fabbio, Gianfranco; Merlo, Maurizio; Tosi, Vittorio (Journal of Environmental Management, 2003)
Outstanding features of Mediterranean forest area are highlighted with a special reference to biodiversity and connections with forest management. The naturally originated and anthropogenic progress of the mosaic-like evolution, as well as the man-induced factors and natural constraints are described. The past and present close linkages between management and biodiversity are then analysed by means of a few, outstanding cases typical of the geographical region. The management shift on increasing economically marginal forest area (abandonment) appears to be the major force currently driving connections with inherent and associated biodiversity. The goals following the new-established environmental roles of forests have shifted towards adaptive management, namely the implementation of locally tailored rules in accordance with prominent forest functions. Key priorities to face up to the new scenarios are then discussed. Economic and policy implications are addressed with reference to multipurpose forestry and the related annual ﬂow of outputs. It is shown the role of water-related services, as well the provision of various non-wood forest products and public goods in addition to wood and other traditional forest outputs. Reference is also made to the dualism between the Northern and the South-Eastern Mediterranean countries due to different level of economic development (and pressure of forest resources) together with very different institutional structures, i.e. public ownership in Southern and South-Eastern Mediterranean countries. Nevertheless, the situation is going to become more harmonious in the medium run by growing economic development, the afﬁrmation of local rights on forest resources, globalisation and, above all, rural out migration and exchanges of peoples conﬁrming the traditional role of the Mediterranean Region at cross road of South–North and Eastern– Western cultures.
Keywords: Adaptive management; Biodiversity; economic and policy implications; Mediterranean Region; multipurpose role of forests; silvicultural management

Silvicultural management in maintaining biodiversity and resistance of forests in Europe—the Mediterranean region - Fabbio, Gianfranco; Merlo, Maurizio; Tosi, Vittorio (Journal of Environmental Management, 2003)
Outstanding features of Mediterranean forest area are highlighted with a special reference to biodiversity and connections with forest management. The naturally originated and anthropogenic progress of the mosaic-like evolution, as well as the man-induced factors and natural constraints are described. The past and present close linkages between management and biodiversity are then analysed by means of a few, outstanding cases typical of the geographical region. The management shift on increasing economically marginal forest area (abandonment) appears to be the major force currently driving connections with inherent and associated biodiversity. The goals following the new-established environmental roles of forests have shifted towards adaptive management, namely the implementation of locally tailored rules in accordance with prominent forest functions. Key priorities to face up to the new scenarios are then discussed. Economic and policy implications are addressed with reference to multipurpose forestry and the related annual ﬂow of outputs. It is shown the role of water-related services, as well the provision of various non-wood forest products and public goods in addition to wood and other traditional forest outputs. Reference is also made to the dualism between the Northern and the South-Eastern Mediterranean countries due to different level of economic development (and pressure of forest resources) together with very different institutional structures, i.e. public ownership in Southern and South-Eastern Mediterranean countries. Nevertheless, the situation is going to become more harmonious in the medium run by growing economic development, the afﬁrmation of local rights on forest resources, globalisation and, above all, rural out migration and exchanges of peoples conﬁrming the traditional role of the Mediterranean Region at cross road of South–North and Eastern– Western cultures.
Keywords: Adaptive management; Biodiversity; economic and policy implications; Mediterranean Region; multipurpose role of forests; silvicultural management

Soil persistence and biodiversity of ericoid mycorrhizal fungi in the absence of the host plant in a Mediterranean ecosystem. - Bergero, Roberta; Girlanda, Mariangela; Bello, Federica; Luppi, Anna Maria; Perotto, Silvia (Mycorrhiza, 2003)
The occurrence of suitable mycorrhizal inocula may be an important factor affecting the dynamics of plant communities. We investigated the persistence and diversity of ericoid mycorrhizal fungi in the soil of a mature Quercus ilex forest where ericaceous hosts were absent. Erica arborea was used as a bait plant and results were compared to soil samples from experimental plots where cuttings had allowed reappearance of this ericaceous species. Fungal endophytes were isolated and tested in mycorrhiza resynthesis trials. Sterile mycorrhizal endophytes were assigned to morphotypes whose consistency was confirmed by ITS-RFLP. The ITS region of a representative of each morphotype was sequenced. BLAST searches and Neighbour-Joining analysis indicated taxonomic affinities with different classes within Ascomycota. Our results indicate that ericoid mycorrhizal fungi persist and maintain mycorrhizal ability in habitats lacking the ericaceous host. Their persistence could favour the establishment of E. arborea seedlings in pure Q. ilex forests after disturbance phenomena.
The following values have no corresponding Zotero field: accession-num: 12682828
Keywords: Erica arborea; Mediterranean ecosystem; Plant succession; Post-cutting; Quercus ilex

Soil persistence and biodiversity of ericoid mycorrhizal fungi in the absence of the host plant in a Mediterranean ecosystem. - Bergero, Roberta; Girlanda, Mariangela; Bello, Federica; Luppi, Anna Maria; Perotto, Silvia (Mycorrhiza, 2003)
The occurrence of suitable mycorrhizal inocula may be an important factor affecting the dynamics of plant communities. We investigated the persistence and diversity of ericoid mycorrhizal fungi in the soil of a mature Quercus ilex forest where ericaceous hosts were absent. Erica arborea was used as a bait plant and results were compared to soil samples from experimental plots where cuttings had allowed reappearance of this ericaceous species. Fungal endophytes were isolated and tested in mycorrhiza resynthesis trials. Sterile mycorrhizal endophytes were assigned to morphotypes whose consistency was confirmed by ITS-RFLP. The ITS region of a representative of each morphotype was sequenced. BLAST searches and Neighbour-Joining analysis indicated taxonomic affinities with different classes within Ascomycota. Our results indicate that ericoid mycorrhizal fungi persist and maintain mycorrhizal ability in habitats lacking the ericaceous host. Their persistence could favour the establishment of E. arborea seedlings in pure Q. ilex forests after disturbance phenomena.
Keywords: Erica arborea; Mediterranean ecosystem; Plant succession; Post-cutting; Quercus ilex

Soil seed bank and floristic diversity in a forest-grassland mosaic in southern Spain - Díaz-Villa, M D; MARAÑÓN, T; Arroyo, J; Garrido, B (Journal of Vegetation Science, 2003)
Soil seed bank and floristic diversity were studied in a forest of Quercus suber, a forest of Quercus canariensis and a grassland, forming a vegetation mosaic in Los Alcornocales Natural Park, southern Spain. The soil seed bank was estimated by the germination technique. In each community patch, diversity, woody species cover and herbaceous species frequency was measured. Three biodiversity components – species richness, endemism and taxonomic singularity – were considered in the vegetation and the seed bank. Forest patches had a soil seed bank of ca. 11 200-14 100 seed.m–2 and their composition had low resemblance to (epigeal) vegetation. The grassland patch had a more dense seed bank (ca. 31 800 seed.m–2 ) and a higher index of similarity with vegetation, compared with the forests nearby. The complete forest diversity was 71-78 species on 0.1 ha, including 12-15 species found only in the seed bank; the grassland species richness was higher (113 species on 0.1 ha). We discuss the role of soil seed banks in the vegetation dynamics and in the complete plant biodiversity of the mosaic landscape studied.
Keywords: Biodiversity; forests conservation; mediterranean forest; nomenclature; Regeneration; Species richness

Soil seed bank and floristic diversity in a forest-grassland mosaic in southern Spain - Díaz-Villa, M. D.; MARAÑON, T.; Arroyo, J.; Garrido, B. (Journal of Vegetation Science, 2003)
Soil seed bank and floristic diversity were studied in a forest of Quercus suber, a forest of Quercus canariensis and a grassland, forming a vegetation mosaic in Los Alcornocales Natural Park, southern Spain. The soil seed bank was estimated by the germination technique. In each community patch, diversity, woody species cover and herbaceous species frequency was measured. Three biodiversity components – species richness, endemism and taxonomic singularity – were considered in the vegetation and the seed bank. Forest patches had a soil seed bank of ca. 11 200-14 100 seed.m–2 and their composition had low resemblance to (epigeal) vegetation. The grassland patch had a more dense seed bank (ca. 31 800 seed.m–2 ) and a higher index of similarity with vegetation, compared with the forests nearby. The complete forest diversity was 71-78 species on 0.1 ha, including 12-15 species found only in the seed bank; the grassland species richness was higher (113 species on 0.1 ha). We discuss the role of soil seed banks in the vegetation dynamics and in the complete plant biodiversity of the mosaic landscape studied.
Keywords: Biodiversity; forests conservation; mediterranean forest; nomenclature; Regeneration; Species richness

Spatial patterns in long-distance dispersal of Quercus ilex acorns by jays in a heterogeneous landscape - Gómez, José María (Ecography, 2003)
In this paper, I analyse the interaction between the holm-oak Quercus ilex, and one of its main dispersers, the European jay Garrulus glandarius, in an heterogeneous Mediterranean landscape. I quantify the spatial dispersal pattern of the seed shadow at two spatial scales, landscape (among patches) and microhabitat (within patches), by directly tracking the movement of seeds. Two main traits of the jay-mediated dispersal of holm-oak acorns across the landscape, the spatial pattern of dissemination and the distance from the source tree, are significantly and directly influenced by jay activity. Jays moved acorns nonrandomly, avoiding one main patch type of the study area to cache acorns, the shrubland-grasslands, and moving most of the acorns to pine stands, whether afforestation or open pinewoods. Within each patch type, jays had also a strong preference for caching acorns in some microhabitats, since>95% of the acorns dispersed by jays were cached beneath pines. The distance of holm-oak acorn dispersal was long in the study site, over 250 m, with some dispersals occurring up to 1 km from the source oaks. The shape of the dispersal kernel function fitted to the dispersal pattern produced by jays differed from those quantified for many other plant species. Jay-mediated dispersal had two components, one local and another produced by long-distance dispersal. Due to the heterogeneity of these Mediterranean environments, this difference in scale overlaps with a difference in habitat composition, short distances events resulting in dispersals within the same oak stands and long distance events resulting in dispersal outside of oak stands, usually to other vegetation units. Jay activity and movement pattern can have thus dramatic effects on both the local regeneration as well as the potential for regional spread of the holm-oak populations.
Keywords: dispersal pattern; European jay (PG); Holm oak

Structure of ground-foraging ant assemblages in relation to land-use change in the northwestern Mediterranean region - Gómez, C; Casellas, D; Oliveras, J; Bas, J M (Biodiversity and Conservation, 2003)
The abandonment by humans of marginal and less productive zones signiﬁes an important change in land use in North Mediterranean agroecosystems. Human perturbations have led to a highly diversiﬁed landscape, with a mosaic made up of patches of land at different stages of succession, from cultivated ﬁelds to closed forest. Our aim here is to characterize ant assemblages and their functional groups in response to these land-use changes. This progressive abandonment results in an initial increase in ant richness and abundance, which can reach high levels if the succession proceeds as far as woodland. In terms of the ant functional groups, this land-use change implies: (1) the appearance of Subordinate Camponotini; (2) an increase in Generalized Myrmicinae, Cryptics and Cold-climate specialists in terms of ant species richness, overall abundance and, for Generalized Myrmicinae and Cryptics, an increase in abundance percentage; (3) a decrease in percentage abundance of Opportunists; (4) a progressive decrease in species richness as well as overall and percentage abundance of Hot-climate Specialists throughout the transformation from crops to woodlands; and (5) an initial increase of Dominant Dolichoderinae followed by a decrease in ant species richness, overall abundance and percentage abundance. Using the ant functional group approach for the clearly separate stages of the regeneration process is a promising method for comparing responses of ant communities to human land use.
Keywords: Ants; Functional groups; Indicator species; Land-use change; Mediterranean Region

The study of reactions influencing the biomass steam gasification process - Franco, C; Pinto, F; Gulyurtlu, I; Cabrita, I (FUEL, 2003)
Steam gasification studies were carried out in an atmospheric fluidised bed. The gasifier was operated over a temperature range of 700900 degreesC whilst varying a steam/biomass ratio from 0.4 to 0.85 w/w. Three types of forestry biomass were studied: Pinus pinaster (softwood), Eucalyptus globulus and holm-oak (hardwood). The energy conversion, gas composition, higher heating value and gas yields were determined and correlated with temperature, steam/biomass ratio, and species of biomass used. The results obtained seemed to suggest that the operating conditions were optimised for a gasification temperature around 830 degreesC and a steam/biomass ratio of 0.6-0.7 w/w, because a gas richer in hydrogen and poorer in hydrocarbons and tars was produced. These conditions also favoured greater energy and carbon conversions, as well the gas yield. The main objective of the present work was to determine what reactions were dominant within the operation limits of experimental parameters studied and what was the effect of biomass type on the gasification process. As biomass wastes usually have a problem of availability because of seasonal variations, this work analysed the possibility of replacing one biomass species by another, without altering the gas quality obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.
Keywords: biomass; fluidised bed; gasification; steam

The study of reactions influencing the biomass steam gasification process - Franco, C.; Pinto, F.; Gulyurtlu, I.; Cabrita, I. (FUEL, 2003)
Steam gasification studies were carried out in an atmospheric fluidised bed. The gasifier was operated over a temperature range of 700900 degreesC whilst varying a steam/biomass ratio from 0.4 to 0.85 w/w. Three types of forestry biomass were studied: Pinus pinaster (softwood), Eucalyptus globulus and holm-oak (hardwood). The energy conversion, gas composition, higher heating value and gas yields were determined and correlated with temperature, steam/biomass ratio, and species of biomass used. The results obtained seemed to suggest that the operating conditions were optimised for a gasification temperature around 830 degreesC and a steam/biomass ratio of 0.6-0.7 w/w, because a gas richer in hydrogen and poorer in hydrocarbons and tars was produced. These conditions also favoured greater energy and carbon conversions, as well the gas yield. The main objective of the present work was to determine what reactions were dominant within the operation limits of experimental parameters studied and what was the effect of biomass type on the gasification process. As biomass wastes usually have a problem of availability because of seasonal variations, this work analysed the possibility of replacing one biomass species by another, without altering the gas quality obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.
The following values have no corresponding Zotero field: pub-location: THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND publisher: ELSEVIER SCI LTD
Keywords: biomass; fluidised bed; gasification; steam

Thermal optima of photosynthetic functions and thermostability of photochemistry in cork oak seedlings - Ghouil, Hana; Montpied, Pierre; Epron, Daniel; Ksontini, Mustapha; Hanchi, Belkacem; Dreyer, Erwin (Tree Physiology, 2003)
Temperature effects on photosynthesis were studied in seedlings of evergreen Mediterranean cork oak (Quercus suber L.). Responses to changes in temperature and the temperature optima of maximal carboxylation rate (Vcmax) and maximal light-driven electron flux (Jmax) were estimated from gas exchange measurements and a leaf-level photosynthesis model. The estimated temperature optima were approximately 34 and 33 °C for Vcmax and Jmax, respectively, which fall within the lower range of temperature optima previously observed in deciduous tree species. The thermostability of the photosynthetic apparatus was estimated according to the temperature at which basal chlorophyll a fluorescence begins to increase (Tc). The Tc was highly variable, increasing from 42 to 51 °C when ambient temperature rose from 10 to 40 °C, and increasing from 44 to 54 °C with decreasing soil water availability while net CO2 assimilation rate dropped to almost zero. When a heat shock was imposed, an additional small increase in Tc was observed in drought-stressed and control seedlings. Maximal Tc values following heat shock were about 56 °C, which, to our knowledge, are the highest values that have been observed in tree species. In conclusion, the intrinsic temperature responses of cork oak did not differ from those of other species (similar Tc under ambient temperature and water availability, and relatively low thermal optima for photosynthetic capacity in seedlings grown at cool temperatures). However, the large ability of cork oak to acclimate to drought and elevated temperature may be an important factor in the tolerance of this evergreen Mediterranean species to summer drought and high temperatures.
10.1093/treephys/23.15.1031
Keywords: chlorophyll fluorescence; Gas exchange; maximal carboxylation rate; maximal light-driven electron flow; Regeneration

Thermal optima of photosynthetic functions and thermostability of photochemistry in cork oak seedlings - Ghouil, Hana; Montpied, Pierre; Epron, Daniel; Ksontini, Mustapha; Hanchi, Belkacem; Dreyer, Erwin (Tree Physiology, 2003)
Temperature effects on photosynthesis were studied in seedlings of evergreen Mediterranean cork oak (Quercus suber L.). Responses to changes in temperature and the temperature optima of maximal carboxylation rate (Vcmax) and maximal light-driven electron flux (Jmax) were estimated from gas exchange measurements and a leaf-level photosynthesis model. The estimated temperature optima were approximately 34 and 33 °C for Vcmax and Jmax, respectively, which fall within the lower range of temperature optima previously observed in deciduous tree species. The thermostability of the photosynthetic apparatus was estimated according to the temperature at which basal chlorophyll a fluorescence begins to increase (Tc). The Tc was highly variable, increasing from 42 to 51 °C when ambient temperature rose from 10 to 40 °C, and increasing from 44 to 54 °C with decreasing soil water availability while net CO2 assimilation rate dropped to almost zero. When a heat shock was imposed, an additional small increase in Tc was observed in drought-stressed and control seedlings. Maximal Tc values following heat shock were about 56 °C, which, to our knowledge, are the highest values that have been observed in tree species. In conclusion, the intrinsic temperature responses of cork oak did not differ from those of other species (similar Tc under ambient temperature and water availability, and relatively low thermal optima for photosynthetic capacity in seedlings grown at cool temperatures). However, the large ability of cork oak to acclimate to drought and elevated temperature may be an important factor in the tolerance of this evergreen Mediterranean species to summer drought and high temperatures.
10.1093/treephys/23.15.103110.1093/treephys/23.15.1031
Keywords: chlorophyll fluorescence; Gas exchange; maximal carboxylation rate; maximal light-driven electron flow; Regeneration

Thinning effects on carbon allocation to fine roots in a Quercus ilex forest - López, B. C.; Sabate, S.; Gracia, C. A. (Tree Physiology, 2003)
The dynamics of the fine root system are relevant to calculations of the carbon balance of the ecosystem, and there is also a need to quantify changes in this component caused by disturbances. Mediterranean forest systems have historically been coppiced to obtain charcoal. As a result of the resprouting capacity of holm oaks (Quercus ilex L.), these forests present more than 50% of their biomass below ground (stump + roots > 1 cm in diameter), but the effects of thinning on the fine root system are unknown. Fine root biomass, production, mortality and longevity were studied in a control and a thinned Mediterranean holm oak forest by minirhizotron methodology. Observations of fine roots started 2 years after thinning and continued for almost 3 years. Extraction of 80% of the former basal area of the forest greatly affected carbon allocation patterns. Biomass increased by more than 100%, production increased by 76%, mortality increased by 32% and longevity decreased by around 2 weeks. The greatest differences between treatments were associated with differences in growth during autumn months in the top 40 cm of soil, particularly between 10 and 20 cm depth.
10.1093/treephys/23.17.121710.1093/treephys/23.17.1217
Keywords: biomass; longevity; mortality; production

Thinning effects on carbon allocation to fine roots in a Quercus ilex forest - López, B C; Sabate, S; Gracia, C A (Tree Physiology, 2003)
The dynamics of the fine root system are relevant to calculations of the carbon balance of the ecosystem, and there is also a need to quantify changes in this component caused by disturbances. Mediterranean forest systems have historically been coppiced to obtain charcoal. As a result of the resprouting capacity of holm oaks (Quercus ilex L.), these forests present more than 50% of their biomass below ground (stump + roots > 1 cm in diameter), but the effects of thinning on the fine root system are unknown. Fine root biomass, production, mortality and longevity were studied in a control and a thinned Mediterranean holm oak forest by minirhizotron methodology. Observations of fine roots started 2 years after thinning and continued for almost 3 years. Extraction of 80% of the former basal area of the forest greatly affected carbon allocation patterns. Biomass increased by more than 100%, production increased by 76%, mortality increased by 32% and longevity decreased by around 2 weeks. The greatest differences between treatments were associated with differences in growth during autumn months in the top 40 cm of soil, particularly between 10 and 20 cm depth.
10.1093/treephys/23.17.1217
Keywords: biomass; longevity; mortality; production

Time budget and habitat use of the Common Crane wintering in dehesas of southwestern Spain - Avilés, Jesus M. (Canadian Journal of Zoology, 2003)
In many bird species juvenile inexperience drastically reduces their survival, and parents must provide for them. I tested whether time budget and habitat use in adult wintering Common Cranes (Grus grus) in dehesas (pastoral woodland) of western Spain were affected by the presence of juveniles. Juvenile cranes devote less time to vigilance and spend more time feeding than adults in dehesas. Likewise, juveniles are involved in fewer aggressive encounters than adult cranes. Contrary to expectation, adults accompanied by juveniles devoted the same amount of time to vigilance and feeding and had the same intake rate than adults without juveniles in attendance. However, adult cranes with offspring in attendance were involved in more aggressive encounters than adults without juveniles in attendance when both adult groups were involved in large flocks. In contrast, when adults accompanied by juveniles were in small flocks they were involved in fewer aggressive encounters than adults without juveniles. I also detected a differential use of dehesas by adult cranes that was linked to juvenile presence and explained by the vulnerability of juvenile cranes in intraspecific social relationships. Adults with juveniles in attendance preferred dehesas with livestock where flock sizes were smaller than those in dehesas without livestock, and therefore where they might reduce the number of aggressive encounters with other cranes.
doi: 10.1139/z03-105doi: 10.1139/z03-105The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: Cranes; Dehesa; feeding (voyant); intake rate; livestock; parental investment; social structure

Time budget and habitat use of the Common Crane wintering in dehesas of southwestern Spain - Avilés, Jesús M (Canadian Journal of Zoology, 2003)
In many bird species juvenile inexperience drastically reduces their survival, and parents must provide for them. I tested whether time budget and habitat use in adult wintering Common Cranes (Grus grus) in dehesas (pastoral woodland) of western Spain were affected by the presence of juveniles. Juvenile cranes devote less time to vigilance and spend more time feeding than adults in dehesas. Likewise, juveniles are involved in fewer aggressive encounters than adult cranes. Contrary to expectation, adults accompanied by juveniles devoted the same amount of time to vigilance and feeding and had the same intake rate than adults without juveniles in attendance. However, adult cranes with offspring in attendance were involved in more aggressive encounters than adults without juveniles in attendance when both adult groups were involved in large flocks. In contrast, when adults accompanied by juveniles were in small flocks they were involved in fewer aggressive encounters than adults without juveniles. I also detected a differential use of dehesas by adult cranes that was linked to juvenile presence and explained by the vulnerability of juvenile cranes in intraspecific social relationships. Adults with juveniles in attendance preferred dehesas with livestock where flock sizes were smaller than those in dehesas without livestock, and therefore where they might reduce the number of aggressive encounters with other cranes.
doi: 10.1139/z03-105
Keywords: Cranes; Dehesa; feeding (voyant); intake rate; livestock; parental investment; social structure

Total antioxidant activity in Quercus ilex resprouts after fire - El Omari, Bouchra; Fleck, Isabel; Aranda, Xavier; Abadía, Anunciación; Cano, Antonio; Arnao, Marino B. (Plant Physiology and Biochemistry, 2003)
After ﬁre, holm oak (Quercus ilex L.) resprouts have a higher light availability and photosynthetic activity than control plants in intact vegetation. To assess the differences in protection between these plants, we determined, in two forests, changes in gas-exchange rates, chlorophyll ﬂuorescence parameters, chloroplast pigment content and total antioxidant activity (TAA) in different seasons, at different times of the day and in relation to leaf age. The end-point method used for TAA determination allowed the evaluation of the relative contribution of hydrophilic and lipophilic antioxidants in leaf extracts. High correlations were obtained between lipophilic TAA and certain chloroplast pigment content, the highest contribution being provided by b-carotene and the components of the xanthophyll cycle (zeaxanthin + antheraxanthin, violaxanthin). All leaves showed a much higher contribution (94–99%) of hydrophilic than lipophilic antioxidants to TAA. In summer, at midday, photosynthetic rates and TAA were higher in resprouts. In these plants, reduced xanthophyll-cycle participation (as shown by non-photochemical quenching (NPQ) and xanthophyll pool content) was compensated by an increased participation of hydrophilic antioxidants. No effect of time of day or plant age was observed. The results suggest that energy dissipation as heat, and detoxiﬁcation mechanisms contribute to the protective strategies of control plants and resprouts, albeit to a different extent.
Keywords: carotenoids; non-photochemical quenching; Quercus ilex; reactive oxygen species; Resprouts; total antioxidant activity

Total antioxidant activity in Quercus ilex resprouts after fire - El Omari, Bouchra; Fleck, Isabel; Aranda, Xavier; Abadía, Anunciación; Cano, Antonio; Arnao, Marino B (Plant Physiology and Biochemistry, 2003)
After ﬁre, holm oak (Quercus ilex L.) resprouts have a higher light availability and photosynthetic activity than control plants in intact vegetation. To assess the differences in protection between these plants, we determined, in two forests, changes in gas-exchange rates, chlorophyll ﬂuorescence parameters, chloroplast pigment content and total antioxidant activity (TAA) in different seasons, at different times of the day and in relation to leaf age. The end-point method used for TAA determination allowed the evaluation of the relative contribution of hydrophilic and lipophilic antioxidants in leaf extracts. High correlations were obtained between lipophilic TAA and certain chloroplast pigment content, the highest contribution being provided by b-carotene and the components of the xanthophyll cycle (zeaxanthin + antheraxanthin, violaxanthin). All leaves showed a much higher contribution (94–99%) of hydrophilic than lipophilic antioxidants to TAA. In summer, at midday, photosynthetic rates and TAA were higher in resprouts. In these plants, reduced xanthophyll-cycle participation (as shown by non-photochemical quenching (NPQ) and xanthophyll pool content) was compensated by an increased participation of hydrophilic antioxidants. No effect of time of day or plant age was observed. The results suggest that energy dissipation as heat, and detoxiﬁcation mechanisms contribute to the protective strategies of control plants and resprouts, albeit to a different extent.
Keywords: carotenoids; non-photochemical quenching; Quercus ilex; reactive oxygen species; Resprouts; total antioxidant activity

Ultrasound acoustic emissions from bark samples differing in anatomical characteristics - Kikuta, S B (PHYTON-ANNALES REI BOTANICAE, 2003)
This study examines ultrasound acoustic emissions (UAE) from various bark types differing in anatomical characteristics. UAE were detected in dehydrating bark strips from twigs of two conifers (Pinus nigra ARNOLD, Taxus baccata L.), and four woody dicotyledons (Hedera helix L.. Malus sylvestris MILL., Sambuctis nigra L., and Tilia platyphyllos SCOP.) with varying contents of dead mechanical elements in the cortex and in the secondary phloem. If filled with water, non-conducting bark elements (sclereids, fibre-sclereids, secondary phloem fibres and periderm cells) emitted ultrasound during dehydration. Signal production varied between the species and the bark layers studied. Pressure infiltration increased the number of UAE conspicuously. UAE were also registered from infiltrated sections of bottle cork (Quercus suber L.) and infiltrated walnut shells (Juglans regia L.) built of sclereids only and characterised by lignified secondary cell walls. Stems of Sphagnum sp. emitted UAE, probably originating in hyalocysts, dead non-conducting water storage cells in the leaves. Living cells (inner epidermes of bulb scales of Allium cepa L. and collenchyma, strands from the herbaceous stern of Lamium maculatum L.) produced only very few UAE. The results suggest that ultrasound acoustic emissions during dehydration do not only occur in cavitating conducting xylem elements but also in non-conducting, dead cells with thick walls.
Keywords: Bark; cavitation; Dehydration; fibres; infiltration; periderm; sclereids; secondary phloem; ultrasound acoustic emissions

Vegetative propagation of Quercus suber L. by somatic embryogenesis. II. Plant regeneration from selected cork oak trees. - HERNÁNDEZ, I; CELESTINO, C; ALEGRE, J; TORIBIO, M (Plant cell reports, 2003)
The regeneration of somatic seedlings from selected 100-year-old cork oak trees is reported. The induction of somatic embryogenesis from leaves of epicormic shoots was significantly affected by genotype, harvesting time and their interaction. Leaves from all five selected trees produced somatic embryos when the segments of branches used as sources of epicormic shoots were collected in May. Genotype, but not the level of photosynthetically active radiation, affected the proliferation of the embryogenic lines and the number of detachable embryos that could be obtained from them. Genotype also affected several steps leading to conversion of somatic embryos, from germination to complete acclimatisation of somatic seedlings. Almost 40% of the somatic embryos from all lines germinated, showing coordinated root and shoot growth. Although the mean percentage of recovery for the whole process was low, plants could be regenerated from four of the five trees tested.
Keywords: Clonal propagation; Cork oak; Quercus suber; Selected trees; Somatic embryogenesis

Vegetative propagation of Quercus suber L. by somatic embryogenesis. I. Factors affecting the induction in leaves from mature cork oak trees. - HERNÁNDEZ, I; CELESTINO, C; TORIBIO, M (Plant cell reports, 2003)
Somatic embryogenesis was induced in expanding leaves from epicormic shoots forced to sprout from segments of branches collected from several hundred-year-old cork oak trees. Following a basic protocol previously defined for leaves taken from seedlings of this species, several factors were studied to improve the response. The induction frequency was significantly higher when the length of exposure to growth regulators was increased from 7 to 30 days. The combined application of NAA and BAP was essential for induction. Although both regulators had a very significant influence, their interaction was not significant, suggesting independent roles. Leaf size had a crucial effect, because beyond a certain threshold, embryogenesis could not be obtained. Embryogenic lines were maintained via repetitive embryogenesis on hormone-free medium for more than 2 years.
Keywords: Clonal propagation; Cork oak; Quercus suber; Somatic embryogenesis

Adaptive strategy at the leaf level of Arbutus unedo L. to cope with Mediterranean climate - Gratani, Loretta; Ghia, Emanuela (Flora-Morphology, Distribution, Functional Ecology of …, 2002)
The adaptive strategy of Arbutus unedo L. under Mediterranean climate seemed to be due to the high leaf area (LA = 11.1 ± 0.1 cm2 ) increasing the potential capacity of light interception, the high leaf lamina thickness (L = 395 ± 10 µm) increasing the potential capacity for gas exchange, and the steeper leaf inclination at midday (α up to 63.9 ± 0.3°) determining 48% of reduction of incident radiation on a sloping leaf surface (RI), which could be a prevention mechanism against the potential photoinhibition of water-stressed leaves during drought. Nevertheless, during the drought period the photosynthetic activity and the water use efficiency (WUE) of A. unedo were strongly reduced (≥ than 50% of the maximum). Principal component analysis (PCA) underlined the higher similarity of A. unedo and Quercus ilex L. from a physiological point of view (photosynthetic rates PN , transpiration rates E, stomatal conductance gs , sub-stomatal CO2 concentration Ci ) and for leaf inclination, and with Cistus incanus L. from a phenological (leaf-life span) and structural point of view (specific leaf area SLA and leaf tissue density LTD), for leaf temperature (Tl ) and for leaf water status (leaf water potential at midday Ψmin and relative water content RWC). Therefore A. unedo might be considered in the borderline between drought semi-deciduous species and evergreen sclerophyllous species.
Keywords: Gas exchange; leaf area; leaf inclination; leaf lamina thickness; leaf-life span; sclerophylly

Adaptive strategy at the leaf level of Arbutus unedo L. to cope with Mediterranean climate - Gratani, Loretta; Ghia, Emanuela (Flora-Morphology, Distribution, Functional Ecology of …, 2002)
The adaptive strategy of Arbutus unedo L. under Mediterranean climate seemed to be due to the high leaf area (LA = 11.1 ± 0.1 cm2 ) increasing the potential capacity of light interception, the high leaf lamina thickness (L = 395 ± 10 µm) increasing the potential capacity for gas exchange, and the steeper leaf inclination at midday (α up to 63.9 ± 0.3°) determining 48% of reduction of incident radiation on a sloping leaf surface (RI), which could be a prevention mechanism against the potential photoinhibition of water-stressed leaves during drought. Nevertheless, during the drought period the photosynthetic activity and the water use efficiency (WUE) of A. unedo were strongly reduced (≥ than 50% of the maximum). Principal component analysis (PCA) underlined the higher similarity of A. unedo and Quercus ilex L. from a physiological point of view (photosynthetic rates PN , transpiration rates E, stomatal conductance gs , sub-stomatal CO2 concentration Ci ) and for leaf inclination, and with Cistus incanus L. from a phenological (leaf-life span) and structural point of view (specific leaf area SLA and leaf tissue density LTD), for leaf temperature (Tl ) and for leaf water status (leaf water potential at midday Ψmin and relative water content RWC). Therefore A. unedo might be considered in the borderline between drought semi-deciduous species and evergreen sclerophyllous species.
Keywords: Gas exchange; leaf area; leaf inclination; leaf lamina thickness; leaf-life span; sclerophylly

Amino acid availability and energy value of acorn in the Iberian pig - Aguilera, J F; Nieto, R; Rivera, M; García, M A (Livestock Production Science, 2002)
Two experiments have been performed to determine amino acid digestibility and energy value of acorn (Quercus rotundifolia L.) for Iberian pigs. In experiment 1 ileal digestibility of amino acids was determined in ﬁve ileum-cannulated growing pigs fed whole ground acorn. An estimation of endogenous protein losses was carried out by feeding a protein-free diet, added (180 g/kg) or not with acorn hulls. True ileal digestibility of all essential amino acids measured was high (0.798–1.03) except for arginine (0.523), lysine (0.601), isoleucine (0.760), leucine (0.777) and phenylalanine (0.716). The average value for the digestibility of the sum of amino acids was 0.664. Lysine was the ﬁrst limiting amino acid compared with the amino acid proﬁle of the ideal protein for pigs. In experiment 2, total tract digestibility of nutrients and N balance were determined in ﬁve, non-cannulated pigs offered whole acorns. High coefﬁcients for the apparent total tract digestibility of dry matter (ApDM) (0.830) and energy metabolizability (ME/GE; 0.805) were found. ME content for acorn kernel was 16.6 MJ/kg DM, while the apparent total tract digestibility of total N (ApTN) was as low as 0.408. However, a positive N retention was observed (3.7 g/day). Comparing experiments 1 vs. 2, inclusion of acorn hulls resulted in a marked decrease in DM intake, ApTN and in N retention (25.1 g/day, in total tract data from experiment 1). The negative effects of acorn hulls on protein digestibility and N balance were corroborated in rats given similar amounts of either whole ground acorn or ground acorn kernel. Dietary supplementation with lysine is proposed to achieve a higher efﬁciency of protein accretion in the Iberian pig when fed on acorn.
Keywords: acorn; amino acids; energy value; pig-feeding and nutrition; protein quality

Amino acid availability and energy value of acorn in the Iberian pig - Aguilera, J. F.; Nieto, R.; Rivera, M.; Garcıa, M. A. (Livestock Production Science, 2002)
Two experiments have been performed to determine amino acid digestibility and energy value of acorn (Quercus rotundifolia L.) for Iberian pigs. In experiment 1 ileal digestibility of amino acids was determined in ﬁve ileum-cannulated growing pigs fed whole ground acorn. An estimation of endogenous protein losses was carried out by feeding a protein-free diet, added (180 g/kg) or not with acorn hulls. True ileal digestibility of all essential amino acids measured was high (0.798–1.03) except for arginine (0.523), lysine (0.601), isoleucine (0.760), leucine (0.777) and phenylalanine (0.716). The average value for the digestibility of the sum of amino acids was 0.664. Lysine was the ﬁrst limiting amino acid compared with the amino acid proﬁle of the ideal protein for pigs. In experiment 2, total tract digestibility of nutrients and N balance were determined in ﬁve, non-cannulated pigs offered whole acorns. High coefﬁcients for the apparent total tract digestibility of dry matter (ApDM) (0.830) and energy metabolizability (ME/GE; 0.805) were found. ME content for acorn kernel was 16.6 MJ/kg DM, while the apparent total tract digestibility of total N (ApTN) was as low as 0.408. However, a positive N retention was observed (3.7 g/day). Comparing experiments 1 vs. 2, inclusion of acorn hulls resulted in a marked decrease in DM intake, ApTN and in N retention (25.1 g/day, in total tract data from experiment 1). The negative effects of acorn hulls on protein digestibility and N balance were corroborated in rats given similar amounts of either whole ground acorn or ground acorn kernel. Dietary supplementation with lysine is proposed to achieve a higher efﬁciency of protein accretion in the Iberian pig when fed on acorn.
Keywords: acorn; amino acids; energy value; pig-feeding and nutrition; protein quality

Análise da Estratégia Fenodinâmica de Cistus salvifolius em Três Locais Distintos (Pinhal de Leiria, Cabeção e Odemira) - Borges, Ana Eleonora; de Almeida, Victor Valente; da Silva, António Morais (Silva Lusitana, 2002)
We describe the phenomorphological strategy of Cistus salvifolius found in pine woods of the Leiria region and in cork oak woodlands of Alentejo (Cabeção and Odemira north and Odemira south). An analysis is made of the evolution of the biological cycle as a function of climatic changes
Keywords: ecomorphology; edaphic factors; Phenology; srubs; underground

Análise da Estratégia Fenodinâmica de Cistus salvifolius em Três Locais Distintos (Pinhal de Leiria, Cabeção e Odemira) - Borges, Ana Eleonora; de Almeida, Victor Valente; da Silva, António Morais (Silva Lusitana, 2002)
We describe the phenomorphological strategy of Cistus salvifolius found in pine woods of the Leiria region and in cork oak woodlands of Alentejo (Cabeção and Odemira north and Odemira south). An analysis is made of the evolution of the biological cycle as a function of climatic changes
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: ecomorphology; edaphic factors; Phenology; srubs; underground

Annual feeding rate of the millipede Glomeris marginata on holm oak ( Quercus ilex) leaf litter under Mediterranean conditions - DAVID, J. F.; Gillon, Dominique (Pedobiologia, 2002)
The annual consumption and assimilation rates of Quercus ilex leaf litter by the millipede Glomeris marginata were estimated under Mediterranean conditions simulated in the laboratory. Measurements were made on six occasions throughout the year to take into account seasonal variations in (i) the quality of decomposing leaves, (ii) the physiological state of the animals, and (iii) temperature plus photoperiod. The mean weight-specific consumption rate was 14 g (dry weight) g-1 (live weight) y-1 , which is much higher than published figures for Mediterranean oak leaf litter. The consumption rate was highest in spring (51 mg g-1 d-1 ) and lowest in summer (28 mg g-1 d-1 ), the summer consumption rate being even lower when determined with air-dried leaves (17 mg g-1 d-1 ). Assimilation efficiency averaged 6 % for the year, with a maximum in spring (9 %) and a minimum in winter (1 %). A much higher assimilation efficiency (29 %) was measured with freshly fallen leaves, but a food preference experiment showed that these leaves were generally avoided and that G. marginata preferred more decomposed leaves despite their lower digestibility. It is concluded that these saprophagous macroarthropods – with field biomasses of 7–11 g (live weight) m-2 – produce considerable amounts of faecal pellets in Mediterranean oak forests.
Keywords: assimilation efficiency; diplopoda; feeding rate; Mediterranean forests; soil macrofauna

Annual feeding rate of the millipede Glomeris marginata on holm oak ( Quercus ilex) leaf litter under Mediterranean conditions - David, J F; Gillon, Dominique (Pedobiologia, 2002)
The annual consumption and assimilation rates of Quercus ilex leaf litter by the millipede Glomeris marginata were estimated under Mediterranean conditions simulated in the laboratory. Measurements were made on six occasions throughout the year to take into account seasonal variations in (i) the quality of decomposing leaves, (ii) the physiological state of the animals, and (iii) temperature plus photoperiod. The mean weight-specific consumption rate was 14 g (dry weight) g-1 (live weight) y-1 , which is much higher than published figures for Mediterranean oak leaf litter. The consumption rate was highest in spring (51 mg g-1 d-1 ) and lowest in summer (28 mg g-1 d-1 ), the summer consumption rate being even lower when determined with air-dried leaves (17 mg g-1 d-1 ). Assimilation efficiency averaged 6 % for the year, with a maximum in spring (9 %) and a minimum in winter (1 %). A much higher assimilation efficiency (29 %) was measured with freshly fallen leaves, but a food preference experiment showed that these leaves were generally avoided and that G. marginata preferred more decomposed leaves despite their lower digestibility. It is concluded that these saprophagous macroarthropods – with field biomasses of 7–11 g (live weight) m-2 – produce considerable amounts of faecal pellets in Mediterranean oak forests.
Keywords: assimilation efficiency; diplopoda; feeding rate; Mediterranean forests; soil macrofauna

Ascertaining Landscape Perceptions and Preferences with Pair-wise Photographs: Planning rural tourism in Extremadura, Spain - García Pérez, Joséd (Landscape Research, 2002)
Making use of available resources in the most efficient way is a fundamental principle of all development strategies. Landscapes are an abundant natural resource and form an important basis for the tourism industry. The case of rural Extremadura is considered for its potentially important landscape and growing rural tourist sector. A method of landscape analysis based on pair-wise comparison of photographs is used to ascertain the landscape preferences for rambling of tourists in rural areas. Their preferences are analysed according to personal characteristics and holiday activities. It is concluded that the identification of preferences can be of considerable value in the planning of ramblers' routes for specific social groups.
doi: 10.1080/01426390220149539doi: 10.1080/01426390220149539The following values have no corresponding Zotero field: publisher: Routledge
Keywords: Extremadura; landscape assessment; pair-wise analysis; planning; ramblers; tourism

Ascertaining Landscape Perceptions and Preferences with Pair-wise Photographs: Planning rural tourism in Extremadura, Spain - García Pérez, Joséd (Landscape Research, 2002)
Making use of available resources in the most efficient way is a fundamental principle of all development strategies. Landscapes are an abundant natural resource and form an important basis for the tourism industry. The case of rural Extremadura is considered for its potentially important landscape and growing rural tourist sector. A method of landscape analysis based on pair-wise comparison of photographs is used to ascertain the landscape preferences for rambling of tourists in rural areas. Their preferences are analysed according to personal characteristics and holiday activities. It is concluded that the identification of preferences can be of considerable value in the planning of ramblers' routes for specific social groups.
doi: 10.1080/01426390220149539
Keywords: Extremadura; landscape assessment; pair-wise analysis; planning; ramblers; tourism

Aspectos económicos de las prácticas agroforestales: un sistema de indicadores monetarios y biofísicos - Campos Palacín, P.; Rodríguez Luengo, Y. (Cuadernos de la Sociedad Española de Ciencias Forestales, 2002)
Se presenta en este trabajo un sistema de Cuentas Económicas Agroforestales (CAF) que tiene como objetivos principales el cálculo de la renta total sustentable desagregada por aprovechamien- tos y la aportación de un grupo seleccionado de indicadores biofísicos del uso múltiple de los recur- sos naturales y ambientales de una tierra. La metodología CAF es desarrollada al hilo de su aplica- ción a una dehesa de la comarca de Monfragüe en el ejercicio contable del año 1997
Keywords: autoconsumo ambiental; cuentas agroforestales; Dehesa; renta total

Aspectos económicos de las prácticas agroforestales: un sistema de indicadores monetarios y biofísicos - CAMPOS PALACIN, P; Rodríguez Luengo, Y (Cuadernos de la Sociedad Española de Ciencias Forestales, 2002)
Se presenta en este trabajo un sistema de Cuentas Económicas Agroforestales (CAF) que tiene como objetivos principales el cálculo de la renta total sustentable desagregada por aprovechamien- tos y la aportación de un grupo seleccionado de indicadores biofísicos del uso múltiple de los recur- sos naturales y ambientales de una tierra. La metodología CAF es desarrollada al hilo de su aplica- ción a una dehesa de la comarca de Monfragüe en el ejercicio contable del año 1997
Keywords: autoconsumo ambiental; cuentas agroforestales; Dehesa; renta total

Assessment of the use of n-alkanes as markers to describe the complex diets of herbivores - Martins, H; Elston, D A; Mayes, R W; Milne, J A (JOURNAL OF AGRICULTURAL SCIENCE, 2002)
Previous approaches to the description of complex diets, based on n-alkanes and optimization techniques, have grouped the plant species to reduce the number of components. Diet estimates have been obtained with least-squares routines by minimizing the discrepancy between faecal alkane concentrations calculated from herbage concentrations and actual faecal alkane concentrations. The effect of diet selection within groups can only be assessed by using sensitivity tests or by giving subjective weights to the individual plants. In the current study, a new optimization algorithm was developed that selects weightings that lead to consistent estimates of group proportions. The diet of the wild rabbit in a southern Portuguese montado was used as a case study. Estimates of the diet composition obtained using the new algorithm were compared with those of a conventional routine. The new algorithm was shown to provide, on average, more accurate estimates of the proportions of the groups in the diet. The effect of grouping plant species according to criteria other than similarity in n-alkane pattern on the accuracy of estimates was shown to be non-significant.

Assessment of the use of n-alkanes as markers to describe the complex diets of herbivores - Martins, H.; Elston, D. A.; Mayes, R. W.; Milne, J. A. (JOURNAL OF AGRICULTURAL SCIENCE, 2002)
Previous approaches to the description of complex diets, based on n-alkanes and optimization techniques, have grouped the plant species to reduce the number of components. Diet estimates have been obtained with least-squares routines by minimizing the discrepancy between faecal alkane concentrations calculated from herbage concentrations and actual faecal alkane concentrations. The effect of diet selection within groups can only be assessed by using sensitivity tests or by giving subjective weights to the individual plants. In the current study, a new optimization algorithm was developed that selects weightings that lead to consistent estimates of group proportions. The diet of the wild rabbit in a southern Portuguese montado was used as a case study. Estimates of the diet composition obtained using the new algorithm were compared with those of a conventional routine. The new algorithm was shown to provide, on average, more accurate estimates of the proportions of the groups in the diet. The effect of grouping plant species according to criteria other than similarity in n-alkane pattern on the accuracy of estimates was shown to be non-significant.
The following values have no corresponding Zotero field: pub-location: 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA publisher: CAMBRIDGE UNIV PRESS

Biomonitoring of Atmospheric PAHs by Evergreen Plants: Correlations and Applicability - Librando, V.; Perrini, G.; Tomasello, M. (Polycyclic Aromatic Compounds, 2002)
This article deals with looking for the best passive samplers among eleven plants diffused in the Mediterranean basin for the determination of polycyclic aromatic hydrocarbons in the atmosphere in substitution to the particulate matter sampling. The most recent research about biological passive samplers showed a quali-quantitative difference in pollutant sampling by different plants. Evergreen trees with long-lived leaves were selected in the urban area of Catania (Italy) and both samples (leaves and particulate matter) were extracted and purified by a two stage method before the analysis was performed by a GC/MS. Leaves and particulate matter were sampled in three different seasons (winter, spring and summer). PAHs concentrations found in the particulate matter and leaves were correlated. Some plants ( Olea europaea and Quercus ilex ) showed high values (r 2 > 0.85) of linear correlation coefficient in all seasons and are characterized by profiles similar to that of the particulate matter. Further, it has been observed that during the warmer seasons the total quantity of PAH adsorbed by the plants is greater but the fitting is better during winter. No difference was found by washing leaves with distilled water: this means that PAHs aren't deposited on the surface but are adsorbed in the lipidic layer of the leaves.
doi: 10.1080/10406630213563doi: 10.1080/10406630213563The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: correlation; GC/MS; leaves; PAH; particulate matter; passive samplers

Biomonitoring of Atmospheric PAHs by Evergreen Plants: Correlations and Applicability - Librando, V; Perrini, G; Tomasello, M (Polycyclic Aromatic Compounds, 2002)
This article deals with looking for the best passive samplers among eleven plants diffused in the Mediterranean basin for the determination of polycyclic aromatic hydrocarbons in the atmosphere in substitution to the particulate matter sampling. The most recent research about biological passive samplers showed a quali-quantitative difference in pollutant sampling by different plants. Evergreen trees with long-lived leaves were selected in the urban area of Catania (Italy) and both samples (leaves and particulate matter) were extracted and purified by a two stage method before the analysis was performed by a GC/MS. Leaves and particulate matter were sampled in three different seasons (winter, spring and summer). PAHs concentrations found in the particulate matter and leaves were correlated. Some plants ( Olea europaea and Quercus ilex ) showed high values (r 2 > 0.85) of linear correlation coefficient in all seasons and are characterized by profiles similar to that of the particulate matter. Further, it has been observed that during the warmer seasons the total quantity of PAH adsorbed by the plants is greater but the fitting is better during winter. No difference was found by washing leaves with distilled water: this means that PAHs aren't deposited on the surface but are adsorbed in the lipidic layer of the leaves.
doi: 10.1080/10406630213563
Keywords: correlation; GC/MS; leaves; PAH; particulate matter; passive samplers

Climatic changes since the Late-glacial/Holocene transition in La Mancha Plain (South-central Iberian Peninsula, Spain) and their incidence on Las Tablas de Daimiel - Dorado, Miriam; Rodr, Ana Valdeolmillos; Zapata, M. Blanca Ruiz; Jos, M.; Garc, Gil; Bustamante, Irene De (Quaternary International, 2002)
A palynological and lithological continuous record from La Mancha Plain (South-central Iberian Peninsula, Spain) is presented. The obtained results have permitted the reconstruction of the climatic evolution in the area since the Late-glacial/Holocene transition. The end of the Late-glacial was characterized by a cold and arid climate and it concluded at about 98907180 yr BP. In the Early Holocene a slight climatic amelioration began, being interrupted by a more arid phase around 8500 yr BP. The Holocene Climatic Optimum started from ca. 8000 yr BP and was characterized by higher temperatures and more humidity. During the MidHolocene–Late Holocene times a stage of marked aridity occurred towards 5000 yr BP that preceded the development of a dry mediterranean climate. Under this new climate a short-time arid phase took place around 2500 yr BP after which the mediterranean conditions became accentuated, with an increasing dry climate. This climatic evolution has affected the characteristics of the marshlands of Las Tablas de Daimiel National Park, originating changes in the sedimentary environment. This environment was mainly ﬂuvial until the end of the Holocene Climatic Optimum and became lacustrine–palustrine from the beginning of the more arid conditions.
Keywords: arid phase; Climatic conditions; Evergreen and deciduous species (voyant); Holocene; Pollen analysis; Quercus; Spain

Climatic changes since the Late-glacial/Holocene transition in La Mancha Plain (South-central Iberian Peninsula, Spain) and their incidence on Las Tablas de Daimiel - Dorado, Miriam; Rodr, Ana Valdeolmillos; Zapata, M Blanca Ruiz; Jos, M; Garc, Gil; Bustamante, Irene De (Quaternary International, 2002)
A palynological and lithological continuous record from La Mancha Plain (South-central Iberian Peninsula, Spain) is presented. The obtained results have permitted the reconstruction of the climatic evolution in the area since the Late-glacial/Holocene transition. The end of the Late-glacial was characterized by a cold and arid climate and it concluded at about 98907180 yr BP. In the Early Holocene a slight climatic amelioration began, being interrupted by a more arid phase around 8500 yr BP. The Holocene Climatic Optimum started from ca. 8000 yr BP and was characterized by higher temperatures and more humidity. During the MidHolocene–Late Holocene times a stage of marked aridity occurred towards 5000 yr BP that preceded the development of a dry mediterranean climate. Under this new climate a short-time arid phase took place around 2500 yr BP after which the mediterranean conditions became accentuated, with an increasing dry climate. This climatic evolution has affected the characteristics of the marshlands of Las Tablas de Daimiel National Park, originating changes in the sedimentary environment. This environment was mainly ﬂuvial until the end of the Holocene Climatic Optimum and became lacustrine–palustrine from the beginning of the more arid conditions.
Keywords: arid phase; Climatic conditions; Evergreen and deciduous species (voyant); Holocene; Pollen analysis; Quercus; Spain

Comparative protective strategies of Cistus albidus and Quercus ilex facing photoinhibitory winter conditions - Oliveira, G; Penuelas, J (Environmental and experimental botany, 2002)
The role of structural photoprotection under photoinhibitory winter conditions was evaluated in two Mediterranean woody species: Cistus albidus (semideciduous) and Quercus ilex (evergreen). Shoots were manipulated in order to modify the light load naturally received by the leaves throughout the cold season, and monitored for changes in maximum photochemical efﬁciency of PSII, phenology, and leaf morphology. Naturally steep leaves of C. albidus were restrained to a horizontal position, and compared with control leaves (naturally horizontal, or steeply inclined). Fully exposed leaves of Q. ilex were artiﬁcially protected through partial shading, and compared with control leaves (not shaded). During the cold season, the most exposed (either naturally or artiﬁcially) leaves were always more photoinhibited (had lower maximal photochemical efﬁciency of PSII) than the photoprotected ones. The differences disappeared at the beginning of spring. Winter photoinhibition was not more pronounced in older than in younger leaves of C. albidus, indicating that inclination rather than age affected their photochemical efﬁciency. Leaf chlorophyll contents were not signiﬁcantly affected by the manipulations. Leaf thickness decreased slightly in the least exposed shoots of the evergreen species, but no changes were detected in leaf morphological traits of the semideciduous one. The increased photoinhibitory pressure led only to slight and non-signiﬁcant changes in phenology and growth
Keywords: evergreen; leaf angle; manipulation; Mediterranean winter; photoprotection; semideciduous

Composition and chemical variability of the triterpene fraction of dichloromethane extracts of cork (Quercus suber L.) - Castola, Vincent; Bighelli, Ange; Rezzi, Serge; Melloni, Giovanni; Gladiali, Serafino; Desjobert, Jean-Marie; Casanova, Joseph (Industrial Crops and Products, 2002)
Dichloromethane extracts were prepared from 38 samples of cork harvested in different locations of Corsica and Sardinia from individual trees of Quercus suber L. Friedelin, 3--hydroxyfriedelan-2-one, betulin, betulinic acid, -sitosterol and sitost-4-en-3-one were identiﬁed and their molar percentages were calculated by 13 C NMR spectroscopy, following a procedure recently developed by our group. The results were submitted to chemometric analysis (k-means and principal component analysis), which allowed three groups to be distinguished with respect to the content of friedelin, betulinic acid and 3--hydroxyfriedelan-2-one.
Keywords: 13C NMR; Chemical variability; Chemometric analysis; Cork; extracts

Composition and chemical variability of the triterpene fraction of dichloromethane extracts of cork (Quercus suber L.) - Castola, Vincent; Bighelli, Ange; Rezzi, Serge; Melloni, Giovanni; Gladiali, Serafino; Desjobert, Jean-Marie; Casanova, Joseph (Industrial Crops and Products, 2002)
Dichloromethane extracts were prepared from 38 samples of cork harvested in different locations of Corsica and Sardinia from individual trees of Quercus suber L. Friedelin, 3--hydroxyfriedelan-2-one, betulin, betulinic acid, -sitosterol and sitost-4-en-3-one were identiﬁed and their molar percentages were calculated by 13 C NMR spectroscopy, following a procedure recently developed by our group. The results were submitted to chemometric analysis (k-means and principal component analysis), which allowed three groups to be distinguished with respect to the content of friedelin, betulinic acid and 3--hydroxyfriedelan-2-one.
Keywords: 13C NMR; Chemical variability; Chemometric analysis; Cork; extracts

Copper(II) and nickel(II) uptake from aqueous solutions by cork wastes: a NMR and potentiometric study - Villaescusa, Isabel; Fiol, Núria; Cristiani, Franco; Floris, Costantino; Lai, Simona; Nurchi, Valeria Marina (Polyhedron, 2002)
Due to the increasing interest in the use of biomasses from agriculture as removing agents for heavy metals in waste effluents, we present here a joint potentiometric and 13C MAS and cross polarization-magic angle spinning NMR (CP-MAS NMR) study on cork interaction with Cu(II) and Ni(II). Through potentiometry we were able to distinguish two kind of interactions, a stronger one which involves protonated sites on cork and a second that allows hydroxide precipitation of the bound metal ion into the cork structure. NMR signal analysis suggests a specific metal complexation on the carbohydrate moieties of polymeric cork matrix. The 13C MAS NMR suggests that the dynamics in the MHz range and the overall arrangement of polymeric matrix is not affected by metal binding; and the spin relaxation times T1ρ(1H) and T1ρ(13C) show that no significant difference of relaxation processes in the KHz range is introduced by metal coordination.
Keywords: copper; Cork; Metal uptake; Nickel; Potentiometric titration; Solid state 13C MAS and CP-MAS NMR

Copper(II) and nickel(II) uptake from aqueous solutions by cork wastes: a NMR and potentiometric study - Villaescusa, Isabel; Fiol, Núria; Cristiani, Franco; Floris, Costantino; Lai, Simona; Nurchi, Valeria Marina (Polyhedron, 2002)
Due to the increasing interest in the use of biomasses from agriculture as removing agents for heavy metals in waste effluents, we present here a joint potentiometric and 13C MAS and cross polarization-magic angle spinning NMR (CP-MAS NMR) study on cork interaction with Cu(II) and Ni(II). Through potentiometry we were able to distinguish two kind of interactions, a stronger one which involves protonated sites on cork and a second that allows hydroxide precipitation of the bound metal ion into the cork structure. NMR signal analysis suggests a specific metal complexation on the carbohydrate moieties of polymeric cork matrix. The 13C MAS NMR suggests that the dynamics in the MHz range and the overall arrangement of polymeric matrix is not affected by metal binding; and the spin relaxation times T1ρ(1H) and T1ρ(13C) show that no significant difference of relaxation processes in the KHz range is introduced by metal coordination.
Keywords: copper; Cork; Metal uptake; Nickel; Potentiometric titration; Solid state 13C MAS and CP-MAS NMR

Cryopreservation of Quercus suber and Quercus ilex embryonic axes: in vitro culture, desiccation and cooling factors. - Gonzalez-Benito, M Elena; Prieto, Roberto-Moreno; Herradon, Esther; Martin, Carmen (Cryo letters, 2002)
This study examines different factors included in the cryopreservation protocols for Quercus ilex and Q. suber embryonic axes. In vitro incubation temperature played an important role in the appropriate development of Q. ilex axes, as 15 degrees C was superior to 25 degrees C. Q. suber axes proved to be more sensitive to desiccation and cooling. Poor survival (35%) was observed when axes were included into cryovials and then in liquid nitrogen, and none when immersed in sub-cooled liquid nitrogen (-210 degrees C). Q. ilex axes showed poorly organised development in vitro (c. 50% of non-cooled axes showed shoot development). However, c. 80% survival was observed after cryopreservation (either in liquid nitrogen or sub-cooled liquid nitrogen at 0.34 g water / g dry weight), of which c. 15% showed shoot development.
Keywords: Cryopreservation; Cryopreservation: methods; Cryoprotective Agents; Cryoprotective Agents: pharmacology; Culture Techniques; Culture Techniques: methods; Desiccation; Desiccation: methods; embryonic axes; germination; germination temperature; Germination: drug effects; liquid nitrogen; plantlet development; Quercus; Quercus: embryology; Seeds; Seeds: chemistry; Seeds: embryology; Survival Rate; Temperature; water; Water: analysis

Culture in vitro des bourgeons axillaires de Chêne-liège (Quercus suber L.). I—Influence des cytokinines sur l'organogenèse et la callogenèse de nœuds de plantules - Kbiach, M L El; Lamarti, A; Abdali, A; Badoc, A (Bull. Soc. Pharm. Bordeaux, 2002)
Le débourrement in vitro des bourgeons axillaires de plantules de Chêne-liège a été abordé. L’influence de cytokinines ou de composés à activité cytokinine, seuls ou combinés aux auxines ou à l’AG3 , sur l’induction des bourgeons, l’élongation des pousses feuillées et la formation des cals a été étudiée. Dans le milieu de culture WPM, additionné des microéléments et du mélange vitaminique MS, la BA à 4,5 µM favorise la caulogenèse. Son association à d’autres régulateurs de croissance ne permet pas une amélioration du taux de débourrement. En revanche, à 4,5 µM et combinée à 7 µM d’ANA, la callogenèse est importante.
Keywords: bourgeons axillaires; call; callogenèse (PG); chêne-liège; cytokinines; débourrement in vitro

Culture in vitro des bourgeons axillaires de Chêne-liège (Quercus suber L.). I—Influence des cytokinines sur l'organogenèse et la callogenèse de nœuds de plantules - Kbiach, M. L. El; Lamarti, A.; Abdali, A.; Badoc, A. (Bull. Soc. Pharm. Bordeaux, 2002)
Le débourrement in vitro des bourgeons axillaires de plantules de Chêne-liège a été abordé. L’influence de cytokinines ou de composés à activité cytokinine, seuls ou combinés aux auxines ou à l’AG3 , sur l’induction des bourgeons, l’élongation des pousses feuillées et la formation des cals a été étudiée. Dans le milieu de culture WPM, additionné des microéléments et du mélange vitaminique MS, la BA à 4,5 µM favorise la caulogenèse. Son association à d’autres régulateurs de croissance ne permet pas une amélioration du taux de débourrement. En revanche, à 4,5 µM et combinée à 7 µM d’ANA, la callogenèse est importante.
Keywords: bourgeons axillaires; call; callogenèse (PG); chêne-liège; cytokinines; débourrement in vitro

CUSTOS ASSOCIADOS AO CRESCIMENTO DE FOLHAS E CAULES EM SOBREIRO E AZINHEIRA - Oliveira, G; Martins-Loução, MA (Revista de biologia, 2002)

de preferencias de hábitat y de distribución y abundancia invernal de aves en el centro de España. Análisis y predicción del efecto de factores ecológicos - Carrascal, L. M.; Palomino, D.; Lobo, J. M. (Animal Biodiversity and Conservation, 2002)
Patterns of habitat preference and distribution and abundance of wintering bird fauna in central Spain. Analysis and prediction of the effect of ecological factors.— This paper analyses the effect of geographic, topographic, land use and habitat structure variables on the composition and structure of wintering bird communities in Central Spain (Iberian peninsula). Parameters describing the avifauna varied in a predictable way considering a small group of coarse–grained variables defining the geographical and altitudinal location of the censuses, and the basic characteristics of the structure and typology of habitats: 49–76% of variance accounted for total bird density and for abundance of four ecological groups, 37–63% accounted for species richness and diversity, and 65% explained the relative abundance of species with conservation problems according to the European scale (SPEC figures). Regarding the most widespread species in the study area, significant models were obtained by means of tree regression analysis for 50 species, with an average reduction of deviance of 39%. Altitude was the most important variable affecting bird community parameters and abundance of each bird species, showing a consistent and marked negative effect. Structural complexity of the vegetation and geographical location followed as the variables of importance explaining variability. The habitats with the lowest bird density, richness and diversity of birds were mountain grasslands/shrublands, young pine re–forestations, and Pyrenean oak forests at 1,200–1,600 m a.s.l. The habitats with the highest values on these parameters were riparian forests, agricultural mosaics, and holmoak "dehesa" parklands, mainly located at the southern and western part of the region and at intermediate altitudes. The total density of birds increased from east to west, was higher in intermediate altitudes than in the extremes of the altitudinal range, and increased with habitat structural complexity (i.e., vertical development and degree of vegetation cover), agricultural use of the land, and the presence of water (e.g., streams, rivers, flooded areas). Density of strictly wintering species in the study region decreased latitudinally from southeast to northwest, being higher at intermediate altitudes in localities with presence of water and woodlands dominated by coniferous trees. Abundance of facultative or obligate frugivorous species was very low. Richness of species was higher toward the western part of the study area, increased with habitat structural complexity, and was lower at higher altitudes. On the other hand, the less diverse bird assemblages were those that inhabit agricultural landscapes and/or areas located at higher altitudes. Habitats and areas with a higher relative abundance of species with conservation problems at the European scale (SPEC scores) were located at intermediate altitudes in the southwest and southeast of the study region. The relative abundance of this group of species was also associated to the presence of water, habitat structural complexity and agricultural use. The relationship between the European conservation status of species (SPEC scores) and the patterns of distribution, abundance, habitat preferences and ecological width of 72 species was also analysed. Species with more conservation problems on the European scale have a marked preference for structurally simpler habitats (e.g., agricultural and grasslands habitats) and have a broader altitudinal and among–habitats distribution. Results from the 44 census localities were extrapolated to the remaining region using a geographical information system in order to build predictive maps for density, species richness, species diversity and weighed European conservation status. This work shows that valuable knowledge can be obtained from fragmentary and dispersed data, in order to describe general patterns of distribution, abundance and habitat preferences of birds. This methodological approach could be a valid in environmentally heterogeneous, large regions, with few qualified bird observers and researchers.
Keywords: Central Spain; Density; habitat preferences; regression models; Species richness; wintering avifauna

de preferencias de hábitat y de distribución y abundancia invernal de aves en el centro de España. Análisis y predicción del efecto de factores ecológicos - Carrascal, L M; Palomino, D; Lobo, J M (Animal Biodiversity and Conservation, 2002)
Patterns of habitat preference and distribution and abundance of wintering bird fauna in central Spain. Analysis and prediction of the effect of ecological factors.— This paper analyses the effect of geographic, topographic, land use and habitat structure variables on the composition and structure of wintering bird communities in Central Spain (Iberian peninsula). Parameters describing the avifauna varied in a predictable way considering a small group of coarse–grained variables defining the geographical and altitudinal location of the censuses, and the basic characteristics of the structure and typology of habitats: 49–76% of variance accounted for total bird density and for abundance of four ecological groups, 37–63% accounted for species richness and diversity, and 65% explained the relative abundance of species with conservation problems according to the European scale (SPEC figures). Regarding the most widespread species in the study area, significant models were obtained by means of tree regression analysis for 50 species, with an average reduction of deviance of 39%. Altitude was the most important variable affecting bird community parameters and abundance of each bird species, showing a consistent and marked negative effect. Structural complexity of the vegetation and geographical location followed as the variables of importance explaining variability. The habitats with the lowest bird density, richness and diversity of birds were mountain grasslands/shrublands, young pine re–forestations, and Pyrenean oak forests at 1,200–1,600 m a.s.l. The habitats with the highest values on these parameters were riparian forests, agricultural mosaics, and holmoak "dehesa" parklands, mainly located at the southern and western part of the region and at intermediate altitudes. The total density of birds increased from east to west, was higher in intermediate altitudes than in the extremes of the altitudinal range, and increased with habitat structural complexity (i.e., vertical development and degree of vegetation cover), agricultural use of the land, and the presence of water (e.g., streams, rivers, flooded areas). Density of strictly wintering species in the study region decreased latitudinally from southeast to northwest, being higher at intermediate altitudes in localities with presence of water and woodlands dominated by coniferous trees. Abundance of facultative or obligate frugivorous species was very low. Richness of species was higher toward the western part of the study area, increased with habitat structural complexity, and was lower at higher altitudes. On the other hand, the less diverse bird assemblages were those that inhabit agricultural landscapes and/or areas located at higher altitudes. Habitats and areas with a higher relative abundance of species with conservation problems at the European scale (SPEC scores) were located at intermediate altitudes in the southwest and southeast of the study region. The relative abundance of this group of species was also associated to the presence of water, habitat structural complexity and agricultural use. The relationship between the European conservation status of species (SPEC scores) and the patterns of distribution, abundance, habitat preferences and ecological width of 72 species was also analysed. Species with more conservation problems on the European scale have a marked preference for structurally simpler habitats (e.g., agricultural and grasslands habitats) and have a broader altitudinal and among–habitats distribution. Results from the 44 census localities were extrapolated to the remaining region using a geographical information system in order to build predictive maps for density, species richness, species diversity and weighed European conservation status. This work shows that valuable knowledge can be obtained from fragmentary and dispersed data, in order to describe general patterns of distribution, abundance and habitat preferences of birds. This methodological approach could be a valid in environmentally heterogeneous, large regions, with few qualified bird observers and researchers.
Keywords: Central Spain; Density; habitat preferences; regression models; Species richness; wintering avifauna

Dimeric and Trimeric Hydrolyzable Tannins from Quercus coccifera and Quercus suber - Ito, Hideyuki; Yamaguchi, Koji; Kim, Tae-Hoon; Khennouf, Seddik; Gharzouli, Kamel; Yoshida, Takashi (Journal of Natural Products, 2002)
Three new hydrolyzable tannins, cocciferins D1 (1), D2 (2), and T1 (4), were isolated from the leaves of Quercus coccifera. Cocciferin D2 (2) and two additional new tannins, cocciferins D3 (3) and T2 (5), were also obtained from the leaves of Quercus suber. Their oligomeric structures were elucidated on the basis of spectroscopic methods and chemical evidence. Compounds 2, 3, and 5 were rare oligomers possessing glucose cores with both open-chain and pyranose forms.
doi: 10.1021/np010465i
Keywords: NMR; Quercus coccifera; Quercus suber; structure (voyant); Tannins

Distribución de especies de matorral en suelos ácidos y básicos de la Sierra de Grazalema, sur de España - Gallego Fernández, Juan Bautista (Anales del Jardín Botánico de Madrid, 2002)
The presence of Mediterranean shrubland woody species on acid or basic soils was studied at Grazalema Mountains. Transects were made at 137 sampling sites in the study área and 74 species were recognized. Phlomis purpurea. Cistus albidus. Quercus rotundifolia and Ulex baeticus were the most frequent species, being present at 70 % of the transects. Pistacia lentiscus. Rubia peregrina and Daphne gnidium were found in 50 % of the transects. From the total species recorded, 67 species were located on basic soils and 55 on acid soils; 19 species (25.7 %) were located only on basic soils and 7 species (9.5 %) only on acid soils; 21 species were significantly more frequent on basic soils, and 10 species on acid soils. The number of species per transect were significantly higher on basic soils (13.2 ± 3.8) than on acid soils (10.3 ± 3.7). Differences in species number are related to a higher number of species displaying a narrow distribution in the basic shrublands as well as due to species loss in the acid shrublands, as a consequence of geographic isolation and human disturbance.
Keywords: Betic ranges; Mediterranean shrubland; soil pH

Distribución de especies de matorral en suelos ácidos y básicos de la Sierra de Grazalema, sur de España - Gallego Fernández, Juan Bautista (Anales del Jardín Botánico de Madrid, 2002)
The presence of Mediterranean shrubland woody species on acid or basic soils was studied at Grazalema Mountains. Transects were made at 137 sampling sites in the study área and 74 species were recognized. Phlomis purpurea. Cistus albidus. Quercus rotundifolia and Ulex baeticus were the most frequent species, being present at 70 % of the transects. Pistacia lentiscus. Rubia peregrina and Daphne gnidium were found in 50 % of the transects. From the total species recorded, 67 species were located on basic soils and 55 on acid soils; 19 species (25.7 %) were located only on basic soils and 7 species (9.5 %) only on acid soils; 21 species were significantly more frequent on basic soils, and 10 species on acid soils. The number of species per transect were significantly higher on basic soils (13.2 ± 3.8) than on acid soils (10.3 ± 3.7). Differences in species number are related to a higher number of species displaying a narrow distribution in the basic shrublands as well as due to species loss in the acid shrublands, as a consequence of geographic isolation and human disturbance.
Keywords: Betic ranges; Mediterranean shrubland; soil pH

Does temporal variability of winter Common Cranes in the dehesas depend on farming practices? - Aviles, J M; Medina, F J; Sánchez, J M; Parejo, D (Waterbirds, 2002)
The inclusion of Spain and Portugal within the European Community has brought about a change in the traditional farming practices in the dehesas of Iberia to intensive cereal and to irrigated crops. Here we use seven-year counts of Common Cranes in 38 wintering sites to evaluate whether habitat structure modified by farm- ing practices in the Holm Oak (Quercus ilex) dehesas is an important determinant of variability in winter crane num- bers. We extracted, from a set of nine variables that express different levels of human management in the Holm Oak dehesas, two factors that accounted for the 66% of the variance. The first factor was related to livestock utiliza- tion of the dehesas, while the second one reflected Holm Oak presence. We ran a general linear model to analyze the influence of farming practices (PC1 and PC2), landscape heterogeneity and roost site stability on inter- and in- tra-season variability in numbers of winter cranes. Livestock presence, Holm Oak presence, landscape heterogeneity and roost type stability did not explain intra- and inter- season variability in crane numbers wintering in the Holm Oak dehesas of Spain.
Keywords: Agricultural intensification; Common Crane; Grus grus; holm oak dehesas; southwestern Spain; winter stability

Does temporal variability of winter Common Cranes in the dehesas depend on farming practices? - Aviles, J. M.; Medina, F. J.; Sánchez, J. M.; Parejo, D. (Waterbirds, 2002)
The inclusion of Spain and Portugal within the European Community has brought about a change in the traditional farming practices in the dehesas of Iberia to intensive cereal and to irrigated crops. Here we use seven-year counts of Common Cranes in 38 wintering sites to evaluate whether habitat structure modified by farm- ing practices in the Holm Oak (Quercus ilex) dehesas is an important determinant of variability in winter crane num- bers. We extracted, from a set of nine variables that express different levels of human management in the Holm Oak dehesas, two factors that accounted for the 66% of the variance. The first factor was related to livestock utiliza- tion of the dehesas, while the second one reflected Holm Oak presence. We ran a general linear model to analyze the influence of farming practices (PC1 and PC2), landscape heterogeneity and roost site stability on inter- and in- tra-season variability in numbers of winter cranes. Livestock presence, Holm Oak presence, landscape heterogeneity and roost type stability did not explain intra- and inter- season variability in crane numbers wintering in the Holm Oak dehesas of Spain.
Keywords: Agricultural intensification; Common Crane; Grus grus; holm oak dehesas; southwestern Spain; winter stability

Drosophyllum lusitanicum, an endangered West Mediterranean endemic carnivorous plant: threats and its ability to control available resources - Correia, E; Freitas, H (BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, 2002)
Drosophyllum lusitanicum (L.) Link (Droseraceae), Erva pinheira orvalhada, an endangered carnivorous plant, is a local endemic of clearings in pine, cork oak and oak forests or their successional shrublands in the western Iberian Peninsula and Morocco. The conservation status, distribution and population dynamics of this species are only partially known, both for Spanish and Portuguese occurrences. Portuguese distribution data from herbarium and bibliographic sources were collected for this study. Field work on 50 populations was undertaken in order to improve knowledge on their conservation status and possible threats. Natural causes, infrastructure and housing construction are stressed as the most important threats. Germination tests were carried out and the distribution patterns, plant height and the number of flowers were studied in an arbitrarily chosen population. A relatively high light requirement and low competitive ability to gain light are considered factors likely for the microdistribution pattern. Drosophyllum lusitanicum cannot compete for light in habitats with intense competition. Seeds from D. lusitanicum have reduced probability of germination when adult plants are already growing in the area. It is hypothesized that seed germination shows a similar pattern to flowering, viz over a considerable time rather than in a sudden flush. This strategy may be a key factor for the species' survival, representing attempts to take advantage of available resources, preventing intraspecific competition and, finally, preventing sudden total disappearance of a population, resulting from any catastrophic events due to natural causes or to human activity. As a result of this study, some conservation measures are suggested. (C) The Linnean Society of London.
Keywords: competition; competitive ability; Droseraceae; intraspecific competition; microdistribution pattern; Portugal; seed bank

Drosophyllum lusitanicum, an endangered West Mediterranean endemic carnivorous plant: threats and its ability to control available resources - Correia, E.; Freitas, H. (BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, 2002)
Drosophyllum lusitanicum (L.) Link (Droseraceae), Erva pinheira orvalhada, an endangered carnivorous plant, is a local endemic of clearings in pine, cork oak and oak forests or their successional shrublands in the western Iberian Peninsula and Morocco. The conservation status, distribution and population dynamics of this species are only partially known, both for Spanish and Portuguese occurrences. Portuguese distribution data from herbarium and bibliographic sources were collected for this study. Field work on 50 populations was undertaken in order to improve knowledge on their conservation status and possible threats. Natural causes, infrastructure and housing construction are stressed as the most important threats. Germination tests were carried out and the distribution patterns, plant height and the number of flowers were studied in an arbitrarily chosen population. A relatively high light requirement and low competitive ability to gain light are considered factors likely for the microdistribution pattern. Drosophyllum lusitanicum cannot compete for light in habitats with intense competition. Seeds from D. lusitanicum have reduced probability of germination when adult plants are already growing in the area. It is hypothesized that seed germination shows a similar pattern to flowering, viz over a considerable time rather than in a sudden flush. This strategy may be a key factor for the species' survival, representing attempts to take advantage of available resources, preventing intraspecific competition and, finally, preventing sudden total disappearance of a population, resulting from any catastrophic events due to natural causes or to human activity. As a result of this study, some conservation measures are suggested. (C) The Linnean Society of London.
The following values have no corresponding Zotero field: pub-location: 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND publisher: ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD
Keywords: competition; competitive ability; Droseraceae; intraspecific competition; microdistribution pattern; Portugal; seed bank

Elevated atmospheric CO2 causes seasonal changes in carbonyl emissions from Quercus ilex - KREUZWIESER, JÜRGEN; Cojocariu, Cristian; Jüssen, Vera; RENNENBERG, HEINZ (New Phytologist, 2002)
* • The effect of elevated atmospheric CO2 on the carbonyl emissions of leaves from two Mediterranean oak species (Quercus ilex and Q. pubescens) was analyzed under field conditions. * • Physiological and meteorological parameters were determined in parallel with measurements of carbonyl emissions. Gas exchange was quantified in dynamic cuvettes combined with an infrared gas analyzer. * • Acetaldehyde and acetone emissions from leaves of Q. ilex were enhanced by elevated CO2 in the autumn (from 14–40 nmol m−2 min−1 and from 2–8 nmol m−2 min−1, respectively), but not in the summer. No significant effects were found for leaves of Q. pubescens. The effects of CO2 on Q. ilex were mainly a result of decreased emissions by control trees under ambient CO2 concentrations in the autumn; emissions from trees exposed to elevated CO2 remained at a high level. * • Elevated atmospheric CO2 causes autumnal changes in carbonyl emissions from Quercus ilex. These effects suggest that the production of acetaldehyde and acetone depend on developmental factors. It is not yet clear whether the altered carbonyl emissions are a unique feature of Q. ilex.
Keywords: Acetaldehyde; carbonyl emission; Elevated CO2; Quercus ilex; Quercus pubescens; VOC

Endoglucanase and β-glycosidase activities in an evergreen oak litter: annual variation and regulating factors - Criquet, S; Tagger, S; Vogt, G; Le petit, J (Soil Biology and Biochemistry, 2002)
This paper represents the third part of a larger study about the processes involved in litter biodegradation in an oak copse in France. It concerns the variations in activities of endoglucanases and of β-glycosidases over 13 months in forest litter. Evergreen oak (Quercus ilex L.) litter was taken as a model because Q. ilex is the most abundant tree species in forests of the French Mediterranean area. The activities of several endoglucanases and β-glycosidases, and the concentrations of the proteins and reducing sugars were measured in the evergreen oak litter between October 1997 and October 1998. Several biotic and abiotic factors, potentially involved in the regulation of the activities of these hydrolyzing enzymes, were also measured: culturable heterotrophic bacteria, cellulolytic bacteria and cellulolytic fungi, moisture, temperature and pH of the litter. Under this Mediterranean climate, the moisture of the litter was strongly correlated with many factors and is likely to be important in regulating the temporal dynamics of various biological parameters. A multiple regression analysis showed that the annual dynamic of the culturable heterotrophic bacteria was primarily influenced by moisture but also by variations in concentration of reducing sugars in the litter. Moreover, these bacteria were correlated with the activities of several β-glycosidases, and specifically with the N-acetyl-glucosaminidases (r=0.93). No relationships were established between the number of cellulolytic microorganisms (bacteria and fungi) and the activities of endoglucanases (i.e. cellulases and hemicellulases). The seasonal trends of certain biotic processes, and the influence of pH and of temperature on these processes are also discussed. Electrophoretic analyses were used to estimate the number of cellulase and xylanase isoenzymes in the litter, and to study their fluctuations over one year. The prevailing cellulase isoenzyme had a Rf of 0.64, and there was no relationship between the abundance of cellulolytic microorganisms and the electrophoretic profiles of the cellulases. In the case of the xylanases, the electrophoretic profiles were homogenous throughout the year, and the prevailing xylanase had a Rf of 0.75.
Keywords: Cellulase; hemicellulase; Isoenzymes; litter; Polysaccharides

Endoglucanase and β-glycosidase activities in an evergreen oak litter: annual variation and regulating factors - Criquet, S.; Tagger, S.; Vogt, G.; Le petit, J. (Soil Biology and Biochemistry, 2002)
This paper represents the third part of a larger study about the processes involved in litter biodegradation in an oak copse in France. It concerns the variations in activities of endoglucanases and of β-glycosidases over 13 months in forest litter. Evergreen oak (Quercus ilex L.) litter was taken as a model because Q. ilex is the most abundant tree species in forests of the French Mediterranean area. The activities of several endoglucanases and β-glycosidases, and the concentrations of the proteins and reducing sugars were measured in the evergreen oak litter between October 1997 and October 1998. Several biotic and abiotic factors, potentially involved in the regulation of the activities of these hydrolyzing enzymes, were also measured: culturable heterotrophic bacteria, cellulolytic bacteria and cellulolytic fungi, moisture, temperature and pH of the litter. Under this Mediterranean climate, the moisture of the litter was strongly correlated with many factors and is likely to be important in regulating the temporal dynamics of various biological parameters. A multiple regression analysis showed that the annual dynamic of the culturable heterotrophic bacteria was primarily influenced by moisture but also by variations in concentration of reducing sugars in the litter. Moreover, these bacteria were correlated with the activities of several β-glycosidases, and specifically with the N-acetyl-glucosaminidases (r=0.93). No relationships were established between the number of cellulolytic microorganisms (bacteria and fungi) and the activities of endoglucanases (i.e. cellulases and hemicellulases). The seasonal trends of certain biotic processes, and the influence of pH and of temperature on these processes are also discussed. Electrophoretic analyses were used to estimate the number of cellulase and xylanase isoenzymes in the litter, and to study their fluctuations over one year. The prevailing cellulase isoenzyme had a Rf of 0.64, and there was no relationship between the abundance of cellulolytic microorganisms and the electrophoretic profiles of the cellulases. In the case of the xylanases, the electrophoretic profiles were homogenous throughout the year, and the prevailing xylanase had a Rf of 0.75.
Keywords: Cellulase; hemicellulase; Isoenzymes; litter; Polysaccharides

Estudio de la variabilidad temporal y espacial de la pérdida de suelo en la dehesa (Extremadura, SO España) mediante lluvia simulada - Ceballos Barbancho, A; Shanabel, S; Cerdá, A (Geographicalia, 2002)
The inain objective of this paper is to study the influence of the seasonal variability of tlze antecedent conditions in soil losses in a dehesa ecosystem, as well as an approach to its spatial variability. The experimental layout includes forty rainfall simulation experiments carried out in two different situa- tions: first on dry conditions, with degraded vegetation, and, second on wet con- ditions, with an important vegetation cover. The results indicate that the highest sediiilent concentrations are located in situations with bare soils, due to the effect of the drought and the soil remo- ved by grazing animals. The control of the process depends more to tlie sediment available on the soil surface than to the runoff transport capacity. From an spatial point of view, it liighlights the contrast between tlie low los- ses registered in the valley bottoms and the highest values measured in tlie areas more frequented by the livestock, where the degradation of the vege- tation cover and the removal of tlie soil material are continuous. Finally, although the rate of soil loss in the dehesa is low, it is important froin a qua- litative point of view because it affects to the inost fertile horizon in the soil profile
Keywords: Dehesa; rainfall simulation; runoff; Season; sediment concentration; soil loss

Estudio de la variabilidad temporal y espacial de la pérdida de suelo en la dehesa (Extremadura, SO España) mediante lluvia simulada - Ceballos Barbancho, A.; Shanabel, S.; Cerdà, A. (Geographicalia, 2002)
The inain objective of this paper is to study the influence of the seasonal variability of tlze antecedent conditions in soil losses in a dehesa ecosystem, as well as an approach to its spatial variability. The experimental layout includes forty rainfall simulation experiments carried out in two different situa- tions: first on dry conditions, with degraded vegetation, and, second on wet con- ditions, with an important vegetation cover. The results indicate that the highest sediiilent concentrations are located in situations with bare soils, due to the effect of the drought and the soil remo- ved by grazing animals. The control of the process depends more to tlie sediment available on the soil surface than to the runoff transport capacity. From an spatial point of view, it liighlights the contrast between tlie low los- ses registered in the valley bottoms and the highest values measured in tlie areas more frequented by the livestock, where the degradation of the vege- tation cover and the removal of tlie soil material are continuous. Finally, although the rate of soil loss in the dehesa is low, it is important froin a qua- litative point of view because it affects to the inost fertile horizon in the soil profile
Keywords: Dehesa; rainfall simulation; runoff; Season; sediment concentration; soil loss

Evaluation of the disposal of firewood of ilex pruning (Quercus ilex) in Andalusia and its characterization for the manufacture of wood cellulose pulp. - Gutierrez, J A; Alcaide, L J; Carmona, J A; Blanco, M J D; Ot, I P; Baldovin, F L (AFINIDAD, 2002)
In this work, it is analyzed the production of firewood of the ilex pruning in Andalusia, its real disposa and future forecast. Chemical characteristics are studied, in comparison with otherr wood species: Pine (Pinus pinaster) and Eucalyptus (Eucalyptus globulus), in order to obtain wood cellulosic pulp for paper. The average firewood production of the ilex pruning corresponding to 1975-78 in Andalusia was of 78.000 T/year, with a practically uniform trend. A statistical analysis with ARMA pattern let us estimate a yearly averge production of ilex pruning firewood around 72.500 T/year for the 1999-2006 period, which could have an upward correction if the exploitation in all hoamoak woods was total. For the manufacture of cellulosic pulp from ilex pruning wood, it would be necessary to separte the cortex due to a lower content of holocellulose and alpha-cellulose and a higher content of soluble substances and lignin. The content of lignin of ilex pruning wood is lower than the one of other wood species like Pinus Pinaster (76,7%), Eucalyptus globulus (56,4%) and olive grove pruning (8%).
Keywords: Firewood; forest residues; ilex; Quercus; Wood

Germination success, survival and seedling vigour of Quercus suber acorns in relation to insect damage - Branco, Manuela; Branco, Carmen; Merouani, Hachemi; Almeida, Maria Helena (Forest Ecology and Management, 2002)
This study assesses the effects of damage caused by Curculio elephas Gyll. (Coleoptera: Curculionidae) and Cydia splendana Hb. (Lepidoptera: Tortricidae) on mature acorns of cork oak trees, Quercus suber L., in Portugal. The average number of insect-attacked acorns varied between 68, 44 and 17%, in three sites, respectively. Acorns assorted into increasing damage classes had a decreasing acorn dry weight and a faster germination rate. The percentage of germination was very high (>90%) in all classes. Seedlings resulting from more intensely damaged acorns exhibited a slower growth rate and lower dry mass production than seedlings resulting from low damaged acorns.
Keywords: acorn germination; insect-attack; seedling production

Germination success, survival and seedling vigour of Quercus suber acorns in relation to insect damage - Branco, Manuela; Branco, Carmen; Merouani, Hachemi; Almeida, Maria Helena (Forest Ecology and Management, 2002)
This study assesses the effects of damage caused by Curculio elephas Gyll. (Coleoptera: Curculionidae) and Cydia splendana Hb. (Lepidoptera: Tortricidae) on mature acorns of cork oak trees, Quercus suber L., in Portugal. The average number of insect-attacked acorns varied between 68, 44 and 17%, in three sites, respectively. Acorns assorted into increasing damage classes had a decreasing acorn dry weight and a faster germination rate. The percentage of germination was very high (>90%) in all classes. Seedlings resulting from more intensely damaged acorns exhibited a slower growth rate and lower dry mass production than seedlings resulting from low damaged acorns.
Keywords: acorn germination; insect-attack; seedling production

A high resolution record of the last deglaciation in the southern Tyrrhenian Sea: environmental and climatic evolution - Buccheri, G.; Capretto, G.; Di Donato, V.; Esposito, P.; Ferruzza, G.; Pescatore, T.; Russo Ermolli, E.; Senatore, M. R.; Sprovieri, M.; Bertoldo, M.; Carella, D.; Madonia, G. (Marine Geology, 2002)
A multidisciplinary study was carried out on core C106 collected in the Salerno Gulf (southern Tyrrhenian Sea). Two tephra layers recovered in the core, δ18O record of Globigerinoides ruber and Globigerina bulloides and seven 14C calibrated ages provided the stratigraphic framework. The core sediments cover the last 28 kyr BP. Seismo-stratigraphic analysis of a high resolution acoustic profile, integrated by the dated core samples, allowed us to reconstruct the architecture and age of sedimentary bodies on the continental shelf. An integrated study based on different taxonomic groups (nannofossils, pteropods, foraminifera, and palynomorphs) provided palaeoclimatic trends, in agreement with changes in the isotopic composition of oxygen. The upper part of the Last Glacial period, the deglaciation phase and the Holocene were identified. Correlation between marine and continental records of palaeoenvironmental changes confirms a similar reconstruction of the last deglaciation as in the central and southern Mediterranean Sea. The Late Pleistocene–Holocene boundary was recognised at about 11.7 kyr BP. Between about 9.5 and 6 kyr BP and at 3.3 kyr BP some warmer episodes were recorded. The measured lower isotopic values, together with some features of the fossil assemblages recorded from 9.5 to 6 kyr BP, may be related to the oceanographic setting that led to the deposition of Sapropel S1 in the Mediterranean basin.
Keywords: isotopes; late quaternary; palaeoclimatology; sedimentology; seismic stratigraphy; Tyrrhenian Sea

Holocene pedoenvironmental situations in the eastern Sierra Morena region (Andújar, Spain) - Granados, N; Espejo, J M Recio (Quaternary International, 2002)
Analysis of soils and vegetational changes during the Holocene period in the eastern Sierra Morena region (Spain) indicates that Mediterranean soils with argillaceous horizons have replaced leptosols. Genesis of regosols has favoured development of mesophytic species
Keywords: Holocene; Sierra Morena (voyant); Soil; vegetation changes

How Plants Cope with Water Stress in the Field? Photosynthesis and Growth - Chaves, M. M.; Pereira, J. S.; MAROCO, J.; Rodrigues, M. L.; RICARDO, C. P. P.; OSÓRIO, M. L.; CARVALHO, I.; FARIA, T.; PINHEIRO, C. (Annals of Botany, 2002)
Plants are often subjected to periods of soil and atmospheric water deficit during their life cycle. The frequency of such phenomena is likely to increase in the future even outside today’s arid/semi‐arid regions. Plant responses to water scarcity are complex, involving deleterious and/or adaptive changes, and under field conditions these responses can be synergistically or antagonistically modified by the superimposition of other stresses. This complexity is illustrated using examples of woody and herbaceous species mostly from Mediterranean‐type ecosystems, with strategies ranging from drought‐avoidance, as in winter/spring annuals or in deep‐rooted perennials, to the stress resistance of sclerophylls. Differences among species that can be traced to different capacities for water acquisition, rather than to differences in metabolism at a given water status, are described. Changes in the root : shoot ratio or the temporary accumulation of reserves in the stem are accompanied by alterations in nitrogen and carbon metabolism, the fine regulation of which is still largely unknown. At the leaf level, the dissipation of excitation energy through processes other than photosynthetic C‐metabolism is an important defence mechanism under conditions of water stress and is accompanied by down‐regulation of photochemistry and, in the longer term, of carbon metabolism.
10.1093/aob/mcf10510.1093/aob/mcf105
Keywords: carbon assimilation; high temperature; Lupinus; photosynthesis; Quercus ilex; Quercus suber; stomatal functioning; Stress; Vitis vinifera; water-stress; xanthophyll cycle

How Plants Cope with Water Stress in the Field? Photosynthesis and Growth - Chaves, M M; Pereira, J S; MAROCO, J; RODRIGUES, M L; RICARDO, C P P; OSÓRIO, M L; CARVALHO, I; Faria, T; PINHEIRO, C (Annals of Botany, 2002)
Plants are often subjected to periods of soil and atmospheric water deficit during their life cycle. The frequency of such phenomena is likely to increase in the future even outside today’s arid/semi‐arid regions. Plant responses to water scarcity are complex, involving deleterious and/or adaptive changes, and under field conditions these responses can be synergistically or antagonistically modified by the superimposition of other stresses. This complexity is illustrated using examples of woody and herbaceous species mostly from Mediterranean‐type ecosystems, with strategies ranging from drought‐avoidance, as in winter/spring annuals or in deep‐rooted perennials, to the stress resistance of sclerophylls. Differences among species that can be traced to different capacities for water acquisition, rather than to differences in metabolism at a given water status, are described. Changes in the root : shoot ratio or the temporary accumulation of reserves in the stem are accompanied by alterations in nitrogen and carbon metabolism, the fine regulation of which is still largely unknown. At the leaf level, the dissipation of excitation energy through processes other than photosynthetic C‐metabolism is an important defence mechanism under conditions of water stress and is accompanied by down‐regulation of photochemistry and, in the longer term, of carbon metabolism.
10.1093/aob/mcf105
Keywords: carbon assimilation; high temperature; Lupinus; photosynthesis; Quercus ilex; Quercus suber; stomatal functioning; Stress; Vitis vinifera; water-stress; xanthophyll cycle

A hydraulic model to predict drought-induced mortality in woody plants: an application to climate change in the Mediterranean - Martínez-Vilalta, J.; Piñol, J.; Beven, K. (Ecological Modelling, 2002)
The potential effects of climate change on vegetation are of increasing concern. In the Mediterranean region, the dominant impact of climate change is expected to be through the modiﬁcation of water balance. In this paper we present a model developed to predict drought-induced mortality of woody plants under different climatic scenarios. The model is physiologically-based and simulates water transport within individual woody plants, which can be isolated or competing for a common water resource. The model assumes that plant mortality is controlled by the carbon balance: when the plant is unable to transport water to the leaves it ceases to acquire carbon and, if this situation lasts long enough, it can no longer survive. In the particular application that we report in this study, two evergreen species are compared, Quercus ilex and Phillyrea latifolia, which were very differently affected by the acute drought that occurred in E Spain in summer 1994. While in some Q. ilex populations the amount of individuals that dried completely was up to 80%, P. latifolia showed almost no damage. During the years 1999 and 2000, canopy transpiration was monitored using sap-ﬂow sensors in individuals of these two species in a Holm-oak forest from NE Spain. A Generalised Likelihood Uncertainty Estimation (GLUE) approach was used to calibrate the model against sap-ﬂow measurements. The only difference between species that was introduced ‘a priori’ was that Q. ilex was more vulnerable to xylem embolism than P. latifolia (based on our own measurements in the study area). During the calibration process the information provided by the measured sap ﬂows was used to retain the more likely parameter sets for each species. These parameter sets were used in all the following simulations. The model was able to accurately simulate transpiration dynamics of the two species in the study area. When the meteorological conditions of summer 1994 were introduced, the model outputs also reproduced the differential impact that drought had on the two species studied. In the simulations under climate change two factors were explored: the increase in mean temperature (+1.5, +3 and +4.5 °C) through its effect on ET , and the duration of summer drought. Under any of the scenarios, mortalities were much higher for Q. ilex: while this species was predicted to survive with less than 5% mortality droughts of up to 84–94 days, the mortality of P. latifolia reached 5% between days 133 and 150. For droughts longer than 3 months, which is approximately the current drought duration in the study area for dry years, the mortality of Q. ilex increased sharply. These results are discussed in relation to the possible long-term impacts of climate change on Q. ilex-dominated forests
Keywords: climate change; drought-induced mortality; Mediterranean ecosystems; Modelling; phillyrea latifolia; Quercus ilex; water transport

Influence of climate on the seasonality of radial growth of cork oak during a cork production cycle - Costa, Augusta; Pereira, Helena; Oliveira, Ângelo (Ann. For. Sci., 2002)
The radial growth of mature cork oaks (Quercus suber L.) was studied during a 9-year production cycle using monthly dendrometer measurements and cork ring widths. The mean tree radial increase was 5.1 mm yr -1 and the cork increment accounting for 3.8 mm yr -1. The radial growth curves for cork, wood and stem were very similar, showing a decreasing trend along the production cycle. Cork increment was always the largest fraction of tree growth (on average 74%) and showed less inter-annual variations as compared to wood. Tree radial growth presented a clear within-the-year seasonal pattern, extending from March to October, with a maximum in June-July. The overall pattern of monthly growth distribution was similar among the years of the production cycle, but some inter-annual variations occurred with 1-2 month shifts or monthly growth rate decreases, related to climatic factors. Early spring growth was enhanced by winter rain, autumn growth by high summer rain and June increments by high temperatures during this month.
Keywords: climatic fluctuations; cork growth; Cork oak; dendroclimatology; diameter growth

Influence of climate on the seasonality of radial growth of cork oak during a cork production cycle - Costa, Augusta; Pereira, Helena; Oliveira, Ângelo (Ann. For. Sci., 2002)
The radial growth of mature cork oaks (Quercus suber L.) was studied during a 9-year production cycle using monthly dendrometer measurements and cork ring widths. The mean tree radial increase was 5.1 mm yr -1 and the cork increment accounting for 3.8 mm yr -1. The radial growth curves for cork, wood and stem were very similar, showing a decreasing trend along the production cycle. Cork increment was always the largest fraction of tree growth (on average 74%) and showed less inter-annual variations as compared to wood. Tree radial growth presented a clear within-the-year seasonal pattern, extending from March to October, with a maximum in June-July. The overall pattern of monthly growth distribution was similar among the years of the production cycle, but some inter-annual variations occurred with 1-2 month shifts or monthly growth rate decreases, related to climatic factors. Early spring growth was enhanced by winter rain, autumn growth by high summer rain and June increments by high temperatures during this month.
Keywords: climatic fluctuations; cork growth; Cork oak; dendroclimatology; diameter growth

The influence of cork oak pruning on the yield and growth of cork - Cañellas, Isabel; Montero, Gregorio (Ann. For. Sci., 2002)
Bearing in mind the importance of pruning as a silvicultural treatment in cork oak (Quercus suber L.) open woodland of the dehesa type, an experiment was designed to assess the effect of pruning on cork yield. This work was carried out in two ways: synchronically, comparing pruned sites with others which were either unpruned or pruned at different times, and diachronically, comparing pruned and unpruned trees within the same site. The five test sites (with forty trees in the synchronic and eighty in the diachronic plots) were selected in south-west Spain. In all cases measurements of the cork production were made in kilos per square metre of surface stripped, total cork yield per tree, and the mean thickness of stripped cork. Analysis was carried out using a paired data comparison test. The effect of pruning on yearly cork growth was also analysed by examining the annual growth rings. In the five plots analysed there were no significant differences (95% confidence intervals) between pruned and unpruned trees in terms of kilos of cork produced per square metre of surface stripped, nor for total cork yield per tree. Neither were there significant differences in annual cork growth rings, even when the pruning was carried out during the cork-stripping period.
Keywords: cork growth; Cork Production; pruned biomass; pruning; Quercus suber

Intercepção da Precipitação em Árvores Isoladas de Quercus rotundifolia Lam - David, Teresa Soares (Silva Lusitana, 2002)
Rainfall interception was monitored for two years in an isolated Quercus rotundifolia Lam. tree, in a low-density oak woodland (montado) near Évora. Interception loss was 21.7% of gross rainfall and 28% of tree evapotranspiration. Rainfall redistribution under the crown resulted in rainfall increases in upwind directions (South and West) and depletions downwind (North and East). Rainfall concentration in some areas beneath the crown is certainly of importance in explaining the spatial heterogeneity of the understory.
Keywords: Evapotranspiration; interception loss; montado; rainfall redistribution

Intercepção da Precipitação em Árvores Isoladas de Quercus rotundifolia Lam - David, Teresa Soares (Silva Lusitana, 2002)
Rainfall interception was monitored for two years in an isolated Quercus rotundifolia Lam. tree, in a low-density oak woodland (montado) near Évora. Interception loss was 21.7% of gross rainfall and 28% of tree evapotranspiration. Rainfall redistribution under the crown resulted in rainfall increases in upwind directions (South and West) and depletions downwind (North and East). Rainfall concentration in some areas beneath the crown is certainly of importance in explaining the spatial heterogeneity of the understory.
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: Evapotranspiration; interception loss; montado; rainfall redistribution

Land use changes, natural regeneration patterns, and restoration practices after a large wildfire in NE Spain: Challenges for fire ecology and landscape restoration - ESPELTA, J M; Rodrigo, a; Habrouk, A; Meghelli, N; Ordonez, J L; RETANA, J (FIRE AND BIOLOGICAL PROCESSES, 2002)
Great wildfires have recently affected sub-Mediterranean areas of central Catalonia (NE Spain). The large extension of the burned areas, as well as the fact that non-fire-prone vegetation has been severely affected, lead to ponder over the natural regeneration patterns occurring, and over the best strategies to restore and manage the burned areas. In the present study, we review the land use changes and the natural regeneration patterns observed after the large wildfire that occurred in Bages-Bergueda in 1994. The fire resulted in: (i) the creation of new croplands and pastures in previously forested areas, (ii) the expansion of mixed oak (Quercus ilex and Q. cerrioides) coppices, (iii) the failure of natural regeneration of the dominant tree species (Pinus nigra), leading to the appearance of areas without any tree regeneration. In this context, we discuss the results of different experiments carried out to reforest P nigra stands and to ameliorate the structure of mixed oak coppices.
Keywords: land use changes; Mediterranean areas; natural regeneration; Spain; wildfires

Land use changes, natural regeneration patterns, and restoration practices after a large wildfire in NE Spain: Challenges for fire ecology and landscape restoration - Espelta, J. M.; Rodrigo, A.; Habrouk, A.; Meghelli, N.; Ordonez, J. L.; Retana, J. (FIRE AND BIOLOGICAL PROCESSES, 2002)
Great wildfires have recently affected sub-Mediterranean areas of central Catalonia (NE Spain). The large extension of the burned areas, as well as the fact that non-fire-prone vegetation has been severely affected, lead to ponder over the natural regeneration patterns occurring, and over the best strategies to restore and manage the burned areas. In the present study, we review the land use changes and the natural regeneration patterns observed after the large wildfire that occurred in Bages-Bergueda in 1994. The fire resulted in: (i) the creation of new croplands and pastures in previously forested areas, (ii) the expansion of mixed oak (Quercus ilex and Q. cerrioides) coppices, (iii) the failure of natural regeneration of the dominant tree species (Pinus nigra), leading to the appearance of areas without any tree regeneration. In this context, we discuss the results of different experiments carried out to reforest P nigra stands and to ameliorate the structure of mixed oak coppices.
The following values have no corresponding Zotero field: periodical: FIRE AND BIOLOGICAL PROCESSES pub-location: PO BOX 321, 2300 AH LEIDEN, NETHERLANDS
Keywords: land use changes; Mediterranean areas; natural regeneration; Spain; wildfires

Leaf fluctuating asymmetry of Holm oak in response to drought under contrasting climatic conditions - Hódar, José a. (Journal of Arid Environments, 2002)
Fluctuating asymmetry (FA) can be defined as small, random deviations from bilateral symmetry in structures that, typically, are bilaterally symmetrical. In plants, FA has been used as a tool for monitoring levels of ecological stress. In this work, I analyse the FA response to drought in the Holm oak (Quercus ilex) in SE Spain, to test whether FA increases or diminishes when climatic conditions are more stressful. Leaves from three different cohorts, corresponding to one drought year (1995) and two wet years (1996 and 1997) were collected at five sites contrasting in rainfall conditions, from very low to rather high rainfall. In two of the zones, two different morphs of leaves were collected. Furthermore, one of the sites was chosen close to a river, to examine the effect of water enhancement in the trees during drought and post-drought conditions. The results revealed no differences in response to drought in terms of FA between leaf morphs. However, while plants from rainy sites showed a decline in leaf FA from drought to wet years, the water-enhanced site and the dry sites showed scant or negligible differences between years. There was a significant decrease in FA from rainy sites to dry sites. These results suggest that (1) plants living in the more stressful sites are more symmetrical, (2) the more symmetrical plants respond less to yearly variations in drought stress, and (3) the response to yearly variations in drought depend on the climatic conditions in which a tree is living
Keywords: Drought; Fluctuating asymmetry; Holm oak; Mediterranean climate; Quercus ilex; RAINFALL

Linking photorespiration, monoterpenes and thermotolerance in Quercus - Penuelas, Josep; Llusia, Joan (New Phytologist, 2002)
* • The functions of two important plant processes, photorespiration and monoterpene production remain controversial. Here, we investigated one possible function, that of protection of plants from photodamage at high temperatures. * • Fluorescence, reflectance, monoterpene concentrations and visual leaf damage were measured in Quercus ilex seedlings exposed to temperature increases from 25 to 50°C (in 5°C steps) under photorespiratory (21% O 2 ) or nonphotorespiratory (2% O 2 ) atmospheres, and under control or terpene fumigation conditions. * • Lower variable to maximum fluorescence ratio (Fv : Fm: potential photochemical efficiency of photosystem II, PSII) and electron transport rate (ETR) were found in nonphotorespiratory conditions at temperatures greater than 35°C. Monoterpene concentrations were also lower, and leaf damage greater, in the low O 2 atmospheres. Monoterpene fumigation, which increased the foliar terpene concentrations by two- to four-fold, increased the photochemical efficiency between 35°C and 50°C, and decreased leaf damage, only under the nonphotorespiratory conditions. * • These results provide evidence that: photorespiration decreases photodamage, especially at high temperatures; photorespiration increases monoterpene production; plants are able to acquire exogenous monoterpenes and the acquisition response to temperature follows the stomatal conductance response; and monoterpenes can replace photorespiration in protection from photodamage at high temperatures, possibly by scavenging oxygen-reactive species, but they do not provide additional thermotolerance.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: electron transport rate (ETR); fumigation; Fv : Fm; limonene; Monoterpenes; photochemical reflectance index (PRI); photorespiration; thermotolerance; α-pinene

Linking photorespiration, monoterpenes and thermotolerance in Quercus - Penuelas, Josep; Llusia, Joan (New Phytologist, 2002)
* • The functions of two important plant processes, photorespiration and monoterpene production remain controversial. Here, we investigated one possible function, that of protection of plants from photodamage at high temperatures. * • Fluorescence, reflectance, monoterpene concentrations and visual leaf damage were measured in Quercus ilex seedlings exposed to temperature increases from 25 to 50°C (in 5°C steps) under photorespiratory (21% O 2 ) or nonphotorespiratory (2% O 2 ) atmospheres, and under control or terpene fumigation conditions. * • Lower variable to maximum fluorescence ratio (Fv : Fm: potential photochemical efficiency of photosystem II, PSII) and electron transport rate (ETR) were found in nonphotorespiratory conditions at temperatures greater than 35°C. Monoterpene concentrations were also lower, and leaf damage greater, in the low O 2 atmospheres. Monoterpene fumigation, which increased the foliar terpene concentrations by two- to four-fold, increased the photochemical efficiency between 35°C and 50°C, and decreased leaf damage, only under the nonphotorespiratory conditions. * • These results provide evidence that: photorespiration decreases photodamage, especially at high temperatures; photorespiration increases monoterpene production; plants are able to acquire exogenous monoterpenes and the acquisition response to temperature follows the stomatal conductance response; and monoterpenes can replace photorespiration in protection from photodamage at high temperatures, possibly by scavenging oxygen-reactive species, but they do not provide additional thermotolerance.
Keywords: electron transport rate (ETR); fumigation; Fv : Fm; limonene; Monoterpenes; photochemical reflectance index (PRI); photorespiration; thermotolerance; α-pinene

Measurement and characterization of cellulase activity in sclerophyllous forest litter. - Criquet, Stéven (Journal of microbiological methods, 2002)
Cellulases are enzymatic proteins which hydrolyze cellulose polymers to smaller oligosaccharides, cellobiose and glucose. They consist in three major types of enzymes: endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) and beta-glucosidases (EC 3.2.1.21) which play an essential role in carbon turnover of forest ecosystem. The aim of this study was firstly to determine the parameters (i.e. buffer type, pH, temperature, quantity of litter, incubation time and reagent type) which affect the measurement of cellulase activity in a sclerophyllous forest litter, and secondly to compare two methods for measuring cellulase activity: a direct method and an extraction method. In the direct method, the litter was directly incubated with a buffered solution containing the enzyme substrate, whereas in the extraction method, the cellulases were firstly extracted before measuring their activity. The results were compared with other studies about soil cellulase activity, and it appeared that several parameters (buffer type, pH, temperature and sample quantity) which influence the measurement of cellulase activity differ according to whether a soil or a litter is considered. Concerning the procedure used for the measurement of cellulase activity, results showed that the activity values were higher when using an extraction procedure than when using a direct procedure. The extraction procedure, combined with a concentration stage of the extract, also allowed electrophoretic analysis (PAGE) of the cellulases extracted from the litter. The electrophoretic pattern revealed two cellulase isoenzymes which may be related to the occurrence of two pH-activity peaks of these enzymes when citrate buffer was used for the measurement of cellulase activity in the litter.
The following values have no corresponding Zotero field: accession-num: 11997167
Keywords: Buffers; Cellulase; Cellulase: analysis; Cellulase: isolation & purification; Cellulose; Cellulose: metabolism; Endoglucanase; Extraction; Hydrogen-Ion Concentration; Isoenzyme; Isoenzymes; Isoenzymes: analysis; litter; Plant Leaves; Plant Leaves: enzymology; Quercus; Quercus: enzymology; Temperature; Trees

Measurement and characterization of cellulase activity in sclerophyllous forest litter. - Criquet, Stéven (Journal of microbiological methods, 2002)
Cellulases are enzymatic proteins which hydrolyze cellulose polymers to smaller oligosaccharides, cellobiose and glucose. They consist in three major types of enzymes: endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) and beta-glucosidases (EC 3.2.1.21) which play an essential role in carbon turnover of forest ecosystem. The aim of this study was firstly to determine the parameters (i.e. buffer type, pH, temperature, quantity of litter, incubation time and reagent type) which affect the measurement of cellulase activity in a sclerophyllous forest litter, and secondly to compare two methods for measuring cellulase activity: a direct method and an extraction method. In the direct method, the litter was directly incubated with a buffered solution containing the enzyme substrate, whereas in the extraction method, the cellulases were firstly extracted before measuring their activity. The results were compared with other studies about soil cellulase activity, and it appeared that several parameters (buffer type, pH, temperature and sample quantity) which influence the measurement of cellulase activity differ according to whether a soil or a litter is considered. Concerning the procedure used for the measurement of cellulase activity, results showed that the activity values were higher when using an extraction procedure than when using a direct procedure. The extraction procedure, combined with a concentration stage of the extract, also allowed electrophoretic analysis (PAGE) of the cellulases extracted from the litter. The electrophoretic pattern revealed two cellulase isoenzymes which may be related to the occurrence of two pH-activity peaks of these enzymes when citrate buffer was used for the measurement of cellulase activity in the litter.
Keywords: Buffers; Cellulase; Cellulase: analysis; Cellulase: isolation & purification; Cellulose; Cellulose: metabolism; Endoglucanase; Extraction; Hydrogen-Ion Concentration; Isoenzyme; Isoenzymes; Isoenzymes: analysis; litter; Plant Leaves; Plant Leaves: enzymology; Quercus; Quercus: enzymology; Temperature; Trees

Modelling start of oak pollen season in different climatic zones in Spain - García-Mozo, H; Galán, C; Aira, M J (Agricultural and Forest Meteorology, 2002)
Quercus pollen and meteorological data for several years from eight sites in Spain have been statistically analysed to select the threshold temperature and calculate the mean heat accumulation for predicting the Quercus pollination start in different climatic areas. The growing degree days method, which assumes the daily temperature varies as a sine wave, was used for heat accumulation calculations. Threshold temperatures between 4 and 12 ◦ C were chosen using linear regression equations forced through the origin and their root mean square error (RMSE) of predicted against the observed dates for each observation site. Above the threshold, the average growing degree days (up to 1999) for the studied years was taken as the predictor value. Results showed a relationship between the selected threshold and elevation and a stronger and statistically signiﬁcant correlation between threshold and yearly mean temperature, for each site. Regression analysis indicated that the selected threshold and the calculated heat accumulation were optimum for most of the localities. The validity of the results was tested using the meteorological data for the year 2000 as independent variable and this conﬁrmed that there were only a few days difference between the predicted and observed day of the ﬁrst pollen release for most of the studied localities
Keywords: Aerobiology; oak forest; Phenology; pollen; threshold temperature

Modelling start of oak pollen season in different climatic zones in Spain - García-Mozo, H.; Galan, C.; Aira, M. J. (Agricultural and Forest Meteorology, 2002)
Quercus pollen and meteorological data for several years from eight sites in Spain have been statistically analysed to select the threshold temperature and calculate the mean heat accumulation for predicting the Quercus pollination start in different climatic areas. The growing degree days method, which assumes the daily temperature varies as a sine wave, was used for heat accumulation calculations. Threshold temperatures between 4 and 12 ◦ C were chosen using linear regression equations forced through the origin and their root mean square error (RMSE) of predicted against the observed dates for each observation site. Above the threshold, the average growing degree days (up to 1999) for the studied years was taken as the predictor value. Results showed a relationship between the selected threshold and elevation and a stronger and statistically signiﬁcant correlation between threshold and yearly mean temperature, for each site. Regression analysis indicated that the selected threshold and the calculated heat accumulation were optimum for most of the localities. The validity of the results was tested using the meteorological data for the year 2000 as independent variable and this conﬁrmed that there were only a few days difference between the predicted and observed day of the ﬁrst pollen release for most of the studied localities
Keywords: Aerobiology; oak forest; Phenology; pollen; threshold temperature

Morphological and physiological response of two populations of Quercus ilex L. to SO2 fumigation - Infante, J M; Garcia-Laureano, R; Merino, J (PHYTON-ANNALES REI BOTANICAE, 2002)
Quercus ilex L., is the predominant evergreen schlerophyllous tree in the Mediterranean landscape of the Iberian Peninsula. Fruit acorns were collected in two populations located in the center (southern Spain) and at the northern border (northern Spain; a distance of 800 km) of the distribution area of Quercus ilex. One-month-old potted plants were grown for 130 days to a high SO2 concentration (0.23 ppm, 14 h d(-1)) under controlled climate conditions. Both northern and southern plants underwent a significant decrease in growth rate as a consequence of the treatment. Even so, plants appear to be quite resistant to SO2 compared with either more temperate or more productive species. The southern population was more sensitive to the treatment, as reflected by the bigger decrease in both growth and photosynthetic rates. Differences in resistance appear to be related to the biogeographic origin of the populations studied, which underlines the importance of biogeographic aspects in studies of resistance to air pollutants.
Keywords: air pollution; Mediterranean ecosystems; Populations; Quercus ilex; Sulfur Dioxide

Morphological segmentation of remotely sensed forest covers in high spatial resolution images - Barata, T; Pina, P (MATHEMATICAL MORPHOLOGY, PROCEEDINGS, 2002)
In this paper novel algorithms developed to automatically segment forest cover types are presented. The digital image analysis followed is mainly based on mathematical morphology operators and exploits the textural features in high spatial resolution images. These input images consist of true colour digital orthophotos and the studied forest covers consist of the main occurrences in Portugal: olive trees, cork oak trees, pine and eucalyptus trees.
Keywords: forest covers; high spatial resolution images; segmentation; textural features

Morphological segmentation of remotely sensed forest covers in high spatial resolution images - Barata, T.; Pina, P. (MATHEMATICAL MORPHOLOGY, PROCEEDINGS, 2002)
In this paper novel algorithms developed to automatically segment forest cover types are presented. The digital image analysis followed is mainly based on mathematical morphology operators and exploits the textural features in high spatial resolution images. These input images consist of true colour digital orthophotos and the studied forest covers consist of the main occurrences in Portugal: olive trees, cork oak trees, pine and eucalyptus trees.
The following values have no corresponding Zotero field: periodical: MATHEMATICAL MORPHOLOGY, PROCEEDINGS pub-location: PO BOX 89 (EAST ALBERT ST), EAST MELBOURNE, 3002, AUSTRALIA
Keywords: forest covers; high spatial resolution images; segmentation; textural features

Nitrogen circulation in a Mediterranean holm oak forest, La Castanya, Montseny, northeastern Spain - Avila, Anna; Rodrigo, Anselm; Rodà, Ferran (Hydrology and Earth System …, 2002)
Bulk deposition, wet-only deposition, throughfall and dry deposition inferred from washing foliage and surrogate surfaces were used to describe inorganic N inputs to a forested catchment in the Montseny Mountains (La Castanya, Catalonia, Spain). Bulk inputs of inorganic N were moderate, with a mean of 5.7 kg N ha -1 yr -1 , ranging between 4 and 10 kg N ha -1 yr -1 for the period 1983 to 2000. Dry deposition fluxes estimated from washing branches added about 9 kg N ha -1 yr -1 to wet inputs and the total atmospheric deposition was estimated in 15 kg N ha -1 yr -1 . Despite this substantial input flux, nearly all the inorganic nitrogen was retained within the forest ecosystem: NH4 + and NO3 - concentrations decreased dramatically as water crossed the canopy and the soil profile. In the stream, at baseflow conditions, NH4 + and NO3 - concentrations were always below the analytical detection limit (< 2 µeq L -1 ). Only briefly during peak flows did NO3 - concentrations increase up to 100 µeq L -1 . Averaged over 10 years (1984-1994), the export of N at the catchment outlet was 0.05 kg N ha -1 yr -1 . This indicates a very tight N cycling allowing for an increase of N availability in these undisturbed forest ecosystems.
Keywords: ammonium; bulk deposition; Dry deposition; la castanya; montseny; nitrate; soil water; Spain; throughfall

Nitrogen circulation in a Mediterranean holm oak forest, La Castanya, Montseny, northeastern Spain - Avila, Anna; Rodrigo, Anselm; Rodà, Ferran (Hydrology and Earth System …, 2002)
Bulk deposition, wet-only deposition, throughfall and dry deposition inferred from washing foliage and surrogate surfaces were used to describe inorganic N inputs to a forested catchment in the Montseny Mountains (La Castanya, Catalonia, Spain). Bulk inputs of inorganic N were moderate, with a mean of 5.7 kg N ha -1 yr -1 , ranging between 4 and 10 kg N ha -1 yr -1 for the period 1983 to 2000. Dry deposition fluxes estimated from washing branches added about 9 kg N ha -1 yr -1 to wet inputs and the total atmospheric deposition was estimated in 15 kg N ha -1 yr -1 . Despite this substantial input flux, nearly all the inorganic nitrogen was retained within the forest ecosystem: NH4 + and NO3 - concentrations decreased dramatically as water crossed the canopy and the soil profile. In the stream, at baseflow conditions, NH4 + and NO3 - concentrations were always below the analytical detection limit (< 2 µeq L -1 ). Only briefly during peak flows did NO3 - concentrations increase up to 100 µeq L -1 . Averaged over 10 years (1984-1994), the export of N at the catchment outlet was 0.05 kg N ha -1 yr -1 . This indicates a very tight N cycling allowing for an increase of N availability in these undisturbed forest ecosystems.
Keywords: ammonium; bulk deposition; Dry deposition; la castanya; montseny; nitrate; soil water; Spain; throughfall

Nitrogen deposition in Mediterranean forests. - Roda, F.; Avila, a; Rodrigo, A. (Environmental pollution (Barking, Essex : 1987), 2002)
Atmospheric deposition of inorganic nitrogen was studied at two forested sites in the Montseny mountains (northeast Spain), peripheral to the Barcelona conurbation, and at a nearby lowland town, using bulk deposition, wet-only deposition, throughfall, and dry deposition inferred from branch-washes and surrogate surfaces (metacrylate plates). Bulk deposition inputs of ammonium and nitrate did not show significant temporal trends over a 16-year period. Bulk inputs of inorganic N were moderate, ranging from 6 to 10 kg N ha(-1) year(-1) depending on the time period considered and the degree of site exposure to polluted air masses from the Barcelona conurbation. Large dry-sedimented particles played a minor role, since wet-only inputs were virtually identical to bulk inputs. On the contrary, branch- and plate-washes indicated substantial dry inputs of N gases and small particles. Total atmospheric deposition was estimated at 15-22 kg N ha(-1) year(-1), most of it being retained within the studied broadleaved evergreen forests. Ecosystem N availability is thus likely to be increasing in these forests.
The following values have no corresponding Zotero field: accession-num: 11939283
Keywords: Air Pollutants; Air Pollutants: analysis; Biological Availability; Ecosystem; Environmental Monitoring; Gases; Geologic Sediments; Geologic Sediments: chemistry; Mediterranean Region; nitrogen; Nitrogen: analysis; Particle Size; Trees; Trees (citation)

Nitrogen deposition in Mediterranean forests. - Rodà, F; Avila, a; Rodrigo, a (Environmental pollution (Barking, Essex : 1987), 2002)
Atmospheric deposition of inorganic nitrogen was studied at two forested sites in the Montseny mountains (northeast Spain), peripheral to the Barcelona conurbation, and at a nearby lowland town, using bulk deposition, wet-only deposition, throughfall, and dry deposition inferred from branch-washes and surrogate surfaces (metacrylate plates). Bulk deposition inputs of ammonium and nitrate did not show significant temporal trends over a 16-year period. Bulk inputs of inorganic N were moderate, ranging from 6 to 10 kg N ha(-1) year(-1) depending on the time period considered and the degree of site exposure to polluted air masses from the Barcelona conurbation. Large dry-sedimented particles played a minor role, since wet-only inputs were virtually identical to bulk inputs. On the contrary, branch- and plate-washes indicated substantial dry inputs of N gases and small particles. Total atmospheric deposition was estimated at 15-22 kg N ha(-1) year(-1), most of it being retained within the studied broadleaved evergreen forests. Ecosystem N availability is thus likely to be increasing in these forests.
Keywords: Air Pollutants; Air Pollutants: analysis; Biological Availability; Ecosystem; Environmental Monitoring; Gases; Geologic Sediments; Geologic Sediments: chemistry; Mediterranean Region; nitrogen; Nitrogen: analysis; Particle Size; Trees; Trees (citation)

Niveles de cargas ganaderas en la dehesa extremeña - Escribano, M.; Rodríguez de Ledesma, A.; Mesías, F. J.; Pulido, F. (Archivos de zootecnia, 2002)
This work analyzes the data collected from 143 sheep and/or cattle farms, representatives of the Extremaduran dehesa (semiarid grazing areas of the SW of Spain). A random survey was carried out in 2000, with an error of less than 5 percent and a confidence level of 95 percent. The aim of the survey was the evaluation of the stocking rate levels of these farms in 1999 and their evolution from 1993, first year after the CAP Reform of 1992. The effects of farm size for different stocking rates are studied. Significant differences were observed (p<0,05 and p<0,01) between the bigger and the lesser farm sizes. This shows a higher productive intensification when the grazing surface decreases. It is to mention a high correlation between the cattle units in sheep farms (UGMo) and the cattle units in the whole sample (UGMt) (r=0,867; p<0,01), as well as the association between sheep density and pig density variables (r=0,773; p<0,01). On the other hand, we can observe an inverse correlation between the levels of livestock density and the farm size, which is more significant in cattle farms.
Keywords: dehesas; Grazing; Stocking rate; Structural analysis

Niveles de cargas ganaderas en la dehesa extremeña - Escribano, M; Rodriguez de Ledesma, A; Mesías, F J; Pulido, F (Archivos de zootecnia, 2002)
This work analyzes the data collected from 143 sheep and/or cattle farms, representatives of the Extremaduran dehesa (semiarid grazing areas of the SW of Spain). A random survey was carried out in 2000, with an error of less than 5 percent and a confidence level of 95 percent. The aim of the survey was the evaluation of the stocking rate levels of these farms in 1999 and their evolution from 1993, first year after the CAP Reform of 1992. The effects of farm size for different stocking rates are studied. Significant differences were observed (p<0,05 and p<0,01) between the bigger and the lesser farm sizes. This shows a higher productive intensification when the grazing surface decreases. It is to mention a high correlation between the cattle units in sheep farms (UGMo) and the cattle units in the whole sample (UGMt) (r=0,867; p<0,01), as well as the association between sheep density and pig density variables (r=0,773; p<0,01). On the other hand, we can observe an inverse correlation between the levels of livestock density and the farm size, which is more significant in cattle farms.
Keywords: dehesas; Grazing; Stocking rate; Structural analysis

The organosolv fractionation of cork components - Cordeiro, N.; Neto, C. P.; Rocha, J.; Belgacem, M. N.; Gandini, A. (HOLZFORSCHUNG, 2002)
Extractive-free cork from Quercus suber L. was submitted to organosolv fractionation and the effects of different process variables, such as ethanol/water ratio, temperature, time and the presence of acidic or alkaline catalysts, were studied. The variation of the relative proportions of extracted components, as a function of the processing conditions, could thus be established. Whereas the addition of 0.1 M acetic acid only increased the yield of extracted materials from about 15 to 23 %, the use of sodium hydroxide, at the same concentration, produced a jump to 76 %. In the case of the alkaline organosolv fractionation. an increase in process temperature, time and catalyst concentration led to an increase in the extraction yield, although in some cases this increase did not follow a sustained trend, as in the case of reaction time. Increasing the ethanol/water ratio led to a higher selectivity in favour of suberin extraction. Residual cork from different organosolv processes was characterised by FTIR and C-13 solid-state NMR. The latter technique provided some valuable information about both process selectivity and cork morphology, particularly with respect to the positioning of suberin macromolecules in the cell wall.
The following values have no corresponding Zotero field: pub-location: GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY publisher: WALTER DE GRUYTER & CO
Keywords: C-13 NMR; Cork; ethanol/water extraction; FTIR; organosolv fractionation; Quercus Suber L; suberin

The origin of the Sierra de Aracena Hollows in the Sierra Morena, Huelva, Andalucia, Spain - Espejo, J M Recio; Faust, D; Granados, M A Nuñez (Geomorphology, 2002)
Hollows in the Sierra de Aracena, part of western sector of Sierra Morena region (Huelva, Spain), are geoecologically unusual macroforms. They are underlain by deeply weathered bedrock but have eutrophic soils with distinctive vegetation. Paleosols with very dark colours, a predominance of smectites and large amounts of total and free iron occur on the floors on the hollows. An evolutionary model is proposed for the hollows, involving differential weathering during the Mesozoic on plutonic and amphibolitic rocks, alpine tectonic activity followed by Quaternary erosion and exhumation leading to formation of erosional terraces
Keywords: deep weathering; hercynian massif; hollows macroforms; sierra morena; Spain

A outra face do descortiçamento: Implicaçoes para a fisiologia e crescimento do sobreiro - Oliveira, G (Fragmentos de Ecologia, Lisboa, 2002)

Patch occupancy by stone martens Martes foina in fragmented landscapes of central Spain: the role of fragment size, isolation and habitat structure - Virgós, Emilio; García, Francisco J (Acta Oecologica, 2002)
We studied the response to forest fragmentation of a generalist carnivore, the stone marten Martes foina, in highly fragmented landscapes of central Spain. Five different areas (n = 178 fragments) in central Spain were surveyed. This paper analyses the relationship between fragment use by martens (measured through scat presence) and a series of variables related to the size, isolation and vegetation structure of each fragment by means of stepwise logistic regression. Size and isolation have an important effect on stone marten presence in fragments. Our results were similar to those found for other marten species in landscapes with coarse-grain fragmentation, but they contrast with other studies conducted in landscapes with ﬁne-grain fragmentation. These data suggested that in highly fragmented landscapes, size and isolation factors resulting from forest fragmentation were responsible for determining marten responses, irrespective of their habitat generalism. Management policies for the stone marten in highly fragmented scenarios require the maintenance of large forests near continuous forest tracts in mountains or riparian woodlands
Keywords: agricultural landscapes; Forest fragmentation; iberian peninsula; martes foina; size-isolation effects

Patch occupancy by stone martens Martes foina in fragmented landscapes of central Spain: the role of fragment size, isolation and habitat structure - Virgós, Emilio; García, Francisco J. (Acta Oecologica, 2002)
We studied the response to forest fragmentation of a generalist carnivore, the stone marten Martes foina, in highly fragmented landscapes of central Spain. Five different areas (n = 178 fragments) in central Spain were surveyed. This paper analyses the relationship between fragment use by martens (measured through scat presence) and a series of variables related to the size, isolation and vegetation structure of each fragment by means of stepwise logistic regression. Size and isolation have an important effect on stone marten presence in fragments. Our results were similar to those found for other marten species in landscapes with coarse-grain fragmentation, but they contrast with other studies conducted in landscapes with ﬁne-grain fragmentation. These data suggested that in highly fragmented landscapes, size and isolation factors resulting from forest fragmentation were responsible for determining marten responses, irrespective of their habitat generalism. Management policies for the stone marten in highly fragmented scenarios require the maintenance of large forests near continuous forest tracts in mountains or riparian woodlands
Keywords: agricultural landscapes; Forest fragmentation; iberian peninsula; martes foina; size-isolation effects

Patterns and processes of Late Quaternary environmental change in a montane region of southwestern Europe - Carrión, J S (Quaternary Science Reviews, 2002)
This paper examines the Late Quaternary (c. 20,300–o505 cal yr BP) environmental history of Siles, a lake situated at 1320 m in the Segura mountains of southern Spain, with the goalof establishing the mechanisms exerting controlon vegetation change. Palaeoecological indicators include pollen, microcharcoal, spores of terrestrial plants, fungi, and non-siliceous algae, and other microfossils. The Siles sequence is shown to be sensitive to climatic change, although the control exerted by climate on vegetation is ultimately shaped by disturbances and species interactions, determining the occurrence of century-scale lags and threshold responses. Biotically induced changes of vegetation are also shown at the intrazonal level of variation. The new sequence is placed in the context of two previous records to postulate a picture of Holocene environmental change for the Segura region. The existence of mid-elevation glacial refugia for a number of temperate and Mediterranean trees is shown. A mid-Holocene phase (c. 7500– 5200 cal yr BP) emerges regionally as the time of maximum forest development and highest lake levels. The early Holocene occurs as a generally dry, pyrophytic period of pine forests, with grassland scrub in high altitudes, and the late Holocene as a period of protracted vegetation sensitivity, with return to development of pine forests, spread of xerophytic communities, and increased ﬁre activity, under the context of dry spells, localized anthropogenic disturbance, and shallowing and desiccation of lakes. Several events described here correlate with established times of abrupt transitions in the climates of northern Europe, the Mediterranean basin, north Africa, and the Sahel
Keywords: Holocene; Mediterranean (voyant); Pollen analysis; vegetation belts

Patterns and processes of Late Quaternary environmental change in a montane region of southwestern Europe - Carrión, J. S. (Quaternary Science Reviews, 2002)
This paper examines the Late Quaternary (c. 20,300–o505 cal yr BP) environmental history of Siles, a lake situated at 1320 m in the Segura mountains of southern Spain, with the goalof establishing the mechanisms exerting controlon vegetation change. Palaeoecological indicators include pollen, microcharcoal, spores of terrestrial plants, fungi, and non-siliceous algae, and other microfossils. The Siles sequence is shown to be sensitive to climatic change, although the control exerted by climate on vegetation is ultimately shaped by disturbances and species interactions, determining the occurrence of century-scale lags and threshold responses. Biotically induced changes of vegetation are also shown at the intrazonal level of variation. The new sequence is placed in the context of two previous records to postulate a picture of Holocene environmental change for the Segura region. The existence of mid-elevation glacial refugia for a number of temperate and Mediterranean trees is shown. A mid-Holocene phase (c. 7500– 5200 cal yr BP) emerges regionally as the time of maximum forest development and highest lake levels. The early Holocene occurs as a generally dry, pyrophytic period of pine forests, with grassland scrub in high altitudes, and the late Holocene as a period of protracted vegetation sensitivity, with return to development of pine forests, spread of xerophytic communities, and increased ﬁre activity, under the context of dry spells, localized anthropogenic disturbance, and shallowing and desiccation of lakes. Several events described here correlate with established times of abrupt transitions in the climates of northern Europe, the Mediterranean basin, north Africa, and the Sahel
Keywords: Holocene; Mediterranean (voyant); Pollen analysis; vegetation belts

Photosynthetic responses to water deficit in six Mediterranean sclerophyll species: possible factors explaining the declining distribution of Rhamnus ludovici-salvatoris, an endemic Balearic species. - Gulías, J; Flexas, J; Abadía, A; Madrano, H (Tree Physiology, 2002)
We sought to explain the declining distribution in the Balearic Islands of the endemic shrub Rhamnus ludovici-salvatoris R. Chodat, by comparing its photosynthetic response to drought with that of several widely distributed, competing Mediterranean species (R. alaternus L., Quercus ilex L., Pistacia lentiscus L., Q. humilis Mill. and P. terebinthus L.). [ABSTRACT FROM PUBLISHER]
Keywords: chlorophyll fluorescence; deciduous; Drought; evergreen; Gas exchange; leaf mass area; nitrogen; Pistacia; Quercus; Rhamnus; xanthophyll cycle

Phytoclimatic characterization of holm-oak provenances (Quercus ilex L.) in the Central-Northern Iberian Peninsula - Garcia Lopez, J. M.; Gonzalo Jimenez, J.; ALLUÉ CAMACHO, C. (Forest Systems, 2002)
This paper presents some contributions to the phytoclimatic characterization of stands of holm-oak (Quercus ilex. L.) in the centre-north of the Iberian Peninsula and the testing of a method of phytoclimatic homologation applicable to the characterization of provenances of the species. For the phytoclimatic characterization, 432 sampling points in the Province of Burgos were considered, corresponding to the centres of cartographic tessellae of actual vegetation in which holm-oak was the principle species of the forest (18,965 ha). The phytoclimatic diagnosis followed the phytoclimatic models of Allué-Andrade. Phytoclimatic territorial models were constructed in digital format on the basis of preliminary territorial factorial estimations, which were used to determine phytoclimatic terns. Based on the establishment of phytoclimatic ambits for the existence of holm-oak stands in Burgos and stratification in accordance with the five phytoclimatic subtypes (VI(IV)1, VI(IV)2, VI(VII), VI(V) and VI), phytoclimatic homologation was performed in three phases of increasing strictness, all based on a comparison of phytoclimatic terns derived from the general and specific phytoclimatic systems. In the strictest homologation, an adequate and territorially compact degree of discrimination was achieved for 2.622.500 ha (Quercus ilex subsp. ballota) and 116.00 ha (Quercus ilex subsp. ilex) in the centre-north of the Iberian Peninsula. The marked edaphic azonality of the species was an important factor in the interpretation of the results.
Keywords: holm-oak; homologation; phytoclimatology; provenances; Quercus ilex L. subsp. ballota (Desf.) Samp.; Quercus ilex L. subsp. ilex

Phytoclimatic characterization of holm-oak provenances (Quercus ilex L.) in the Central-Northern Iberian Peninsula - Garcia Lopez, J M; Gonzalo Jimenez, J; ALLUÉ CAMACHO, C (Forest Systems, 2002)
This paper presents some contributions to the phytoclimatic characterization of stands of holm-oak (Quercus ilex. L.) in the centre-north of the Iberian Peninsula and the testing of a method of phytoclimatic homologation applicable to the characterization of provenances of the species. For the phytoclimatic characterization, 432 sampling points in the Province of Burgos were considered, corresponding to the centres of cartographic tessellae of actual vegetation in which holm-oak was the principle species of the forest (18,965 ha). The phytoclimatic diagnosis followed the phytoclimatic models of Allué-Andrade. Phytoclimatic territorial models were constructed in digital format on the basis of preliminary territorial factorial estimations, which were used to determine phytoclimatic terns. Based on the establishment of phytoclimatic ambits for the existence of holm-oak stands in Burgos and stratification in accordance with the five phytoclimatic subtypes (VI(IV)1, VI(IV)2, VI(VII), VI(V) and VI), phytoclimatic homologation was performed in three phases of increasing strictness, all based on a comparison of phytoclimatic terns derived from the general and specific phytoclimatic systems. In the strictest homologation, an adequate and territorially compact degree of discrimination was achieved for 2.622.500 ha (Quercus ilex subsp. ballota) and 116.00 ha (Quercus ilex subsp. ilex) in the centre-north of the Iberian Peninsula. The marked edaphic azonality of the species was an important factor in the interpretation of the results.
Keywords: holm-oak; homologation; phytoclimatology; provenances; Quercus ilex L. subsp. ballota (Desf.) Samp.; Quercus ilex L. subsp. ilex

Propagação Vegetativa de Sobreiros Seleccionados - de Freitas, Maria Isabel Carrasquinho (Silva Lusitana, 2002)
The aim of this investigation was to evaluate the possibilities of vegetative propagation techniques of adult cork oak trees so as to develop an approach applicable to a genetic improvement breeding program. Bud grafting and cuttings were used to multiply and mass propagate selected cork oak trees. Forty-six cork oak trees were reproduced from clone banks. September proved to be a better season for grafting than June/July. Rooting season and the temperature of the rooting substrate were demonstrated to be important factors in juvenile cuttings response. The highest rooting ability was achieved in August with a rooting substrate temperature of 28°C (57.0%). The best rooting rate was obtained by maintaining cuttings in rooting media for four months. The application of IBA influenced rooting ability both in cuttings from seedlings and those from the clone bank. Nevertheless, juvenile material needed a lower IBA concentration (0.5%) than the older material (1%). The clone and age of grafting were shown to influence the rooting ability. The decrease of rooting ability with age of grafting requires a dynamic management of the clone bank. The vegetative propagation of selected adult cork oak trees seems to be a viable technique, establishing a prior clone bank, by means of grafting, and then mass propagation through cuttings of this material.
Keywords: Bud grafting; Clones; Cuttings; Quercus suber L.; vegetative propagation

Propagação Vegetativa de Sobreiros Seleccionados - de Freitas, Maria Isabel Carrasquinho (Silva Lusitana, 2002)
The aim of this investigation was to evaluate the possibilities of vegetative propagation techniques of adult cork oak trees so as to develop an approach applicable to a genetic improvement breeding program. Bud grafting and cuttings were used to multiply and mass propagate selected cork oak trees. Forty-six cork oak trees were reproduced from clone banks. September proved to be a better season for grafting than June/July. Rooting season and the temperature of the rooting substrate were demonstrated to be important factors in juvenile cuttings response. The highest rooting ability was achieved in August with a rooting substrate temperature of 28°C (57.0%). The best rooting rate was obtained by maintaining cuttings in rooting media for four months. The application of IBA influenced rooting ability both in cuttings from seedlings and those from the clone bank. Nevertheless, juvenile material needed a lower IBA concentration (0.5%) than the older material (1%). The clone and age of grafting were shown to influence the rooting ability. The decrease of rooting ability with age of grafting requires a dynamic management of the clone bank. The vegetative propagation of selected adult cork oak trees seems to be a viable technique, establishing a prior clone bank, by means of grafting, and then mass propagation through cuttings of this material.
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: Bud grafting; Clones; Cuttings; Quercus suber L.; vegetative propagation

Purification of a new isoform of laccase from a Marasmius quercophilus strain isolated from a cork oak litter (Quercus suber L.) - Farnet, A M; Criquet, S; Pocachard, E; Gil, G; Ferré, E (MYCOLOGIA, 2002)
A new isoform of laccase from Marasmius quercophilus is described in this study. The strain of this white-rot fungus was isolated for the first time on a cork oak litter. This isoform exhibited certain common properties of laccases (a molecular weight of 65 Kda, an optimum pH of 6.2 with syringaldazine). But this laccase has also particularly novel features: the best activity measured was observed at high temperatures (80 C) and this isoform was not inhibited with EDTA. Furthermore, this induced laccase was able to transform most of the aromatic compounds tested without the addition of mediators to the reaction mixture, and the transformation of certain chlorophenols (2-chlorophenol and 2,4-dichlorophenol) by a laccase isoform from M. quercophilus is reported here for the first time. We also demonstrate the importance of 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) as a mediator since it allowed veratryl alcohol and p-hydroxybenzoic acid transformation. Moreover, new products of transformation were observed using the combination of ABTS with this isoform of laccase.
Keywords: aromatic compounds; mediator; polyphenoloxidase; white-rot fungus

Purification of a new isoform of laccase from a Marasmius quercophilus strain isolated from a cork oak litter (Quercus suber L.) - Farnet, A. M.; Criquet, S.; Pocachard, E.; Gil, G.; Ferré, E. (MYCOLOGIA, 2002)
A new isoform of laccase from Marasmius quercophilus is described in this study. The strain of this white-rot fungus was isolated for the first time on a cork oak litter. This isoform exhibited certain common properties of laccases (a molecular weight of 65 Kda, an optimum pH of 6.2 with syringaldazine). But this laccase has also particularly novel features: the best activity measured was observed at high temperatures (80 C) and this isoform was not inhibited with EDTA. Furthermore, this induced laccase was able to transform most of the aromatic compounds tested without the addition of mediators to the reaction mixture, and the transformation of certain chlorophenols (2-chlorophenol and 2,4-dichlorophenol) by a laccase isoform from M. quercophilus is reported here for the first time. We also demonstrate the importance of 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) as a mediator since it allowed veratryl alcohol and p-hydroxybenzoic acid transformation. Moreover, new products of transformation were observed using the combination of ABTS with this isoform of laccase.
The following values have no corresponding Zotero field: pub-location: PUBLICATIONS DEPT, BRONX, NY 10458 USA publisher: NEW YORK BOTANICAL GARDEN
Keywords: aromatic compounds; mediator; polyphenoloxidase; white-rot fungus

Radiocarbon as a biomarker of urban pollution in leaves of evergreen species sampled in Rome and in rural areas (Lazio—Central Italy) - Alessio, M.; Anselmi, S.; Conforto, L.; Improta, S.; Manes, F.; Manfra, L. (Atmospheric Environment, 2002)
The aim of the present study is the use of 14 C, sampled in leaves of evergreen species, as a natural geochemical marker to estimate the contribution of artiﬁcial sources (heating plants, vehicles, etc.) to the complex of atmospheric gases in an urban environment. Leaves were chosen due to sampling easiness and their reliability: in particular the evergreen species, being exposed all the year round to pollutants are especially indicated for bioindication and biomonitoring studies. The response to atmospheric pollutants has been studied of two plant species (Quercus ilex L., Pinus pinea L.) measuring isotopic ( 14 r, d 13 C), chemical (Pb concentration) and ecophysiological (gaseous exchange and leaf ﬂuorescence of chlorophyll a) parameters. Leaves of holm-oaks and stone pine needles collected over a 3-year time span in an urban park in Rome (Villa Ada) and in reference localities outside the city on the Tyrrhenian coast and in the preAppennine area have been analysed. In Villa Ada measurements were carried out along a transect from the road bordering the park towards the interior; all the parameters, together in agreement, showed a decreasing pollution gradient towards the inner park. It was possible to estimate a 5.570.3% contribution of CO2 from fossil fuels close to the road, decreasing to 1.770.3% at o300 m from it towards the inner park. The isotopic analyses conducted on stone pines and holm-oaks show that 14 C provides indications on the degree of pollution from fossil fuels, while d 13 C appears to be conditioned mainly by the interspeciﬁc difference, and also by many other environmental factors that affect the plant functionality. Results conﬁrmed that radiocarbon is a useful tool in environmental studies, allowing to quantify the contributions of CO2 of anthropic origin: this parameter, together with appropriate isotopic, chemicaland ecophysiological analyses, could provide a good indication of the ‘‘air quality’’ in urban and rural contexts.
Keywords: air quality; carbon isotopes; co 2; lead; photosynthesis

Radiocarbon as a biomarker of urban pollution in leaves of evergreen species sampled in Rome and in rural areas (Lazio—Central Italy) - Alessio, M; Anselmi, S; Conforto, L; Improta, S; Manes, F; Manfra, L (Atmospheric Environment, 2002)
The aim of the present study is the use of 14 C, sampled in leaves of evergreen species, as a natural geochemical marker to estimate the contribution of artiﬁcial sources (heating plants, vehicles, etc.) to the complex of atmospheric gases in an urban environment. Leaves were chosen due to sampling easiness and their reliability: in particular the evergreen species, being exposed all the year round to pollutants are especially indicated for bioindication and biomonitoring studies. The response to atmospheric pollutants has been studied of two plant species (Quercus ilex L., Pinus pinea L.) measuring isotopic ( 14 r, d 13 C), chemical (Pb concentration) and ecophysiological (gaseous exchange and leaf ﬂuorescence of chlorophyll a) parameters. Leaves of holm-oaks and stone pine needles collected over a 3-year time span in an urban park in Rome (Villa Ada) and in reference localities outside the city on the Tyrrhenian coast and in the preAppennine area have been analysed. In Villa Ada measurements were carried out along a transect from the road bordering the park towards the interior; all the parameters, together in agreement, showed a decreasing pollution gradient towards the inner park. It was possible to estimate a 5.570.3% contribution of CO2 from fossil fuels close to the road, decreasing to 1.770.3% at o300 m from it towards the inner park. The isotopic analyses conducted on stone pines and holm-oaks show that 14 C provides indications on the degree of pollution from fossil fuels, while d 13 C appears to be conditioned mainly by the interspeciﬁc difference, and also by many other environmental factors that affect the plant functionality. Results conﬁrmed that radiocarbon is a useful tool in environmental studies, allowing to quantify the contributions of CO2 of anthropic origin: this parameter, together with appropriate isotopic, chemicaland ecophysiological analyses, could provide a good indication of the ‘‘air quality’’ in urban and rural contexts.
Keywords: air quality; carbon isotopes; co 2; lead; photosynthesis

The relative importance of cork harvesting and climate for stem radial growth of Quercus suber L. - Oliveira, Graca; Martins-Loução, Maria Amélia; Correia, Otilia (Annals of forest science, 2002)

Seasonal and species-specific response of VOC emissions by Mediterranean woody plant to elevated ozone concentrations - Llusia, J; Penuelas, J; Gimeno, B S (ATMOSPHERIC ENVIRONMENT, 2002)
Although certain factors controlling plant emission rates of volatile organic compounds (VOCs) are reasonably well understood, the influence of elevated ozone concentrations as abiotic stress is mostly unknown. Therefore, we studied the effects of ozone concentrations on seasonal biogenic volatile organic compound (BVOC) emissions by different Mediterranean plant species in open top chambers (OTC). Three ozone treatments were established: filtered air (F), non-filtered air (NF), and fumigated air (NF +) adding 40 nl l(-1) of ozone over NF. We studied the response of VOC emission in saplings of four Mediterranean woody plant species and subspecies: Ceratonia siliqua L., Olea europaea L., Quercus ilex spp. ilex L., and Quercus ilex spp. rotundifolia L. as representative of natural Mediterranean vegetation. No visible symptoms were detected on the leaves. No significant effect was found on net photosynthetic rates or stomatal conductance except for an increase in net photosynthetic rates in Quercus ilex ilex in spring and summer and an overall slight increase in Quercus ilex rotundifolia. Emissions of the total VOCs from Ceratonia siliqua in summer, and from Olea europaea and Quercus ilex rotundifolia in spring increased in ozone fumigated OTC in comparison with F or NF OTC. Decreased emissions were found in Quercus ilex rotundifolia in summer. There were no significant differences between ozone fumigation treatments for the other plant species and seasons. When considering particular VOCs, the results were also variable among species and time of the year. While alpha-pinene emissions decreased with ozone fumigation in Olea europaea, alpha-pinene and limonene emissions increased in Quercus ilex ilex. The responses of these particular VOCs did not always match the responses of total VOCs. In spite of this strong variability, when considering overall annual data for all species and seasons, there were increased net photosynthetic rates (37%) and limonene (95%) and total VOC (45%) emission rates in ozone-fumigated plants, whereas stomatal conductance did not change. Since VOCs are precursors of ozone, the increase in BVOC emission as a consequence of elevated tropospheric ozone concentrations may lead to positive feedback mechanisms in ozone formation. (C) 2002 Elsevier Science Ltd. All rights reserved.
Keywords: biogenic VOCS; Ceratonia siliqua; Olea europaea; Quercus ilex ilex; Quercus ilex rotundifolia; terpenes; tropospheric ozone

Seasonal and species-specific response of VOC emissions by Mediterranean woody plant to elevated ozone concentrations - Llusia, J.; Penuelas, J.; Gimeno, B. S. (ATMOSPHERIC ENVIRONMENT, 2002)
Although certain factors controlling plant emission rates of volatile organic compounds (VOCs) are reasonably well understood, the influence of elevated ozone concentrations as abiotic stress is mostly unknown. Therefore, we studied the effects of ozone concentrations on seasonal biogenic volatile organic compound (BVOC) emissions by different Mediterranean plant species in open top chambers (OTC). Three ozone treatments were established: filtered air (F), non-filtered air (NF), and fumigated air (NF +) adding 40 nl l(-1) of ozone over NF. We studied the response of VOC emission in saplings of four Mediterranean woody plant species and subspecies: Ceratonia siliqua L., Olea europaea L., Quercus ilex spp. ilex L., and Quercus ilex spp. rotundifolia L. as representative of natural Mediterranean vegetation. No visible symptoms were detected on the leaves. No significant effect was found on net photosynthetic rates or stomatal conductance except for an increase in net photosynthetic rates in Quercus ilex ilex in spring and summer and an overall slight increase in Quercus ilex rotundifolia. Emissions of the total VOCs from Ceratonia siliqua in summer, and from Olea europaea and Quercus ilex rotundifolia in spring increased in ozone fumigated OTC in comparison with F or NF OTC. Decreased emissions were found in Quercus ilex rotundifolia in summer. There were no significant differences between ozone fumigation treatments for the other plant species and seasons. When considering particular VOCs, the results were also variable among species and time of the year. While alpha-pinene emissions decreased with ozone fumigation in Olea europaea, alpha-pinene and limonene emissions increased in Quercus ilex ilex. The responses of these particular VOCs did not always match the responses of total VOCs. In spite of this strong variability, when considering overall annual data for all species and seasons, there were increased net photosynthetic rates (37%) and limonene (95%) and total VOC (45%) emission rates in ozone-fumigated plants, whereas stomatal conductance did not change. Since VOCs are precursors of ozone, the increase in BVOC emission as a consequence of elevated tropospheric ozone concentrations may lead to positive feedback mechanisms in ozone formation. (C) 2002 Elsevier Science Ltd. All rights reserved.
The following values have no corresponding Zotero field: pub-location: THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND publisher: PERGAMON-ELSEVIER SCIENCE LTD
Keywords: biogenic VOCS; Ceratonia siliqua; Olea europaea; Quercus ilex ilex; Quercus ilex rotundifolia; terpenes; tropospheric ozone

Seasonal pattern of monoterpene synthase activities in leaves of the evergreen tree Quercus ilex - Fischbach, Robert Josef; Staudt, Michael; Zimmer, Ina; Rambal, Serge; Schnitzler, Jörg-Peter (Physiologia Plantarum, 2002)
Monoterpene synthase activities were measured in current year and 1-year-old leaves of holm oak (Quercus ilex L.). The monoterpene synthase activities of the leaves strongly changed with leaf development and leaf age. Enzyme activities increased rapidly in spring after leaf emergence, reaching maximum values in summer, which declined during the following winter period. In the next spring monoterpene synthase activities recovered in the old leaves to about one-third of values in the previous years and showed a similar seasonal variation as in young leaves. In both leaf age classes the pattern of enzymatic monoterpene formation was stable with α-pinene (33%), β-pinene (28%), and myrcene (26%) as prominent compounds followed by minor fractions of sabinene (10%) and limonene (3%). Monoterpene emission correlated with the activity of the synthetizing enzymes, indicating that monoterpene synthase activities in Q. ilex reflect the seasonal monoterpene emission potential of the leaves.
The following values have no corresponding Zotero field: publisher: Munksgaard International Publishers accession-num: 12060257
Keywords: monoterpene emissions; monoterpene synthase activities; Quercus ilex; seasonal patterns (voyant)

Seasonal pattern of monoterpene synthase activities in leaves of the evergreen tree Quercus ilex - Fischbach, Robert Josef; Staudt, Michael; Zimmer, Ina; Rambal, Serge; Schnitzler, Jörg-Peter (Physiologia Plantarum, 2002)
Monoterpene synthase activities were measured in current year and 1-year-old leaves of holm oak (Quercus ilex L.). The monoterpene synthase activities of the leaves strongly changed with leaf development and leaf age. Enzyme activities increased rapidly in spring after leaf emergence, reaching maximum values in summer, which declined during the following winter period. In the next spring monoterpene synthase activities recovered in the old leaves to about one-third of values in the previous years and showed a similar seasonal variation as in young leaves. In both leaf age classes the pattern of enzymatic monoterpene formation was stable with α-pinene (33%), β-pinene (28%), and myrcene (26%) as prominent compounds followed by minor fractions of sabinene (10%) and limonene (3%). Monoterpene emission correlated with the activity of the synthetizing enzymes, indicating that monoterpene synthase activities in Q. ilex reflect the seasonal monoterpene emission potential of the leaves.
Keywords: monoterpene emissions; monoterpene synthase activities; Quercus ilex; seasonal patterns (voyant)

Shoot development in Quercus suber L. somatic embryos - Gonzalez-Benito, M Elena; García-Martín, Gemma; Antonio Manzanera, José (In Vitro Cellular & Developmental Biology - Plant, 2002)
N 6 -Benzyladenine (BA; 0.04–4 mM) application to germinated Quercus suber somatic embryos considerably increased caulinar apex elongation frequency and maintained active growth in the plantlets, although it did not have a signiﬁcant effect on the percentage of shoots with normal morphology. The addition of 0.5 mM indoleacetic acid together with the cytokinin did not have any effect. The use of a low concentration (0.04mM) of BA allowed the appropriate radicle elongation in all germinating somatic embryos, but higher concentrations arrested this elongation.
Keywords: Cork oak; growth regulators; in vitro; plantlet.

Shoot growth efficiency and production of Quercus ilex L. in different climates - Crescente, M F; Gratani, Loretta; Larcher, Walter (Flora-Morphology, Distribution, …, 2002)
Structural and functional traits of Quercus ilex L. were monitored in plants growing in the climax area (Castelporziano, Rome; site A) and at the northern distribution limit (Nago, Trento; site B) in Italy. The most distinctive climatic differences between the two sites were duration and frequency of drought, heat spells in summer at site A, and the occurrence of frost and sub-zero temperatures in winter at site B. The potential productivity of Quercus ilex lies in its tendency to be slow growing with maximum vegetative activity from the end of April to the end of June at Castelporziano, and from the middle of May to the middle of July at Nago, when air temperatures favoured the highest photosynthetic rates (90–100%). The lower shoot biomass production at site B was due to the lower relative growth rates in shoot length (RGRl < 20%) and in shoot dry mass (RGRm <11%). The lower shoot length growth efficiency (LE < 62%) at the northern limit was related to the low temperatures in winter and beginning of spring which reduced favourable periods (<20% than site A) for photosynthetic carbon gain and growth dynamics. It resulted in a lower total leaf surface area per shoot (<60% than site A) and a reduced shoot leaf mass (<31%).
Keywords: Net photosynthesis; Phenology; Quercus ilex L; Relative growth rate; shoot length growth efficiency; shoot production

Shoot growth efficiency and production of Quercus ilex L. in different climates - Crescente, M. F.; Gratani, Loretta; Larcher, Walter (Flora-Morphology, Distribution, …, 2002)
Structural and functional traits of Quercus ilex L. were monitored in plants growing in the climax area (Castelporziano, Rome; site A) and at the northern distribution limit (Nago, Trento; site B) in Italy. The most distinctive climatic differences between the two sites were duration and frequency of drought, heat spells in summer at site A, and the occurrence of frost and sub-zero temperatures in winter at site B. The potential productivity of Quercus ilex lies in its tendency to be slow growing with maximum vegetative activity from the end of April to the end of June at Castelporziano, and from the middle of May to the middle of July at Nago, when air temperatures favoured the highest photosynthetic rates (90–100%). The lower shoot biomass production at site B was due to the lower relative growth rates in shoot length (RGRl < 20%) and in shoot dry mass (RGRm <11%). The lower shoot length growth efficiency (LE < 62%) at the northern limit was related to the low temperatures in winter and beginning of spring which reduced favourable periods (<20% than site A) for photosynthetic carbon gain and growth dynamics. It resulted in a lower total leaf surface area per shoot (<60% than site A) and a reduced shoot leaf mass (<31%).
Keywords: Net photosynthesis; Phenology; Quercus ilex L; Relative growth rate; shoot length growth efficiency; shoot production

Simulação e projecção de alternativas de gestão para o montado de sobro - Falcão, André (Documento Técnico, 2002)
A simulação de alternativas de gestão para o montado de sobro reveste-se de diversas subtilezas que a diferenciam dos tradicionais sistemas silvícolas de produção. Isto devido em particular à ecologia da espécie e à forma tradicional como estes sistemas têm sido geridos. De particular relevo é o facto da principal intervenção produtiva no montado (o descortiçamento) não ter um efeito destrutivo nem obrigar a uma regeneração do coberto arbóreo. Outra questão não menos premente é a dificuldade em elaborar modelos de produção e de crescimento desta espécie que se adequem à integração num simulador de alternativas de gestão. Finalmente, e tendo os modelos de produção adequados, a questão é fundamental é: como se gere o montado de sobro? quais são as possibilidades que um produtor tem de gerir o seu montado? Este documento procura responder a estas questões. Assim, descreve-se o módulo de apoio à decisão do programa SADGEM. Este componente é constituido por 3 aplicativos distintos: Um simulador de alternativas de gestão, um gerador de restrições e um modelo de gestão previamente parametrizado. O gerador de alternativas de gestão usa informação de inventário e geográfica recuperada directamente do SGBD. Neste trabalho detalha-se, em primeiro lugar, o modelo de produção utilizado para efectuar a simulação. Seguidamente, descrevem-se os requisitos de dados necessários para alimentar o modelo e finalmente todos os mecanismos de geração de alternativas de gestão para montados de sobro. Dá-se ainda algum relevo ao tipo de informação produzida pelo simulador e sistema de pré-processamento de soluções.
Keywords: alternativas; cortiça; Descortiçamento (voyant); gestão; idade; montado; simulação

Simulação e projecção de alternativas de gestão para o montado de sobro - Falcão, André (2002)
A simulação de alternativas de gestão para o montado de sobro reveste-se de diversas subtilezas que a diferenciam dos tradicionais sistemas silvícolas de produção. Isto devido em particular à ecologia da espécie e à forma tradicional como estes sistemas têm sido geridos. De particular relevo é o facto da principal intervenção produtiva no montado (o descortiçamento) não ter um efeito destrutivo nem obrigar a uma regeneração do coberto arbóreo. Outra questão não menos premente é a dificuldade em elaborar modelos de produção e de crescimento desta espécie que se adequem à integração num simulador de alternativas de gestão. Finalmente, e tendo os modelos de produção adequados, a questão é fundamental é: como se gere o montado de sobro? quais são as possibilidades que um produtor tem de gerir o seu montado? Este documento procura responder a estas questões. Assim, descreve-se o módulo de apoio à decisão do programa SADGEM. Este componente é constituido por 3 aplicativos distintos: Um simulador de alternativas de gestão, um gerador de restrições e um modelo de gestão previamente parametrizado. O gerador de alternativas de gestão usa informação de inventário e geográfica recuperada directamente do SGBD. Neste trabalho detalha-se, em primeiro lugar, o modelo de produção utilizado para efectuar a simulação. Seguidamente, descrevem-se os requisitos de dados necessários para alimentar o modelo e finalmente todos os mecanismos de geração de alternativas de gestão para montados de sobro. Dá-se ainda algum relevo ao tipo de informação produzida pelo simulador e sistema de pré-processamento de soluções.
The following values have no corresponding Zotero field: secondary-title: Documento Técnico periodical: Documento Técnico
Keywords: alternativas; cortiça; Descortiçamento (voyant); gestão; idade; montado; simulação

Soil evolution over the Quaternary period in a Mediterranean climate (SE Spain) - Ortiz, I.; Simón, M.; Dorronsoro, C.; MartÄ±n, F.; GarcÄ±a, I. (Catena, 2002)
Palaeosols in the Granada Basin (SE Spain) have been studied in two different situations: surface soils on geomorphically stable surfaces since the Early Pleistocene with younger pedogenic overprinting and buried soils on unstable surfaces from the Middle –Late Pleistocene on which successive erosional – depositional episodes have alternated with pedogenic episodes. For each soil clay and iron accumulation indices, the Fet + Al t /Si t ratio, clay mineralogy and micromorphological features were used to estimate the degree of soil development. From the Early to the early Late Pleistocene, the main pedogenic processes were the leaching of carbonates, weathering, illuviation and rubification, which resulted in Bt horizons with red colours, clay texture, clay coatings and kaolinite neoformation. The degree of weathering and the development of these Bt horizons varied over time, and the soils that formed on the surfaces from the Early Pleistocene show strongest weathering and development. However, after their formation, there were periods in which they were partially truncated and recalcified, resulting in polygenetic soils. The different degrees of development of the buried soils during the last 474,000 years indicate that the wettest warm period was stage 7 and the driest, stage 5. Stages 9 and 11 must have had climates with intermediate wetness. Since the clay accumulation and iron oxide accumulation indices, the differences in Fet + Al t /Si t ratio between Bt and C horizons, the extent of kaolinite neoformation and the micromorphological features of the soils formed during stage 7 are all similar to the surface soils that formed on Early Pleistocene deposits, these features cannot be used to date surfaces older than 242,000 BP. By contrast, the soils that formed during stage 7 and later periods show different extents of development and thus can be used for the approximate dating of landforms.
Keywords: Buried soils; climatic changes; Pleistocene; Relict soils; Soil development

Soil evolution over the Quaternary period in a Mediterranean climate (SE Spain) - Ortiz, I; Simón, M; Dorronsoro, C; MartÄ±n, F; GarcÄ±a, I (Catena, 2002)
Palaeosols in the Granada Basin (SE Spain) have been studied in two different situations: surface soils on geomorphically stable surfaces since the Early Pleistocene with younger pedogenic overprinting and buried soils on unstable surfaces from the Middle –Late Pleistocene on which successive erosional – depositional episodes have alternated with pedogenic episodes. For each soil clay and iron accumulation indices, the Fet + Al t /Si t ratio, clay mineralogy and micromorphological features were used to estimate the degree of soil development. From the Early to the early Late Pleistocene, the main pedogenic processes were the leaching of carbonates, weathering, illuviation and rubification, which resulted in Bt horizons with red colours, clay texture, clay coatings and kaolinite neoformation. The degree of weathering and the development of these Bt horizons varied over time, and the soils that formed on the surfaces from the Early Pleistocene show strongest weathering and development. However, after their formation, there were periods in which they were partially truncated and recalcified, resulting in polygenetic soils. The different degrees of development of the buried soils during the last 474,000 years indicate that the wettest warm period was stage 7 and the driest, stage 5. Stages 9 and 11 must have had climates with intermediate wetness. Since the clay accumulation and iron oxide accumulation indices, the differences in Fet + Al t /Si t ratio between Bt and C horizons, the extent of kaolinite neoformation and the micromorphological features of the soils formed during stage 7 are all similar to the surface soils that formed on Early Pleistocene deposits, these features cannot be used to date surfaces older than 242,000 BP. By contrast, the soils that formed during stage 7 and later periods show different extents of development and thus can be used for the approximate dating of landforms.
Keywords: Buried soils; climatic changes; Pleistocene; Relict soils; Soil development

A spatial statistical analysis of cork oak competition in two Portuguese silvopastoral systems - Paulo, M. J.; Stein, A.; Tomé, M. (Canadian Journal of Forest Research, 2002)
This paper considers competition among cork oaks (Quercus suber L.) at three plots in two representative Portuguese stands. It uses spatial point pattern functions to describe densities and quantify differences among stands. Relations between cork oak characteristics and indices measuring intertree competition are modelled. Tree competition has a significant effect on tree crown characteristics. In particular, cork oaks with much competition have smaller and more elongated crowns. A standard model that relates crown diameter with diameter at breast height was improved. The R2 value increased from 0.53 to 0.63 by including a crown shape parameter and competition indices.
doi: 10.1139/x02-107doi: 10.1139/x02-107The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: Competition (voyant); Cork oak; crown characteristics

Stocking rate and capital indicators in extensive sheep farms (sw spain) - Escribano Sánchez, Miguel; Rodríguez de Ledesma Vega, Antonio; Mesías Díaz, Francisco Javier; Pulido García, Francisco (Arch. Zootec, 2002)
The animal production systems in the SW of the Iberian Peninsula are characterized by extensive livestock farming. The data for the present study were collected by survey in the year 2000 from 96 dehesa sheep farms in Extremadura. We studied the stocking rate effects on a number of capital indicators for each farm. The data were analysed for three stocking rate levels: low (<0.25 UGM/ha), medium (0.25-0.5 UGM/ha), and high (0.5 UGM/ha). The differences were compared by analysis of variance, following the GLM procedure.
Keywords: Economic analysis; Extensive system; Sheep; Stocking rates

Stocking rate and capital indicators in extensive sheep farms (sw spain) - Escribano Sánchez, Miguel; Rodríguez de Ledesma Vega, Antonio; Mesías Díaz, Francisco Javier; Pulido García, Francisco (Arch. Zootec, 2002)
The animal production systems in the SW of the Iberian Peninsula are characterized by extensive livestock farming. The data for the present study were collected by survey in the year 2000 from 96 dehesa sheep farms in Extremadura. We studied the stocking rate effects on a number of capital indicators for each farm. The data were analysed for three stocking rate levels: low (<0.25 UGM/ha), medium (0.25-0.5 UGM/ha), and high (0.5 UGM/ha). The differences were compared by analysis of variance, following the GLM procedure.
Keywords: Economic analysis; Extensive system; Sheep; Stocking rates

Structural and functional traits of Quercus ilex in response to water availability - Bussotti, Filippo; Bettini, Davide; Grossoni, Paolo; Mansuino, Silvia; Nibbi, Renzo; Soda, Costanza; Tani, Corrado (Environmental and Experimental Botany, 2002)
Water potential and morpho-anatomical parameters were measured, during the course of 1 year, on leaves of Quercus ilex trees growing in two coastal stands in Tuscany (Central Italy) with different conditions of water availability: Colognole (CL, mesic site) and Cala Violina (CV, xeric site). Morpho-anatomical measurements included: general leaf features and sclerophylly indices (surface area, thickness, mass per area and density), leaf moisture indices (water content, relative water content, succulence) and histochemical analysis (detection and localization of cutine and tannins in the leaves and starch reserves in the twigs). During the warmest and driest period (August) pre-dawn water potential (pd ) in Holm-oak leaves reached −2.7 MPa at CV and −0.6 MPa at CL. Leaf surface was lower (−34%) and total leaf thickness (+10%), as well as spongy-palisade parenchyma ratio (+20%) were higher at CV. The sclerophylly parameters (leaf mass per area and leaf tissue density) were higher at CV than at CL (+24% leaf mass per area and +19% leaf tissue density). Among the moisture parameters, water content was higher at CL (+8%) and succulence was higher at CV (+13%). No differences in relative water content were observed between the two sites. All the parameters considered were substantially stable during the study period, with the exception of relative water content at CL, that ﬂuctuated within the year. Histochemical analysis revealed a greater thickness of the upper cuticular layer at CV, whereas there were no differences in tannin distribution and content between the two sites. Differences in starch storage were detected in branchlets: it was abundant in CV but very scarce at CL. The strategies of Quercus ilex to cope with water stress were discussed at morpho-structural level.
Keywords: leaf structure; starch; Tannins; water potential

Structural and functional traits of Quercus ilex in response to water availability - Bussotti, Filippo; Bettini, Davide; Grossoni, Paolo; Mansuino, Silvia; Nibbi, Renzo; Soda, Costanza; Tani, Corrado (Environmental and Experimental Botany, 2002)
Water potential and morpho-anatomical parameters were measured, during the course of 1 year, on leaves of Quercus ilex trees growing in two coastal stands in Tuscany (Central Italy) with different conditions of water availability: Colognole (CL, mesic site) and Cala Violina (CV, xeric site). Morpho-anatomical measurements included: general leaf features and sclerophylly indices (surface area, thickness, mass per area and density), leaf moisture indices (water content, relative water content, succulence) and histochemical analysis (detection and localization of cutine and tannins in the leaves and starch reserves in the twigs). During the warmest and driest period (August) pre-dawn water potential (pd ) in Holm-oak leaves reached −2.7 MPa at CV and −0.6 MPa at CL. Leaf surface was lower (−34%) and total leaf thickness (+10%), as well as spongy-palisade parenchyma ratio (+20%) were higher at CV. The sclerophylly parameters (leaf mass per area and leaf tissue density) were higher at CV than at CL (+24% leaf mass per area and +19% leaf tissue density). Among the moisture parameters, water content was higher at CL (+8%) and succulence was higher at CV (+13%). No differences in relative water content were observed between the two sites. All the parameters considered were substantially stable during the study period, with the exception of relative water content at CL, that ﬂuctuated within the year. Histochemical analysis revealed a greater thickness of the upper cuticular layer at CV, whereas there were no differences in tannin distribution and content between the two sites. Differences in starch storage were detected in branchlets: it was abundant in CV but very scarce at CL. The strategies of Quercus ilex to cope with water stress were discussed at morpho-structural level.
Keywords: leaf structure; starch; Tannins; water potential

Transpiração em Árvores Isoladas de um Montado de Azinho: Evolução Sazonal e Condicionantes Hidráulicas - David, Teresa Soares; Ferreira, Isabel; Pereira, João Santos; Cohen, Shabtai; David, Jorge Soares (Silva Lusitana, 2002)
Sapflow and related variables were monitored for two years in an isolated Quercus rotundifolia Lam. tree, in a low density oak woodland (montado) near Évora. The study aimed at identifying tree strategies in adverse soil and climatic conditions in order to understand the conditions for survival and sustainability. Seasonal variations in transpiration, mainly related to solar radiation and vapour pressure deficit, showed a peak in summer (3 mm day-1) even in dry soil conditions. Water availability to the roots did not change much over time, due to the likely access of the root system to an aquifer located at 13 m depth. Stomatal control prevents transpiration from exceeding the maximum water uptake capacity by the roots. An upper limit is thus imposed on transpiration, preventing leaf water potential to decrease below -3,2 MPa, which may probably be the threshold for cavitation
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: aquifer; Evapotranspiration; Quercus rotundifolia Lam.; sapflow

Transpiração em Árvores Isoladas de um Montado de Azinho: Evolução Sazonal e Condicionantes Hidráulicas - David, Teresa Soares; Ferreira, Isabel; Pereira, João Santos; Cohen, Shabtai; David, Jorge Soares (Silva Lusitana, 2002)
Sapflow and related variables were monitored for two years in an isolated Quercus rotundifolia Lam. tree, in a low density oak woodland (montado) near Évora. The study aimed at identifying tree strategies in adverse soil and climatic conditions in order to understand the conditions for survival and sustainability. Seasonal variations in transpiration, mainly related to solar radiation and vapour pressure deficit, showed a peak in summer (3 mm day-1) even in dry soil conditions. Water availability to the roots did not change much over time, due to the likely access of the root system to an aquifer located at 13 m depth. Stomatal control prevents transpiration from exceeding the maximum water uptake capacity by the roots. An upper limit is thus imposed on transpiration, preventing leaf water potential to decrease below -3,2 MPa, which may probably be the threshold for cavitation
Keywords: aquifer; Evapotranspiration; Quercus rotundifolia Lam.; sapflow

Trichomes and photosynthetic pigment composition changes: responses of Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L. to Mediterranean stress conditions - Morales, F; Abadía, A; Abadia, J; Montserrat, G; Gil-Pelegrín, E (Trees, 2002)
Sun and shade leaves of two Mediterranean Quercus species, Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L., were compared by measuring leaf optical properties, photosynthetic pigment composition and photosystem II efficiency. The presence of trichomes in the adaxial (upper) leaf surface of Q. ilex subsp. ballota seems to constitute an important morphological mechanism that allows this species to maintain a good photosystem II efficiency during the summer. Q. coccifera has almost no trichomes and seems instead to develop other physiological responses, including a smaller light-harvesting antenna size, higher concentrations of violaxanthin cycle pigments and a higher (zeaxanthin + antheraxanthin)/(violaxanthin + antheraxanthin + zeaxanthin) ratio. Q. coccifera was not able to maintain a good photosystem II efficiency up to the end of the summer. In Q. ilex subsp. ballota leaves, natural loss or mechanical removal of adaxial-face leaf trichomes induced short-term decreases in photosystem II efficiency. These changes were accompanied by deepoxidation of violaxanthin cycle pigments, suggesting that the absence of trichomes would trigger physiological responses in this species. Our data have revealed different patterns of response of Q. ilex subsp. ballota and Q. coccifera facing the stress conditions prevailing in the Mediterranean area.
Keywords: adaxial epidermis; photoprotection; Quercus; Trichomes

Trichomes and photosynthetic pigment composition changes: responses of Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L. to Mediterranean stress conditions - Morales, F.; Abadia, A.; Abadía, J.; Montserrat, G.; GIL-PELEGRÍN, E. (Trees, 2002)
Sun and shade leaves of two Mediterranean Quercus species, Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L., were compared by measuring leaf optical properties, photosynthetic pigment composition and photosystem II efficiency. The presence of trichomes in the adaxial (upper) leaf surface of Q. ilex subsp. ballota seems to constitute an important morphological mechanism that allows this species to maintain a good photosystem II efficiency during the summer. Q. coccifera has almost no trichomes and seems instead to develop other physiological responses, including a smaller light-harvesting antenna size, higher concentrations of violaxanthin cycle pigments and a higher (zeaxanthin + antheraxanthin)/(violaxanthin + antheraxanthin + zeaxanthin) ratio. Q. coccifera was not able to maintain a good photosystem II efficiency up to the end of the summer. In Q. ilex subsp. ballota leaves, natural loss or mechanical removal of adaxial-face leaf trichomes induced short-term decreases in photosystem II efficiency. These changes were accompanied by deepoxidation of violaxanthin cycle pigments, suggesting that the absence of trichomes would trigger physiological responses in this species. Our data have revealed different patterns of response of Q. ilex subsp. ballota and Q. coccifera facing the stress conditions prevailing in the Mediterranean area.
Keywords: adaxial epidermis; photoprotection; Quercus; Trichomes

Typologie et dynamique des chênaies vertes en Algérie - Dahmani-Megrerouche, M (Forêt Mediterranéenne, 2002)
Cet article traite des différents groupements végétaux relevant de la dynamique des chênaies vertes en Algérie, et de leurs différents stades de dégradation. Lorsque l’on connait la valeur écologique du chêne vert, en particulier, dans un pays comme l’Algérie, son rôle contre la désertification et la disparition des sols, les résultats de cette analyse ne peuvent qu’aider les gestionnaires à mieux appréhender la situation
Keywords: chêne vert; matorral; phytosociologie; relation sol-végétation; structure (voyant)

Typologie et dynamique des chênaies vertes en Algérie - Dahmani-Megrerouche, M. (Forêt Mediterranéenne, 2002)
Cet article traite des différents groupements végétaux relevant de la dynamique des chênaies vertes en Algérie, et de leurs différents stades de dégradation. Lorsque l’on connait la valeur écologique du chêne vert, en particulier, dans un pays comme l’Algérie, son rôle contre la désertification et la disparition des sols, les résultats de cette analyse ne peuvent qu’aider les gestionnaires à mieux appréhender la situation
Keywords: chêne vert; matorral; phytosociologie; relation sol-végétation; structure (voyant)

Use of monocharacteristic growth forms and phenological phases to describe and differentiate plant communities in Mediterranean-type ecosystems - Latorre, A V Pérez; Cabezudo, B (Plant Ecology, 2002)
The ecomorphological and phenological study was carried out within a Mediterranean vegetation context, in Quercus suber forests, which have been substituted by shrublands of Cistus spp within two Natural Parks in the south of the Iberian Peninsula. The ecomorphological characters that show meaningful differences between both types of vegetation are: location of renewal buds, spinescence, stratiﬁcation, maximum height of the vegetation, organs periodically shed, leaf consistency, leaf tomentosity, leaf size, and life duration of leaves, plant duration, vegetative regeneration after ﬁre, main vegetative growth season, main ﬂowering season and fruit type. The phenological phases also help to discern between forest and shrubland, specially ﬂower bud formation, fruiting, seed dispersal, and the existence of brachyblast vegetative growth and brachyblast leaf shedding. We propose three new indexes based on phenological phases: “active period of the species” (APS), “active period of the community” (APC) and “reproductive/vegetative activity of the species” (RVA). The results of their application, in combination with the ecomorphological characters, have proved promising in describing vegetation and in clearly differentiating communities. The results also show the existence of different ecomorphological groups of plants at community level, with consequent ecological, historical, phytocoenological and adaptive implications
Keywords: cistus shrublands; Mediterranean vegetation; phenological indexes; plant functional types; quercus suber forests

Variations in Quercus ilex chloroplast pigment content during summer stress: involvement in photoprotection according to principal component analysis - Llorens, L.; Aranda, X.; Abadia, A.; Fleck, I. (FUNCTIONAL PLANT BIOLOGY, 2002)
We examined chloroplast pigment variation in holm oak (Quercus ilex L.) leaves for two periods under two climatic conditions, at midday during summer. We compared variation between control (unburned) plants and plants burned the preceding summer, since post-fire resprouts show higher photosynthetic rates and lower thermal energy dissipation. Principal component (PC) analysis was performed on nine pigment-content variables for the two periods separately. Two PC factors (PC1 and PC2) explained 83 and 84% of the variance of the data for each period. In both periods, PC 1 was marked by positive loading of pigments associated with light absorption or structural function namely neoxanthin, lutein, beta-carotene, chlorophyll a, and chlorophyll b. These pigments were only affected by leaf age. In contrast, PC2 was marked by high loadings of xanthophyll-cycle pigments (associated with photoprotection), and lutein-5,6-epoxide. Leaf content of these pigments was affected by climatic conditions. In the situations considered in PC analysis (leaf types, periods), the lutein-5,6-epoxide content presented a variation pattern similar to that of violaxanthin, and was significantly correlated with thermal dissipation of excess energy (represented by non-photochemical quenching or NPQ). These results suggest a relationship of lutein and lutein-5,6-epoxide with photoprotection.
The following values have no corresponding Zotero field: pub-location: 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA publisher: C S I R O PUBLISHING
Keywords: 6-epoxide; chlorophyll; lutein-5; photoprotection; Principal component analysis

The viscoelastic properties of cork - Mano, J. F. (Journal of materials science, 2002)
The viscoelastic properties of cork (from Quercus suber) have been investigated in the temperature range −40 to 120 ◦ C using the technique of Dynamic Mechanical Analysis (DMA). The results were compared with dielectric data previously reported. A relaxation was detected with a maximum in tan δ at ca 20 ◦ C (f = 1 Hz) and with a mean activation energy of 140 kJ ·mol−1 . A decrease in the intensity of the relaxation and an increase of the storage modulus is observed when cork is previously subjected to an annealing process above 60 ◦ C. This result is in agreement with previously reported dielectric data. Thermogravimetric experiments seem to conﬁrm that such effect could be caused by the desorption of water molecules. Specimens oriented along the prismatic direction presented higher storage modulus than the ones oriented along the transverse prismatic direction. The rheological properties of cork also showed a dependence upon the mechanical mode used during measurements: for example, the stiffness is the highest for the tensile mode and the lowest for the compression mode.
Keywords: Cork; Dynamic mechanical analysis (DMA); Relaxation; viscoelastic properties (voyant)

The viscoelastic properties of cork - Mano, J F (Journal of materials science, 2002)
The viscoelastic properties of cork (from Quercus suber) have been investigated in the temperature range −40 to 120 ◦ C using the technique of Dynamic Mechanical Analysis (DMA). The results were compared with dielectric data previously reported. A relaxation was detected with a maximum in tan δ at ca 20 ◦ C (f = 1 Hz) and with a mean activation energy of 140 kJ ·mol−1 . A decrease in the intensity of the relaxation and an increase of the storage modulus is observed when cork is previously subjected to an annealing process above 60 ◦ C. This result is in agreement with previously reported dielectric data. Thermogravimetric experiments seem to conﬁrm that such effect could be caused by the desorption of water molecules. Specimens oriented along the prismatic direction presented higher storage modulus than the ones oriented along the transverse prismatic direction. The rheological properties of cork also showed a dependence upon the mechanical mode used during measurements: for example, the stiffness is the highest for the tensile mode and the lowest for the compression mode.
Keywords: Cork; Dynamic mechanical analysis (DMA); Relaxation; viscoelastic properties (voyant)

Volatile organic compound emissions in relation to plant carbon fixation and the terrestrial carbon budget - Kesselmeier, Jürgen; Ciccioli, Paolo; Kuhn, Uwe; Stefani, Paolo; Biesenthal, Thomas; Rottenberger, Stefanie; Wolf, Annette; Vitullo, Marina; Valentini, Ricardo; Nobre, Antonio; Kabat, Pavel; Andreae, Meinrat O. (Global Biogeochemical Cycles, 2002)
A substantial amount of carbon is emitted by terrestrial vegetation as biogenic volatile organic compounds (VOC), which contributes to the oxidative capacity of the atmosphere, to particle production and to the carbon cycle. With regard to the carbon budget of the terrestrial biosphere, a release of these carbon compounds is regarded as a loss of photosynthetically fixed carbon. The significance of this loss for the regional and global carbon cycles is controversial. We estimate the amount of VOC carbon emitted in relation to the CO2 taken up, based on our own enclosure and micrometeorological flux measurements of VOC emissions and CO2 exchange within the Mediterranean area and the tropical rainforest in Amazonia and on literature data. While VOC flux estimates are small in relation to net primary productivity and gross primary productivity, the amount of carbon lost as VOC emissions can be highly significant relative to net ecosystem productivity. In fact, VOC losses are of the same order of magnitude as net biome productivity. Although we must assume that large amounts of these reemissions are recycled within the biosphere, a substantial part can be assumed to be lost into longer-lived oxidation products that are lost from the terrestrial biosphere by transport. However, our current knowledge does not allow a reliable estimation of this carbon loss.
Keywords: carbon cycle; volatile organic compounds (VOC)

Allocation of absorbed light energy into photochemistry and dissipation in a semi-deciduous and an evergreen Mediterranean woody species during winter - Oliveira, G; Penuelas, J (AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY, 2001)
The importance of photodissipation in the protection from excessive solar energy absorption during winter was evaluated in shrubs of Cistus albidus L. (semi-deciduous) and Quercus ilex L. (evergreen). Diurnal and seasonal changes in chlorophyll a (Chl a) fluorescence-related parameters of leaves with different microclimates (south- and north-facing leaves) were assessed from early winter to late spring in a Mediterranean plant community. Maximal photochemical efficiency of photosystem II (PSII) (F-v/F-m) was lowest on sunny and cold winter days, but low values on overcast (and cold) days indicated that the whole winter season was potentially stressful. Photoinhibition was greater in south than in north leaves during winter. There was a decreased proportion of absorbed light utilised in photochemistry, and an increase in that proportion diverted into dissipation processes on cold sunny days. Under low light conditions (e.g. of north-facing leaves throughout the winter, or all the canopy on overcast days), a greater proportion of light energy was allocated to photochemistry than in bright conditions, although still smaller than the dissipated fraction. Allocation to photochemistry prevailed over dissipation only in spring. The phenological and structural characteristics of C. albidus protect it from excessive light loads, and reduce the need for investment in physiological mechanisms to avoid their harmful effects. Quercus ilex lacks such protection, and relies essentially on increased and sustained photodissipative activity at the physiological level.
Keywords: chlorophyll fluorescence; Cistus albidus L.

Análisis de la variabilidad de adn de cloroplastos en Quercus ilex L., Q. suber L. Y Q. coccifera L.. - COLLADA, C; Jimenez, P; Gil, L (III Congreso Forestal Español, 2001)
Chloroplast (Cp) and mitochondrial (mt) DNA variation have been studied by PCR-RFLP in 14 location (13 with Q. suber, 12 with Q. ilex and 6 with Q. coccifera) along the natural distribution area of these species in the Iberian Peninsula. Five chloroplast DNA primers pairs and one mitochondrial DNA primer pair have been used, each one in combination with a restriction enzyme. 29 different haplotypes have been detected, In the case of Q. suber a characteristic haplotype, very divergent of the remaining ones has been described. Usually, species don’t share haplotypes within the same populations. The distribution of haplotypes suggests a geographical structuring. The levels of genetic differentiation are similar to those obtained in oaks.hS is significantly higher in Q. ilex (hS=0,262). Differentiation coefficients (Gst) are similar in the three species and indicate a high typical structuring of maternal markers.
Keywords: chloroplast DNA; differentiation; geographic distribution; Haplotypes; phylogeny; Quercus

Análisis de la variabilidad de adn de cloroplastos en Quercus ilex L., Q. suber L. Y Q. coccifera L.. - COLLADA, C.; JIMÉNEZ, P.; Gil, L. (III Congreso Forestal Español, 2001)
Chloroplast (Cp) and mitochondrial (mt) DNA variation have been studied by PCR-RFLP in 14 location (13 with Q. suber, 12 with Q. ilex and 6 with Q. coccifera) along the natural distribution area of these species in the Iberian Peninsula. Five chloroplast DNA primers pairs and one mitochondrial DNA primer pair have been used, each one in combination with a restriction enzyme. 29 different haplotypes have been detected, In the case of Q. suber a characteristic haplotype, very divergent of the remaining ones has been described. Usually, species don’t share haplotypes within the same populations. The distribution of haplotypes suggests a geographical structuring. The levels of genetic differentiation are similar to those obtained in oaks.hS is significantly higher in Q. ilex (hS=0,262). Differentiation coefficients (Gst) are similar in the three species and indicate a high typical structuring of maternal markers.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: chloroplast DNA; differentiation; geographic distribution; Haplotypes; phylogeny; Quercus

Aplicación de los diagramas bioclimáticos a la provincia de lérida: determinación de los parametros bioclimáticos para las masas de QUERCUS ILEX BALLOTA Y QUERCUS FAGINEA - Rovirola, D; Alcazar, J; Peman, J (III Congreso Forestal Español Congreso, 2001)
The present work tries to characterize the different bulks of Quercus ilex and Q. .faginea that are distributed all over the province of Lérida through the utilization of the Diagramas bioclimáticos. Results are intended to give criteria for the utilization of these species in reforestation projects.
Keywords: diagramas bioclimáticos; forestation; Quercus faginea; Quercus ilex ballota

Aplicación de los diagramas bioclimáticos a la provincia de lérida: determinación de los parametros bioclimáticos para las masas de QUERCUS ILEX BALLOTA Y QUERCUS FAGINEA - Rovirola, D.; Alcazar, J.; Peman, J. (III Congreso Forestal Español Congreso, 2001)
The present work tries to characterize the different bulks of Quercus ilex and Q. .faginea that are distributed all over the province of Lérida through the utilization of the Diagramas bioclimáticos. Results are intended to give criteria for the utilization of these species in reforestation projects.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español Congreso issue: 1987 pub-location: Granada
Keywords: diagramas bioclimáticos; forestation; Quercus faginea; Quercus ilex ballota

ASPECTOS METODOLÓGICOS DE LA ORDENACIÓN DE ENCINARES EN SIERRA MORENA OCCIDENTAL - DOMINGO, J. M.; MARÍN, F. J. (III Congreso Forestal Español, 2001)
This paper presents the analysis of three Management Projects made up for Mediterranean Forest Management Units, mainly composed by evergreen oaks (Quercus ilex ssp. rotundifolia) stands with a low tree density, which are called dehesas. The dehesa is mainly used as range land and normally presents hilly landforms, acidic soils non suitable for agriculture, a temperate-warm climate, and trees covering at least 10% of the surface. It is a man made system which needs work in order to maintain its balance, but it is also a traditional landscape giving highly valued productions. Therefore we must try to find management solutions to preserve an enhance the dehesa systems; one of the greatest problems, tree preservation and renewal is presented here.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: Dehesa; evergreen oak; Mediterranean forest management

ASPECTOS METODOLÓGICOS DE LA ORDENACIÓN DE ENCINARES EN SIERRA MORENA OCCIDENTAL - DOMINGO, J M; MARÍN, F J (III Congreso Forestal Español, 2001)
This paper presents the analysis of three Management Projects made up for Mediterranean Forest Management Units, mainly composed by evergreen oaks (Quercus ilex ssp. rotundifolia) stands with a low tree density, which are called dehesas. The dehesa is mainly used as range land and normally presents hilly landforms, acidic soils non suitable for agriculture, a temperate-warm climate, and trees covering at least 10% of the surface. It is a man made system which needs work in order to maintain its balance, but it is also a traditional landscape giving highly valued productions. Therefore we must try to find management solutions to preserve an enhance the dehesa systems; one of the greatest problems, tree preservation and renewal is presented here.
Keywords: Dehesa; evergreen oak; Mediterranean forest management

Bioensayo para la detección de PHYTOPHTHORA CINNAMOMI EN EL SUELO DE RODALES AFECTADOS POR LA SECA DE QUERCUS - HERMOSO, R; SÁNCHEZ, E; TRAPERO, A (III Congreso Forestal Español, 2001)
The isolation of Phytophthora spp. from soil samples is often difficult, even using indirect methods which combine baiting techniques and selective media. Apple or avocado fruits or carnation petals are some of the most common baits used for the isolation of P. cinnamomi from infested soils where Quercus ilex and Q. suber have been affected by root rot and decline. However, the use of these baits has serious limitations because of the contamination by several fungi and bacteria. The aim of this work was to improve the baiting technique for the pathosystem P. cinnamomi / Quercus spp. The effect of different factors, including several baits (leaves, fruits, cotyledons, radicles), the soil:water dilution, and the incubation time, was checked using a soil mixture artificially infested with several isolates of P. cinnamomi. The most effective baiting method included baits of eucalyptus phyllodium pieces (Eucalyptus globulus and less effective E. camaldulensis), 1:6 soil:water relation, and 4 days incubation period. The efficiency of this method has been tested for the detection of P. cinnamomi in naturally infested soil samples from fields where the root rot caused by this pathogen had been previously diagnosed
Keywords: phytophthora cinnamomi; Quercus decline; soil detection

Caracterización de las poblaciones de Fusarium Link de suelos de dehesas de Badajoz - Rodríguez-Molina, M. C.; TORRES-VILA, L. M.; TELLO MARQUINA, J. C.; BLANCO SANTOS, A.; PALO NÚÑEZ, E. J.; Marquina, J. C. Tello (Boletín de Sanidad Vegetal Plagas, 2001)
La dehesa ocupa en Extremadura una superficie aproximada de 1.800.000 ha y constituye un ecosistema único en el que se combina la producción agro-silvo-pastoraí. Aunque la dehesa está sometida a la acción antrópica, normalmente ésta no provoca la misma perturbación que en las zonas de cultivo agrícola. Sin embargo se desconoce si la micoflora de sus suelos es similar a la de los suelos de áreas no cultivadas o a los de zonas agrícolas. La caracterización de las poblaciones de Fusarium de los suelos de 18 dehesas de Badajoz con arbolado de encina efectuada en este estudio indica que el gé- nero se encuentra ampliamente distribuido en estos suelos. Además de ser detectada su presencia en todos los suelos muestreados, las densidades de población fueron elevadas en general. Las especies aisladas fueron F. oxysporum, F. roseum y F. solani, con un pre- dominio claro de F. oxysporum seguida por F. roseum. Los resultados obtenidos indican que los Fusaria son pobladores naturales de los suelos de dehesa de Badajoz.
Keywords: Dehesa; densidad de población; fusarium; suelo

Catkin frost damage in Mediterranean cork-oak (Quercus suber L.). - García-mozo, Herminia; Hidalgo, Pablo J; Galán, Carmen; Gómez-Casero, Maria Teresa; Domínguez, Eugenio (Israel Journal of Plant Sciences, 2001)
During a period of study of floral phenology and pollen production in the cork-oak, Quercus suber L. (199799), an interruption of catkin development was detected in spring 1998. The cause might have been a sharp drop in minimum temperatures during that period, which coincided with the initial stages of microsporogenesis. Results show that environmental temperatures close to 0 ºC halted microsporogenesis and catkinelongation, resulting in their complete death. No fruits were observed in the affected zone, as a possible consequence of the lack of pollen. Phenological, histological, andaerobiological data are analyzed as a whole in order to gain a better understanding of the phenomenon. Cold spells during flowering may be one of the factors influencing the high interannual variability of acorn production in Quercus species. [ABSTRACT FROM AUTHOR]
Keywords: CATKIN-bearing plants; Cork oak; flowers; Fruit; Phenology; PLANT spores; POLLEN (citation)

Catkin frost damage in Mediterranean cork-oak (Quercus suber L.). - García-mozo, Herminia; Hidalgo, Pablo J.; Galán, Carmen; Gómez-Casero, Maria Teresa; Domínguez, Eugenio (Israel Journal of Plant Sciences, 2001)
During a period of study of floral phenology and pollen production in the cork-oak, Quercus suber L. (199799), an interruption of catkin development was detected in spring 1998. The cause might have been a sharp drop in minimum temperatures during that period, which coincided with the initial stages of microsporogenesis. Results show that environmental temperatures close to 0 ºC halted microsporogenesis and catkinelongation, resulting in their complete death. No fruits were observed in the affected zone, as a possible consequence of the lack of pollen. Phenological, histological, andaerobiological data are analyzed as a whole in order to gain a better understanding of the phenomenon. Cold spells during flowering may be one of the factors influencing the high interannual variability of acorn production in Quercus species. [ABSTRACT FROM AUTHOR]
Keywords: CATKIN-bearing plants; Cork oak; flowers; Fruit; Phenology; PLANT spores; POLLEN (citation)

Characterization of the responses of cork oak (Quercus suber) to iron deficiency - Gogorcena, Yolanda; Molias, Nuria; Larbi, Ajmi; Abadía, Javier; Abadía, Anunciación (Tree Physiology, 2001)
We studied responses of cork oak (Quercus suber L.) to iron (Fe) deficiency by comparing seedlings grown hydroponically in nutrient solution with and without Fe. Seedlings grown without Fe developed some responses typical of the Strategy I group of Fe-efficient plants, including two- and fourfold increases in plasma membrane ferric chelate reductase activity of root tips after 2 and 4 weeks of culture in the absence of Fe, respectively. Moreover, seedlings grown hydroponically for 2 weeks without Fe caused marked decreases in the pH of the nutrient solution, indicating that root plasma membrane ATPase activity was induced by Fe deficiency. Iron deficiency also caused marked decreases in leaf chlorophyll and carotenoid concentrations, and chlorophyll concentrations were decreased more than carotenoid concentrations. Iron deficiency resulted in an 8% decrease in the dark-adapted efficiency of photosystem II and a 43% decrease in efficiency of photosystem II at steady-state photosynthesis. No major root morphological changes were observed in seedlings grown without Fe, although seedlings grown in Fe-deficient nutrient solution had light-colored roots in contrast to the dark brown color of control roots.
10.1093/treephys/21.18.1335
Keywords: Fe deficiency; ferric chelate reductase; plant nutrition; rhizosphere acidification.

Characterization of the responses of cork oak (Quercus suber) to iron deficiency - Gogorcena, Yolanda; Molias, Nuria; Larbi, Ajmi; Abadía, Javier; Abadía, Anunciación (Tree Physiology, 2001)
We studied responses of cork oak (Quercus suber L.) to iron (Fe) deficiency by comparing seedlings grown hydroponically in nutrient solution with and without Fe. Seedlings grown without Fe developed some responses typical of the Strategy I group of Fe-efficient plants, including two- and fourfold increases in plasma membrane ferric chelate reductase activity of root tips after 2 and 4 weeks of culture in the absence of Fe, respectively. Moreover, seedlings grown hydroponically for 2 weeks without Fe caused marked decreases in the pH of the nutrient solution, indicating that root plasma membrane ATPase activity was induced by Fe deficiency. Iron deficiency also caused marked decreases in leaf chlorophyll and carotenoid concentrations, and chlorophyll concentrations were decreased more than carotenoid concentrations. Iron deficiency resulted in an 8% decrease in the dark-adapted efficiency of photosystem II and a 43% decrease in efficiency of photosystem II at steady-state photosynthesis. No major root morphological changes were observed in seedlings grown without Fe, although seedlings grown in Fe-deficient nutrient solution had light-colored roots in contrast to the dark brown color of control roots.
10.1093/treephys/21.18.133510.1093/treephys/21.18.1335
Keywords: Fe deficiency; ferric chelate reductase; plant nutrition; rhizosphere acidification.

Comportement physiologique des glands de chêne liège (Quercus suber L.) durant leur conservation et variabilité inter-individus producteurs - Merouani, Hachemi; Branco, Carmen; Almeida, Maria Helena; Pereira, João S. (Ann. For. Sci., 2001)
The mature acorns were harvested on twelve selected trees from a cork oak population in Southern Portugal (Herdade da Palma). After drying, the seed lots were stored on three types bags (polyethylene with 30 mm and 50 mm thick and plastic mesh), for six months at 0 oC. At the time of natural dissemination, the acorns from the majority of the trees from the same population were under the same state of morphological and physiological maturity. The moisture content was about 44-47% and a germination rate above 92% . At this time, the germination was very slow because of the existent embryonic dormancy that seems to be dependent on the individual trees. During the storage, germination rate is improved. This might be explained by the breaking dormancy during storage. The mean germination time was on an average 10 days for fresh seeds and decreased to about 4 days after 6 months storage. A relationship between viability and seed moisture content was observed. The Mean Germination Time of dried seed and stored seed for 4 months in plastic mesh bag increased to about 13 days. The germination capacity was strongly decreased when the seed moisture content was below 30%
Keywords: electrolyte leakage; germination; Moisture content; Quercus suber; seed; storage

Comportement physiologique des glands de chêne liège (Quercus suber L.) durant leur conservation et variabilité inter-individus producteurs - Merouani, Hachemi; Branco, Carmen; Almeida, Maria Helena; Pereira, João S (Ann. For. Sci., 2001)
The mature acorns were harvested on twelve selected trees from a cork oak population in Southern Portugal (Herdade da Palma). After drying, the seed lots were stored on three types bags (polyethylene with 30 mm and 50 mm thick and plastic mesh), for six months at 0 oC. At the time of natural dissemination, the acorns from the majority of the trees from the same population were under the same state of morphological and physiological maturity. The moisture content was about 44-47% and a germination rate above 92% . At this time, the germination was very slow because of the existent embryonic dormancy that seems to be dependent on the individual trees. During the storage, germination rate is improved. This might be explained by the breaking dormancy during storage. The mean germination time was on an average 10 days for fresh seeds and decreased to about 4 days after 6 months storage. A relationship between viability and seed moisture content was observed. The Mean Germination Time of dried seed and stored seed for 4 months in plastic mesh bag increased to about 13 days. The germination capacity was strongly decreased when the seed moisture content was below 30%
Keywords: electrolyte leakage; germination; Moisture content; Quercus suber; seed; storage

DEFOLIADORES DE ENCINAR EN EL ANDÉVALO OCCIDENTAL DE LA PROVINCIA DE HUELVA. COMPARACIÓN ENTRE DOS SITUACIONES PUNTUALES: EL PERIODO 1985-1988 Y EL AÑO 2000 - Granados, C; Ramírez, D; Sánchez, I; López, G; Vázquez, E (III Congreso Forestal Español, 2001)
The great economic and ecological importance of holm oak (Quercus ilex L.) in Spain makes necessary to study the presence and repercussion of leaf-damaging insects in holm oak forests. The field study has been carried out in “Los Millares”, one property of Andévalo Occidental (southern Spain, Andalusia, Huelva). This zone was chosen for two reasons: the existence of previous data about the presence and evolution of leaf-damaging insects during the period 1985-1988, fruit of the work of F.J. Toimil and collaborators; as well as the certainty that this year the population of this insects was very high. The results showed that Tortrix viridana, Archips xylosteana, Periclista andrei and, on a smaller scale, Catocala nynphagoga y Dryobotodes eremita constitute at the moment the main leaf-damaging insects, representing more than 87% of the leaf-damaging found. This population can cause big damages in the holm oak forests, with important economic and ecological losses
Keywords: Andévalo; Huelva; leaf-damaging Quercus ilex; Tortrix viridana

A dendroclimatological approach to diameter growth in adult cork-oak trees under production - Costa, A.; Pereira, H.; Oliveira, A. (Trees, 2001)
The diameter growth of mature cork oaks under cork production in southwestern Portugal was studied during a 9-year cork-production cycle in relation to fluctuations in precipitation and temperature, and to drought indices combining the two variables. A dendroclimatological approach was applied to the series of 8 complete years contained in the cork-production cycle and growth effects were removed by standardization and calculation of annual growth indices. The most important factor positively influencing diameter growth was cumulative precipitation in the growing season (January–June) and in the previous autumn and winter (October/November of the previous year–June). The monthly temperature is a less influential factor, negatively correlated with diameter growth in high summer drought (August) and positively correlated at the beginning of physiological activity (March).
Keywords: climatic fluctuations; dendroclimatology; diameter growth; Mediterranean climate; Quercus suber L.

DETERMINACIÓN DE ROTACIONES ÓPTIMAS EN LA APLICACIÓN DE RESALVEOS DE CONVERSIÓN A MONTE ALTO EN TALLARES DE ENCINA Y DE QUEJIGO EN LA ZONA CENTRAL DE LA PENÍNSULA IBÉRICA. - BRAVO, J. A.; SÁNCHEZ, I.; SERRADA, R. (III Congreso Forestal Español, 2001)
Conversion thinning seems to be a good option for most of the coppicce forests of holm oak and gall oak, where the lack of management is causing severe problems. Intensity and rotation of thinning are the two main parameters to be studied. This paper deals with the second one. Six coppicce forests of holm oak and two for gall oak in the Guadalajara province where selected. Those stands had been thinned in a known date, and have been compared with near control stands, which have not been thinned in the past. Diameter growth after thinning has been studied throught rings count and ring width measurement in both kind of stands. 129 trees of holm oak and 79 trees of gall oak have been studied. The main conclusions are the evidence of a significant growth of diameter in holm oaks that is present 11 years after the thinning, while in gall oak results are not so clear. In gall oak just one site showed a positive answer to thinning, that was present until 17 years after. K.W.:
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español issue: 1 pub-location: Granada
Keywords: conversion thinning; coppicce forest; gall oak; Growth; Holm oak; rotation

DETERMINACIÓN DE ROTACIONES ÓPTIMAS EN LA APLICACIÓN DE RESALVEOS DE CONVERSIÓN A MONTE ALTO EN TALLARES DE ENCINA Y DE QUEJIGO EN LA ZONA CENTRAL DE LA PENÍNSULA IBÉRICA. - BRAVO, J A; Sánchez, I; Serrada, R (III Congreso Forestal Español, 2001)
Conversion thinning seems to be a good option for most of the coppicce forests of holm oak and gall oak, where the lack of management is causing severe problems. Intensity and rotation of thinning are the two main parameters to be studied. This paper deals with the second one. Six coppicce forests of holm oak and two for gall oak in the Guadalajara province where selected. Those stands had been thinned in a known date, and have been compared with near control stands, which have not been thinned in the past. Diameter growth after thinning has been studied throught rings count and ring width measurement in both kind of stands. 129 trees of holm oak and 79 trees of gall oak have been studied. The main conclusions are the evidence of a significant growth of diameter in holm oaks that is present 11 years after the thinning, while in gall oak results are not so clear. In gall oak just one site showed a positive answer to thinning, that was present until 17 years after. K.W.:
Keywords: conversion thinning; coppicce forest; gall oak; Growth; Holm oak; rotation

Diaspore bank of bryophytes in the holm oak ecosystem of the Bois d'Astros in Vidauban (Var, France) - Hebrard, J P (NOVA HEDWIGIA, 2001)
Cultivation for 4 months, under controlled conditions, of 22 core samples of soils (from the surface down to 3-4 cm depth) from each of the 3 stages of the dynamics of the holm oak (Quercus ilex L.) ecosystem at the bois d'Astros, near Vidauban (Var), shows that the edaphic diaspore bank of bryophytes is about as rich in species as the surface communities at the boring points (surface/soil bank, holm oak forest: 8/8 species, Rosmarinus garrigue: 15111, Brachypodium phoenicoides lawn: 11/12). It consists mainly of mosses, 50 to 58% of which are found only in the soil. Among these, the presence of oligotrophic species of open habitats (Trichostomum brachydontium, Philonotis arnellii, Funaria grex muehlenbergii and the liverwort Riccia sorocarpa) that occur below ground in the Quercus ilex forest is remarkable, whereas soil cores from the,garrigue and the lawn have given Bryum radiculosum and Pseudocrossidium hornschuchianum which, like the 4 preceding taxa, are lacking in the above ground inventories (surface: 100 m(2)) carried out on the site in the holm oak ecosystem. Our results confirm that the proportion of acrocarpous mosses belonging to the colonist life strategy tends to be more important below than above ground, whereas the reverse is true for pleurocarpous perennials. There is also an increase in the percentage of colonists present in the soil, when passing from the forest to the garrigue and the lawn.
Keywords: bryophytes; diaspore bank; Provence; Quercus ilex

Differential success in northwards range expansion between ecotypes of the marble gallwasp Andricus kollari: a tale of two lifecycles - Stone, G.; Atkinson, R.; Rokas, A.; Csoka, G.; Nieves-Aldrey, J. L.; Csoka, G.; Nieves-Aldrey, J. L. (MOLECULAR ECOLOGY, 2001)
The Marble gallwasp Andricus kollari has a native range divided into two geographically separated lifecycles. In Eastern Europe and Turkey, the lifecycle involves a sexual generation on Turkey oak, Quercus cerris, while in Iberia and North Africa the sexual generation host is cork oak, Q. suber. Over the last 500 years, A. kollari has expanded its range into northern Europe, following human planting of Q. cem's from Italy and the Balkans. We ask: (i) what is the genetic relationship between eastern and western distributions of Andricus kollari? Can we determine which lifecycle is ancestral, and how long ago they diverged? (ii) To what extent have eastern and western native ranges contributed to northwards range expansion? (iii) Is there any evidence for hybridization between the two life cycle types? We present analyses of allozyme data for 13 polymorphic loci and of sequence variation for a 433 bp fragment of the mitochondrial cytochrome b gene. These show: (i) that four haplotype lineages (one in Spain, two in Hungary/Italy and one in Turkey) diverged more or less simultaneously between 1 and 2 million years ago, suggesting the existence of at least four refuges through recent ice age cycles. Our data cannot resolve which lifecycle type is ancestral. (ii) Populations north of putative refuges are divided into two sets. Populations in south-west France are allied to Spain, while ail remaining populations in northern Europe have been colonized from Italy and the Balkans. (iii) The transition from one race to another in south-west France is marked by abrupt transitions in the frequency of refuge-specific private alleles and corresponds closely to the northern limit of the distribution of cork oak. Although hybrids were detected in north-west France, none were detected where the two lifecycles meet in south-western France. The biology of oak gallwasps predicts that any hybrid zone will be narrow and limited to regions where Q. cem's and Q. suber meet. Our data suggest that eastern and western A. kollari are effectively separate species.
From Duplicate 2 (Differential success in northwards range expansion between ecotypes of the marble gallwasp Andricus kollari: a tale of two lifecycles - Stone, G; Atkinson, R; Rokas, A; Csoka, G; Nieves-Aldrey, J L)From Duplicate 2 (Differential success in northwards range expansion between ecotypes of the marble gallwasp Andricus kollari: a tale of two lifecycles - Stone, G; Atkinson, R; Rokas, A; Csoka, G; Nieves-Aldrey, J L)The following values have no corresponding Zotero field: pub-location: COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA publisher: WILEY-BLACKWELL accession-num: 11298986
Keywords: Alleles; Andricus; Animals; Base Sequence; Cellulose Acetate; Cytochrome b Group; Cytochrome b Group: chemistry; Cytochrome b Group: genetics; DNA; Electrophoresis; Environment; EUROPE; Evolution; Female; gallwasp; Genetic Variation; Genetic Variation: physiology; glacial refugia; host race; Hymenoptera; Hymenoptera: genetics; Hymenoptera: growth & development; Hymenoptera: physiology; invasion; Life Cycle Stages; Mitochondrial; Mitochondrial: chemistry; Mitochondrial: isolation & purification; Molecular; Molecular Sequence Data; Parthenogenesis; phylogeny; Polymerase Chain Reaction; range expansion; Sequence Alignment; Sequence Analysis

Differential success in northwards range expansion between ecotypes of the marble gallwasp Andricus kollari: a tale of two lifecycles - Stone, G; Atkinson, R; Rokas, A; Csoka, G; Nieves-Aldrey, J L; Csoka, G; Nieves-Aldrey, J L (MOLECULAR ECOLOGY, 2001)
The Marble gallwasp Andricus kollari has a native range divided into two geographically separated lifecycles. In Eastern Europe and Turkey, the lifecycle involves a sexual generation on Turkey oak, Quercus cerris, while in Iberia and North Africa the sexual generation host is cork oak, Q. suber. Over the last 500 years, A. kollari has expanded its range into northern Europe, following human planting of Q. cem's from Italy and the Balkans. We ask: (i) what is the genetic relationship between eastern and western distributions of Andricus kollari? Can we determine which lifecycle is ancestral, and how long ago they diverged? (ii) To what extent have eastern and western native ranges contributed to northwards range expansion? (iii) Is there any evidence for hybridization between the two life cycle types? We present analyses of allozyme data for 13 polymorphic loci and of sequence variation for a 433 bp fragment of the mitochondrial cytochrome b gene. These show: (i) that four haplotype lineages (one in Spain, two in Hungary/Italy and one in Turkey) diverged more or less simultaneously between 1 and 2 million years ago, suggesting the existence of at least four refuges through recent ice age cycles. Our data cannot resolve which lifecycle type is ancestral. (ii) Populations north of putative refuges are divided into two sets. Populations in south-west France are allied to Spain, while ail remaining populations in northern Europe have been colonized from Italy and the Balkans. (iii) The transition from one race to another in south-west France is marked by abrupt transitions in the frequency of refuge-specific private alleles and corresponds closely to the northern limit of the distribution of cork oak. Although hybrids were detected in north-west France, none were detected where the two lifecycles meet in south-western France. The biology of oak gallwasps predicts that any hybrid zone will be narrow and limited to regions where Q. cem's and Q. suber meet. Our data suggest that eastern and western A. kollari are effectively separate species.
From Duplicate 2 (Differential success in northwards range expansion between ecotypes of the marble gallwasp Andricus kollari: a tale of two lifecycles - Stone, G; Atkinson, R; Rokas, A; Csoka, G; Nieves-Aldrey, J L)
Keywords: Alleles; Andricus; Animals; Base Sequence; Cellulose Acetate; Cytochrome b Group; Cytochrome b Group: chemistry; Cytochrome b Group: genetics; DNA; Electrophoresis; Environment; EUROPE; Evolution; Female; gallwasp; Genetic Variation; Genetic Variation: physiology; glacial refugia; host race; Hymenoptera; Hymenoptera: genetics; Hymenoptera: growth & development; Hymenoptera: physiology; invasion; Life Cycle Stages; Mitochondrial; Mitochondrial: chemistry; Mitochondrial: isolation & purification; Molecular; Molecular Sequence Data; Parthenogenesis; phylogeny; Polymerase Chain Reaction; range expansion; Sequence Alignment; Sequence Analysis

EARLY CHECKING OF GENETIC STABILITY OF CORK OAK SOMATIC EMBRYOS BY AFLP ANALYSIS. - Hornero, J; Martinez, I; CELESTINO, C; Gallego, F J; Torres, V; TORIBIO, M (International Journal of Plant Sciences, 2001)
Early checking of the genetic stability, of tissue culture-derived plants is necessary to obtain all the potential benefits of clonal forestry. Previous work in Quercus suber L. using random amplified polymorphic DNA (RAPD) markers showed no genetic variation among somatic embryos within embryogenic lines of zygotic origin. Genetic fingerprinting based on amplified fragment length polymorphisms (AFLP) allows the direct analysis of variation at the entire DNA level by generating more reproducible markers than RAPDs. To confirm the absence of genetic variation within six embryogenic lines of zygotic origin, six primer pairs were selected out of 48 combinations of primers for revealing up to 512 AFLP markers, 301 of them (58.8%) being polymorphic. The mean number of markers per genotype was 375. Again differences were recorded among embryogenic lines, even between those that arose from half-sib zygotic embryos, but no variation was observed among somatic embryos within embryogenic lines. To check variation in embryogenic lines raised from non-embryonic tissues, somatic embryogenesis was induced in expanding leaves collected from sprouts originating in three mature cork oak. DNA was extracted from leaves and from somatic embryos derived from each tree, and three primer pairs showed 165, 110, and 108 markers per genotype/tree, respectively. In one tree, AFLP patterns generated from leaves and somatic embryos were identical, but variation was detected in samples from the other two trees. Although the level of genetic variation detected in these lines (5.6% and 7.3% of polymorphism, respectively) is lower than that recorded for half sibs of cork oak (25%–31%), its influence on phenotypic variation needs further assessment. [ABSTRACT FROM AUTHOR]
Keywords: AFLP; Cork oak; DNA markers; in vitro culture; Quercus suber; somaclonal variation; Somatic embryogenesis

EARLY CHECKING OF GENETIC STABILITY OF CORK OAK SOMATIC EMBRYOS BY AFLP ANALYSIS. - Hornero, J.; Martinez, I.; Celestino, C.; Gallego, F. J.; Torres, V.; Toribio, M. (International Journal of Plant Sciences, 2001)
Early checking of the genetic stability, of tissue culture-derived plants is necessary to obtain all the potential benefits of clonal forestry. Previous work in Quercus suber L. using random amplified polymorphic DNA (RAPD) markers showed no genetic variation among somatic embryos within embryogenic lines of zygotic origin. Genetic fingerprinting based on amplified fragment length polymorphisms (AFLP) allows the direct analysis of variation at the entire DNA level by generating more reproducible markers than RAPDs. To confirm the absence of genetic variation within six embryogenic lines of zygotic origin, six primer pairs were selected out of 48 combinations of primers for revealing up to 512 AFLP markers, 301 of them (58.8%) being polymorphic. The mean number of markers per genotype was 375. Again differences were recorded among embryogenic lines, even between those that arose from half-sib zygotic embryos, but no variation was observed among somatic embryos within embryogenic lines. To check variation in embryogenic lines raised from non-embryonic tissues, somatic embryogenesis was induced in expanding leaves collected from sprouts originating in three mature cork oak. DNA was extracted from leaves and from somatic embryos derived from each tree, and three primer pairs showed 165, 110, and 108 markers per genotype/tree, respectively. In one tree, AFLP patterns generated from leaves and somatic embryos were identical, but variation was detected in samples from the other two trees. Although the level of genetic variation detected in these lines (5.6% and 7.3% of polymorphism, respectively) is lower than that recorded for half sibs of cork oak (25%–31%), its influence on phenotypic variation needs further assessment. [ABSTRACT FROM AUTHOR]
Keywords: AFLP; Cork oak; DNA markers; in vitro culture; Quercus suber; somaclonal variation; Somatic embryogenesis

Efecto de la inoculación de cuatro bacterias promotoras del crecimiento vegetal sobre parámetros biométricos aéreos de plántulas de QUERCUS ILEX SSP.BALLOTA B. - Ramos, B.; Lucas García, J. A.; Santamaría, C.; Camacho, M.; Daza, A.; García, J. A. Lucas (III Congreso Forestal Español Congreso, 2001)
In the present work has studied the effect of four plant growth-promoting rhizobacteria (PGPRs) on growth of holm-oak plants (Quercus ilex ssp. ballota) in nursery before transplanting. The four strains assayed show in vitro metabolic capacities related with their action PGPR. All strains were able to increase significantly some parameters studied (high, diameter neck and dry weight). However, in the first sampling time (T1) only the strains Aur 6 and Aur 9 increased the high of the plants. In the last sampling time (T3) all strains increased the high, only Aur 6 increased the diameter neck and Cell 3, Aur 6 and Aur 9 increased the dry weight. It is important to point out that Aur 6 and Aur 9 increased the high and also the dry weight, this show that these strains enhance the general metabolism of the plants and also enhance the nutritional capacity and as a result the plants are more robust and with a better adaptative capacity.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español Congreso issue: 1 pub-location: Granada
Keywords: adaptative capacity; colonization; PGPR; Quercus ilex ssp. ballota

Efecto de la inoculación de cuatro bacterias promotoras del crecimiento vegetal sobre parámetros biométricos aéreos de plántulas de QUERCUS ILEX SSP.BALLOTA B. - Ramos, B; Lucas García, J A; Santamaría, C; Camacho, M; Daza, a; García, J A Lucas (III Congreso Forestal Español Congreso, 2001)
In the present work has studied the effect of four plant growth-promoting rhizobacteria (PGPRs) on growth of holm-oak plants (Quercus ilex ssp. ballota) in nursery before transplanting. The four strains assayed show in vitro metabolic capacities related with their action PGPR. All strains were able to increase significantly some parameters studied (high, diameter neck and dry weight). However, in the first sampling time (T1) only the strains Aur 6 and Aur 9 increased the high of the plants. In the last sampling time (T3) all strains increased the high, only Aur 6 increased the diameter neck and Cell 3, Aur 6 and Aur 9 increased the dry weight. It is important to point out that Aur 6 and Aur 9 increased the high and also the dry weight, this show that these strains enhance the general metabolism of the plants and also enhance the nutritional capacity and as a result the plants are more robust and with a better adaptative capacity.
Keywords: adaptative capacity; colonization; PGPR; Quercus ilex ssp. ballota

Efecto de las inyecciones de fosfonato potásico en tronco de encina (QUERCUS ILEX SUBSP. BALLOTA) SOBRE EL CRECIMIENTO DE RAMILLAS Y LA FRUCTIFICACIÓN. - CORDÓN, S.; BRAVO, V.; Tapias, R.; Lopez, G.; SÁNCHEZ, I. (III Congreso Forestal Español, 2001)
The present communication intends to see the answer of the oaks (Quercus ilex subsp. ballota) treateds using antifungal materials (potassium phosphonate) injections to the trunk. In the first year, has been measured the growth of the buds and the production of acorns of three treated oaks and other three not treated, in one property of the Western Andévalo (Andalusia, Huelva).
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: Andévalo; Huelva; Quercus ilex; trunk injections

Efecto de las inyecciones de fosfonato potásico en tronco de encina (QUERCUS ILEX SUBSP. BALLOTA) SOBRE EL CRECIMIENTO DE RAMILLAS Y LA FRUCTIFICACIÓN. - CORDÓN, S; BRAVO, V; TAPIAS, R; López, G; Sánchez, I (III Congreso Forestal Español, 2001)
The present communication intends to see the answer of the oaks (Quercus ilex subsp. ballota) treateds using antifungal materials (potassium phosphonate) injections to the trunk. In the first year, has been measured the growth of the buds and the production of acorns of three treated oaks and other three not treated, in one property of the Western Andévalo (Andalusia, Huelva).
Keywords: Andévalo; Huelva; Quercus ilex; trunk injections

The effect of cork removal on the radial growth and phenology of young cork oak trees - Fialho, C.; Lopes, F.; Pereira, H. (Forest Ecology and Management, 2001)
The effect of the removal of cork was studied in 11-years old cork oak trees (Quercus suber L.), growing in favorable conditions, in relation to phenology and radial growth during two years. Longevity of leaves was 14±15 months (1996, 1998) and 10 months (1997). Bud burst started in mid-February and leaf ¯ushing in April, extending until June. Neither a distinct two-period ¯ushing nor an autumn bud burst or leaf ¯ushing were observed. Radial growth started in mid-April and continued until the end of November, with the maximum growth in June and July. In trees with the removal of cork, leaf abscission occurred a little earlier and new branches had on average 23% fewer new leaves. The radial growth of the trees and its general seasonal pattern were not affected by cork removal in the year of removal or in the year after. The only observation was a shift of the maximum radial growth rate from June to July for the trees where cork had been removed
Keywords: cork removal; cork-oak; Phenology; Quercus suber; Radial growth

The effect of cork removal on the radial growth and phenology of young cork oak trees - Fialho, C; Lopes, F; Pereira, H (Forest Ecology and Management, 2001)
The effect of the removal of cork was studied in 11-years old cork oak trees (Quercus suber L.), growing in favorable conditions, in relation to phenology and radial growth during two years. Longevity of leaves was 14±15 months (1996, 1998) and 10 months (1997). Bud burst started in mid-February and leaf ¯ushing in April, extending until June. Neither a distinct two-period ¯ushing nor an autumn bud burst or leaf ¯ushing were observed. Radial growth started in mid-April and continued until the end of November, with the maximum growth in June and July. In trees with the removal of cork, leaf abscission occurred a little earlier and new branches had on average 23% fewer new leaves. The radial growth of the trees and its general seasonal pattern were not affected by cork removal in the year of removal or in the year after. The only observation was a shift of the maximum radial growth rate from June to July for the trees where cork had been removed
Keywords: cork removal; cork-oak; Phenology; Quercus suber; Radial growth

Effects of acorn storage duration and parental tree on emergence and physiological status of Cork oak (Quercus suber L.) seedlings - Merouani, Hachemi; Branco, Carmen; Almeida, Maria Helena; Pereira, João S (Ann. For. Sci., 2001)
This study was conducted to evaluate how parental trees and seed storage duration influenced subsequent seedling physiological status and growth. Seedling emergence rate was higher than 90% independently of the duration of seed storage or parental trees. Seed storage shortened significantly the time and increased the uniformity of seedling emergence. Consequently, the delayed seedling emergence from fresh seeds could be explained by epicotyl dormancy. Seed size varied with parental tree. Seedling growth rate was greatly affected by seed size, independently of storage treatment. Seedlings originating from large seeds (> 5 g) had the fastest growth rates and seedlings from the smallest seeds (< 4 g) had the slowest. Final shoot height, however, depended on the duration of seed storage. The seed size and the duration of storage had a great effect on the initial rate of leaf production, but did not affect the final number of leaves. Leaf chlorophyll concentration was reduced as the duration of seed storage increased but was independent of parental tree (i.e., seed size). Seedling biomass was positively related to seed size. The duration of seed storage reduced the shoot/root ratio, but no significant effect was observed among parental trees. The shoot/root value of seedlings from stored seed was about 1.5 and the one of seedlings from fresh seed was about 2.
Keywords: Quercus suber; root radio; Seed size; seed storage; seedling growth; shoot

Effects of acorn storage duration and parental tree on emergence and physiological status of Cork oak (Quercus suber L.) seedlings - Merouani, Hachemi; Branco, Carmen; Almeida, Maria Helena; Pereira, João S. (Ann. For. Sci., 2001)
This study was conducted to evaluate how parental trees and seed storage duration influenced subsequent seedling physiological status and growth. Seedling emergence rate was higher than 90% independently of the duration of seed storage or parental trees. Seed storage shortened significantly the time and increased the uniformity of seedling emergence. Consequently, the delayed seedling emergence from fresh seeds could be explained by epicotyl dormancy. Seed size varied with parental tree. Seedling growth rate was greatly affected by seed size, independently of storage treatment. Seedlings originating from large seeds (> 5 g) had the fastest growth rates and seedlings from the smallest seeds (< 4 g) had the slowest. Final shoot height, however, depended on the duration of seed storage. The seed size and the duration of storage had a great effect on the initial rate of leaf production, but did not affect the final number of leaves. Leaf chlorophyll concentration was reduced as the duration of seed storage increased but was independent of parental tree (i.e., seed size). Seedling biomass was positively related to seed size. The duration of seed storage reduced the shoot/root ratio, but no significant effect was observed among parental trees. The shoot/root value of seedlings from stored seed was about 1.5 and the one of seedlings from fresh seed was about 2.
Keywords: Quercus suber; root radio; Seed size; seed storage; seedling growth; shoot

EL SÍNDROME DE LA SECA EN MASAS DE QUERCUS SPP. EN ANDALUCÍA. - Navarro Cerrillo, Rafael Mª; Fernández Rebollo, Pilar; Ruiz Navarro, José; Vidiella Salaberry, Álvaro (III Congreso Forestal Español, 2001)
In Andalucia, the syndrome known as seca has weakened the Quercus forests with the following appearance of the syndrome’s spots in all its provinces. In order to determine the actual situation of the syndrome in the region a census of the damages caused by the seca has been elaborated. The information obtained from this census has made possible a territorial analysis of the damages in Andalucia that can be useful to define a biogeography of the seca, from a fitoclimatic or causal agents point of view. The interpretation of the information has made possible to characterize three large areas with similar characteristics concerning the syndrome’s incidence: Sierra Morena, the Cadiz-Malaga western sierra and the oriental region of Andalucia. In Sierra Morena and the Cadiz-Malaga western sierra the damages follow a pattern characterized by small to medium sized spots, with a medium to high percentage of affected trees, distributed in a random pattern, and dominance of gradual death of the trees. This reveals the progressive weakening of the forests, probably associated to the region’s tendency towards more arid fitoclimates. However, the Cadiz-Malaga western sierra differentiates due to the hi presence of cork trees (Quercus suber), that adds the cork harvesting practices, origin of many direct and indirect damages, to the incidence of the climatic factors. In the oriental region of Andalucia the pattern of damages differentiates in having larger spots, with a higher percentage of sudden death of trees, and distributed in areas with low water retention soils or where a high thermal accumulation is expected. In this case, the tendency towards more arid fitoclimates is more accented, with a higher incidence of heat-strokes
Keywords: agentes causales; andalucía (voyant); daños; seca

ESTADO ACTUAL Y PROPUESTAS DE GESTIÓN DEL ALCORNOCAL EN MONTES DEL P.N. LOS ALCORNOCALES (CÁDIZ) - Linares, L.; Fariña, J. Mª (III Congreso Forestal Español, 2001)
First it’s analyzed the actual situation of Sierras del Aljibe and Campo de Gibraltar cork-oaks; afterwards are made different managment proposals for the future conservation and improvement of this forest.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: managment proposals; oak desease; Quercus suber

Estado hídrico y demanda de fotosintesis de Quercus ilex, Quercus faginea y Pinus halepensis MICORRIZADOS ARTIFICIALMENTE CON Tuber melanosporum EN VIVERO - DOMÍNGUEZ, J A; R. PLANELLES; RODRÍGUEZ BARREAL, J A; SAÍZ DE OMEÑACA, J A; ZAZO, J; TEYSSIERE, M; MARTINEZ, G; PINAZO, O (III Congreso Forestal Español Congreso, 2001)
We have been carried out a periodic control in Quercus ilex, Quercus faginea and Pinus halepensis inoculated with Tuber melanosporum Vitt. during the first year of growth in nursery with a water-non stressed régime; in all the species, the minimum water potential and transpiration rate didn't reflect any differences for the treatment, but in some cases, the photosynthesis rate was major in inoculated seedlings. K.W.:
Keywords: ectomycorrhiza; photosynthesis; Pinus halepensis; Quercus faginea; Quercus ilex; Tuber

Estado hídrico y demanda de fotosintesis de Quercus ilex, Quercus faginea y Pinus halepensis MICORRIZADOS ARTIFICIALMENTE CON Tuber melanosporum EN VIVERO - DOMÍNGUEZ, J. A.; R. PLANELLES; RODRÍGUEZ BARREAL, J. A.; SAÍZ DE OMEÑACA, J. A.; ZAZO, J.; TEYSSIERE, M.; MARTINEZ, G.; PINAZO, O. (III Congreso Forestal Español Congreso, 2001)
We have been carried out a periodic control in Quercus ilex, Quercus faginea and Pinus halepensis inoculated with Tuber melanosporum Vitt. during the first year of growth in nursery with a water-non stressed régime; in all the species, the minimum water potential and transpiration rate didn't reflect any differences for the treatment, but in some cases, the photosynthesis rate was major in inoculated seedlings. K.W.:
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español Congreso pub-location: Granada
Keywords: ectomycorrhiza; photosynthesis; Pinus halepensis; Quercus faginea; Quercus ilex; Tuber

ESTRUCTURA Y EVOLUCIÓN DE DOS MASAS MIXTAS DE FRONDOSAS PROCEDENTES DE UN ANTIGUO MONTE ADEHESADO - Hermosilla, D; Pardo, F; Gil, L; Pardos, J A (III Congreso Forestal Español Congreso, 2001)
The presence of an important number of deciduous Central European species in Hayedo de Montejo makes it to be considered a singular place in Madrid. Past traditional practices conditioned the present characteristics of this forest. Two mixed deciduous stands were chosen for its study, both formed by a stratum of old-growth trees and another made up of poles. A vegetation inventory was made around twenty old-growth trees. The influence in the structure and evolution of the stand composed by poles was studied. The species of old-growth tree and the distance were relevant on the structure of the stand grown around them.
Keywords: competition; open wood; shade tolerance

Estudio de la influencia de la fertilizacion nitrogenada y la iluminacion sobre atributos morfologicos y fisiologicos de brinzales de Q.suber L. CULTIVADO EN VIVERO. RESULTADOS DEL 1er. AÑO EN CAMPO - Martínez Romero, G.; Planelles González, R.; Zazo Muncharaz, J.; Bela Quero, D.; Vivar Sanz, A.; López Arias, M. (III Congreso Forestal Español Congreso, 2001)
This essay studies the influence of fertilization and illumination of Q.suber L. in container seedlings. Plants were tested in three diferents levels of fertilization (control substrate, fertilizated substrate and fertilizated substrate plus nitrogen supplied) with two of illumination (full light conditions and a reduction of 50% illumination). After the first year in nursery, plants was installed in survey parcels, where growing measures and survival rates were studied
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español Congreso pub-location: Granada
Keywords: Cork oak; fertilization; ilumination; Quercus suber L.

Estudio de la influencia de la fertilizacion nitrogenada y la iluminacion sobre atributos morfologicos y fisiologicos de brinzales de Q.suber L. CULTIVADO EN VIVERO. RESULTADOS DEL 1er. AÑO EN CAMPO - Martínez Romero, G; Planelles González, R; Zazo Muncharaz, J; Bela Quero, D; Vivar Sanz, A; López Arias, M (III Congreso Forestal Español Congreso, 2001)
This essay studies the influence of fertilization and illumination of Q.suber L. in container seedlings. Plants were tested in three diferents levels of fertilization (control substrate, fertilizated substrate and fertilizated substrate plus nitrogen supplied) with two of illumination (full light conditions and a reduction of 50% illumination). After the first year in nursery, plants was installed in survey parcels, where growing measures and survival rates were studied
Keywords: Cork oak; fertilization; ilumination; Quercus suber L.

Etiología de las podredumbres radicales de plántulas de QUERCUS SPP. Y PINUS HALEPENSIS EN VIVEROS FORESTALES DE ANDALUCÍA - Andicoberry, S.; LORA, F.; SÁNCHEZ, E.; Trapero, A. (III Congreso Forestal Español, 2001)
A disease surey carried out during 1998-99 showed that holm oak (Quercus ilex) and Aleppo pine (Pinus halepensis) seedlings were affected by damping-off and root rot in three forest nurseries in Andalucía, southern Spain. A similar problem was detected affecting four species of Quercus (Q. coccinea, Q. faginea, Q. ilex, and Q. suber) in a forest nursery in 2000. Three species of Phytophthora (P. cinnamomi, P. cryptogea, and P. drechsleri) were isolated from holm oak feeder roots, and P. drechsleri was isolated from feeder roots of Aleppo pine in the first survey in 1998-99. In the second survey, Cylindrocarpon didymum was isolated from the feeder roots of the four Quercus spp. essayed, and C. destructans was isolated only from Q. faginea. Pathogenicity tests were conducted using 1 year-old healthy plants of cork oak, holm oak and Aleppo pine. Isolates of the three Phytophthora species were pathogenic to the three host species, inducing root rot and plant death. Holm oak was the most susceptible host and P. cinnamomi was the most virulent species. Isolates of Cylindrocarpon were pathogenic to cork oak and holm oak causing root rot, yellowing, defoliation, and plant death.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: Cylindrocarpon; Phytophthora; Quercus coccinea; Quercus faginea; Quercus ilex; Quercus suber

Etiología de las podredumbres radicales de plántulas de QUERCUS SPP. Y PINUS HALEPENSIS EN VIVEROS FORESTALES DE ANDALUCÍA - Andicoberry, S; LORA, F; SÁNCHEZ, E; TRAPERO, A (III Congreso Forestal Español, 2001)
A disease surey carried out during 1998-99 showed that holm oak (Quercus ilex) and Aleppo pine (Pinus halepensis) seedlings were affected by damping-off and root rot in three forest nurseries in Andalucía, southern Spain. A similar problem was detected affecting four species of Quercus (Q. coccinea, Q. faginea, Q. ilex, and Q. suber) in a forest nursery in 2000. Three species of Phytophthora (P. cinnamomi, P. cryptogea, and P. drechsleri) were isolated from holm oak feeder roots, and P. drechsleri was isolated from feeder roots of Aleppo pine in the first survey in 1998-99. In the second survey, Cylindrocarpon didymum was isolated from the feeder roots of the four Quercus spp. essayed, and C. destructans was isolated only from Q. faginea. Pathogenicity tests were conducted using 1 year-old healthy plants of cork oak, holm oak and Aleppo pine. Isolates of the three Phytophthora species were pathogenic to the three host species, inducing root rot and plant death. Holm oak was the most susceptible host and P. cinnamomi was the most virulent species. Isolates of Cylindrocarpon were pathogenic to cork oak and holm oak causing root rot, yellowing, defoliation, and plant death.
Keywords: Cylindrocarpon; Phytophthora; Quercus coccinea; Quercus faginea; Quercus ilex; Quercus suber

Evolução da paisagem de montado no Alentejo interior ao longo do século XX: dinâmica e incidências ambientais - Ferreira, D. Brum (Finisterra: Revista portuguesa de geografia, 2001)
EVOLUTION OF THE MONTADO LANDSCAPE IN THE INNER ALENTEJO DURING THE 20TH CENTURY. DYNAMICS AND ENVIRONMENTAL CONSEQUENCES – This paper presents the general context within which the montado landscape changed in the inner Alentejo during the 20th century as well as some of the environmental consequences, such as soil degradation and modification of the local climate. In large areas nowadays abandoned, the landscape dynamics depends more on environmental limitations created by soil degradation that on purely socio-economical factors.
Keywords: agricultural system; Agroforestry; climate modification; land use history; montado landscape; soil erosion

Evolução da paisagem de montado no Alentejo interior ao longo do século XX: dinâmica e incidências ambientais - Ferreira, D Brum (Finisterra: Revista portuguesa de geografia, 2001)
EVOLUTION OF THE MONTADO LANDSCAPE IN THE INNER ALENTEJO DURING THE 20TH CENTURY. DYNAMICS AND ENVIRONMENTAL CONSEQUENCES – This paper presents the general context within which the montado landscape changed in the inner Alentejo during the 20th century as well as some of the environmental consequences, such as soil degradation and modification of the local climate. In large areas nowadays abandoned, the landscape dynamics depends more on environmental limitations created by soil degradation that on purely socio-economical factors.
Keywords: agricultural system; Agroforestry; climate modification; land use history; montado landscape; soil erosion

Exchange of short-chain oxygenated volatile organic compounds (VOCs) between plants and the atmosphere: A compilation of field and laboratory studies - Kesselmeier, J (Journal of Atmospheric Chemistry, 2001)
Field and laboratory investigations of the exchange of the short-chain organic acids – formic acid and acetic acid – as well as their homologous aldehydes are discussed. Both acids are substantially released from several plant species. Emission measurements under ﬁeld conditions are compiled to give an overview of three years of measurements. Emission rates from several tree species were found in the range between zero and 60 nmoles m−2 min−1 for acetic acid and between zero and 90 nmoles m−2 min−1 for formic acid though also a deposition has been observed to orange trees. Investigations under laboratory conditions showed an order of magnitude lower emission rates with signiﬁcant differences under light and dark conditions, and a deposition was observed under certain conditions. Hence, low emission rates or even a bi-directional exchange, emission as well as deposition have to be taken into account. Further differences between ﬁeld and laboratory studies are discussed considering age of trees, stress effects and a potential production of acids by photochemical conversion of precursors inside enclosures during sampling. Field data on the exchange of formand acetaldehyde show a complex behavior. We found emission as well as uptake. The bi-directional exchange is signiﬁcantly triggered by the ambient mixing ratios of both aldehyde species and exhibits a compensation point. Further studies are needed for generalization of the exchange of these and potentially also for other compounds
Keywords: Acetaldehyde; acetic acid; biogenic deposition; Biogenic emission; carbonyls; compensation point; Formaldehyde; formic acid; organic acids; Volatile Organic Compounds

Factors affecting bird communities in fragments of secondary pine forests in the north-western Mediterranean basin - Brotons, L.; Herrando, S. (ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY, 2001)
We assessed the influence of size, extent of isolation and vegetation structure of secondary forest fragments on the richness and species composition of breeding bird communities in a sample of pine forest fragments surrounded by an agricultural matrix in the north-western Mediterranean basin. Fragment size was the main predictor of bird's occurrence, since it accounted for 70 % of the model variation. Isolation was also a valuable predictor of species occurrence, especially for forest specialists. Finally, subarboreal vegetation such as holm oak and a well-developed tree layer of large pines favoured forest species occurrence. Therefore, in spite of the long history of human impact, forest birds in Mediterranean mosaics are sensitive to both habitat loss and isolation of remnant patches in a similar manner to the patterns found in other temperate fragmented landscapes where human impact is more recent. (C) 2001 Editions scientifiques et medicales Elsevier SAS.
The following values have no corresponding Zotero field: pub-location: 23 RUE LINOIS, 75015 PARIS, FRANCE publisher: GAUTHIER-VILLARS/EDITIONS ELSEVIER
Keywords: birds; fragmentation; isolation; Mediterranean mosaics; vegetation structure

Factors affecting bird communities in fragments of secondary pine forests in the north-western Mediterranean basin - Brotons, L; Herrando, S (ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY, 2001)
We assessed the influence of size, extent of isolation and vegetation structure of secondary forest fragments on the richness and species composition of breeding bird communities in a sample of pine forest fragments surrounded by an agricultural matrix in the north-western Mediterranean basin. Fragment size was the main predictor of bird's occurrence, since it accounted for 70 % of the model variation. Isolation was also a valuable predictor of species occurrence, especially for forest specialists. Finally, subarboreal vegetation such as holm oak and a well-developed tree layer of large pines favoured forest species occurrence. Therefore, in spite of the long history of human impact, forest birds in Mediterranean mosaics are sensitive to both habitat loss and isolation of remnant patches in a similar manner to the patterns found in other temperate fragmented landscapes where human impact is more recent. (C) 2001 Editions scientifiques et medicales Elsevier SAS.
Keywords: birds; fragmentation; isolation; Mediterranean mosaics; vegetation structure

Fine-root longevity of Quercus ilex - López, B.; Sabate, S.; Gracia, C. A. (New Phytologist, 2001)
* • Fine-root longevity and phenology were studied in a Quercus ilex (holm oak) forest in Prades (NE Spain). Differences were investigated among roots that had appeared in different seasons and at different depth intervals, differentiating between white and brown roots. * • Using minirhizotrons installed in March 1994, 1211 roots were monitored every 3 wk from June 1994 to March 1997. * • Mean and median fine-root longevity were 125 ± 4 d and 67 d, respectively. Longevity of summer and winter roots was greater than that of spring and autumn roots. Although roots appeared and disappeared throughout the year, the rate of appearance was greatest in spring. Maximum longevity occurred at a soil depth of 20–30 cm. Differences among 10-cm depth intervals were due to the number of days that roots were brown, since roots remained white for a similar number of days, independent of soil depth. * • Temperate soil temperatures and lignotubers permitted the appearance of roots throughout the year. Holm oak fine roots might be more efficient during the first 50 d of their life before the white roots become less efficient brown roots.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: Fine root longevity; Holm oak; minirhizotron; Quercus ilex; vertical longevity pattern

Fine-root longevity of Quercus ilex - López, B; Sabate, S; Gracia, C A (New Phytologist, 2001)
* • Fine-root longevity and phenology were studied in a Quercus ilex (holm oak) forest in Prades (NE Spain). Differences were investigated among roots that had appeared in different seasons and at different depth intervals, differentiating between white and brown roots. * • Using minirhizotrons installed in March 1994, 1211 roots were monitored every 3 wk from June 1994 to March 1997. * • Mean and median fine-root longevity were 125 ± 4 d and 67 d, respectively. Longevity of summer and winter roots was greater than that of spring and autumn roots. Although roots appeared and disappeared throughout the year, the rate of appearance was greatest in spring. Maximum longevity occurred at a soil depth of 20–30 cm. Differences among 10-cm depth intervals were due to the number of days that roots were brown, since roots remained white for a similar number of days, independent of soil depth. * • Temperate soil temperatures and lignotubers permitted the appearance of roots throughout the year. Holm oak fine roots might be more efficient during the first 50 d of their life before the white roots become less efficient brown roots.
Keywords: Fine root longevity; Holm oak; minirhizotron; Quercus ilex; vertical longevity pattern