Feruloyl Esters of ω-Hydroxyacids in Cork Suberin - Graça, José; Pereira, Helena (Journal of Wood Chemistry and Technology, 1998)
Feruloyl esters of ?-hydroxyacids were found in the alcoholysis products of suberin from Quercus suber cork. Their identification was made from mass spectra and by comparison with synthetic model compounds. The co-hydroxyls of suberinic hydroxyacids are thought to be the ester-bonding points between suberin aliphatics and associated aromatics.
doi: 10.1080/02773819809349577
Keywords: Cork; ferulic acid; Feruloyl esters; GC-MS (voyant); suberin

Field decomposition of leaf litters: earthworm–microorganism interactions—the ploughing-in effect - Cortez, J.; Bouché, M. B. (Soil Biology and Biochemistry, 1998)
We describe a new decomposition model including the consequences of earthworm mechan- ical activity, especially the ploughing-in eect. In an experiment we tested this ploughing-in eect on the disappearance of leaf litter from four tree species (sessile oak, Quercus petraea L., holm oak, Quer- cus ilex L., sweet chestnut, Castanea sativa Mill and beech, Fagus sylvatica L.) during two 2 y exposure at the site of Anduze which contained the highest earthworm biomass. Our experiment, carried out with leaf litter placed in litterbags allowing (0.5 cm mesh size) or preventing (0.1 cm mesh size) the access of earthworms, con®rms (1) the rates of litter decomposition observed in the ®rst experiment and (2) the important eect of earthworms on litter decomposition (from 20.5% to 30.2% depending on the litter). The breakdown of the dierent litters by soil fauna varied from 24.2% to 40.6% depending on the litters after 2 y exposure in the ®eld at Anduze and the litter decomposition rate was increased by a mean factor of about 5.2. We describe a technique for detecting litter contamination attributed to earthworm casts. This technique is based on the change of the litter total weight loss (TWL)-to-litter total C loss (TCL) ratios which varied from 0.652 to 0.915 in the presence of earthworms and were close to 1 (from 0.952 to 0.995) in the absence of earthworms. We assumed that this large change in these ratios indicated a mineral contamination of litters due to earthworm casting. This hypothesis was con®rmed by the litter ash contents varying from 2.6% to 9.6% with earthworms and from 1.3% to 2.1% without earthworms only. These results point out the ecological importance of contamination of the litter by casts during decomposition.
Keywords: decomposition; earthworm; litter; microbial decomposition; ploughing-in (voyant); weight loss

Field decomposition of leaf litters: earthworm–microorganism interactions—the ploughing-in effect - Cortez, J; Bouché, M B (Soil Biology and Biochemistry, 1998)
We describe a new decomposition model including the consequences of earthworm mechan- ical activity, especially the ploughing-in eect. In an experiment we tested this ploughing-in eect on the disappearance of leaf litter from four tree species (sessile oak, Quercus petraea L., holm oak, Quer- cus ilex L., sweet chestnut, Castanea sativa Mill and beech, Fagus sylvatica L.) during two 2 y exposure at the site of Anduze which contained the highest earthworm biomass. Our experiment, carried out with leaf litter placed in litterbags allowing (0.5 cm mesh size) or preventing (0.1 cm mesh size) the access of earthworms, con®rms (1) the rates of litter decomposition observed in the ®rst experiment and (2) the important eect of earthworms on litter decomposition (from 20.5% to 30.2% depending on the litter). The breakdown of the dierent litters by soil fauna varied from 24.2% to 40.6% depending on the litters after 2 y exposure in the ®eld at Anduze and the litter decomposition rate was increased by a mean factor of about 5.2. We describe a technique for detecting litter contamination attributed to earthworm casts. This technique is based on the change of the litter total weight loss (TWL)-to-litter total C loss (TCL) ratios which varied from 0.652 to 0.915 in the presence of earthworms and were close to 1 (from 0.952 to 0.995) in the absence of earthworms. We assumed that this large change in these ratios indicated a mineral contamination of litters due to earthworm casting. This hypothesis was con®rmed by the litter ash contents varying from 2.6% to 9.6% with earthworms and from 1.3% to 2.1% without earthworms only. These results point out the ecological importance of contamination of the litter by casts during decomposition.
Keywords: decomposition; earthworm; litter; microbial decomposition; ploughing-in (voyant); weight loss

Fine roots dynamics in a Mediterranean forest: effects of drought and stem density - López, Bernat; SABATE, Santiago; Gracia, Carlos (Tree Physiology, 1998)
Summer drought is a characteristic trait of Mediterranean climates and can limit primary production. The holm oak (Quercus ilex L.) forest at the Prades Experimental Complex of Catchments (PECC, NE Spain) was managed by clearcutting until the 1950s. As a result of this practice, the forest has a high density (13000 stems ha−1) that is causing growth stagnation and intense competition for water. A thinning experiment was conducted to release resources, reduce stem competition and improve forest productivity. Minirhizotrons were installed in two plots in each of the thinned and control stands and fine root dynamics quantified to a soil depth of 60 cm over a 2-year period (June 1994–May 1996).Soil water content was higher and soil water penetrated deeper in the soil (30–50 cm) in the thinned plots than in the control plots. In the control plots, soil temperature did not vary substantially with depth (mean = 11.65 °C), whereas soil temperature was higher in shallow horizons compared with deep horizons in the thinned plots. Mean soil temperature was one degree higher in the thinned plots than in the control plots (12.9 versus 11.9 °C). There were always more roots in the top 20 cm of soil in thinned plots than in control plots. In the thinned plots, more than 50% of root density (root no. cm−2) was located in the top 20 cm of soil, whereas root density never reached 50% in the 0–20 cm soil layer of the control plots. Roots longevity varied from 35 to 471 days, and there were significant differences between soil depths. Root longevity was greater in the control plots than in the thinned plots.
10.1093/treephys/18.8-9.601
Keywords: holm oaks; minirhizotron; Quercus ilex; Soil water content; thinning

First record of Phytophthora cinnamomi on cork and holm oaks in France and evidence of pathogenicity - Robin, Cécile; Desprez-Loustau, Marie-Laure; Capron, Gilles; Delatour, Claude (Ann. For. Sci., 1998)
In 1995 and 1996, a survey for the presence of Phytophthora cinnamomi in cork and holm oak sites in southeastern France was carried out. Twenty-four sites were chosen. Tree decline severity and other characteristics were assessed. Subplots of four trees were more fully investigated: relative soil water content was assessed and Phytophthora isolation was attempted from soil samples. When cortical lesions were observed, isolations were carried out from infected tissues. In six cork oak and one holm oak sites, P. cinnamomi was isolated from soil or trunks. All the different isolates obtained in 1995 were aggressive on cork and holm oaks. However, these species were less susceptible than Castanea sativa and more susceptible than Q. rubra. These results confirm the pathogenicity of P. cinnamomi towards Mediterranean oaks and its possible involvement in the decline process of these species.
Keywords: Cork; phytophthora cinnamomi; Quercus ilex; Quercus suber; soil detection; trunk cankers

Food resource matching by foraging tits Parus spp. during spring-summer in a Mediterranean mixed forest; evidence for an ideal free distribution - Díaz, Mario; ILLERA, JUAN CARLOS; ATIENZA, JUAN CARLOS (Ibis, 1998)
We analysed whether patterns of microhabitat use by Blue Tits Parus caeruleus, Great Tits Parus major and Crested Tits Parus cristatus inhabiting a mixed forest consistently matched the patterns of food availability experienced by foraging birds during spring-summer. The use of five microhabitats by each bird species (the foliage of three tree species, shrubs and ground) and the availability of food in trees during the prebreeding, breeding and post-breeding periods of the birds' annual cycle were measured. All three tit species foraged mainly in the outer part of tree canopies (small branches and leaves or needles). Tit distributions between tree species matched food resource distributions irrespective of overall food resource levels, which varied four-fold between the study periods, and tit species. Tits also exploited secondary microhabitats (shrubs and ground) in periods of low food availability; Blue Tits tended to use shrubs, whereas Great and Crested Tits foraged on the ground. Between-trees distributions fitted that expected from an ideal free distribution, suggesting that food availability and intraspecific exploitative competition were the main factors governing tree use by tits. In contrast, patterns of use of secondary microhabitats (shrubs and ground) seemed to indicate a role for the species-specific morphological configurations of each tit species since Blue Tits are better adapted to hang and tended to forage in shubs, whereas Great and Crested Tits are better adapted to feed on horizontal surfaces and tended to forage on the ground. No evidence of interspecific interactions was observed. Overall, the results pointed to an independent exploitation of Mediterranean mixed forest by each bird species, food availability and food accessibility being the main factors affecting microhabitat use by foraging tits.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: food availability; Foraging (voyant); microhabitat use; tits; Tree species

Food resource matching by foraging tits Parus spp. during spring-summer in a Mediterranean mixed forest; evidence for an ideal free distribution - Díaz, Mario; ILLERA, JUAN CARLOS; ATIENZA, JUAN CARLOS (Ibis, 1998)
We analysed whether patterns of microhabitat use by Blue Tits Parus caeruleus, Great Tits Parus major and Crested Tits Parus cristatus inhabiting a mixed forest consistently matched the patterns of food availability experienced by foraging birds during spring-summer. The use of five microhabitats by each bird species (the foliage of three tree species, shrubs and ground) and the availability of food in trees during the prebreeding, breeding and post-breeding periods of the birds' annual cycle were measured. All three tit species foraged mainly in the outer part of tree canopies (small branches and leaves or needles). Tit distributions between tree species matched food resource distributions irrespective of overall food resource levels, which varied four-fold between the study periods, and tit species. Tits also exploited secondary microhabitats (shrubs and ground) in periods of low food availability; Blue Tits tended to use shrubs, whereas Great and Crested Tits foraged on the ground. Between-trees distributions fitted that expected from an ideal free distribution, suggesting that food availability and intraspecific exploitative competition were the main factors governing tree use by tits. In contrast, patterns of use of secondary microhabitats (shrubs and ground) seemed to indicate a role for the species-specific morphological configurations of each tit species since Blue Tits are better adapted to hang and tended to forage in shubs, whereas Great and Crested Tits are better adapted to feed on horizontal surfaces and tended to forage on the ground. No evidence of interspecific interactions was observed. Overall, the results pointed to an independent exploitation of Mediterranean mixed forest by each bird species, food availability and food accessibility being the main factors affecting microhabitat use by foraging tits.
Keywords: food availability; Foraging (voyant); microhabitat use; tits; Tree species

FROM BIODIVERSITY TO ECODIVERSITY – HOLISTIC CONSERVATION OF THE BIOLOGICAL AND CULTURAL DIVERSITY OF MEDITERRANEAN LANDSCAPES . - Naveh, Z (LANDSCAPE DISTURBANCE AND BIODIVERSITY IN MEDITERRANEAN – TYPE ECOSYSTEMS. ECOLOGICAL STUDIES VOL. 136, 1998)
Human disturbance in mediterranean-type ecosystems continues to be a subject of serious concern, and nowhere is such disturbance and degradation of natural ecological processes and biodiversity more evident than in the Mediterranean Basin itself. In this chapter I will point out currently prevailing trends in Mediterranean landscapes in the context of our global environmental crisis. This will lead to a discussion of the close interrelations between biological diversity, ecological heterogeneity, and cultural diver- sity, or in one word, total landscape ecodiversity in the Mediterranean Basin, and to recent advances in landscape ecology in the evaluation of this issue. I will conclude by offering some new approaches and tools for holistic ecodiversity conservation as an integral part of the urgently needed environmental revolution
Keywords: biological diversity; Cultural diversity; ecodiversity; human activities (voyant); land uses; Mediterranean landscapes

Functional groups in phytoecology: an application to the study of isolated plant communities in Mediterranean France - Médail, F; Roche, Philip; Tatoni, Thierry (Acta Oecologica, 1998)
e main objective of this study is to compare functional patterns versus plant composition in holm-oak forest isolates from two sites of Provence (Mediterranean France), on siliceous (Maures) or calcareous substrates (Luberon). In order to define plant functional groups, 9 traits out of a total of 71 attributes, were used. Twenty functional groups were defined with predominantly vegetative traits. Within each site, edges and forested core areas refer to different functional groups, in relation to the isolate structure and disturbance effects. In siliceous Provence, a higher structural and functional diversity occurs inside isolates, whereas on calcareous substrate, the diversity of plant functional groups which charac- terizes edges, is as important as in internal parts of isolates. Functional diversity does not necessarily follow the same patterns as the specific diversity, which is always greater in edges. Thus, the use of some sets of attributes, resulting from evolutionary trade-off between plants and their environment, can provide a better understanding of ecological consequences of disturbances. 0
Keywords: biological conservation; disturbances; ecosystems; fragmentation; functional diversity; Functional groups; Mediterranean-type ecosystems; terrestrial islands

Gas exchange measurements and an indirect estimate of primary production in a holm-oak ecosystem - Manes, F; Vitale, M; Feoli, E; Scimone, M; Canfora, E (FRESENIUS ENVIRONMENTAL BULLETIN, 1998)
An original and simple primary production model is presented. Annual trends of the daily average values of net photosynthesis and leaf transpiration for helm oak are showed. Moreover, primary production data were obtained. To validate the model, an evaluation between estimated results and field measurements was performed, obtaining a strong correspondence.
Citation
Keywords: holm-oak; photosynthesis; plant simulation model; primary production; Transpiration

Genome size and base composition of seven Quercus species: inter- and intra-population variation - Zoldo, V; Pape, D; Brown, S C; Panaud, O; Zoldos, V; Papes, D; Siljak-Yakovlev, S (Genome, 1998)
Seven Quercus species, four deciduous (Q. cerris, Q. petraea, Q. pubescens, andQ. robur) and three evergreen (Q. coccifera, Q. ilex, andQ. suber), were assessed for DNA content. Their genome sizes ranged from 1.88 to 2.00 pg/2C, namely an interspecific DNA content variation of 6%. In addition, the DNA content of several populations of Q. petraea andQ. robur with different geographical origins, French and Croatian, was estimated. DNA content did not vary among four populations of Q. robur, but did differ between two populations of Q. petraea, the French population having a higher 2C DNA value than the Croatian. The genome size of this French population showed important dispersion among 10 measured individuals. This was in accordance with subsequent cytogenetic data that revealed extra chromosomes in some individuals from this population. The percent GC varied little between the species; a GC content of 39.9% is established as typical for oak.Key words: Quercus, flow cytometry, genome size, GC percent, DNA content variations, extra chromosomes.
Keywords: DNA content variations; extra chromosomes; flow cytometry; GC percent; genome size; Quercus

Growth and survival in Quercus ilex L. seedlings after irrigation and artificial shading on Mediterranean set-aside agricultural land - Rey Benayas, José M (Ann. For. Sci., 1998)
Considerable quantities of agricultural land are being transformed into forested lands in E.U. countries. To assess afforestation practice, we analyzed the growth and survival of 800 Quercus ilex sp. ballota seedlings in set-aside agricultural land under semi-arid Mediterranean climate conditions in central Spain. The survival and growth of the seedlings were monitored for 3 years after planting with an experimental design that included all four combinations of: i) irrigation or no irrigation during the dry season; and ii) artificial shading or no shading. Significant differences in survival and growth (height, stem diameter and crown projected area) were found among treatments. Survival was lowest (53 %) in the control plots, and very similar (around 93 %) for the irrigation, shade and combined treatments. Most of the mortality occurred after the first dry season. The high survival rate in irrigated but not shaded plots coincided with a thick layer of the weed Amaranthus retroflexus L. (in the first dry season). Seedling growth was greatest on average under irrigation and shade conditions. Shade was found to have a significant effect for all growth measurements, while irrigation alone only affected stem diameter growth and crown projected area in interaction with shade. Growth measurements were correlated to microclimatic conditions in the plots as measured by the amounts of water and actual evapotranspiration. We conclude that the attenuation of summer stress must be considered in the early stages of successful plantation practice of set-aside agricultural land in a dry environment.
Keywords: Agricultural land; Growth; irrigation; shade; Survival

Growth and survival in Quercus ilex L. seedlings after irrigation and artificial shading on Mediterranean set-aside agricultural land - Rey Benayas, José M. (Ann. For. Sci., 1998)
Considerable quantities of agricultural land are being transformed into forested lands in E.U. countries. To assess afforestation practice, we analyzed the growth and survival of 800 Quercus ilex sp. ballota seedlings in set-aside agricultural land under semi-arid Mediterranean climate conditions in central Spain. The survival and growth of the seedlings were monitored for 3 years after planting with an experimental design that included all four combinations of: i) irrigation or no irrigation during the dry season; and ii) artificial shading or no shading. Significant differences in survival and growth (height, stem diameter and crown projected area) were found among treatments. Survival was lowest (53 %) in the control plots, and very similar (around 93 %) for the irrigation, shade and combined treatments. Most of the mortality occurred after the first dry season. The high survival rate in irrigated but not shaded plots coincided with a thick layer of the weed Amaranthus retroflexus L. (in the first dry season). Seedling growth was greatest on average under irrigation and shade conditions. Shade was found to have a significant effect for all growth measurements, while irrigation alone only affected stem diameter growth and crown projected area in interaction with shade. Growth measurements were correlated to microclimatic conditions in the plots as measured by the amounts of water and actual evapotranspiration. We conclude that the attenuation of summer stress must be considered in the early stages of successful plantation practice of set-aside agricultural land in a dry environment.
Keywords: Agricultural land; Growth; irrigation; shade; Survival

Herbivory affects developmental instability of stone oak, Quercus rotundifolia - Moller, A P; de Lope, F (OIKOS, 1998)
The effects of herbivory on plant fitness have traditionally been assessed by reductions in performance measured in terms of physiological, growth, and reproductive parameters. We investigated the direct effect of herbivory on a measure of foliar developmental instability (fluctuating asymmetry in leaf width) in evergreen stone oak. Quercus rotundifolia. Since leaves from more than a single growth season are present simultaneously, it is possible to compare measures of developmental instability of newly formed leaves in relation to the extent of herbivory in the previous season as assessed from damage to old leaves. We found significantly increased asymmetry in leaf width when leaves From the previous year showed signs of herbivory. This result was confirmed experimentally by using leaf removal to mimic herbivory. Oak trees where many old leaves were removed had increased foliar asymmetry compared to oak trees where only few leaves had been removed and untreated control trees. Using foliar asymmetry in old leaves from the previous year as a baseline for these comparisons confirmed that foliar asymmetry of individual trees increased as a consequence of herbivory. Oak trees with high degrees of asymmetry were more likely to die than oak trees with low asymmetry. These results suggest that foliar asymmetry is symptomatic of a stressed plant. Herbivores can both produce such a stress, leading to increased asymmetry, and attack differentially more asymmetric plants. In the extreme, the most asymmetric plants are those most likely to die.
APS
Keywords: foliar asymmetry; herbivory essect; Holm oak; plant fitness

A hierarchical view of the interactions of runoff and infiltration with vegetation and microtopography in semiarid shrublands - Bergkamp, Ger (Catena, 1998)
Measurements of runoff and infiltration were made at five spatial scales, terracette . -1 m , 2 . 2 hummock 10–20 m , part-slope 1000–2000 m , slope 1 ha and catchment 50 ha , on a . . . shrubland and an open forest site. The study was aimed at understanding the relationships between runoff production, vegetation patterns and microtopography at different spatial scales within a sparsely vegetated, semiarid area. The results of runoff monitoring and rainfall simulation experiments showed that runoff did not occur at the slope scale. It was buffered at the terracette level by nonuniform infiltration at the rims of terracettes and at the hummock scale by rapid infiltration under oak shrubs and trees. Slope and catchment runoff were not connected to runoff at these fine scales. The field evidence is discussed within the context of hierarchy theory, and the implications for management of these shrublands are related to maintaining both the vegetation mosaic and runoff on these slopes
Keywords: infiltration; mediterranean hillslopes; runoff; semiarid; vegetation patterns

Holocene climatic change in Morocco: a quantitative reconstruction from pollen data - Cheddadi, R; Lamb, H F; Guiot, J; van der Kaars, S (Climate Dynamics, 1998)
Annual precipitation, July and January tem- peratures were reconstructed from a continuous Holo- cene pollen sequence from the Middle Atlas, Morocco, using the best modern analogues method. The recon- structions show a clear difference between the early and late Holocene: from &10 ka to &6.5 ka the climate was drier and warmer than during the period since 6.5 ka. The average value of annual precipitation was &870mm until 6.5 ka, then rose to &940 mm. Be- tween 10 ka and 6.5 ka January and July temperatures were about 4 °C higher than the present. Both temper- atures show a marked decrease between 7 ka and 6 ka. After 6.5 ka July and January temperatures fluctuated between 21 and 23 °C, and 2.5 and 5 °C respectively. January temperatures show a period of intermediate values (&3.5 °C) between 4 ka and 5.5 ka. The recon- structed climate values generally match palaeolim- nological data from the same core, which show five intervals of low lake level during the Holocene. They are also consistent with regional-scale COHMAP simulated palaeoclimate that shows contrasting pat- terns of rainfall variation between the northwester- nmost part of Africa and the intertropical band
APS
Keywords: climate; Holocene; Morocco; paleoclimate; pollen

Holocene climatic change in Morocco: a quantitative reconstruction from pollen data - Cheddadi, R.; Lamb, H. F.; Guiot, J.; van der Kaars, S. (Climate Dynamics, 1998)
Annual precipitation, July and January tem- peratures were reconstructed from a continuous Holo- cene pollen sequence from the Middle Atlas, Morocco, using the best modern analogues method. The recon- structions show a clear difference between the early and late Holocene: from &10 ka to &6.5 ka the climate was drier and warmer than during the period since 6.5 ka. The average value of annual precipitation was &870mm until 6.5 ka, then rose to &940 mm. Be- tween 10 ka and 6.5 ka January and July temperatures were about 4 °C higher than the present. Both temper- atures show a marked decrease between 7 ka and 6 ka. After 6.5 ka July and January temperatures fluctuated between 21 and 23 °C, and 2.5 and 5 °C respectively. January temperatures show a period of intermediate values (&3.5 °C) between 4 ka and 5.5 ka. The recon- structed climate values generally match palaeolim- nological data from the same core, which show five intervals of low lake level during the Holocene. They are also consistent with regional-scale COHMAP simulated palaeoclimate that shows contrasting pat- terns of rainfall variation between the northwester- nmost part of Africa and the intertropical band
APSAPS
Keywords: climate; Holocene; Morocco; paleoclimate; pollen

Hydrogen Peroxide Production is a General Property of the Lignifying Xylem from Vascular Plants - BARCELÓ, A R O S (Annals of Botany, 1998)
Production of hydrogen peroxide (H2O2) by the lignifying xylem of several vascular plants has been studied using a new histochemical method based on the H2O2-dependent oxidation of 3,5,3′5′-tetramethylbenzidine (TMB) catalysed by cell wall peroxidases. This method allows H2O2to be determined in the range of 5–100 μm, where other methods, such as the KI/starch reagent, fail. With this method, it has been possible to determine H2O2production in the lignifying xylem of a wide range of vascular plants (gymnosperms and angiosperms). The capability of xylem tissues of sustaining H2O2production lends support to the hypothesis that cinnamyl alcohol polymerization in xylem vessels is caused by an H2O2-dependent oxidative coupling process.Copyright 1998 Annals of Botany Company
10.1006/anbo.1998.0655
Keywords: H2O2 generation; lignification; peroxidase; tetramethylbenzidine; Xylem

Hydrogen Peroxide Production is a General Property of the Lignifying Xylem from Vascular Plants - BARCELÓ, A. R. O. S. (Annals of Botany, 1998)
Production of hydrogen peroxide (H2O2) by the lignifying xylem of several vascular plants has been studied using a new histochemical method based on the H2O2-dependent oxidation of 3,5,3′5′-tetramethylbenzidine (TMB) catalysed by cell wall peroxidases. This method allows H2O2to be determined in the range of 5–100 μm, where other methods, such as the KI/starch reagent, fail. With this method, it has been possible to determine H2O2production in the lignifying xylem of a wide range of vascular plants (gymnosperms and angiosperms). The capability of xylem tissues of sustaining H2O2production lends support to the hypothesis that cinnamyl alcohol polymerization in xylem vessels is caused by an H2O2-dependent oxidative coupling process.Copyright 1998 Annals of Botany Company
10.1006/anbo.1998.065510.1006/anbo.1998.0655
Keywords: H2O2 generation; lignification; peroxidase; tetramethylbenzidine; Xylem

Hydrological behaviour of a small catchment in the dehesa landuse system (Extremadura, SW Spain) - Ceballos, Antonio; Schnabel, Susanne (Journal of Hydrology, 1998)
Investigations of the hydrological processes operating in a small experimental catchment representative of the dehesa ecosystem were carried out. The dehesa constitutes a system of agro-silvo-pastoral landuse, which is characterized by a Mediterranean, semi-arid climate. The study includes an analysis of the relationships between rainfall, soil water content and discharge, as well as the establishment of the annual water budget. The results demonstrate a complex hydrological response. The relationships between the factors involved and the operating processes are difﬁcult to explain because of the decisive role played by the valley bottoms. These areas typically possess a sediment ﬁll, and contrast with the shallow soils developed on the hillslopes. Genesis and quantity of runoff (Hortonian or saturation) measured at the outlet depend on the antecedent moisture conditions of the valley bottoms because of their water-retention capacity. Annual runoff coefﬁcients are similar to those reported from other semi-arid areas. The analysis of the annual water budget shows that rainfall is positively related with both actual evapotranspiration and discharge
The following values have no corresponding Zotero field: publisher: Elsevier
Keywords: Dehesa; Runoff–rainfall relationship; Semi-arid areas; Small catchment; Water budget

Hydrological behaviour of a small catchment in the dehesa landuse system (Extremadura, SW Spain) - Ceballos, Antonio; Schnabel, Susanne (Journal of Hydrology, 1998)
Investigations of the hydrological processes operating in a small experimental catchment representative of the dehesa ecosystem were carried out. The dehesa constitutes a system of agro-silvo-pastoral landuse, which is characterized by a Mediterranean, semi-arid climate. The study includes an analysis of the relationships between rainfall, soil water content and discharge, as well as the establishment of the annual water budget. The results demonstrate a complex hydrological response. The relationships between the factors involved and the operating processes are difﬁcult to explain because of the decisive role played by the valley bottoms. These areas typically possess a sediment ﬁll, and contrast with the shallow soils developed on the hillslopes. Genesis and quantity of runoff (Hortonian or saturation) measured at the outlet depend on the antecedent moisture conditions of the valley bottoms because of their water-retention capacity. Annual runoff coefﬁcients are similar to those reported from other semi-arid areas. The analysis of the annual water budget shows that rainfall is positively related with both actual evapotranspiration and discharge
Keywords: Dehesa; Runoff–rainfall relationship; Semi-arid areas; Small catchment; Water budget

Hydrological influences on the resilience of Quercus spp. dominated geoecosystems in central Spain - Bergkamp, Ger (Geomorphology, 1998)
Differences in vegetation cover within a landscape having a similar land use history, can be used to identify differences in recovery following disturbance according to landscape position. The objective of this study was to determine the resilience of oak-dominated communities at different landscape positions in a research area in central Spain as indicated by the relative recovery of Quercus ilex and Q. coccifera, and to relate this to the most important hydrological processes and properties at the slope sections scale. The results indicate that the geoecosystems on slope sections on north-facing slopes are more resilient than those on south-facing slopes. On the more degraded shrubland sites, the higher values of vegetation cover on the lower slope sections indicate the systems on these slope sections to be more resilient than those on the slope sections located higher up the slope. The hydrological factors that could possibly explain differences in vegetation type and cover were found to be distance to water resources at greater depths and incoming radiation controlling evapotranspiration. A conceptual model is presented that links the resilience of these systems to the hydrological conditions. On the basis of the presented model, it is postulated that recovery of the system is determined partly by access to deep water resources. It is suggested that differences in or degree of access to such water resources may cause these comparably looking systems to react differently to degradation and recovery
Keywords: Mediterranean; Quercus; resilience; Shrubland; water balance

Hydrological influences on the resilience of Quercus spp. dominated geoecosystems in central Spain - Bergkamp, Ger (Geomorphology, 1998)
Differences in vegetation cover within a landscape having a similar land use history, can be used to identify differences in recovery following disturbance according to landscape position. The objective of this study was to determine the resilience of oak-dominated communities at different landscape positions in a research area in central Spain as indicated by the relative recovery of Quercus ilex and Q. coccifera, and to relate this to the most important hydrological processes and properties at the slope sections scale. The results indicate that the geoecosystems on slope sections on north-facing slopes are more resilient than those on south-facing slopes. On the more degraded shrubland sites, the higher values of vegetation cover on the lower slope sections indicate the systems on these slope sections to be more resilient than those on the slope sections located higher up the slope. The hydrological factors that could possibly explain differences in vegetation type and cover were found to be distance to water resources at greater depths and incoming radiation controlling evapotranspiration. A conceptual model is presented that links the resilience of these systems to the hydrological conditions. On the basis of the presented model, it is postulated that recovery of the system is determined partly by access to deep water resources. It is suggested that differences in or degree of access to such water resources may cause these comparably looking systems to react differently to degradation and recovery
Keywords: Mediterranean; Quercus; resilience; Shrubland; water balance

A hypothesis on the evolution of isoprenoid emission by oaks based on the correlation between emission type and Quercus taxonomy - Loreto, Francesco; Ciccioli, Paolo; Brancaleoni, Enzo; Valentini, Riccardo; De Lillis, Manuela; Csiky, Olav; Seufert, Guenther (Oecologia, 1998)
We show that Mediterranean oaks that emit isoprene, monoterpenes or no isoprenoids belong to dierent subgenera as indicated by morpho-taxonomy and molecular genetics. On the other hand, oaks from North America and Asia that are taxonomically similar to the Mediterranean monoterpene emitter Q. ilex emit isoprene only. We surmise that isoprene emission is a genetic character which evolved ancestrally in the oak genus since this is the prevalent emission type in oaks widespread around the world and adapted to dierent environments. This ancestral character may have been either lost or modi®ed in more recent clades such as those originating the Mediterranean oaks. If our hy- pothesis is correct then the taxonomy of European oaks is validated by this independent trait. Isoprenoid emis- sion could serve as a chemo-taxonomical marker and could be used to reconstruct the phylogeny of oaks in association with molecular markers.
Keywords: chemo-taxonomy; Evolution; isoprenoid emission; Quercus

Iberian ham - Sabio, E; Fallola, A; Sanabria, C; Vidal-Aragon, M C (BASIS OF THE QUALITY OF TYPICAL MEDITERRANEAN ANIMAL PRODUCTS, 1998)
Iberian dry-cured ham is a meat product elaborated from legs of Iberian pigs. This high quality product has been traditionally elaborated in Spain since ancient times. The production is centred in the Southwest of the Iberian Peninsula where it has a great economic, social, and ecological importance. Iberian dry-cured ham quality depends on the raw matter and the technology employed Raw matter quality depends on intrinsic factors (genotype, age, sex), extrinsic factors (feeding, habitat, management), and the slaughtering conditions. Respecting to genotype. at present it is frequent the employment of cross-breeding mainly with Duroc-Jersey (50% and 75% Iberian). The production system is extensive and has three different periods: preweaning, growing, and fattening, this last being fundamental from a quality viewpoint, establishing three commercial categories: `pienso', `recebo', and `bellota'. This production system causes seasoning in Iberian ham production. The elaboration process of Iberian dry-cured ham consists of four steps: salting, post-salting, drying, and cellar The long lasting of the process (18-24 months) and the high temperatures during the drying period (25-30 degrees C) are distinctive aspects of this technology. As compared to Parma or Serrano dry-cured hams, Iberian ham is characterised by: 1) low salt content, 2) high amount of intramuscular fat, rich in oleic acid, 3) high level of proteolysis and lipolysis, and 4) high amount of volatile compounds, mainly linear, medium-chain aldehydes and ketones. There are three Appellation of Origin: `Dehesa de Extremadura', `Guijuelo' and `Sierra de Huelva', and in the next future will appear `Valle de Pedroches'. The most important producer associations are AECERIBER, ACOREX, and ASICI. There are several research centres where this product is preferentially studied, standing out the Department of Agrofood technology of the Junta de Extremadura and the Veterinary faculty of the University of Extremadura.
Keywords: Extensive system; Iberian ham; raw matter

Identification of the main fatty acids component of the cork suberine by GC/MS - Bleton, J; Mejanelle, P; Goursaud, S; Tchapla, A (ANALUSIS, 1998)
The aim of this work was to verify the presence of cork (Quercus Suber) in two samples of linoleum the beginning of the twentieth century Using GC/MS after acidic methanolysis and silylation, it was possible to identify most of the components of a modern sample of cork. The dominant is a lipid polymer: the suberin. Its monomeric composition is examined in details.
APS
Keywords: Cork; GC/MS; Quercus suber L.; suberin

Identification of the main fatty acids component of the cork suberine by GC/MS - Bleton, J.; Mejanelle, P.; Goursaud, S.; Tchapla, A. (ANALUSIS, 1998)
The aim of this work was to verify the presence of cork (Quercus Suber) in two samples of linoleum the beginning of the twentieth century Using GC/MS after acidic methanolysis and silylation, it was possible to identify most of the components of a modern sample of cork. The dominant is a lipid polymer: the suberin. Its monomeric composition is examined in details.
APSAPSThe following values have no corresponding Zotero field: pub-location: 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE publisher: E D P SCIENCES
Keywords: Cork; GC/MS; Quercus suber L.; suberin

Impacts of climate change and elevated CO2 on trees in regions with a Mediterranean type of climate - Pereira, J S; Chaves, M M (IMPACTS OF GLOBAL CHANGE ON TREE PHYSIOLOGY AND FOREST ECOSYSTEMS, 1998)
Research on the effects of global changes on Mediterranean trees is still limited. In terms of growth response to elevated CO2, Mediterranean trees were not different from temperate-zone trees, i.e., growth enhancement seems to be short-lived, declining after the first growing seasons in elevated CO2. In Mediterranean landscapes important soil fertility gradients can be found. Such differences, mainly in soil nitrogen, may interact with elevated CO2, as shown by the enhancement of the response to high CO2 by abundant N in Fraxinus angustifolia (a deciduous, riparian tree) and Quercus suber (an evergreen oak). Given the characteristics of the regional climate, special attention in research was given to the interaction between elevated CO2 and the summer stress, i.e., heat and high irradiance stresses superimposed on water deficits. We discuss the possibility that elevated CO2 may alleviate some of the negative effects of that summer stresses, as was found in Quercus suber seedlings under controlled conditions or in Quercus ilex with a life-time exposure to elevated CO2.
Keywords: Elevated CO2; Mediterranean; Trees; water stress

Influence of 50 Hz electromagnetic fields on recurrent embryogenesis and germination of cork oak somatic embryos - Celestino, Cristina; Picazo, M L (Plant cell, tissue and …, 1998)
Plant tissue culture techniques are carried out under environmentally controlled conditions in phytotrons. However, electric components of phytotrons generate electromagnetic ﬁelds that may act as a environmental factor inﬂuencing plant growth and morphogenesis. Isolated somatic embryos of Quercus suber, picked from embryogenic lines, were chronically exposed to a 50 Hz and 15 µT electromagnetic ﬁeld generated in a Helmholtz-coil system for 8 weeks, in order to examine if the extremely low frequency (ELF) magnetic ﬁeld (MF) affected the morphogenic behaviour of embryogenic cultures during recurrent embryogenesis. Germination of somatic embryos from genotype G7.1 was carried out under the same electromagnetic ﬁeld, and also under conditions in which the local geomagnetic ﬁeld was suppressed. The ELF MF did not inﬂuence the growth of embryogenic clumps of the assayed genotypes, but reduced the number of detachable embryos produced by genotype G3.27. The ELF MF did not modify the percentages of germination or plant formation of somatic embryos. However, somatic embryos had better germination when cultured under the suppressed geomagnetic ﬁeld condition.
Keywords: bioelectromagnetism; elf magnetic fields; germination; Quercus Suber L; Somatic embryogenesis; tissue culture

Influence of 50 Hz electromagnetic fields on recurrent embryogenesis and germination of cork oak somatic embryos - Celestino, Cristina; Picazo, M. L. (Plant cell, tissue and …, 1998)
Plant tissue culture techniques are carried out under environmentally controlled conditions in phytotrons. However, electric components of phytotrons generate electromagnetic ﬁelds that may act as a environmental factor inﬂuencing plant growth and morphogenesis. Isolated somatic embryos of Quercus suber, picked from embryogenic lines, were chronically exposed to a 50 Hz and 15 µT electromagnetic ﬁeld generated in a Helmholtz-coil system for 8 weeks, in order to examine if the extremely low frequency (ELF) magnetic ﬁeld (MF) affected the morphogenic behaviour of embryogenic cultures during recurrent embryogenesis. Germination of somatic embryos from genotype G7.1 was carried out under the same electromagnetic ﬁeld, and also under conditions in which the local geomagnetic ﬁeld was suppressed. The ELF MF did not inﬂuence the growth of embryogenic clumps of the assayed genotypes, but reduced the number of detachable embryos produced by genotype G3.27. The ELF MF did not modify the percentages of germination or plant formation of somatic embryos. However, somatic embryos had better germination when cultured under the suppressed geomagnetic ﬁeld condition.
Keywords: bioelectromagnetism; elf magnetic fields; germination; Quercus Suber L; Somatic embryogenesis; tissue culture

Influence of intra-and inter-specific interference on terpene emission by Pinus halepensis and Quercus ilex seedlings - Penuelas, J; Llusia, J (Biologia plantarum, 1998)
Seedlings of two common Mediterranean trees, Pinus halepensis L. and Quercus ilex L., were grown alone and together with seedlings of the same or of the other species in the same pot during one year to test the effects of intra- and inter-specific interference on terpene emission. Light, nutrients and water were amply supplied. There were higher emission rates in P. halepensis than in Q. ilex. The emission increased when the neighbour was a pine and decreased when the neighbour was a holm oak. Volatile organic compound and terpene emission rates followed inverse trends to foliar biomass or growth, which decreased when the neighbour was a pine.
Keywords: a-pinene; Allelopathy; autopathy; camphene; Volatile Organic Compounds

Isotope discrimination and photosynthesis of vegetation growing in the Bossoleto CO 2 spring - Miglietta, F; Raschi, A; Körner, C; Vaccari, F P (Chemosphere, 1998)
The Bossoleto CO2 spring emits CO2 which has a stable carbon isotopic ratio (~5~3C = - 8%o). We determined ~3C on leaves of several individual species growing in Bossoleto and in a nearby control site at ambient CO,.. ~5t3C was 6% more negative in leaves of species collected from the grassland community of Bossoleto, indicating increased discrimination (A) against the heavy carbon isotope. No such changes were found in ruderal species growing in the same spring, suggesting that photosynthetic capacity was much less affected. A was substantially increased under elevated CO2 in leaves of Quercus pubescens but not in Quercus ilex, which also did not show any increase in non-structural carbohydrates. Gas-exchange measurements made on Plantago lanceolata, supported the view that photosynthetic capacity is decreased in plants grown under elevated CO: and on poor soils
Keywords: Elevated CO2; Grassland vegetation (voyant); isotopic discrimination; photosynthetic capacity

Isotope discrimination and photosynthesis of vegetation growing in the Bossoleto CO 2 spring - Miglietta, F.; Raschi, A.; Körner, C.; Vaccari, F. P. (Chemosphere, 1998)
The Bossoleto CO2 spring emits CO2 which has a stable carbon isotopic ratio (~5~3C = - 8%o). We determined ~3C on leaves of several individual species growing in Bossoleto and in a nearby control site at ambient CO,.. ~5t3C was 6% more negative in leaves of species collected from the grassland community of Bossoleto, indicating increased discrimination (A) against the heavy carbon isotope. No such changes were found in ruderal species growing in the same spring, suggesting that photosynthetic capacity was much less affected. A was substantially increased under elevated CO2 in leaves of Quercus pubescens but not in Quercus ilex, which also did not show any increase in non-structural carbohydrates. Gas-exchange measurements made on Plantago lanceolata, supported the view that photosynthetic capacity is decreased in plants grown under elevated CO: and on poor soils
Keywords: Elevated CO2; Grassland vegetation (voyant); isotopic discrimination; photosynthetic capacity

ITS sequences from nuclear rDNA suggest unexpected phylogenetic relationships between Euro-Mediterranean, East Asiatic and North American taxa ofQuercus ( - Samuel, Rosabelle; Bachmair, Andreas (Plant systematics and …, 1998)
Nucleotide sequences from the internal transcribed spacer (ITS) regions of the 18S-26S nuclear ribosomal DNA have been studied from ten species of Quercus (representing four subgenera), Castanea sativa and Fagus sylvatica, as a preliminary molecular contribution to the still poorly understood systematics and evolution of Fagaceae. The resulting matrix has been used to calculate pair-wise sequence divergence indices and to construct a maximum parsimony tree for Quercus coding indels as a fifth state. Divergence is greater for Quercus vs. Fagus than for Quercus vs. Castanea. The tree for the Quercus taxa studied reveals two clearly divergent clades. In clade I the evergreen W Mediterranean Q. suber appears in a basal position as sister to more distal deciduous taxa, i.e. the E Mediterranean Q. macrolepis and the E Asiatic Q. acutissima (all formerly united as different sections under the apparently polyphyletic subg. Cerris), and Q. rubra (a representative of the N American subg. Erythrobalanus), forming a pair with Q. acutissima. In clade II the evergreen southeastem N American Q. virginiana is basal and sister to the remaining three branches, i.e. a pair of evergreen Mediterranean taxa with Q. ilex and Q. coccifera (subg. Sclerophyllodrys), the deciduous but otherwise plesiomorphic SE European/SW Asiatic Q. cerris (type species of subg. Cerris), and the related but more apomorphic European pair Q. petraea and Q. robur (subg. Quercus). These results partly conflict with current taxonomic classification but a_re supported by some anatomical and morphological characters. They document polyphyletic lines from evergreen to deciduous taxa and suggest Tertiary transcontinental connections within the genus.
Keywords: Castanea; Fagaceae; Fagus. - Nuclear rDNA; ITS; molecular phylogeny; molecular systematics; N Hemisphere; Phytogeography; Quercus

La nueva política agrícola europea frente a la problemática ambiental: el caso de la sierra norte de Sevilla - Avilez Benítez, A (Revista de estudios regionales, 1998)
This work consists in an adequation of the European agro-environmental policy with the environmental issue of a Mediterranean area such as Andalusia. This paper fist includes a brief presentation and criticism of the nature and contents of agro environmental and forest programmes at the European and also Spanish and Andalusian levels. In a second part, we analyze the first results we obtained concerning Sierra Norte of Seville, «comarca» represen- tative of the area of middle mountain of Andalusia. It is characterised by an agrarian system with a strong environmental value, the agro-silvipastural system of «dehesa». The aim is to evaluate to what extend the environmental politicy could improve a sustainable agrarian management of natural resources of the «dehesa», as well as the economic development of this «comarca»
Keywords: agro-environmental programme; disadvantaged area; forest programme; rural development; Sierra Norte de Sevilla

Laying date and clutch size of Great Tits (Parus major) in the Mediterranean region: a comparison of four habitat types - Belda, E J; Barba, Emilio; Gil-Delgado, J A (Journal of Ornithology, 1998)
Laying date and clutch size of Great Tits were studied in four different habitats in eastern Spain: two holm oak (Quercus ilex) forests, at 500 and 900-950 m a.s.1., a zeen oak (Quercusfaginea) forest, at 900-1100 m a.s.l., a pine (Pinus sylvestris) forest, at 1000.1050 m a.s.1., and orange (Citrus aurantium) plantations, at 30 m a.s.1. All sites were placed at about the same latitude (39-41°N), and all were studied during the same years (1992-95). Our results show that (1) laying date did not differ between the natural habitats at the same altitude (range of the means of yearly means 4-8 May); (2) within the same habitat type (holm oak forest) laying date was earlier at low altitude (30 April vs. 8 May); (3) laying date was earlier in the orange plantations (21 April) than in natural habitats; (4) among natural habitats at the same altitude, clutch size decreased from zeen oak (mean of yearly means 7.3 eggs) to holm oak (7.0 eggs) to pine forests (6.4 eggs), though only the difference between zeen oak and pine forests was significant; (5) within the same habitat type (holm oak forest), the clutch size tended to be larger at high altitude (7.0 vs. 5.9 eggs); and (6) clutch size in orange plantations (7.7 eggs) did not differ significantly from that of the zeen oak forest, but was larger than in the holm oak and pine forests. We discuss the effect of the habitat type on laying date and clutch size of Great Tits.
Keywords: breeding parameters; Mediterranean forests; orange plantations; paridae

Leaf gas exchange and ﬂuorescence of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex saplings in severe drought and high temperature conditions - Filella, I.; Llusia, J.; Piñol, J.; Penuelas, J. (Environmental and Experimental Botany, 1998)
Saplings of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex were witheld watering for 7 days, followed by reirrigation. Incident photosynthetic photon ﬂux density (PPFD), leaf temperature, net photosynthetic rates, stomatal conductance, and photochemical efﬁciency of the photosystem II (DF:F’m) were measured three times during the day. The watered plants had higher photosynthetic rates, stomatal conductances, DF:F’m and ETR than non-watered plants. However, watered plants were mildly water stressed as shown by low ratio of variable to maximal ﬂuorescence (Fv:Fm) and high non-photochemical ﬂuorescence quenching (qN). Their DF:F%m was low in the morning and increased in the evening, following the variations in PPFD. Watered plants of Q. ilex had lower photosynthetic activity, stomatal conductance and photosynthetic radiation use efﬁciency than Ph. latifolia and P. lentiscus, and, conversely, reached the highest DF:F%m and ETR. This seems to indicate a different relationship between photosynthetic activity and electron transport rate in Q. ilex compared to the other two species. Ph. latifolia and P. lentiscus appeared to be better adapted to severe drought than Q. ilex.
Keywords: Drought; hF/F’m; phillyrea latifolia; photosynthetic rate; Pistacia lentiscus; Quercus ilex; Stomatal conductance

Leaf gas exchange and ﬂuorescence of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex saplings in severe drought and high temperature conditions - Filella, I; Llusia, J; Piñol, J; Penuelas, J (Environmental and Experimental Botany, 1998)
Saplings of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex were witheld watering for 7 days, followed by reirrigation. Incident photosynthetic photon ﬂux density (PPFD), leaf temperature, net photosynthetic rates, stomatal conductance, and photochemical efﬁciency of the photosystem II (DF:F’m) were measured three times during the day. The watered plants had higher photosynthetic rates, stomatal conductances, DF:F’m and ETR than non-watered plants. However, watered plants were mildly water stressed as shown by low ratio of variable to maximal ﬂuorescence (Fv:Fm) and high non-photochemical ﬂuorescence quenching (qN). Their DF:F%m was low in the morning and increased in the evening, following the variations in PPFD. Watered plants of Q. ilex had lower photosynthetic activity, stomatal conductance and photosynthetic radiation use efﬁciency than Ph. latifolia and P. lentiscus, and, conversely, reached the highest DF:F%m and ETR. This seems to indicate a different relationship between photosynthetic activity and electron transport rate in Q. ilex compared to the other two species. Ph. latifolia and P. lentiscus appeared to be better adapted to severe drought than Q. ilex.
Keywords: Drought; hF/F’m; phillyrea latifolia; photosynthetic rate; Pistacia lentiscus; Quercus ilex; Stomatal conductance

Light and temperature dependence of the emission of cyclic and acyclic monoterpenes from holm oak (Quercus ilex L.) leaves - Staudt, M; Bertin, N (Plant, Cell & Environment, 1998)
In a laboratory study, we investigated the monoterpene emissions from Quercus ilex, an evergreen sclerophyllous Mediterranean oak species whose emissions are light dependent. We examined the light and temperature responses of individual monoterpenes emitted from leaves under various conditions, the effect of heat stress on emissions, and the emission-onset during leaf development. Emission rate increased 10-fold during leaf growth, with slight changes in the composition. At 30 °C and saturating light, the monoterpene emission rate from mature leaves averaged 4·1 nmol m–2 s–1, of which α-pinene, sabinene and β-pinene accounted for 85%. The light dependence of emission was similar for all monoterpenes: it resembled the light saturation curve of CO2 assimilation, although monoterpene emission continued in the dark. Temperature dependence differed among emitted compounds: most of them exhibited an exponential increase up to 35 °C, a maximum at 42 °C, and a slight decline at higher temperatures. However, the two acyclic isomers cis-β-ocimene and trans-β-ocimene were hardly detected below 35 °C, but their emission rates increased above this temperature as the emission rates of other compounds fell, so that total emission of monoterpenes exponentially increased from 5 to 45 °C. The ratio between ocimene isomers and other compounds increased with both absolute temperature and time of heat exposure. The light dependence of emission was insensitive to the temperature at which it was measured, and vice versa the temperature dependence was insensitive to the light regime. The results demonstrated that none of the models currently applied to simulate isoprene or monoterpene emissions correctly predicts the short-term effects of light and temperature on Q. ilex emissions. The percentage of fixed carbon lost immediately as monoterpenes ranged between 0·1 and 6·0% depending on temperature, but rose up to 20% when leaves were continuously exposed to temperatures between 40 and 45 °C.
Keywords: biogenic VOC emission; emission model; heat stress; Holm oak; Isoprenoids; light effect; Monoterpenes; Quercus ilex; temperature effect

lmpact of reafforestation with Eucalyptus globulus La bi l l . on the edaphic collembolan fauna of Serra de Monchique ( Algarve , Portugal ) - Barrocas, H M; Gama, M M; Sousa, J P; Ferreira, C S (Miscel.lania Zoologica, 1998)
lmpact of reafforestation with Eucalyptus globulus Labill. on the edaphic collembolan fauna of Serra de Monchique (Algarve, Portugal).- Native forests in Portugal have been gradually replaced by Eucalyptus globulus plantations. This exotic tree has been referred as a major factor of ecosystem disturbance (Gama et al. 1989, 1991, 1994, 1995; Sousa & Gama, 1994; Vasconcelos et al., 1994). The authors compared edaphic Collembola populations occurring in coppices of Quercussuber L. and Q. canariensis Willd. with those from stands of Eucalyptusglobulus Labill. from Serra de Monchique, to evaluate the effects of reafforestation with this exotic tree. The total analysis of data shows a rupture in the collembola communities associated with eucalyptus. Oak biotopes usually present higher values of diversity and species richness, with a greater total number of species and also more exclusive andlor preferential species than eucalyptus biotopes. No significant differences were detected among the different biotopes in terms of mean number of individuals. However, the abundance of individuals in eucalyptus biotopes results mainly from the presence of a few species which are represented by a great number of specimens, making up more than 85% of the individuals on eucalyptus sites
Keywords: Algarve; Collembola; Eucalyptus globulus; Q. canariensis; Quercus suber; REAFFORESTATION

Long-term CO 2-enrichment in a Mediterranean natural forest: An application of large Open Top Chambers - Angelis, P. De; Scarascia-Mugnozza, G. E. (Chemosphere, 1998)
It is crucial to be able to anticipate the possible effects of environmental changes on the Mediterranean woodland communities given their essential role on protecting lands that are under a strong pressure by man and climate. Predictions of the effects of increasing C0~ concentration on plants have been inferred by short- and long-term studies, conducted at different scales and by different technologies. Open Top Chambers (OTCs) are experimental facilities that have been widely used to expose field grown plants to different pollutant gases, and more recently to elevated [CO2] . In this paper, we present the natural site and the experimental system (six large OTCs enclosing clumps of natural vegetation) that we have been utilizing for 3 years, to assess the impact of elevated [CO2] on a Mediterranean natural forest community. The results show that large OTCs can be usefully used to simulate C02 doubling even under the harsh environmental conditions of the mediteffanean region
Keywords: decomposition; Elevated CO3; leaf litter; Mediterranean forest (voyant)

Long-term CO 2-enrichment in a Mediterranean natural forest: An application of large Open Top Chambers - Angelis, P De; Scarascia-Mugnozza, G E (Chemosphere, 1998)
It is crucial to be able to anticipate the possible effects of environmental changes on the Mediterranean woodland communities given their essential role on protecting lands that are under a strong pressure by man and climate. Predictions of the effects of increasing C0~ concentration on plants have been inferred by short- and long-term studies, conducted at different scales and by different technologies. Open Top Chambers (OTCs) are experimental facilities that have been widely used to expose field grown plants to different pollutant gases, and more recently to elevated [CO2] . In this paper, we present the natural site and the experimental system (six large OTCs enclosing clumps of natural vegetation) that we have been utilizing for 3 years, to assess the impact of elevated [CO2] on a Mediterranean natural forest community. The results show that large OTCs can be usefully used to simulate C02 doubling even under the harsh environmental conditions of the mediteffanean region
Keywords: decomposition; Elevated CO3; leaf litter; Mediterranean forest (voyant)

Measurement of isoprenoid content in leaves of Mediterranean Quercus spp. by a novel and sensitive method and estimation of the isoprenoid partition between liquid and gas phase inside the leaves - Loreto, Francesco; Ciccioli, Paolo; Brancaleoni, Enzo; Cecinato, Angelo; Frattoni, Massimiliano (Plant Science, 1998)
We used a novel. simple and sensitive method to extract isoprenoids contained in the leaves and compared emission and content of isoprenoids in the leaves of three Mediterranean oak species emitting isoprene (Quercus puhcsccws), monoterpenes (Querc~s ilrs) or non-emitting isoprenoids (Quercus cerris). The content is qualitatively consistent with the emission of isoprenoids by Qucrczls spp. However. the fraction of isoprenoids in the gas phase was estimated to be r 0.02 and 5% of the total content for monoterpenes and isoprene, respectively. On the other hand, the content of monoterpenes in the leaf was much higher than that of isoprene and particularly rich of compounds which can hardly be detected in an emission such as linalool. It is concluded that isoprenoids are contained in temporary pools and that the different partition between gas and liquid phases plays an important role in determining the pool size in isoprene and monoterpene-emitting oaks. The pools of isoprenoid-emitting oaks sustain the emission for few minutes when isoprenoid formation is prevented. which rules out the presence of specialized organs for isoprenoid storage and are absent altogether in non-emitting species.
Keywords: Isoprene emission (content); Monoterpene emission (content): Quercus spp.

Modelling the responses to climate change of a Mediterranean forest managed at different thinning intensities: Effects on growth and water fluxes - Gracia, C. A.; Sabate, S.; Tello, E. (IMPACTS OF GLOBAL CHANGE ON TREE PHYSIOLOGY AND FOREST ECOSYSTEMS, 1998)
This study explores the effect of various climatic change scenarios over a 50 year period on plots managed at a range of thinning intensities. In order to determine how management practises can modify the effect of climatic change on Mediterranean Forests we integrated field experiments and the results of the GOTILWA model so as to take into account both water fluxes and forest structure interactions. The results show that the positive effects of atmospheric CO2 fertilisation, causing an increase in WUE, counteract with the negative effects of both temperature increase and rainfall decrease. Thinning might attenuate the effects of adverse conditions by reducing both leaf respiratory costs and the foliage turnover rate.
The following values have no corresponding Zotero field: periodical: IMPACTS OF GLOBAL CHANGE ON TREE PHYSIOLOGY AND FOREST ECOSYSTEMS pub-location: PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS
Keywords: climate change; mediterranean forest; Modelling

Modelling the responses to climate change of a Mediterranean forest managed at different thinning intensities: Effects on growth and water fluxes - Gracia, C A; Sabate, S; Tello, E (IMPACTS OF GLOBAL CHANGE ON TREE PHYSIOLOGY AND FOREST ECOSYSTEMS, 1998)
This study explores the effect of various climatic change scenarios over a 50 year period on plots managed at a range of thinning intensities. In order to determine how management practises can modify the effect of climatic change on Mediterranean Forests we integrated field experiments and the results of the GOTILWA model so as to take into account both water fluxes and forest structure interactions. The results show that the positive effects of atmospheric CO2 fertilisation, causing an increase in WUE, counteract with the negative effects of both temperature increase and rainfall decrease. Thinning might attenuate the effects of adverse conditions by reducing both leaf respiratory costs and the foliage turnover rate.
Keywords: climate change; mediterranean forest; Modelling

Modifications of the leaf surface structures of Quercus ilex L. in open, naturally CO2-enriched environments - Paoletti, E; Nourrisson, G; Garrec, J P; Raschi, A (Plant, Cell & Environment, 1998)
Two Italian CO2 springs allowed us to study the long-term effect of a 350–2600 μmol mol–1 increase in CO2 concentrations on the surface structures of leaves of Quercus ilex L. Carbon dioxide increased the quantity of cuticular waxes, above an apparent threshold of 750 μmol mol–1 CO2. Leaf wettability was not modified by CO2 concentrations. Reduction in stomatal frequency was observable up to 750 μmol mol–1 CO2, the slope being almost the same as that estimated for the increase in CO2 concentration from pre-industrial times to the present. At higher concentrations, CO2 seemed to exert no more impact on stomatal frequency.
Keywords: Elevated CO2; leaf wettability; natural CO2 spring; Quercus ilex; stomatal frequency; wax amount

Modifications of the leaf surface structures of Quercus ilex L. in open, naturally CO2-enriched environments - Paoletti, E.; Nourrisson, G.; Garrec, J. P.; Raschi, A. (Plant, Cell & Environment, 1998)
Two Italian CO2 springs allowed us to study the long-term effect of a 350–2600 μmol mol–1 increase in CO2 concentrations on the surface structures of leaves of Quercus ilex L. Carbon dioxide increased the quantity of cuticular waxes, above an apparent threshold of 750 μmol mol–1 CO2. Leaf wettability was not modified by CO2 concentrations. Reduction in stomatal frequency was observable up to 750 μmol mol–1 CO2, the slope being almost the same as that estimated for the increase in CO2 concentration from pre-industrial times to the present. At higher concentrations, CO2 seemed to exert no more impact on stomatal frequency.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Elevated CO2; leaf wettability; natural CO2 spring; Quercus ilex; stomatal frequency; wax amount

On the monoterpene emission under heat stress and on the increased thermotolerance of leaves of Quercus ilex L. fumigated with selected monoterpenes - Loreto, F; Förster, A; Dürr, M; Csiky, O; Seufert, G (Plant, Cell & Environment, 1998)
Leaves of the monoterpene emitter Quercus ilex were exposed to a temperature ramp with 5 °C steps from 30 to 55 °C while maintained under conditions in which endogenous emission of monoterpenes was allowed or suppressed, or under fumigation with selected exogenous monoterpenes. Fumigation with monoterpenes reduced the decline of photosynthesis, photorespiration and monoterpene emission found in non-fumigated leaves exposed to high temperatures. It also substantially increased respiration when photosynthesis and photorespiration were inhibited by low O2 and CO2-free air. These results indicate that, as previously reported for isoprene, monoterpenes may help plants cope with heat stress. Monoterpenes may enhance membrane stability, thus providing a rather non-specific protection of photosynthetic and respiratory processes. Monoterpene emission was maximal at a temperature of 35 °C and was inhibited at higher temperatures. This is likely to be the result of the temperature dependency of the enzymes involved in monoterpene synthesis. In contrast to other monoterpenes, cis- and trans-β-ocimene did not respond to exposure to high temperatures. Cis-β-ocimene also did not respond to low O2 or to fumigation. These results indicate that cis and trans-β-ocimene may have a different pathway of formation that probably does not involve enzymatic synthesis.
Keywords: monoterpene emission; monoterpene fumigation; photosynthesis; Quercus ilex; respiration; thermotolerance

On the monoterpene emission under heat stress and on the increased thermotolerance of leaves of Quercus ilex L. fumigated with selected monoterpenes - Loreto, F.; Förster, A.; Dürr, M.; Csiky, O.; Seufert, G. (Plant, Cell & Environment, 1998)
Leaves of the monoterpene emitter Quercus ilex were exposed to a temperature ramp with 5 °C steps from 30 to 55 °C while maintained under conditions in which endogenous emission of monoterpenes was allowed or suppressed, or under fumigation with selected exogenous monoterpenes. Fumigation with monoterpenes reduced the decline of photosynthesis, photorespiration and monoterpene emission found in non-fumigated leaves exposed to high temperatures. It also substantially increased respiration when photosynthesis and photorespiration were inhibited by low O2 and CO2-free air. These results indicate that, as previously reported for isoprene, monoterpenes may help plants cope with heat stress. Monoterpenes may enhance membrane stability, thus providing a rather non-specific protection of photosynthetic and respiratory processes. Monoterpene emission was maximal at a temperature of 35 °C and was inhibited at higher temperatures. This is likely to be the result of the temperature dependency of the enzymes involved in monoterpene synthesis. In contrast to other monoterpenes, cis- and trans-β-ocimene did not respond to exposure to high temperatures. Cis-β-ocimene also did not respond to low O2 or to fumigation. These results indicate that cis and trans-β-ocimene may have a different pathway of formation that probably does not involve enzymatic synthesis.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: monoterpene emission; monoterpene fumigation; photosynthesis; Quercus ilex; respiration; thermotolerance

Morpho-anatomical aterations in leaves of Fagus sylvatica L. and Quercus ilex L. in different environmental stress condition - Grossoni, P; Bussotti, F; Tani, C; Gravano, E (Chemosphere, 1998)
By means of anatomical and foliar structure observations, this paper examines the ecological behaviour of two different species of broadleaf (a mesophile one, beech, and a xerophile one, holm-oak), under different conditions of water supply. The purpose of this study was to evaluate their response in relation to possible climate changes. The results highlight certain similarities of behaviour (reduction of leaf surface, increased leaf thickness, increase of mechanical structures in xeric stands). The main difference between the two species lies in the tannins content, which increase in the epidermal cells (vacuoles and walls) only in beech trees in xeric conditions
Keywords: Fagus sylvatica; foliar structure; Quercus ilex; xeric conditions (voyant)

Morpho-anatomical aterations in leaves of Fagus sylvatica L. and Quercus ilex L. in different environmental stress condition - Grossoni, P.; Bussotti, F.; Tani, C.; Gravano, E. (Chemosphere, 1998)
By means of anatomical and foliar structure observations, this paper examines the ecological behaviour of two different species of broadleaf (a mesophile one, beech, and a xerophile one, holm-oak), under different conditions of water supply. The purpose of this study was to evaluate their response in relation to possible climate changes. The results highlight certain similarities of behaviour (reduction of leaf surface, increased leaf thickness, increase of mechanical structures in xeric stands). The main difference between the two species lies in the tannins content, which increase in the epidermal cells (vacuoles and walls) only in beech trees in xeric conditions
Keywords: Fagus sylvatica; foliar structure; Quercus ilex; xeric conditions (voyant)

Myxomycetes from the bark of the evergreen oak Quercus ilex - de Basanta, Diana Wrigley (Anales del Jardín Botánico de Madrid; Vol 56, No 1 (1998), 1998)
The results of 81 moist chamber cultures of bark from living Quercus ilex trees are reponed. A total of 37 taxa are cited, extending the number of species found on this substrate to 55. The presence of Licea deplanata on the Iberian Península is confirmed. Seven new records are included for the province of Madrid. Some data are contributed on species frequency and incubation times.
Keywords: Corticolous myxomycetes; Madrid; moist chamber culture; Quercus ilex

Myxomycetes from the bark of the evergreen oak Quercus ilex - de Basanta, Diana Wrigley (Anales del Jardín Botánico de Madrid; Vol 56, No 1 (1998), 1998)
The results of 81 moist chamber cultures of bark from living Quercus ilex trees are reponed. A total of 37 taxa are cited, extending the number of species found on this substrate to 55. The presence of Licea deplanata on the Iberian Península is confirmed. Seven new records are included for the province of Madrid. Some data are contributed on species frequency and incubation times.
Keywords: Corticolous myxomycetes; Madrid; moist chamber culture; Quercus ilex

The NDVI and spectral decomposition for semi-arid vegetation abundance estimation - Hurcom, S J; Harrison, A R (International Journal of Remote Sensing, 1998)
This paper describes the use of the Normalized Difference Vegetation Index (NDVI) and spectral decomposition techniques to estimate vegetation abundance using ground-based spectroradiometric data of semi-arid vegetation. It is found that the NDVI provides a better measure of the proportion of directly irradiated leaves within the field-of-view of the spectroradiometer than it does the Leaf Area Index or biomass. Moreover, it is found that spectral decomposition isolates a factor which is strongly influenced by spectral variation at the region of the red edge. This factor is highly correlated with the NDVI -(R2=0.91) and as such also provides a good estimate of the proportion of directly irradiated leaves. It is suggested that spectral decomposition techniques provide a unique framework in which to analyse the factors affecting the spectral response of vegetation.
doi: 10.1080/014311698214217
Keywords: LAI (voyant); NDVI; spectral decomposition; vegetation abundance

New palynological and tephrostratigraphical investigations of two salt lagoons on the island of Mljet, south Dalmatia, Croatia - Jahns, Susanne; Bogaard, Christel (Vegetation History and Archaeobotany, 1998)
In the sediments of both of the investigated lakes, the tephra from the Mercato-Ottaviano eruption (Vesuvius, southern Italy) (ca. 7900 B.P.) could be identified. The palynological investigations show that from ca. 9000-7200 B.P. (8000-6000 cal B.C.) deciduous oak forests predominated, with only a few representatives of Mediterranean vegetation. At the transition to the central European Atlantic Period those forests changed to an open vegetation type, dominated byJuniperus andPhillyrea. At about 5500 B.P. (4400 cal B.C.), theJuniperus-Phillyrea vegetation was replaced byQuercus ilex woodland that still occurs on the island of Mljet today and is considered to be the natural vegetation of the Dalmatian coastland. The associated vegetation of theQ. ilex forests changed several times. At the beginning of theQ. ilex period,Juniperus values were still high, but soon they decreased andErica spread. In more recent times theQ. ilex forests were partially replaced by plantations ofPinus halcpensis. Indicators of human impact are sparse throughout the pollen record. Clear evidence for human influence exists only from ca. 3100 B.P. (1300 cal B.C.) whenJuglans andPinus halepensis were introduced to the area. Later,Olea andSecale cultivation can be suggested and further spreading ofJuniperus indicates use of the land as pasture.
Keywords: Climatic impact; human impact; Mercato-Ottaviano tephra; vegetation history; Vesuvius

O3 AND 03+C02 EFFECTS ON A MEDITERRANEAN EVERGREEN BROADLEAF TREE, HOLM OAK (QUERCUS iLEX L.) - Manes, F; Vitale, M; Donato, E; Paoletti, E (Chemosphere, 1998)
The aim of this work is to analyze the effects of a) short-term treatments with different concentrations of 0, (daily 6-hour fumigation with 0, 65, 175 and 300 ppb for 3-4 days); and 6) a medium term treatment with O9 (150 ppb three times a week for thirty days on the whole) and CO2 (700 ppm) on gas exchange, chlorophyll fluorescence, and peroxidase activity in holm oak (Quercus ilex L.) leaves. The results show that net photosynthesis, transpiration, Fv/Frvr ratio and POD activity were not influenced until an O1 concentration of 300 ppb was reached. At this threshold, significant alterations in these physiological and biochemical parameters were found. The treatment with +C02 +O, showed an increase of net photosynthesis suggesting thus an antagonistic effect of CO2 with regard to Oj-induced injuries, while CO2 alone increased photosynthesis and decreased transpiration but induced no effects on FV/‘F, ratio or peroxidase activity. From our data, holm oak shows a resistance to episodes ofphotochemical 0, stress, that in the Mediterranean region can reach peaks of > 100 ppb. This response is likely to be due to the morpho-anatomic structure of helm oak leaves and their sclerophyllous adaptations. This might leads helm oak to adopt a stress tolerance strategy with regard to leaf response to O,, the effects of which cannot be ameliorated by an increase of atmospheric CO2
Keywords: CO2 (voyant); Holm oak; Net photosynthesis; ozone exposure; peroxidase activity; Transpiration

Ozonolysis at vegetation surfaces:: a source of acetone, 4-oxopentanal, 6-methyl-5-hepten-2-one, and geranyl acetone in the troposphere - Fruekilde, P; Hjorth, J; Jensen, N R (Atmospheric Environment, 1998)
ÐThe present study gives a possible explanation for the ubiquitous occurrence of 6-methyl-5- hepten-2-one and acetone in ambient air and reports for the Þrst time on a widespread occurrence of geranyl acetone and 4-oxopentanal. We have conducted a series of laboratory experiments in which it is demonstrated that signiÞcant amounts of geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO), 4-oxopen- tanal (4-OPA), and acetone are formed by the reaction of ozone with foliage of common vegetation in the Mediterranean area (Quercus ilex'Citrus sinensis'Quercus suber'Quercus freinetto'Pinus pinea). In order to rule out biological formation, epicuticular waxes were extracted from the leaves, dispersed on glass wool and allowed to react with a ßow of artiÞcial air. SigniÞcant amounts of 6-MHO and 4-OPA were formed at ozone concentrations of 50Ð100 ppbv, but not at zero ozone. A number of terpenoids common in vegetation contain the structural element necessary for ozonolytic formation of 6-MHO. Two sesquiter- penes (nerolidol; farnesol), and a triterpene (squalene) selected as representative test compounds were demonstrated to be strong precursors for acetone, 4-OPA, and 6-MHO. Squalene was also a strong precursor for geranyl acetone. The atmospheric lifetime of geranyl acetone and 6-MHO is less than 1 h under typical conditions. For the present study, we have synthesized 4-OPA and investigated the kinetics of its gas-phase reaction with OH, NO 3 , and O 3 . A tropospheric lifetime longer than 17 h under typical conditions was calculated from the measured reaction rate constants, which explains the tropospheric occurrence of 4-OPA. It is concluded that future atmospheric chemistry investigations should included geranyl acetone, 6-MHO, and 4-OPA. In a separate experiment it was demonstrated that human skin lipid which contains squalene as a major component is a strong precursor for the four above-mentioned compounds plus nonanal and decanal. The accidental touching of material which later comes into contact with ozone can lead to strong artifact formation of these carbonyl compounds. Previously published results on these compounds must be seen in this new light
Keywords: epicuticular wax; heterogenous reactions; NO3; O3; OH; products; rate; sesquiterpenes; Squalene

Ozonolysis at vegetation surfaces:: a source of acetone, 4-oxopentanal, 6-methyl-5-hepten-2-one, and geranyl acetone in the troposphere - Fruekilde, P.; Hjorth, J.; Jensen, N. R. (Atmospheric Environment, 1998)
ÐThe present study gives a possible explanation for the ubiquitous occurrence of 6-methyl-5- hepten-2-one and acetone in ambient air and reports for the Þrst time on a widespread occurrence of geranyl acetone and 4-oxopentanal. We have conducted a series of laboratory experiments in which it is demonstrated that signiÞcant amounts of geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO), 4-oxopen- tanal (4-OPA), and acetone are formed by the reaction of ozone with foliage of common vegetation in the Mediterranean area (Quercus ilex'Citrus sinensis'Quercus suber'Quercus freinetto'Pinus pinea). In order to rule out biological formation, epicuticular waxes were extracted from the leaves, dispersed on glass wool and allowed to react with a ßow of artiÞcial air. SigniÞcant amounts of 6-MHO and 4-OPA were formed at ozone concentrations of 50Ð100 ppbv, but not at zero ozone. A number of terpenoids common in vegetation contain the structural element necessary for ozonolytic formation of 6-MHO. Two sesquiter- penes (nerolidol; farnesol), and a triterpene (squalene) selected as representative test compounds were demonstrated to be strong precursors for acetone, 4-OPA, and 6-MHO. Squalene was also a strong precursor for geranyl acetone. The atmospheric lifetime of geranyl acetone and 6-MHO is less than 1 h under typical conditions. For the present study, we have synthesized 4-OPA and investigated the kinetics of its gas-phase reaction with OH, NO 3 , and O 3 . A tropospheric lifetime longer than 17 h under typical conditions was calculated from the measured reaction rate constants, which explains the tropospheric occurrence of 4-OPA. It is concluded that future atmospheric chemistry investigations should included geranyl acetone, 6-MHO, and 4-OPA. In a separate experiment it was demonstrated that human skin lipid which contains squalene as a major component is a strong precursor for the four above-mentioned compounds plus nonanal and decanal. The accidental touching of material which later comes into contact with ozone can lead to strong artifact formation of these carbonyl compounds. Previously published results on these compounds must be seen in this new light
Keywords: epicuticular wax; heterogenous reactions; NO3; O3; OH; products; rate; sesquiterpenes; Squalene

Phenolic compounds in cork used for production of wine stoppers as affected by storage and boiling of cork slabs - Mazzoleni, V; Caldentey, P; Silva, A (AMERICAN JOURNAL OF ENOLOGY AND VITICULTURE, 1998)
Phenolic compounds (benzoic and cinnamic acid derivatives, vanillin, syringaldehyde and acetovanillone) were identified in cork used for production of wine stoppers by extraction in an ethanolic solution and by HPLC analysis. The effect of storage and boiling of cork slabs on these compounds were investigated. In each sample, cinnamic acids and vanillin have predominated among phenolics. Boiled cork was significantly different from raw slabs in the concentration of protocatechuic, caffeic, p-coumaric acids, and vanillin. The significant differences between cork from stored and from unstored slabs were evident in protocatechuic, 4-hydroxybenzoic, caffeic, and ferulic acids. Storage of slabs increased the amount of extractable cinnamic acids. On the other hand, boiling decreased the concentration of the same phenolic acids and increased that of vanillin. Boiling after storage can be beneficial to the cork quality, reducing the amount of potentially negative flavor compounds (cinnamic acids) and increasing potentially positive flavor compounds (vanillin).
Keywords: Cork; phenolic compounds; processing of cork slabs

Phenological pattern of fifteen Mediterranean phanaerophytes from shape Quercus ilex communities of NE-Spain - Pilar, C D; Gabriel, M M (Plant Ecology, 1998)
The phenological pattern of ﬁfteen Mediterranean phanaerophytes has been studied in several sites per species, by visiting the populations on a monthly basis over a one year period. Studied phenophases were dolichoblast vegetative growth (DVG), ﬂower bud formation (FBF), ﬂowering (F), fruit setting (FS), seed dispersal (SD), and leaf shedding of dolichoblasts (LSD). Considering the whole set of species, DVG, FBF and F took place mainly in spring, FS in summer, SD in autumn and LSD in summer and in autumn. Interspeciﬁc comparisons showed a wide variety of phenological patterns, which have been sorted according to the ‘phenophase sequence index’ (PSI). This index quantiﬁed the degree of superposition between DVG, FBF and F, and it constituted the basis for a functional classiﬁcation of phenological patterns. Two groups were established. The ‘type I’ group was characterised by the concentration of phenophases in a short time in spring, while the ‘type II’ by the protraction and sequential arrangement of phenophases. Type I species performed most of their functions during a resource surplus period, but they have to face an intraplant competition between vegetative and reproductive demands. Type II species avoided intraplant competition but had to develop part of DVG, FBF and F during sub-optimal periods. It is hypothesised that type I species possess deeper roots, rely on predictable water sources and occupy mature stages of succession. Type II species, on the contrary, are expected to depend on more unpredictable water sources, to possess shallower root systems and to colonise earlier stages of succession. Intraspeciﬁc variability of phenology was found to be low among populations of the same species. Bud structure, which is a phylogenetic trait, may exert important constraints on plant phenology
Keywords: annual cycle; bud type; Mediterranean shrublands; phenophase sequence index

Phenoloxidases of the white-rot fungus Marasmius quercophilus isolated from an evergreen oak litter (Quercus ilex L.) - Tagger, S; Périssol, C; Gil, G; Vogt, G; Le petit, J (Enzyme and Microbial Technology, 1998)
A white-rot basidiomycete, Marasmius quercophilus, was isolated from an evergreen oak litter. This fungus, which very thoroughly bleaches the whole leaf area, produces laccases, a property which has not been studied before. Except on a ground leaf medium, we did not reveal phenoloxidases other than laccases. M. quercophilus is able to transform many aromatic compounds which are by-products of lignin and tannin metabolism. We observed, for example, that lignin monomers, namely p-coumaryl, coniferyl, and sinapyl alcohols are oxidized at different rates by the extracellular crude enzyme extract. The highest production of laccases is obtained with shaking cultures on malt extract supplemented with Tween 80 (0.1%) and CuSO4 (0.5 mg l 21 ). These enzymes have an optimum activity at 80°C and a stable activity at 40°C for 18 h. The extracellular crude enzyme extract medium contains three isoenzymes with pI values of 3.8, 3.5, and 3.2. It is able to significantly reduce the kappa number (21.2%) of a kraft pulp without inclusion of any mediator
Keywords: aromatic compounds; kraft pulp; laccases; Lignin; Marasmius quercophilus; phenoloxidases; tannin monomers

Photochemical response to summer drought in Quercus ilex trees growing in a naturally CO2 enriched site - FARIA, T.; Cerasoli, S.; García-Plazaola, J. I.; Guimaraes, M. P.; Abadia, A.; Raschi, A.; Miglietta, F.; Pereira, J. S.; Chaves, M. M. (IMPACTS OF GLOBAL CHANGE ON TREE PHYSIOLOGY AND FOREST ECOSYSTEMS, 1998)
The effect of the interaction between water stress and growth at elevated CO2 on the leaf photochemistry were studied in Quercus ilex trees, growing in a naturally CO2 enriched site (the Bossoleto, Italy). Those plants were compared with plants growing nearby in similar soils but at ambient CO2 concentration. Our data indicate that down-regulation of photosynthesis is lower in non-watered trees from the enriched site than in non-watered trees from the ambient-CO2 site This may be associated to the higher carbon availability for the consumption of the excess absorbed light energy or to an increased protection of the photochemical apparatus against oxidative stress in plants grown under elevated CO2.
The following values have no corresponding Zotero field: periodical: IMPACTS OF GLOBAL CHANGE ON TREE PHYSIOLOGY AND FOREST ECOSYSTEMS pub-location: PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS
Keywords: Elevated CO2; fluorescence; water stress; xanthophylls

Photochemical response to summer drought in Quercus ilex trees growing in a naturally CO2 enriched site - Faria, T; Cerasoli, S; Garcia-Plazaola, J I; Guimaraes, M P; Abadía, A; Raschi, A; Miglietta, F; Pereira, J S; Chaves, M M (IMPACTS OF GLOBAL CHANGE ON TREE PHYSIOLOGY AND FOREST ECOSYSTEMS, 1998)
The effect of the interaction between water stress and growth at elevated CO2 on the leaf photochemistry were studied in Quercus ilex trees, growing in a naturally CO2 enriched site (the Bossoleto, Italy). Those plants were compared with plants growing nearby in similar soils but at ambient CO2 concentration. Our data indicate that down-regulation of photosynthesis is lower in non-watered trees from the enriched site than in non-watered trees from the ambient-CO2 site This may be associated to the higher carbon availability for the consumption of the excess absorbed light energy or to an increased protection of the photochemical apparatus against oxidative stress in plants grown under elevated CO2.
Keywords: Elevated CO2; fluorescence; water stress; xanthophylls

Photosynthesis and photoprotection in Quercus ilex resprouts after fire - Fleck, I; Hogan, K P; Llorens, L; Abadía, A; Aranda, X (Tree Physiology, 1998)
Plants that resprout after fires often have higher rates of photosynthesis than before a fire. To elucidate the mechanism of this response, we studied gas exchange and chlorophyll fluorescence in Quercus ilex L. plants growing on control (unburned) sites and on sites that had been burned the preceding summer. In early July, photosynthetic rates and stomatal conductance were similar in plants on unburned and burned plots, and in young and old foliage within unburned plots. At this time, photochemical efficiency of photosystem II (PSII), nonphotochemical quenching of chlorophyll fluorescence (NPQ), and the de-epoxidation of violaxanthin to zeaxanthin were also similar among leaves of different ages and treatments. In late July, photosynthetic rates and stomatal conductances were much greater in resprouts on the burned areas than in unburned plants. From early to late July, unburned plants showed an increase in NPQ and the de-epoxidation of violaxanthin to zeaxanthin, indicating increased photoprotection as a result of enhanced nonradiative dissipation of excess light energy. Plants on the burned plots did not show these changes. Leaves of all ages and treatments showed no substantial reduction in potential quantum yield of PSII (Fv/Fm) at midday or predawn, indicating that there was little or no photoinhibition. Leaf nitrogen and soluble protein contents varied with leaf age during July, but did not vary between treatments. We conclude that the primary effect of burning is an increase in water availability to resprouting plants that eliminates the need for photoprotection, at least in the short term. The decrease in photosynthetic rates of unburned leaves in late July was the result of reduced stomatal conductance. We suggest that lowered stomatal conductance is the primary limiting factor in Q. ilex leaves, governing the regulation of carboxylation activity and energy dissipation processes.
10.1093/treephys/18.8-9.607
Keywords: chlorophyll fluorescence; Gas exchange; Holm oak; photoinhibition; Photosystem II; zeaxanthin

Pollen calendar of the city of Salamanca (Spain). Aeropalynological analysis for 1981-1982 and 1991-1992. - Hernández Prieto, M; Lorente Toledano, F; Romo Cortina, A; Dávila González, I; Laffond Yges, E; Calvo Bullón, A (Allergol Immunopathol (Madr), 1998)
We report a study on the contents of airborne pollen in the city of Salamanca (Spain) aimed at establishing a pollen calendar for the city for the yearly periods of maximum concentrations, relating these with quantifiable atmospheric variables over two two-year periods with an interval of 10 years between them: 1981-82 and 1991-92. The pollen was captured with Burkard spore-traps, based on Hirst's volumetric method. Determinations were made daily and were used to make preparations, previously stained with basic fuscin, for study under light microscopy at x 1,000 magnification. 946 preparations were analyzed, corresponding to the same number of days distributed over 150 weeks of the periods studied. The results afforded the identification of 48 different types of pollen grain: Grasses (Poaceae), Olea europea (olive), Quercus rotundifolia (Holm-oak), other Quercus spp. (Q. pyrenaica, Q. suber, Q. faginea, etc.), Cupressaceae (Cupressus sempervivens, C. arizonica, Juniperus communis etc.), Plantago (Plantago lanceolata, Plantago media, etc.), Pinaceae (Pinus communis, Abies alba, etc.), Rumex sp. (osier), Urtica dioica (nettle), Parietaria (Parietaria officinalis, P. judaica), Chenopodio-Amaranthaceae (Chenopodium sp., Amaranthus sp., Salsola kali, etc.), Artemisia vulgaris (Artemisia), other Compositae (Taraxacum officinalis, Hellianthus sp. etc.), Castanea sativa (Chestnut), Ligustrum sp. (privet), Betula sp. (birch), Alnus sp. (common alder), Fraxinus sp (ash), Populus sp. (poplar), Salix sp. (willow), Ulmus sp. (elm), Platanus sp. (plantain, plane), Carex sp. (sweet flag), Erica sp. (common heather), Leguminosae or Fabaceae:--Papillionaceae (Medicago sp.; Cercis sp., Robina sp.)--Cesalpinoideae Acacia sp. (Acacia),--Mimosoideae: Sophora japonica, Umbelliferae (Foeniculum sp., Cirsium sp., etc.), Centaurea sp., Cistus sp. (rock rose), Typha sp (bulrush), Mirtaceae (Myrtus communis), Juglans regia (Walnut), Galium verum, Filipendula sp. (spirea/drop wort), Rosaceae (Pyrus sp., Prunus sp., etc.), Tilia sp. (Linden), Morus sp. (mulberry), Taxus baccata (yew), Papaveraceae (Papaver rhoeas etc.), Labiata (Lavandula sp.), Cannabaceae (Humulus sp. etc.), Liliaceae (Lilium sp.), Echium sp. (viper's bugloss). The most abundant taxa, detected in the highest quantities (grains/m3 air), by order of counting were as follows: holm-oak, olive, grasses, Plantago and Parietaria. With the data obtained we have established a pollen calendar for Salamanca and report the period in which each type of pollen is found along the years and the periods with the highest airborne concentrations of such pollens. The diversity and the spectrum of the pollen in the city of Salamanca correspond to the typical plant communities found on the dehesas (large ranges of grasslands) of Castile, where Salamanca is located, although the wind directions and the peculiar climatic characteristics of the area govern the peaks of maximum presence of the different taxa. As examples, in the case of olive, which is cultivated at some distance from the city, its maximum presence coincides with south-westerly winds; in the case of grasses, the peaks of maximum counts coincide with a sharp rise in mean temperature, close to or higher than 20 degrees C and between five and six weeks after rainfall equal to or greater than 5 L/m2.
APS
Keywords: pollen concentrations; Spain

The pollen spectrum of trees and shrubs in SW Spain (1987–1996) - Gonzalez Minero, Francisco Jose; Candau, Pilar; Morales, Julia; Tomas, Carmen (Grana, 1998)
A Cour trap was used to sample the air of Seville of continuously from 1987 to 1996. The most important climatological feature recorded during that period was the drought that began in 1990 and which was at its most severe in the first half of 1995. The behaviour of a total of 20 pollen types was studied: those exceeding 0.01% of the total pollen collected during the ten?year period. These were Quercus, Olea Cupressaceae, Platanus Myrtaceae, Pinaceae, Palmae, Moraceae, Fraxinus Ericaceae, Citrus, Pistacia, Acer, Casuarina Salicaceae, Ulmus, Alnus, Castanea Cistaceae, and Viburnum. The following aspects are described and analysed: the spectrum of tree and shrub types identified in the air, and their possible significance for allergies; the relationship between the woody vegetation of the region and the composition of the pollen spectrum in quantitative terms; and the possible effect of the drought on annual variations total pollen concentrations. A detailed study of olive pollen, aimed at finding applications in allergy and agriculture is also given. In particular, the possibility of forecasting both the date of olive pollination from observations of preceding mean temperatures, and the size of the crop from palynological and agronomical data.
doi: 10.1080/00173139809362653doi: 10.1080/00173139809362653The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: airborne pollen; Olive pollination; pollen concentrations (voyant); Pollen spectrum

Polyphenol deposition in leaf hairs of Olea europaea (Oleaceae) and Quercus ilex (Fagaceae) - Karabourniotis, G; Kofidis, G; Fasseas, C; Liakoura, V; Drossopoulos, I (AMERICAN JOURNAL OF BOTANY, 1998)
The subcellular localization (cytoplasm, vacuoles, cell walls) of polyphenol compounds during the development of the multicellular nonglandular leaf hairs of Olea europaea (scales) and Quercus ilex (stellates), was investigated. Hairs of all developmental stages were treated with specific inducers of polyphenol fluorescence, and the bright yellow-green fluorescence of individual hairs was monitored with epifluorescence microscopy. During the early ontogenetic stages, bright fluorescence was emitted from the cytoplasm of the cells composing tie multicellular shield of the scales of O. europaea. Transmission electron micrographs of the same stages showed that these cells possessed poor vacuolation and thin cell walls. The nucleus of these cells may be protected against ultraviolet-B radiation damage. The progressive vacuolation that occurred during maturation was followed by a shifting of the bright green-yellow fluorescence from the perinuclear region and the cytoplasm to the cell walls. The same trends were observed during the development of the nonglandular stellate hairs of Quercus ilex, in which maturation was also accompanied by a considerable secondary thickening of the cell walls. Despite the differences in morphology, high concentrations of polyphenol compounds are initially located mainly in the cytoplasm of the developing nonglandular hairs, and their deposition on the cell walls rakes place during the secondary cell wall thickening. These structural changes during the development of the leaf hairs make them a very effective barrier against abiotic (UV-B radiation) and probably biotic (pathogenic) stresses.
Keywords: cell walls; development; leaf hairs; Olea europaea; phenolics; Quercus ilex; ultraviolet-B radiation damage

Polyphenolic Composition of Quercus suber Cork from Different Spanish Provenances - Conde, Elvira; Cadahía, Estrella; García-Vallejo, María Concepción; Fernández de Simón, Brígida (Journal of Agricultural and Food Chemistry, 1998)
Polyphenolic composition was studied by HPLC and classical chemical methods in reproduction cork of Quercus suber from different Spanish provenances. The low molecular weight polyphenols (gallic, protocatechuic, vanillic, caffeic, ferulic, and ellagic acids; protocatechuic, vanillic, coniferyl, and sinapic aldehydes; and aesculetin and scopoletin) and the ellagitannins (roburins A and E, grandinin, vescalagin, and castalagin) were identified and quantified. Ellagic acid was the main component in the ether soluble fraction, and the group of hydrolyzable tannins, and among them castalagin, was the most abundant in the tannic extract in all the samples. Although there was an important variability among provenances, no significant differences were found in the total tannin content and in the individual content of each ellagitannin. However, gallic and caffeic acids and protocatechuic aldehyde provided the greatest discrimination among provenances. Keywords: Quercus suber; cork; polyphenols; tannins; phenolic acids and aldehydes; coumarins; ellagitannins; high-performance liquid chromatography
doi: 10.1021/jf970863k
Keywords: Cork; coumarins; ellagitannins; high-performance liquid chromatography; phenolic acids and aldehydes; polyphenols; Quercus suber; Tannins

Polyphenolic Composition of Quercus suber Cork from Different Spanish Provenances - Conde, Elvira; Cadahía, Estrella; García-Vallejo, María Concepción; Fernández de Simón, Brígida (Journal of Agricultural and Food Chemistry, 1998)
Polyphenolic composition was studied by HPLC and classical chemical methods in reproduction cork of Quercus suber from different Spanish provenances. The low molecular weight polyphenols (gallic, protocatechuic, vanillic, caffeic, ferulic, and ellagic acids; protocatechuic, vanillic, coniferyl, and sinapic aldehydes; and aesculetin and scopoletin) and the ellagitannins (roburins A and E, grandinin, vescalagin, and castalagin) were identified and quantified. Ellagic acid was the main component in the ether soluble fraction, and the group of hydrolyzable tannins, and among them castalagin, was the most abundant in the tannic extract in all the samples. Although there was an important variability among provenances, no significant differences were found in the total tannin content and in the individual content of each ellagitannin. However, gallic and caffeic acids and protocatechuic aldehyde provided the greatest discrimination among provenances. Keywords: Quercus suber; cork; polyphenols; tannins; phenolic acids and aldehydes; coumarins; ellagitannins; high-performance liquid chromatography
doi: 10.1021/jf970863kdoi: 10.1021/jf970863kThe following values have no corresponding Zotero field: publisher: American Chemical Society
Keywords: Cork; coumarins; ellagitannins; high-performance liquid chromatography; phenolic acids and aldehydes; polyphenols; Quercus suber; Tannins

Predators of gypsy moth egg masses in the Mamora cork oak forest (Morocco) - Villemant, C (BULLETIN DE LA SOCIETE ZOOLOGIQUE DE FRANCE, 1998)
In Morocco oophagous predators are one of the main mortality factors of the gypsy moth. These insects consume the eggs but cause more noticeable damage by disrupting the egg masses. During July-March, when gypsy moth eggs are present, 14 species of predators follow, eating and damaging egg masses. From 1987 to 1990, oophagous predators destroyed 60 to 90% of eggs and therefore played a determinant role in the collapse of a localized gypsy moth population.

Prediction of the feeding background of Iberian pigs using the fatty acid profile of subcutaneous, muscle and hepatic fat. - Ruiz, J; Cava, R; Antequera, T; Martín, L; Ventanas, J; López-Bote, C J (Meat science, 1998)
Thirty Iberian pigs weighing 95 kg were randomly distributed into three groups of 10 animals each and fattened in three traditional management systems ['montanera' (MO), fed extensively on acorns, 'cebo' (CE) fed on a commercial diet and 'recebo' (RE), fed on acorns and a commercial diet]. Fatty acids from the Masseter muscle, lard and liver were analysed. In the lard, fatty acid profiles from MO and RE pigs presented minor differences; however, in the liver, RE pigs showed differences to MO pigs in most of the fatty acids studied. This suggests that the muscle and especially the liver fatty acid profile reflects the feeding regime during the last phase of feeding, while the lard reflects longer term differences.
Keywords: Fatty acid profile; Feeding regime (voyant); iberian pig

Production of free range chickens in the Spanish South-west - Duran, A M; Pascual, M R P (BASIS OF THE QUALITY OF TYPICAL MEDITERRANEAN ANIMAL PRODUCTS, 1998)
The object of this study is to elaborate a description of the products obtained from the breeding of free range chickens in the Spanish South-west, considering the possible sex influence. 24 Redstar Shaver chickens were used, 12 males and 12 females chickens. The animals were controlled weekly to determine productive yields when alive. After their slaughter, notes on carcasses and meats were taken. The males weighted more at the slaughter time and presented a better yield of the eviscerated carcass. The females showed a greater abdominal fat content and the regional composition was virtually the same in both sexes, however a greater percentage of legs was found in the males. The dissection of the inferior extremities showed a greater edible meat content in the females chickens. The organoLeptic tests (pH and water holding capacity CRA) presented relevant differences between sexes (greater pH and CRA. in the males). The comparison of the meat nutritive Value (protein and ashes) did not show relevant differences between males and females. This study shows that male and female chickens are products with similar nutritive value but distinguishable by other parameters.
Keywords: Dehesa; extensive chickens; production; Quality meat; sex poultry carcass

Production of free range chickens in the Spanish South-west - Duran, A. M.; Pascual, M. R. P. (BASIS OF THE QUALITY OF TYPICAL MEDITERRANEAN ANIMAL PRODUCTS, 1998)
The object of this study is to elaborate a description of the products obtained from the breeding of free range chickens in the Spanish South-west, considering the possible sex influence. 24 Redstar Shaver chickens were used, 12 males and 12 females chickens. The animals were controlled weekly to determine productive yields when alive. After their slaughter, notes on carcasses and meats were taken. The males weighted more at the slaughter time and presented a better yield of the eviscerated carcass. The females showed a greater abdominal fat content and the regional composition was virtually the same in both sexes, however a greater percentage of legs was found in the males. The dissection of the inferior extremities showed a greater edible meat content in the females chickens. The organoLeptic tests (pH and water holding capacity CRA) presented relevant differences between sexes (greater pH and CRA. in the males). The comparison of the meat nutritive Value (protein and ashes) did not show relevant differences between males and females. This study shows that male and female chickens are products with similar nutritive value but distinguishable by other parameters.
The following values have no corresponding Zotero field: periodical: BASIS OF THE QUALITY OF TYPICAL MEDITERRANEAN ANIMAL PRODUCTS issue: 90 pub-location: POSTBUS 220, 6700 AE WAGENINGEN, NETHERLANDS
Keywords: Dehesa; extensive chickens; production; Quality meat; sex poultry carcass

PRODUCTIVIDAD Y PERSISTENCIA DE ECOTIPOS AUTÓCTONOS DE TRÉBOL SUBTERRÁNEO DE LA DEHESA SALMANTINA EN CONDICIONES DE - Crespo Martínez, M. C.; Cordero Castaño, S. A. (Pastos, 1998)
Se ha estudiado el comportamiento de 10 ecotipos autóctonos de trébol subterráneo (Trifolium subterraneum L.), de la provincia de Salamanca, aprovechados bajo pastoreo continuo y cargas ganaderas de 4, 6 y 8 ovejas por hectárea, con el objeto de evaluar su persistencia y productividad. Se ha utilizado como testigo principal la variedad de trébol subterráneo 'Valmoreno' seleccionada en Extremadura. Los ecotipos autóctonos han mostrado su buena adaptación, logrando en algunos casos prácticamente duplicar en número de plantas por metro cuadrado en el segundo año del ensayo a la variedad testigo, que además fue superada en producción de materia seca por el ecotipo autóctono menos productivo en 1100 kg/ha, lo que supone un incremento del 85 %. Se considera el interés de utilizar material autóctono en la mejora de la productividad de los pastizales de esta zona ganadera. Palabras
Keywords: mejora de pastos; recursos fítogenéticos; Trifolium subterraneum L.

PRODUCTIVIDAD Y PERSISTENCIA DE ECOTIPOS AUTÓCTONOS DE TRÉBOL SUBTERRÁNEO DE LA DEHESA SALMANTINA EN CONDICIONES DE - Crespo Martínez, M C; Cordero Castaño, S A (Pastos, 1998)
Se ha estudiado el comportamiento de 10 ecotipos autóctonos de trébol subterráneo (Trifolium subterraneum L.), de la provincia de Salamanca, aprovechados bajo pastoreo continuo y cargas ganaderas de 4, 6 y 8 ovejas por hectárea, con el objeto de evaluar su persistencia y productividad. Se ha utilizado como testigo principal la variedad de trébol subterráneo 'Valmoreno' seleccionada en Extremadura. Los ecotipos autóctonos han mostrado su buena adaptación, logrando en algunos casos prácticamente duplicar en número de plantas por metro cuadrado en el segundo año del ensayo a la variedad testigo, que además fue superada en producción de materia seca por el ecotipo autóctono menos productivo en 1100 kg/ha, lo que supone un incremento del 85 %. Se considera el interés de utilizar material autóctono en la mejora de la productividad de los pastizales de esta zona ganadera. Palabras
Keywords: mejora de pastos; recursos fítogenéticos; Trifolium subterraneum L.

Recent evolution of the Jbel Hebri forest (Western Middle Atlas, Morocco) - Labhar, M; Tanghe, M (BELGIAN JOURNAL OF BOTANY, 1998)
This study deals with the different aspects of forest evolution on the Jbel Hebri mountain ranges. On the basis of a comparative aerial photograph analysis (1962 and 1987 missions) completed by photogrammetry and field observations, the vegetation structure and its succession stages have been recognized. Although the total forest area remains unchanged, the physiognomic stages of identified communities (Cedrus atlantica forest; Quercus rotundifolia forest; mixed forest with Cedrus atlantica and Quercus rotundifolia) show heterogenous evolution. Depending on species and forest components we note paradoxal evolutionary tendencies. Systematic degradation due to harvesting and resource overuse is locally observed beside regenerated and densified parts. Therefore, the system dynamics reflects the locally variable factors such as soil hydrology and human impact.
APS
Keywords: areial photograph; forest evolution; photogrammetry; Quercus ilex; vegetation structure

Reconstruction of Late-glacial and Holocene environments in southeast France based on the study of a 66-m long core from Biot, Alpes Maritimes - Nicol-Pichard, S; Dubar, M (VEGETATION HISTORY AND ARCHAEOBOTANY, 1998)
A pollen analytical study of a 66-m long core from the Prague valley, Plot, Alpes-Maritimes, France, suggests that thalwegs in eastern Provence may have served as refugia for mesophilous trees such as Tilia, Fagus and Abies during the last glacial period. During the Younger Dryas the vegetation was considerably less steppic in character than that described from western Provence. The varying role of taxa such as Quercus ilex-type in pollen profiles from the wider region suggests a longitudinal gradient in both climate and vegetation development in the French/Italian north-western mediterranean region during the Holocene.
Keywords: France Glacial refugia; Holocene; Late-glacial; Mediterranean; Pollen analysis

Relationship between photosynthetic activity and chlorophyll content in an isolated Quercus ilex L. tree during the year - Gratani, L; Pesoli, P; Crescente, M F (Photosynthetica, 1998)
The relationship between chlorophyll (Chl) content and net photosynthetic rate (PN) in an isolated Quercus ilex tree, growing inside Villa Pamphili Park in Rome, was explored. The highest Pn was in March, May and September (10.1 umol.m-2.s-1, maximum rate). Pn decreased by 65% (with respect to the yearly maximum) when leaf temperature reached 34ºC, and by 50% when leaf temperature was 9ºC. The highest Chl contents were in April, October [1.47g.kg-1 (d.m.), maximum value], and December. The lowest Chl content was found in July (0.78 g.kg-1). The decrease of PN in July was in close connection with the decrease of Chl content. On the contrary, the high Chl content during winter did not correspond with PN of this season. Discordances between Chl content and PN over the year influenced the regression analysis, which although positive did not show very high correlation coefficients (r=0.79. The high Chl (a+b) content during most of the year indicated that the photosynthetic apparatus remained basically intact also during stress periods.
Keywords: net photosynthetic rate; oak; Regression Analysis; seasonal course; Stomatal conductance

Response of foliar metabolism in mature trees of Quercus pubescens and Quercus ilex to long-term elevated CO 2 - Tognetti, Roberto; Johnson, J. D. (Environmental and Experimental Botany, 1998)
Long-term effects on and adaptations of the carbon physiology of long-lived trees exposed to increasing atmospheric levels of CO2 are unknown. We compared two indigenous Quercus species, Q. ilex and Q. pubescens, growing in a natural CO2 spring located in central Italy and at a nearby control site. In May, 1995 photosynthetic rate at least doubled when measured with supplemental CO2 in both species and sites. Dark respiration was much higher at the CO2 spring site in both species. Foliar sugar and starch concentrations in Q. ilex exhibited signiﬁcant site and diurnal differences (May and September). In July, 1995 there was little difference in the water potential values of the measured trees at the different sites over the diurnal period. Photosynthetic rate was higher for both species in the CO2 spring, particularly in the early morning and late afternoon. Mid-day stomatal closure reduced photosynthesis to similar levels. In the morning leaf conductance and transpiration were generally lower in the CO2 spring trees, contributing to higher instantaneous water use efﬁciency for both species. Isoprene emission rates were higher in Q. pubescens trees growing in the CO2 spring. The maximum difference between control and CO2 spring trees occurred in late afternoon. In contrast, Q. ilex exhibited isoprene emission near background level. Foliage and branch carbon and nitrogen status showed increased concentrations of starch and tannins in Q. ilex and of soluble sugars in Q. pubescens in the elevated CO2 environment, while nitrogen concentration decreased in both species. Wood gravity increased 6 and 3% in Q. ilex and Q. pubescens, respectively, growing in the CO2 spring. Q. ilex exhibited afternoon recovery of water potential compared to Q. pubescens which had better night-time recovery. Q. ilex and Q. pubescens exposed to elevated CO2 for prolonged periods exhibit different mechanisms for dealing with additional reduced carbon and do maintain an altered carbon physiology, even in midst of the region’s characteristic summer drought
Keywords: Elevated CO2; Gas exchange; natural CO2 springs; Quercus; Secondary compounds

Response of foliar metabolism in mature trees of Quercus pubescens and Quercus ilex to long-term elevated CO 2 - Tognetti, Roberto; Johnson, J D (Environmental and Experimental Botany, 1998)
Long-term effects on and adaptations of the carbon physiology of long-lived trees exposed to increasing atmospheric levels of CO2 are unknown. We compared two indigenous Quercus species, Q. ilex and Q. pubescens, growing in a natural CO2 spring located in central Italy and at a nearby control site. In May, 1995 photosynthetic rate at least doubled when measured with supplemental CO2 in both species and sites. Dark respiration was much higher at the CO2 spring site in both species. Foliar sugar and starch concentrations in Q. ilex exhibited signiﬁcant site and diurnal differences (May and September). In July, 1995 there was little difference in the water potential values of the measured trees at the different sites over the diurnal period. Photosynthetic rate was higher for both species in the CO2 spring, particularly in the early morning and late afternoon. Mid-day stomatal closure reduced photosynthesis to similar levels. In the morning leaf conductance and transpiration were generally lower in the CO2 spring trees, contributing to higher instantaneous water use efﬁciency for both species. Isoprene emission rates were higher in Q. pubescens trees growing in the CO2 spring. The maximum difference between control and CO2 spring trees occurred in late afternoon. In contrast, Q. ilex exhibited isoprene emission near background level. Foliage and branch carbon and nitrogen status showed increased concentrations of starch and tannins in Q. ilex and of soluble sugars in Q. pubescens in the elevated CO2 environment, while nitrogen concentration decreased in both species. Wood gravity increased 6 and 3% in Q. ilex and Q. pubescens, respectively, growing in the CO2 spring. Q. ilex exhibited afternoon recovery of water potential compared to Q. pubescens which had better night-time recovery. Q. ilex and Q. pubescens exposed to elevated CO2 for prolonged periods exhibit different mechanisms for dealing with additional reduced carbon and do maintain an altered carbon physiology, even in midst of the region’s characteristic summer drought
Keywords: Elevated CO2; Gas exchange; natural CO2 springs; Quercus; Secondary compounds

Response of two populations of holm oak (Quercus rotundifolia Lam.) to sulfur dioxide. - García, D.; Rodríguez, J.; Sanz, J. M.; Merino, J. (Ecotoxicology and environmental safety, 1998)
Experiments were carried out with seedlings of Quercus rotundifolia Lam., an evergreen schlerophyllous tree typical of the Spanish Mediterranean climate environments. Fruits were collected in two distant (800 km) populations located in the center (southern Spain) and northern border (northern Spain) of the area of distribution of the species. One-month-old potted plants were grown for 130 days in an enriched atmosphere of SO2 (0.23 ppm, 14 h/day) in controlled (growth chamber) 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.
The following values have no corresponding Zotero field: accession-num: 9626534
Keywords: Adaptation; Air Pollutants; Air Pollutants: adverse effects; air pollution; biomass; Environment; GROWTH RATE; photosynthesis; Photosynthesis: physiology; Physiological; Plant physiology; Pollutants; Quercus rotundifolia; Sulfur Dioxide; Sulfur Dioxide: adverse effects; Sulphur dioxide; Trees; Trees: drug effects; Trees: genetics; Trees: physiology

Response of two populations of holm oak (Quercus rotundifolia Lam.) to sulfur dioxide. - García, D; Rodríguez, J; Sanz, J M; Merino, J (Ecotoxicology and environmental safety, 1998)
Experiments were carried out with seedlings of Quercus rotundifolia Lam., an evergreen schlerophyllous tree typical of the Spanish Mediterranean climate environments. Fruits were collected in two distant (800 km) populations located in the center (southern Spain) and northern border (northern Spain) of the area of distribution of the species. One-month-old potted plants were grown for 130 days in an enriched atmosphere of SO2 (0.23 ppm, 14 h/day) in controlled (growth chamber) 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: Adaptation; Air Pollutants; Air Pollutants: adverse effects; air pollution; biomass; Environment; GROWTH RATE; photosynthesis; Photosynthesis: physiology; Physiological; Plant physiology; Pollutants; Quercus rotundifolia; Sulfur Dioxide; Sulfur Dioxide: adverse effects; Sulphur dioxide; Trees; Trees: drug effects; Trees: genetics; Trees: physiology

Retrieving leaf conductances from sap flows in a mixed Mediterranean woodland: a scaling exercise - Filho Teixeira, José; Damesin, Claire; Rambal, Serge; Joffre, Richard (Ann. For. Sci., 1998)
Xylem sap-flux densities were monitored continuously using Granier-type sensors on five Quercus ilex, four Arbutus unedo and one Quercus pubescens from June 1993 to October 1994. Half-hourly measurements of incoming solar radiation, air temperature and humidity, horizontal wind speed and precipitation were carried out at the top of a tower at a height of 12 m, about 2 m above the canopy. Leaf physiological measurements (stomatal conductance, water potential) on individual sunlit leaves from each of the three tree species were obtained on seven complete or partial diurnal time courses. For these three species, to estimate leaf stomatal conductance, we used the big-leaf approach of Penman-Monteith. We have divided the leaves into sunlit and shaded. The model sums the individual-leaf model for only the sunlit fraction to produce the whole-canopy predictions. Transpiration was deduced from sap flux through a transfer function taking into account stem water storage. Stomatal conductance for a given species was evaluated half-hourly from transpiration and microclimate data inverting the Penman-Monteith equation. An empirical model was identified that related stomatal aperture to simultaneous variations of microclimate and plant water potential for the 1993 period. The predicted leaf conductances were validated against porometer data and those of the 1994 period. The diurnal patterns of predicted and measured transpiration indicated that stomatal conductance was accurately predicted. The leaf conductance models were also compared with already published literature values from the same tree species. In spite of the simplifications inherent to the big-leaf representation of the canopy, the model is useful for predicting interactions between Mediterranean mixed woodland and environment and for interpreting H2 O exchange measurements
Keywords: Arbutus unedo; mixed Mediterranean woodland; Penman-Monteith equation; Quercus ilex; Quercus pubescens; sap flow; stomatal and canopy conductances

Retrieving leaf conductances from sap flows in a mixed Mediterranean woodland: a scaling exercise - Filho Teixeira, José; Damesin, Claire; Rambal, Serge; Joffre, Richard (Ann. For. Sci., 1998)
Xylem sap-flux densities were monitored continuously using Granier-type sensors on five Quercus ilex, four Arbutus unedo and one Quercus pubescens from June 1993 to October 1994. Half-hourly measurements of incoming solar radiation, air temperature and humidity, horizontal wind speed and precipitation were carried out at the top of a tower at a height of 12 m, about 2 m above the canopy. Leaf physiological measurements (stomatal conductance, water potential) on individual sunlit leaves from each of the three tree species were obtained on seven complete or partial diurnal time courses. For these three species, to estimate leaf stomatal conductance, we used the big-leaf approach of Penman-Monteith. We have divided the leaves into sunlit and shaded. The model sums the individual-leaf model for only the sunlit fraction to produce the whole-canopy predictions. Transpiration was deduced from sap flux through a transfer function taking into account stem water storage. Stomatal conductance for a given species was evaluated half-hourly from transpiration and microclimate data inverting the Penman-Monteith equation. An empirical model was identified that related stomatal aperture to simultaneous variations of microclimate and plant water potential for the 1993 period. The predicted leaf conductances were validated against porometer data and those of the 1994 period. The diurnal patterns of predicted and measured transpiration indicated that stomatal conductance was accurately predicted. The leaf conductance models were also compared with already published literature values from the same tree species. In spite of the simplifications inherent to the big-leaf representation of the canopy, the model is useful for predicting interactions between Mediterranean mixed woodland and environment and for interpreting H2 O exchange measurements
Keywords: Arbutus unedo; mixed Mediterranean woodland; Penman-Monteith equation; Quercus ilex; Quercus pubescens; sap flow; stomatal and canopy conductances

Rhythmic growth rings of wood and their relationship with the foliage in oak seedlings grown in a favourable environment - MANSOUR, A.; de FAŸ, E. (Annals of botany, 1998)
{{The anatomy of wood was studied in Quercus robur L. and Quercus suber L. seedlings exhibiting 3±8 units of extension, each with a tier of photosynthesizing leaves in their upper parts, generated as the result of rhythmic shoot growth under favourable conditions. At all the axis levels examined (i.e. the base of each of the diﬀerent units of extension, four other equidistant levels within the ®rst unit of extension and the upper part of the taproot), the wood displayed rings when treated with Wiesner reagents. This indicated cinnamaldehyde groups present in lignins. No rings appeared when the Mau$le reaction was used for speci®c detection of syringyl subunits in lignins. A trend towards a periodical arrangement of xylem parenchyma bands was also found when sections were treated with I # }KI. The number of rings coincided with the number of leaf tiers above the level of measurement, and did not vary inside the ®rst unit of extension. Thus, the rings are called rhythmic growth rings. In sections of the ®rst and the second units of extension, and in the taproot, the area and width of a given rhythmic growth ring were highly correlated with the total area of leaves present above the level of measurement at the presumed time of growth ring formation. Moreover, stem diameter at the base of the units of extension was highly correlated with the leaf area above. These results indicate that diﬀerentiation of xylem, particularly its ligni®cation, varies rhythmically in oak seedlings. They imply that wood production is linked to the photosynthesizing and}or transpiring area of the plant. Thus, during a growth cycle of Q. robur and Q. suber seedlings, there appears to be integration of the primary metabolic activities with the laying down of rhythmic growth rings
Keywords: allometric relationship; juvenile wood; leaf area; lignification; oak seedling; periodic structure; quercus robur l; Quercus Suber L; rhythmic growth ring; unit of extension

Rhythmic growth rings of wood and their relationship with the foliage in oak seedlings grown in a favourable environment - MANSOUR, A; de FAŸ, E (Annals of botany, 1998)
{{The anatomy of wood was studied in Quercus robur L. and Quercus suber L. seedlings exhibiting 3±8 units of extension, each with a tier of photosynthesizing leaves in their upper parts, generated as the result of rhythmic shoot growth under favourable conditions. At all the axis levels examined (i.e. the base of each of the diﬀerent units of extension, four other equidistant levels within the ®rst unit of extension and the upper part of the taproot), the wood displayed rings when treated with Wiesner reagents. This indicated cinnamaldehyde groups present in lignins. No rings appeared when the Mau$le reaction was used for speci®c detection of syringyl subunits in lignins. A trend towards a periodical arrangement of xylem parenchyma bands was also found when sections were treated with I # }KI. The number of rings coincided with the number of leaf tiers above the level of measurement, and did not vary inside the ®rst unit of extension. Thus, the rings are called rhythmic growth rings. In sections of the ®rst and the second units of extension, and in the taproot, the area and width of a given rhythmic growth ring were highly correlated with the total area of leaves present above the level of measurement at the presumed time of growth ring formation. Moreover, stem diameter at the base of the units of extension was highly correlated with the leaf area above. These results indicate that diﬀerentiation of xylem, particularly its ligni®cation, varies rhythmically in oak seedlings. They imply that wood production is linked to the photosynthesizing and}or transpiring area of the plant. Thus, during a growth cycle of Q. robur and Q. suber seedlings, there appears to be integration of the primary metabolic activities with the laying down of rhythmic growth rings
Keywords: allometric relationship; juvenile wood; leaf area; lignification; oak seedling; periodic structure; quercus robur l; Quercus Suber L; rhythmic growth ring; unit of extension

Roe deer habitat selection in Spain: constraints on the distribution of a species - Virgos, E; Tellería, J L (Canadian Journal of Zoology, 1998)
This study analyzes the role of summer habitat selection in determining the distribution of a population of roe deer (Capreolus capreolus L.) in central Spain, where surplus individuals have emigrated from mountains to the surrounding plateaus during the last decade. The species was more abundant in the mesic mountain forests (Scots pine (Pinus sylvestris), Pyrenean oak (Quercus pyrenaica)) than in the xeric, sclerophyllous holm oak (Quercus ilex) forests of surrounding plateaus. Roe deer prefer patches occupied by brambles (Rubus spp.) and rose bushes (Rosa spp.) and patches with higher cover on pastures and moors (Erica spp. and Calluna spp.). These vegetation types are linked to moist soils in the Mediterranean zone, indicating that roe deer prefer the moister, more productive patches. Roe deer actively selected productive patches covered by leguminous shrubs (Sarothamnus, Retama) and rejected poor patches covered by Cistus ladanifer and Cistus laurifolius (two shrubs that produce chemicals toxic to other plants). Low summer primary productivity of xeric, sclerophyllous forests can explain the low abundance of roe deer in these forests. This supports the view that habitat constraints limit numbers and distribution of this Palaearctic species at the southern edge of its range.
doi: 10.1139/z98-065
Keywords: habitat selection; leguminous shrubs (PG); roe deer

Roe deer habitat selection in Spain: constraints on the distribution of a species - Virgos, E.; Tellería, J. L. (Canadian Journal of Zoology, 1998)
This study analyzes the role of summer habitat selection in determining the distribution of a population of roe deer (Capreolus capreolus L.) in central Spain, where surplus individuals have emigrated from mountains to the surrounding plateaus during the last decade. The species was more abundant in the mesic mountain forests (Scots pine (Pinus sylvestris), Pyrenean oak (Quercus pyrenaica)) than in the xeric, sclerophyllous holm oak (Quercus ilex) forests of surrounding plateaus. Roe deer prefer patches occupied by brambles (Rubus spp.) and rose bushes (Rosa spp.) and patches with higher cover on pastures and moors (Erica spp. and Calluna spp.). These vegetation types are linked to moist soils in the Mediterranean zone, indicating that roe deer prefer the moister, more productive patches. Roe deer actively selected productive patches covered by leguminous shrubs (Sarothamnus, Retama) and rejected poor patches covered by Cistus ladanifer and Cistus laurifolius (two shrubs that produce chemicals toxic to other plants). Low summer primary productivity of xeric, sclerophyllous forests can explain the low abundance of roe deer in these forests. This supports the view that habitat constraints limit numbers and distribution of this Palaearctic species at the southern edge of its range.
doi: 10.1139/z98-065doi: 10.1139/z98-065The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: habitat selection; leguminous shrubs (PG); roe deer

Sclerophyllous vegetation dynamics in the north of the Iberian peninsula during the last 16,000 years - RAMIL-REGO, P; RODRÍGUEZ-GUITIÁN, M; MUÑOZ-SOBRINO, C (Global Ecology and Biogeography, 1998)
We used pollen analysis to evaluate the dynamics of sclerophyllous arboreal taxa during the last 16,000 years. Quercus ilex type pollen and, to a lesser degree, other sclerophyllous elements (e.g. Olea and Phillyrea) have been documented during the Late-glacial in the majority of the sequences obtained in continental territories in the north of the Iberian peninsula, as well as in the eastern coastal/sub-coastal area in the Cantabric region. During the Late-glacial and the Holocene, sclerophyllous elements became widespread in many areas of the north Iberian peninsula (the Sil, Duero and Ebro depressions and the southernmost slopes of adjacent mountains), with the smallest pollinic representation of these taxa being for the most septentrional areas (coastal/sub-coastal territories and the northermost slopes of the Cantabrian-Atlantic Mountains). During these periods, there is no indication of the presence of Quercus ilex pollen in the northwestern territories, which would explain the absence of this species in the present-day landscape. Despite the widespread distribution that sclerophyllous elements have maintained during the last 16,000 years, they have never attained a predominant role in the landscape, having a smaller representation, both during hotter and colder phases, than deciduous forests, pine forests and mixed forests.
Keywords: Holocene; iberian peninsula; Late-glacial; palynology; Quercus ilex; sclerophyllous forests; species range; vegetation history

Seasonal and annual changes in leaf δ13C in two co-occurring Mediterranean oaks: relations to leaf growth and drought progression - Damesin, C; Rambal, S; Joffre, R (Functional Ecology, 1998)
1. Changes of δ13C and its relation to leaf development, biochemical content and water stress were monitored over a 2 year period in two co-occurring Mediterranean oak species: the deciduous Quercus pubescens and the evergreen Quercus ilex. 2. The time course of leaf δ13C showed different patterns in the two species. Young Q. pubescens leaves had a high δ13C and a marked decrease occurred during leaf growth. In contrast, leaves at budburst and maturity did not differ significantly in the case of Q. ilex. We suggest that the difference between δ13C of young leaves was linked to differential use of reserves of carbon compounds in the two species. 3.δ13C values of mature leaves were negatively correlated with minimum seasonal values of predawn water potential, suggesting that a functional adjustment to water resources occurred. 4. There was a significant correlation between individual δ13C values for two successive years. This interannual dependence showed that δ13C rankings between trees were constant through time.
Keywords: Biochemical content; isotope composition; leaf development; Quercus; water constraint

Seasonal changes of root hydraulic conductance (K RL) in four forest trees: an ecological interpretation - Nardini, A; Gullo, M A Lo; Salleo, S (Plant Ecology, 1998)
This paper deals with the possibility of relating root hydraulic parameters to an ecological index describing the continentality/oceanicity of four forest trees. Root hydraulic conductance (KR) of seedlings of Fagus sylvatica L., Quercus ilex L., Quercus suber L. and Quercus pubescens Willd. was measured in May, August and November 1996. KR was calculated in terms of the relation of the water ﬂow through intact root systems in situ measured with the pressure chamber, and the pressure driving the ﬂow. The sufﬁciency of the root system to supply the foliage was estimated by dividing KR by the seedlings leaf surface area (AL) thus obtaining KRL. In the spring, KRL was largest in F. sylvatica and smallest in Q. pubescens with intermediate values recorded in Q. ilex and Q. suber. All the species studied showed a large decline in KRL just prior to the winter rest except for Q. suber which mantained KRL approximately constant through the period of study. In most cases, KRL changed in accordance with analogous changes in the ﬂow. When the total seedlings’ leaf surface area (AL) was plotted versus KRL, it appeared that KRL of Q. pubescens increased with AL, proportionally, while KRL of F. sylvatica was inversely related to AL. This, together with the largest KRL recorded in the summer in Q. pubescens, was interpreted as advantageous to this species (which is adapted to semi-arid environments) in that: (a) roots could supply water to foliage efﬁciently even during the adverse season and (b) the foliage growth could be sustained even in summer. No statistically signiﬁcant relation of KRL to the continentality index calculated for the four species studied on the basis of their European distribution, was found to exist. Nonetheless, our data appear to be encouraging for future research aimed at better interpreting the typical distribution areas of plant species.
Keywords: continentality index; Fagus sylvatica; Quercus ilex; Quercus pubescens; Quercus suber; root hydraulic efficiency

Simultaneous field measurements of terpene and isoprene emissions from two dominant Mediterranean oak species in relation to a north American species - Kesselmeier, J; Bode, K; Schafer, L (Atmospheric Environment, 1998)
ÐWe investigated the emission of monoterpenes and isoprene from tree species growing at a site near Montpellier (South France). We compared the emission pattern and behaviour of two important oak species representative of the Mediterranean ecosystem, namely, Quercus ilex (Holm oak), a strong monoter- pene emitter, and Quercus pubescens (White oak), a strong isoprene emitter by measuring the two species growing side by side simultaneously. Additionally, we included a Californian oak species Quercus agrifolia (Coast Live Oak), which is anatomically and morphologically comparable with Quercus ilex. The data show that Live Oak and Holm oak though they appear identical, di¤er as far as the emission of terpenoids is concerned, emitting isoprene or terpenes, respectively. The isoprene emitting White oak and the monoter- pene emitting Holm oak react identically to the same environmental conditions, ßuctuating light and temperature, indicating that close metabolic pathways are involved in the actual emission of the C5 and C10 compounds from these two species, as seen under Þeld conditions. ( 1998 Elsevier Science Ltd. All rights reserved
Keywords: isoprene; Monoterpenes; oak; quercus agrifolia; Quercus ilex; Quercus pubescens; volatile biogenic hydrocarbons

Soil aggregate stability under different Mediterranean vegetation types - Cerdá, A (Catena, 1998)
The influence of vegetation type on soil erodibility was studied by means of aggregate stability measurements using the Modified Emerson Water Dispersion Test MEWDT , water-drop impacts . . . CND and TDI and Ultrasonic Disruption UD methods on soils from north-facing slopes of the mountain range of La Serra Grossa in the eastern Iberian Peninsula. Soils with similar characteristics but covered by the main plant species at the study area were selected. Quercus ilex woodland showed the most resistant soil aggregates followed by Q. coccifera and Pistacea lentiscus scrubland, Brachypodium retusum grassland and Pinus halepensis woodland. Aggregates developed beneath dwarf shrubs like Rosmarinus officinalis, Thymus Íulgaris, Ulex parÍiflorus and Anthyllis cystisoides were least resistant. The different methods and tests applied are useful to study the soil aggregate stability. The MEWDT and TDI tests showed only minor differences between samples due to the high aggregate resistance and the low energy applied by these tests. CND and UD tests are considered to be more suitable for resistant Mediterranean soil developed on limestone due to the greater energy applied. Aggregates tested from an initially moist pF1 condition were always more stable than air dried aggregates. Rangeland management . after disturbances by fire, agriculture or grazing, etc. should try to establish natural woodland Q. ilex. in order to get the most stable soil. Alternative vegetation cover to the climax vegetation that give high aggregate stability are Q. coccifera and P. lentiscus scrublands. Immediately after disturbance, B. retusum grassland seems to be the best option for soil protection.
Keywords: Aggregate stability; Laboratory test; Mediterranean; Vegetation

Soil aggregate stability under different Mediterranean vegetation types - Cerdà, A. (Catena, 1998)
The influence of vegetation type on soil erodibility was studied by means of aggregate stability measurements using the Modified Emerson Water Dispersion Test MEWDT , water-drop impacts . . . CND and TDI and Ultrasonic Disruption UD methods on soils from north-facing slopes of the mountain range of La Serra Grossa in the eastern Iberian Peninsula. Soils with similar characteristics but covered by the main plant species at the study area were selected. Quercus ilex woodland showed the most resistant soil aggregates followed by Q. coccifera and Pistacea lentiscus scrubland, Brachypodium retusum grassland and Pinus halepensis woodland. Aggregates developed beneath dwarf shrubs like Rosmarinus officinalis, Thymus Íulgaris, Ulex parÍiflorus and Anthyllis cystisoides were least resistant. The different methods and tests applied are useful to study the soil aggregate stability. The MEWDT and TDI tests showed only minor differences between samples due to the high aggregate resistance and the low energy applied by these tests. CND and UD tests are considered to be more suitable for resistant Mediterranean soil developed on limestone due to the greater energy applied. Aggregates tested from an initially moist pF1 condition were always more stable than air dried aggregates. Rangeland management . after disturbances by fire, agriculture or grazing, etc. should try to establish natural woodland Q. ilex. in order to get the most stable soil. Alternative vegetation cover to the climax vegetation that give high aggregate stability are Q. coccifera and P. lentiscus scrublands. Immediately after disturbance, B. retusum grassland seems to be the best option for soil protection.
Keywords: Aggregate stability; Laboratory test; Mediterranean; Vegetation

Soil hydrological response under simulated rainfall in the Dehesa land system (Extremadura, SW Spain) under drought conditions - Cerdà, A.; Schnabel, S. (Earth Surface Processes and Landforms, 1998)
Soil hydrology was investigated in the Guadelperalón experimental watershed in order to determine the inﬂuence of land use and vegetation cover on runoff and inﬁltration within the Dehesa land system. Five soil–vegetation units were selected: (1) tree cover, (2) sheep trials, (3) shrub cover, (4) hillslope grass and (5) bottom grass. The results of the simulated rainfall experiments performed at an intensity of 53·6mm h −1 during one hour on plots of 0·25m 2 , and the water drop penetration time test indicate the importance of water repellency in the Dehesa land system under drought conditions. Low inﬁltration rates (c. 9–44mm h −1 ) were found everywhere except at shrub sites and in areas with low grazing pressure. Soil water repellency greatly reduced inﬁltration, especially beneath Quercus ilex canopies, where fast ponding and greater runoff rates were observed. The low vegetation cover as a consequence of a prolonged drought and grazing pressure, in conjunction with the soil water repellency, induces high runoff rates (15–70 per cent). In spite of this, macropore ﬂuxes were found in different locations, beneath trees, on shrub-covered surfaces, as well as at sites with a dominance of herbaceous cover. Discontinuity of the runoff ﬂuxes due to variations in hydrophobicity causes preferential ﬂows and as a consequence deeper inﬁltration, especially where macropores are developed
Keywords: Dehesa; Drought; hydrophobicity; rainfall simulation; soil hydrology

Soil hydrological response under simulated rainfall in the Dehesa land system (Extremadura, SW Spain) under drought conditions - Cerdá, A; Schnabel, S (Earth Surface Processes and Landforms, 1998)
Soil hydrology was investigated in the Guadelperalón experimental watershed in order to determine the inﬂuence of land use and vegetation cover on runoff and inﬁltration within the Dehesa land system. Five soil–vegetation units were selected: (1) tree cover, (2) sheep trials, (3) shrub cover, (4) hillslope grass and (5) bottom grass. The results of the simulated rainfall experiments performed at an intensity of 53·6mm h −1 during one hour on plots of 0·25m 2 , and the water drop penetration time test indicate the importance of water repellency in the Dehesa land system under drought conditions. Low inﬁltration rates (c. 9–44mm h −1 ) were found everywhere except at shrub sites and in areas with low grazing pressure. Soil water repellency greatly reduced inﬁltration, especially beneath Quercus ilex canopies, where fast ponding and greater runoff rates were observed. The low vegetation cover as a consequence of a prolonged drought and grazing pressure, in conjunction with the soil water repellency, induces high runoff rates (15–70 per cent). In spite of this, macropore ﬂuxes were found in different locations, beneath trees, on shrub-covered surfaces, as well as at sites with a dominance of herbaceous cover. Discontinuity of the runoff ﬂuxes due to variations in hydrophobicity causes preferential ﬂows and as a consequence deeper inﬁltration, especially where macropores are developed
Keywords: Dehesa; Drought; hydrophobicity; rainfall simulation; soil hydrology

Stemflow and throughfall determination in a resprouted Mediterranean holm-oak forest - Bellot, Juan; Escarre, Antonio (Ann. For. Sci., 1998)
Stemflow, throughfall and precipitation data were collected for 30 consecutive months in a holm-oak forest dominated by Quercus ilex, Arbutus unedo and Phyllirea media. These flux data were obtained from 50 randomly distributed no-roving throughfall collectors and 20 stemflow measuring devices (ten on Q. ilex and five on each of the other species). The stemllow was highly influenced by tree size and amount of rainfall, showing a significant correlation for each tree. Throughfall results showed a high spatial variability for each storm, with a significant independence of collectors. At forest scale, stemflow and throughfall represented 12.1 and 75 % of precipitation, respectively, and interception was estimated as 12.9 % of precipitation. Partitioning of rainfall between stemflow and throughfall created a high spatial heterogeneity of water distribution under the canopy. Stemflow increased more than 30 times the mean amount of water received per unit soil area around tree trunks. Finally, the effect of a change in the amount of precipitation according to a regional scenario was analyzed. It was shown that the increase in high rainfall events rather than small events increased the stemflow percentage.
Keywords: Holm oak; interception; spatial heterogeneity; stemflow; throughfall

Stemflow and throughfall determination in a resprouted Mediterranean holm-oak forest - Bellot, Juan; Escarre, Antonio (Ann. For. Sci., 1998)
Stemflow, throughfall and precipitation data were collected for 30 consecutive months in a holm-oak forest dominated by Quercus ilex, Arbutus unedo and Phyllirea media. These flux data were obtained from 50 randomly distributed no-roving throughfall collectors and 20 stemflow measuring devices (ten on Q. ilex and five on each of the other species). The stemllow was highly influenced by tree size and amount of rainfall, showing a significant correlation for each tree. Throughfall results showed a high spatial variability for each storm, with a significant independence of collectors. At forest scale, stemflow and throughfall represented 12.1 and 75 % of precipitation, respectively, and interception was estimated as 12.9 % of precipitation. Partitioning of rainfall between stemflow and throughfall created a high spatial heterogeneity of water distribution under the canopy. Stemflow increased more than 30 times the mean amount of water received per unit soil area around tree trunks. Finally, the effect of a change in the amount of precipitation according to a regional scenario was analyzed. It was shown that the increase in high rainfall events rather than small events increased the stemflow percentage.
Keywords: Holm oak; interception; spatial heterogeneity; stemflow; throughfall

Stress proteins co-expressed in suberized and lignified cells and in apical meristems - Pla, Maria; Huguet, Gemma; Verdaguer, Dolors; Puigderrajols, Pere; Llompart, Blanca; Nadal, Anna; Molinas, Marisa (Plant Science, 1998)
We report the cloning of a small heat shock protein, Qs –HSP17, and an osmotin like protein, Qs –OLP, from cork oak phellem tissue (cork cells). Both genes are expressed in suberizing cells and in other cells subject to endogenous stress associated with free radicals. We provide evidence that smHSPs and OLPs accumulate in overwintering buds and speculate that their role is similar to that in seed dormancy. We also show that both stress proteins are mainly located in the region of the quiescent center in root apex and in central meristem in the shoot apex. We emphasize that smHSPs and OLPs are expressed in cells growing under endogenous stress or facing long life-span. We discuss a possible role of these stress proteins against oxidative stress
Keywords: cork-oak; osmotin like proteins; phellem; Quercus suber; small heat shock proteins; tissue specificity

Suberin-based polyurethanes: Synthesis, characterization and kinetics of their formation - Cordeiro, N; Belgacem, M N; Gandini, A; Neto, C P (BIOMASS FOR ENERGY AND INDUSTRY, 1998)
The synthesis and characterization of novel family of polyurethanes prepared by the polycondensation of suberin from Quercus suber L. with aliphatic and aromatic isocyanates are reported. A preliminary kinetic study, conducted with the aim of establishing the reactivity of suberin with different mono-, di- and polyisocyanates, showed that the kinetics of these condensations followed the classical second-order behaviour up to conversion of about 90%. The reactivity of different isocyanates followed patterns that could be readily rationalized in terms of steric hindrance and electronic factors, associated with each specific structure. The investigation was then extended to the synthesis of the new polymers which were characterized by FTIR and NMR spectroscopy and DSC. These suberin-based polyurethanes were a mixture of linear, branched and crosslinked structures. The proportion of the latter (insoluble fraction) being the highest for thr syntheses carried out in stoichiometric conditions, viz. \{[\}NCO](o) = \{[\}OH](o). The Tg of these materials depended of the diisocyanates used and correlated with their structural stiffness.
Keywords: aliphatic isocyanates; aromatic isocyanates; kinetic study; Quercus suber L.

Sustained utilization of the Iberian pig breed. - López-Bote, C J (Meat science, 1998)
The Iberian pig is one of the scarce non-improved swine breeds which survives the modern techniques of pig production based on improved genotypes. This is attributed both to its perfect adaptation to the Mediterranean natural ecosystem and the high quality of its products. The production of meat products from Iberian pigs has very little in common with that of meat products obtained from selected pigs raised under intensive conditions, and it constitutes an example of the preparation of high quality meat products, comparable to the most exquisite food products in the world. The production of Iberian pig is deeply bound to the Mediterranean ecosystem. It is a rare example in the world swine production where the pig contributes so decisively to the preservation of the ecosystem. The aim of this review is to describe in detail the traditional feeding of the Iberian pigs in La Dehesa and to discuss some aspects of the use of alternatives to this production system. Some of the experience in the formulation of compounds feeds for Iberian pigs and in the processing of meat products could be useful in the feeding of other pig genotypes and in different meat processing strategies.
Keywords: Dehesa; high quality products (voyant); iberian pig; Meat Products; Montanera

Thermally assisted transmethylation gas chromatography–mass spectrometry of suberin components in cork from Quercus suber L. - Bento, M. F.; Pereira, H. (Phytochemical Analysis, 1998)
Thermally assisted transmethylation gas chromatography - mass spectrometry with tetramethylammonium hydroxide has been applied for the qualitative and quantitative analysis of the suberin fraction of wax-free cork. With this method, hydrolysis of esters together with methylation of carboxylic and hydroxylic groups was observed. Mostly long chain aliphatic components, such as alkanols, alkanoic acids, v-hydroxyacids, v,v-alkanoic diacids, and several 9,10-epoxy and 9,10-dihydroxy forms have been found in keeping with results of other workers in the ﬁeld. Two other components that may give a more complete view of the architecture of suberin were also found, namely the phenolic compound ferulic acid, and glycerol which is probably esteriﬁed to carboxylic groups of the aliphatic building units of suberin
Keywords: Cork; pyrolysis mass spectrometry; Quercus suber; suberin; thermally assisted methylation

Thermally assisted transmethylation gas chromatography–mass spectrometry of suberin components in cork from Quercus suber L. - Bento, M F; Pereira, H (Phytochemical Analysis, 1998)
Thermally assisted transmethylation gas chromatography - mass spectrometry with tetramethylammonium hydroxide has been applied for the qualitative and quantitative analysis of the suberin fraction of wax-free cork. With this method, hydrolysis of esters together with methylation of carboxylic and hydroxylic groups was observed. Mostly long chain aliphatic components, such as alkanols, alkanoic acids, v-hydroxyacids, v,v-alkanoic diacids, and several 9,10-epoxy and 9,10-dihydroxy forms have been found in keeping with results of other workers in the ﬁeld. Two other components that may give a more complete view of the architecture of suberin were also found, namely the phenolic compound ferulic acid, and glycerol which is probably esteriﬁed to carboxylic groups of the aliphatic building units of suberin
Keywords: Cork; pyrolysis mass spectrometry; Quercus suber; suberin; thermally assisted methylation

Transpiration and stomatal behaviour of Quercus ilex plants during the summer in a Mediterranean carbon dioxide spring - Tognetti, R; Longobucco, A; Miglietta, F; Raschi, A (Plant, Cell & Environment, 1998)
Variations in the water relations and stomatal response of Quercus ilex were analysed under field conditions by comparing trees at two locations in a Mediterranean environment during two consecutive summers (1993 and 1994). We used the heat-pulse velocity technique to estimate transpirational water use of trees during a 5 month period from June to November 1994. At the end of sap flow measurements, the trees were harvested, and the foliage and sapwood area measured. A distinct environmental gradient exists between the two sites with higher atmospheric CO2 concentrations in the proximity of a natural CO2 spring. Trees at the spring site have been growing for generations in elevated atmospheric CO2 concentrations. At both sites, maximum leaf conductance was related to predawn shoot water potential. The effects of water deficits on water relations and whole-plant transpiration during the summer drought were severe. Leaf conductance and water potential recovered after major rainfall in September to predrought values. Sap flow, leaf conductance and predawn water potential decreased in parallel with increases in hydraulic resistance, reaching a minimum in mid-summer. These relationships are in agreement with the hypothesis of the stomatal control of transpiration to prevent desiccation damage but also to avoid ‘runaway embolism’. Trees at the CO2 spring underwent less reduction in hydraulic resistance for a given value of predawn water potential. The decrease in leaf conductance caused by elevated CO2 was limited and tended to be less at high than at low atmospheric vapour pressure deficit. Mean (and diurnal) sap flux were consistently higher in the control site trees than in the CO2 spring trees. The degree of reduction in water use between the two sites varied among the summer periods. The control site trees had consistently higher sap flow at corresponding values of either sapwood cross-sectional area or foliage area. Larger trees displayed smaller differences than smaller trees, between the control and the CO2 spring trees. A strong association between foliage area and sapwood cross-sectional area was found in both the control and the CO2 spring trees, the latter supporting a smaller foliage area at the corresponding sapwood stem cross-sectional area. The specific leaf area (SLA) of the foliage was not influenced by site. The results are discussed in terms of the effects of elevated CO2 on plant water use at the organ and whole-tree scale.
Keywords: Drought; Mediterranean; natural CO2 springs; Quercus ilex; sap flow; Stomatal conductance; water relations

Trends and fluctuations in species abundance and richness in Mediterranean annual pastures - Peco, B; Espigares, T; Levassor, C (Applied Vegetation Science, 1998)
Floristic data collected from permanent plots during 14 consecutive years are used to model the frequency of the 62 most abundant species in relation to post-ploughing succession, topography and rainfall in annual Mediterranean grasslands located in a Quercus rotundifolia dehesa. The interannual dynamics of species richness are also analysed. From 1980 to 1993, presence/absence data of grassland species were noted in five 20 cm × 20 cm permanent quadrats placed at random in 1980 in 14 permanent plots on a southfacing slope along the topographic gradient. Weekly autumn rainfall data over the 14 years were analysed using a profile attributes index and Hybrid Multidimensional Scaling to arrange the years according to their autumn rainfall pattern. Generalized Linear Models were used to fit the species richness and species frequency according to topographic position, age since the last ploughing episode, total rainfall in the growing season and autumn rainfall pattern using a forward stepwise procedure. The richness model includes all of these variables, and reveals a relatively high goodness-of-fit (71%). The fact that the meteorological factors play a key role in modelling richness forces us to include them if we wish to use richness as an indicator of the degree of disturbance in these highly fluctuating annual pastures. Models of species dynamics show that although roughly 33% of the species have a successional behaviour, the majority are more dependent on temporal heterogeneity associated with rainfall or spatial heterogeneity linked to the topographic gradient.
Keywords: Autumn rainfall distribution; Generalized Linear; Models; Post-ploughing succession; Topography

Two vegetation maps of the same island: floristic units versus structural units - Lux, Andrea; Bemmerlein-Lux, Florian A (Applied Vegetation Science, 1998)
Abstract. This paper presents a comparison of two alternative methods to describe and map vegetation: on the basis of plant species and growth forms, respectively. A stratified random sampling was taken from spontaneous vegetation in 1989 on the volcanic island of Pantelleria (near Sicily, Italy). Cartographic and other comparisons of the results from classification and ordination analysis suggest that the major differences were associated with differences in the time scale of the underlying processes. Species results (leading to floristic vegetation units) were representative of longer-term processes, growth-form results (leading to structural vegetation units) with shorter-term processes. Further implications of these results are discussed.
Keywords: dynamics; fire; growth form; Italy; Pantelleria; structure; succession; Temporal scale

Unevenaged coppice holm oak stands: silvicultural description - Gonzalez, J Mª.; Ibariz, P (Forest Systems, 1998)
Uneven coppice stands of evergreen oak (Quercus ilex L.) of Gerona (NE Spain) are described. Three structurally different situations are analysed: close after silvicultural intervention, in the middle of two interventions and before cutting. Therefore 19 plots were selected in the area, obtaining dasometric and qualitative values in order to characterise traditional management. Positive tree selection of traditional management is proved, as well as a high percentage of trees of a good stem quality, particularly at dominant layer (33%). Liocourt constant values in these stands were determined: they change for every described situation (2.8-1.6; 1.2-2.6; 1.7-2.8). With these values, 45 types of uneven evergreen oak forests were modelized modifying initial density (900, 1100 and 1200 stems/ha) and q values (DC10: 2.5; 2.7; 2.8; DC>15: 1.5; 1.6; 1.7; 1.8; 1.9), while keeping maximum initial diameter (25 cm) and rotation (30 years). The comparison between these models don’t show significant differences independent from initial values. Using mean values obtained from the sample plots, a preliminary optimal equilibrium curve for uneven oak-coppice stands has been developed. Finally structural differences between those stands, traditional ones of Central Europe and uneven Pinus nigra forests of Pyrenees are upbright.
Keywords: Coppice stands; Quercus ilex; silviculture; Unevenaged stands

URBAN GROWTH DYNAMICS ( 1956-1998 ) IN MEDITERRANEAN COASTAL REGIONS : THE CASE OF ALICANTE , SPAIN - Aguilar, Juan A. Pascual; Añó, Carlos; Valera, Antonio; Sánchez, Juan (Desertification in the Mediterranean Region a Security Issue, 1998)
Among factors causing soil degradation one of the most important, although less studied in Mediterranean environments, is the irreversible loss of soil due to urbanisation processes, inserted into the more general concept of soil sealing. In coastal Mediterranean regions, such as the Valencia Region, Spain, land cover transformations are mainly produced by contemporary socio-economic changes that have produced a drift from traditional agriculture to industrial and tourism economies, reinforced by population’s trends to concentrate in cities or larger urban regions. Evaluation of soil sealing is then a key element to understand soil degradation and the disappearance, in most cases, of highly productive soils. This work, inserted within a major study on land use-cover change and soil degradation of metropolitan areas in the Valencia Region, presents the preliminary results on the urban-non urban (open agrarian and natural spaces) dynamics in the municipality of Alicante, the second largest city in the region. Three sets of panchromatic air photos for the years 1956, 1985 and 1998 have been used. After air photo scanning, on screen digitising using a base digital topographic map at scale 1:10,000, was applied to extract two major types of soil cover: agrarian and urban. A Geographical Information System vector structure has been implemented for cartographic comparison. Finally, to identify spatial and temporal changes maps and overlays together with synthetic tables were produced in order to assess soil degradation. Results show that there has been a substantial loss of soil devoted mainly to agriculture. Urban growth can be differentiated into three distinct spatial patterns: 1) edge compact enlargement of the city boundaries, including growth following the main road network; 2) compact new urbanisation alongside the coast and 3) the colonisation by groups of individual residences mainly over continental open spaces. One of the main impacts of such new urban pattern has been the loss of the most fertile soils distributed over the alluvial plains around the city, which has been mainly occupied by the tourist and residential buildings
The following values have no corresponding Zotero field: periodical: Desertification in the Mediterranean Region a Security Issue
Keywords: Aerial photograph; desertification; Geographical information Systems.; Land degradation; Mediterranean environments; Soil sealing; Urban dynamics

URBAN GROWTH DYNAMICS ( 1956-1998 ) IN MEDITERRANEAN COASTAL REGIONS : THE CASE OF ALICANTE , SPAIN - Aguilar, Juan A Pascual; Añó, Carlos; Valera, Antonio; Sánchez, Juan (Desertification in the Mediterranean Region a Security Issue, 1998)
Among factors causing soil degradation one of the most important, although less studied in Mediterranean environments, is the irreversible loss of soil due to urbanisation processes, inserted into the more general concept of soil sealing. In coastal Mediterranean regions, such as the Valencia Region, Spain, land cover transformations are mainly produced by contemporary socio-economic changes that have produced a drift from traditional agriculture to industrial and tourism economies, reinforced by population’s trends to concentrate in cities or larger urban regions. Evaluation of soil sealing is then a key element to understand soil degradation and the disappearance, in most cases, of highly productive soils. This work, inserted within a major study on land use-cover change and soil degradation of metropolitan areas in the Valencia Region, presents the preliminary results on the urban-non urban (open agrarian and natural spaces) dynamics in the municipality of Alicante, the second largest city in the region. Three sets of panchromatic air photos for the years 1956, 1985 and 1998 have been used. After air photo scanning, on screen digitising using a base digital topographic map at scale 1:10,000, was applied to extract two major types of soil cover: agrarian and urban. A Geographical Information System vector structure has been implemented for cartographic comparison. Finally, to identify spatial and temporal changes maps and overlays together with synthetic tables were produced in order to assess soil degradation. Results show that there has been a substantial loss of soil devoted mainly to agriculture. Urban growth can be differentiated into three distinct spatial patterns: 1) edge compact enlargement of the city boundaries, including growth following the main road network; 2) compact new urbanisation alongside the coast and 3) the colonisation by groups of individual residences mainly over continental open spaces. One of the main impacts of such new urban pattern has been the loss of the most fertile soils distributed over the alluvial plains around the city, which has been mainly occupied by the tourist and residential buildings
Keywords: Aerial photograph; desertification; Geographical information Systems.; Land degradation; Mediterranean environments; Soil sealing; Urban dynamics

The use of cork oak in the ecological and landscape restoration of the Latium Hills - Bellarosa, R.; Schirone, B.; Busatto, M. (SYMPOSIUM ON PLANT BIOTECHNOLOGY AS A TOOL FOR THE EXPLOITATION OF MOUNTAIN LANDS, 1998)
The cork oak (Quercus suber L.) is a western Mediterranean speciesfrequently found in Italy along the Tyrrhenian coast and on the islands. Its economic importance is well known, but the species is also ecologically precious. Notably, in fact, it is extremely resistant to forest fires. Because of its properties a project is on its way to restore the marginal lands of northern Latium through the reforestation with selected specimens of cork oak. The main aims of the project are: the genetic comparison between cork oak of different Italian provenances the establishment of an experimental arboretum which will collect cork oak deriving from the 34 main European areas the running of experimental trials on innovative reforestation techniques, such as the Miyawaki method. The methodology and initial results of the project are reported.
The following values have no corresponding Zotero field: periodical: SYMPOSIUM ON PLANT BIOTECHNOLOGY AS A TOOL FOR THE EXPLOITATION OF MOUNTAIN LANDS issue: 457 pub-location: PO BOX 500, 3001 LEUVEN 1, BELGIUM
Keywords: cork oak; genetic variability; arboretum; reforest

The use of cork oak in the ecological and landscape restoration of the Latium Hills - Bellarosa, R; Schirone, B; Busatto, M (SYMPOSIUM ON PLANT BIOTECHNOLOGY AS A TOOL FOR THE EXPLOITATION OF MOUNTAIN LANDS, 1998)
The cork oak (Quercus suber L.) is a western Mediterranean species frequently found in Italy along the Tyrrhenian coast and on the islands. Its economic importance is well known, but the species is also ecologically precious. Notably, in fact, it is extremely resistant to forest fires. Because of its properties a project is on its way to restore the marginal lands of northern Latium through the reforestation with selected specimens of cork oak. The main aims of the project are: the genetic comparison between cork oak of different Italian provenances the establishment of an experimental arboretum which will collect cork oak deriving from the 34 main European areas the running of experimental trials on innovative reforestation techniques, such as the Miyawaki method. The methodology and initial results of the project are reported.
Keywords: arboretum; Cork oak; Genetic variability; reforest

UV-band and acid rain effects on beach ( Fagus sylvatica L.) and holm oak ( Quercus ilex L.) leaves - Paoletti, E (Chemosphere, 1998)
Beech (Fagus sylvatica L.) and holm oak (Quercus ilex L) leaves were subjected to simulated acid rain and UV-B radiation for 10 days. The almost glabrous beech leaves revealed a greater predisposition to developing macroscopic necrotic lesions than the pubescent holm oak leaves. This response is due primarily to their different morpho-anatomical structure, rather than to a difference in the synthesis of UV-B absorbing pigments (flavonoids); the response was also accompanied by microscopically observable alterations (collapse of epidermal cells, fusion of surface wax structures, structural damage to the stomata) and by the reduction of stomatal conductance
Keywords: acid rain; beech; damage; Holm oak; leaves; necrosis; stomatal conductance (voyant); uv-b radiation

Variability in seedling water status during drought within a Quercus ilex subsp. ballota population, and its relation to seedling morphology - Leiva, María José; Fernández-Alés, Rocı́o (Forest Ecology and Management, 1998)
Differences in morphology, growth and plant water status during drought were studied in greenhouse-grown Quercus ilex subsp. ballota seedlings produced by different mother trees occurring in a savannah-like forest (locally named dehesa) in southern Spain. There were signi®cant differences among mother trees in the biomass of their seeds (mother tree level accounted for 62% of total variance in this trait), in the percentage of seedlings that emerged and in the time of shoot emergence. The progeny that had high emergence rates (80±90%) also had short emergence times while the opposite was true for the progeny that had low (43%) and intermediate (70%) emergence rates. Acorn biomass covaried signi®cantly with seedling total biomass and with the biomass of different parts of the seedlings, but not with the partitioning of biomass among roots and shoots (root/shoot ratio) nor to morphological seedling traits such as shoot height, total leaf area, average leaf size, speci®c leaf area (SLA) and leaf number. All these traits varied signi®cantly among the seedlings produced by different mother trees. The conductance to water vapour (glw) of the foliage of the seedlings also varied signi®cantly among mother trees and was dependent on the root/shoot ratio as on the total leaf area of the seedlings, but not on the total seedling biomass. One of the six trees that were studied produced seedlings which had a signi®cantly higher root/shoot ratio, smaller leaf area, smaller leaves, higher speci®c leaf area and shorter stems than the seedlings produced by any other tree. In addition, the former set of seedlings had signi®cantly higher glw 15 and 30 days after drought, and higher leaf water content at the end of the experiment than the other seedlings. We discuss the value of using single seedling traits related to drought tolerance such as root/shoot ratio and leaf area in the framework of the restoration of savannah-like oak forest in the Mediterranean areas. We also discuss the functional implications of the diversity of genotypes within the oak populations in the framework of the global climate change
Keywords: Drought tolerance; Holm oak; root/shoot ratio; savannah-like forest; seedling biomass

Vegetation of tuscan ultramafic soils in relation to edaphic and physical factors - Chiarucci, Alessandro; Robinson, Brett H.; Bonini, Ilaria; Petit, Daniel; Brooks, Robert R.; Dominicis, Vincenzo (Folia Geobotanica, 1998)
Vegetation and soil sampling were carried out in 80 plots located in five different ultramafic (serpentine) sites of Tuscany, central Italy. The physical and chemical features of each plot. were determined and the species composition and cover recorded. The exchangeable fraction of soil metals was analysed because it gives a measure of their concentrations available to plants. The plots were classified by cluster analysis and ANOVA was used to compare the environmental variables of the groups of plots. Canonical correspondence analysis was used to detect the principal factors for gradients of species composition within the plant communities. A higher content of exchangeable metals was found under the more evolved and structured plant communities, suggesting that serpentine vegetation of Tuscany is not strongly limited by soil metals, such as chromium, cobalt, nickel and magnesium, typically associated with ultramafic soils. The low nutrient content of the soils and drought stress mainly due to topographical features, appear to have a more significant role in determining the typical scattered vegetation of the Tuscan ultramafics.
Keywords: canonical correspondence analysis; Drought; serpentine; soil features; species diversity; vegetation ecology

VOC Emissions from Cork Products for Indoor Use - Horn, W.; Ullrich, D.; Seifert, B. (Indoor Air, 1998)
Abstract Complaints about unpleasant odour from wall, ceiling and floor coverings made of composite cork, induced chamber tests to study the emissions of volatile organic compounds (VOC) from composite cork products for indoor use. Emissions of phenol and furfural were found to be high, particularly those from cork parquet. Emission factors after 1 week ranged from 150 to 650 μg m−2 h−1 and from 15 to 350 μg m−2 h−1 for phenol and furfural, respectively, and decreased only slowly over time, by a factor of approx. 10 for a 6-month period. The ranges of emission factors were found to be similar for some solvents such as cyclohexanone or toluene which are constituents of varnishes used to protect cork surfaces. The emission of furfural may result from chemical reactions in the cork during the production process or may be caused by additives such as binders.
The following values have no corresponding Zotero field: publisher: Munksgaard International Publishers
Keywords: Chamber measurements; Composite cork; Emission factors; Furfural; Phenol

Volatile compounds produced by microorganisms isolated from cork - Caldentey, Paloma; Fumi, Maria Daria; Mazzoleni, Valeria; Careri, Maria (Flavour and Fragrance Journal, 1998)
Microorganisms present on cork (i.e. the reproduction bark of Quercus suber L.) can produce odorous compounds aecting the quality of cork stoppers. This work aims to contribute to the study of the correlation between microbial growth and formation of volatile compounds in the cork. Dierent strains of microorganisms were cultivated on both malt extract and cork, and the odour of the culture was described by a panel. The volatile compounds were isolated directly from the culture media by a dynamic headspace technique followed by adsorption on to Tenax traps. The volatiles were identi®ed by GC±MS: 63 substances were identi®ed in malt extract cultures, mainly consisting of carbonyl compounds (16), alcohols (16), and sesquiterpenes (13). Cultures on cork produced only 12 volatile compounds, more than half being sesquiterpenes. Sensory evaluation con®rmed that cork is an unfavourable culture medium if compared with malt extract.
Keywords: Cork; microbial growth; Quercus Suber L; volatile components

Vulnerability of xylem to embolism in relation to plant hydraulic resistance in Quercus pubescens and Quercus ilex co-occurring in a Mediterranean coppice stand in central Italy - Tognetti, R; Longobucco, A; Raschi, A (New Phytologist, 1998)
The seasonal patterns of xylem embolism and xylem transport properties in Quercus pubescens Willd. and Quercus ilex L. trees growing in a natural mixed coppice stand in conditions of severe water stress were investigated. Xylem embolism was evaluated in both dehydrating branches and in apical twigs during a whole year. Measurements of xylem water potential were conducted from predawn to sunset on selected sunny days. On the same days, diurnal courses of leaf conductance were monitored. Measurements of half-hourly sap flow were made by the heat-pulse technique throughout the summer. At the onset of summer, a sharp decrease in water potential was observed in both species. Full recovery of water potentials was observed for both species after the first major rainfall event in September. Both experienced serious embolism throughout the year, ranging between minima of c. 60% (expressed as percentage loss of hydraulic conductivity) after the rains in autumn and after bud burst in spring, and maxima of c. 80% during summer and after freezing-thawing events during the winter season. A significant negative linear relationship was found between water potential and xylem embolism in branches dehydrating in air for Q. pubescens and Q. ilex. Q. pubescens had greater efficiency in hydraulic transport (higher specific conductivity and leaf specific conductivity) by the xylem than Q. ilex. In June, leaf conductance was high early in the morning and decreased gradually during the day. Midday depression of leaf conductance, as a result of high evaporative demand combined with water deficit, was observed in both species. In August, leaf conductance of both species was greatly reduced, as water potential dropped to extremely low values, and the stomata were almost completely closed during the afternoon. No hysteresis resulting from plant capacitance was observed in the relationship between shoot water potential and sap flow. Q. pubescens exhibited very high values of whole-tree hydraulic resistance between July and September, whereas Q. ilex generally showed lower values. The effect of soil moisture depletion on the relationship between sap flow and shoot water potential appears as a lowering of water potential at zero flow. A significant decrease of whole-tree hydraulic resistance in both species was observed with the onset of the autumn, preceding the partial recovery of twig hydraulic conductivity. The results demonstrate that both Q. pubescens and Q. ilex, although highly tolerant of severe water stress and tissue dehydration, operate at the limits of safety which are surpassed under severe droughts, and prolonged climatic stress might predispose these Quercus species to decline.
Keywords: cavitation; Drought; Hydraulic resistance; Quercus ilex L.; Quercus pubescens Willd.; water relations; xylem embolism

Vulnerability to freeze stress of seedlings of Quercus ilex L.: an ecological interpretation - Nardini, Andrea; Ghirardelli, Lia; Salleo, Sebastiano (Ann. For. Sci., 1998)
The vulnerability to freeze stress of seedlings of Quercus ilex L. was studied with the aim of defining the limits of the potential distribution area of this species in its northernmost habitat. In December 1996 seedlings were freeze stressed up to -8 °C for 3 d. Frost caused extensive functional damage to seedlings in terms of: a) leaf water status; b) root (Kr) and stem (Ks) hydraulic conductance; c) tissue disorder in the root (only nine seedlings out of 50 survived). In comparison with unstressed seedlings, Kr and Ks of freeze-stressed seedlings were reduced by 90 %. Root anatomy of freeze-stressed seedlings revealed that: a) cortex cells were dehydrated and had become separated from one another; b) the endodermis was oversuberized, thus isolating the stele from the cortex. Our conclusion was that Q. ilex is extremely vulnerable to freeze stress so that the distribution area of the species is restricted to zones with no frost events
Keywords: freeze stress; Quercus ilex L.; root and stem hydraulic conductance; water relations

A 13C solid state nuclear magnetic resonance spectroscopic study of cork cell wall structure: the effect of suberin removal. - Gil, A M; Lopes, M; Rocha, J; Pascoal Neto, C (International journal of biological macromolecules, 1997)
Solid state 13C NMR measurements of cork, before and after suberin removal, showed that aliphatic suberin is spatially separated from carbohydrate and lignin and experiences higher motional freedom. Two types of chain methylenes, differing in chemical shift and in dynamic properties, were identified in aliphatic suberin. Experimental evidence indicated that the more motionally hindered methylenes are those situated nearer the linkages of aliphatic suberin to the cell wall. These linkages were shown to involve -CH2O- groups, probably engaged in ester linkages to phenylpropane units and carbohydrate C6 carbons. Spectral intensity changes indicated that, during the first steps of alkaline desuberization, these linkages are broken and the shorter aliphatic suberin chains removed. Longer chains require hydrolysis of the ester linkages within the chains and are removed upon stronger alkaline treatment. T1(C), T1 rho (H) and T1 rho (C) relaxation times have shown that the removal of suberin from cork leads to a motionally restricted and more compact environment, on the megahertz and mid-kilohertz timescales. The properties of cork suberin showed that suberin organization in cork is distinct from that in potato tissue.
Keywords: Cork; NMR; Quercus suber; suberin

Adaptation and local validation in a Mediterranean environment of a process-level ecosystem model driven by remotely sensed inputs - Lacaze, B; Tabarant, F; Rambal, S (REMOTE SENSING `96: INTEGRATED APPLICATIONS FOR RISK ASSESSMENT AND DISASTER PREVENTION FOR THE MEDITERRANEAN, 1997)
A process-level ecosystem model (FOREST-BGC) has been used to simulate the short-term variability of functional processes and the slower responding allocation of photosynthesis products to plant components maintenance or growth, and to decomposition. The model emphasises Leaf Area Index (LAI) as a key structural attribute with substantial control over ecosystem process rates. Model simulations (soil water balance, photosynthesis, net primary production,...) have been obtained for a 10 years period (1984-1993) and partially validated with ground measurements from an experimental test site located in Southern France (dominant species: holm oak). Further work include scaling up from local to regional level, using remote sensing inputs and ancillary data.
Keywords: funtional processes; Holm oak; leaf area index; model simutalins; photosynthesis alocation; structural attribute

Analysis of Cork Taint in Wine and Cork Material at Olfactory Subthreshold Levels by Solid Phase Microextraction - Fischer, Claus; Fischer, Ulrich (Journal of Agricultural and Food Chemistry, 1997)
doi: 10.1021/jf970121r
Keywords: 2-4-6-trichloroanisole; Cork taint; SPME; wine

Analysis of Cork Taint in Wine and Cork Material at Olfactory Subthreshold Levels by Solid Phase Microextraction - Fischer, Claus; Fischer, Ulrich (Journal of Agricultural and Food Chemistry, 1997)
doi: 10.1021/jf970121rdoi: 10.1021/jf970121rThe following values have no corresponding Zotero field: publisher: American Chemical Society
Keywords: 2-4-6-trichloroanisole; Cork taint; SPME; wine

Anatomical changes and evolutionary trends in the foliar epidermis of extant and fossil Euro-Mediterranean oaks (Fagaceae) - Uzunova, K.; Palamarev, E.; Ehrendorfer, F. (Plant systematics and Evolution, 1997)
The differentiation of foliar epidermis structures, cuticles, stomata, and indumen- turn of most of the extant Euro-Mediterranean taxa of Quercus have been studied by light and scanning electron microscopy, and compared with other genera and fossil material. Results allow the recognition of the subgg. Sclerophyllodrys, Cerris and Quercus, and of various sections and even individual species. The cyclocytic stomata type, regarded as plesiomorphic, is found in the geologically oldest representatives of the familiy (DryophylIum, resp. Eotrigonobalanus) and in the relatively old, evergreen to semi-evergreen species of Quercus subgg. Sclerophyllodrys and Cerris. These taxa also have relatively thick and smooth cuticles. Anomocytic stomata, thinner cuticles and the presence of crystalline wax flakes are regarded as apomorphic features and characterize the deciduous taxa ofsubg. Quercus. These changes are interpreted as ecological adaptations to the changing climates from the Tertiary to the present. An analysis of the various character combinations found in macrofossils and the often poor species separation i n Quercus suggest that hybridization has played a major role in the evolution of the Euro-Mediterranean oaks.
Keywords: epidermis characters; evolutionary trends; Fagaceae; fossil and extant taxa; Quercus

Anatomical changes and evolutionary trends in the foliar epidermis of extant and fossil Euro-Mediterranean oaks (Fagaceae) - Uzunova, K; Palamarev, E; Ehrendorfer, F (Plant systematics and Evolution, 1997)
The differentiation of foliar epidermis structures, cuticles, stomata, and indumen- turn of most of the extant Euro-Mediterranean taxa of Quercus have been studied by light and scanning electron microscopy, and compared with other genera and fossil material. Results allow the recognition of the subgg. Sclerophyllodrys, Cerris and Quercus, and of various sections and even individual species. The cyclocytic stomata type, regarded as plesiomorphic, is found in the geologically oldest representatives of the familiy (DryophylIum, resp. Eotrigonobalanus) and in the relatively old, evergreen to semi-evergreen species of Quercus subgg. Sclerophyllodrys and Cerris. These taxa also have relatively thick and smooth cuticles. Anomocytic stomata, thinner cuticles and the presence of crystalline wax flakes are regarded as apomorphic features and characterize the deciduous taxa ofsubg. Quercus. These changes are interpreted as ecological adaptations to the changing climates from the Tertiary to the present. An analysis of the various character combinations found in macrofossils and the often poor species separation i n Quercus suggest that hybridization has played a major role in the evolution of the Euro-Mediterranean oaks.
Keywords: epidermis characters; evolutionary trends; Fagaceae; fossil and extant taxa; Quercus

The aquatic processing of sclerophyllous and malacophyllous leaves on a Mediterranean island (Corsica) : spatial and temporal pattern - Schwarz, A E; Schwoerbel, J (Annales de Limnologie - International Journal of Limnology, 1997)
Leaves of two species, alder (Alnus glutinosa) and holm-oak (Quercus ilex), were exposed in bags of two mesh sizes in two climatically contrasting sites of a Corsican softwater stream. Leaves were incubated both in winter and in summer for about 6 months. The field experiment was designed to determine the influence of both spatial (climate) and temporal (season) variations of temperature, as well as differences in the chemical and physical properties of sclerophyilous and malacophyllous leaves, on leaf decomposition rates. Comparisons were made between leaves colonized by macroinvertebrates and leaves protected by finemesh. In winter and summer, holm-oak leaves were colonized much less by macroinvertebrates than alder leaves. Spatial and temporal differences in leaf litter processing were mainly dependent on three factors (i) the chemical and physical properties of the leaves, (ii) the abundance of macroinvertebrates in the sediment and (iii) the temperature. The climatical pattern of temperature had a greater influence than its seasonal pattern. In contrast with many other studies, abiotic factors dominated over biotic factors in this study.
Keywords: alnus glutinosa; decomposition; leaves; macroinvertebrates; Mediterranean ecosystem; Quercus ilex; Temperature

Barium and other trace metals as indicators of vehicle emissions - Monaci, F; Bargagli, R (WATER AIR AND SOIL POLLUTION, 1997)
In the Siena urban environment, unwashed Q when leaves had a significantly higher Al, Ba, Cr, Fe, Mn, Na, Ni, Pb, Ti, and V content than samples from a neighbouring Mediterranean maquis. Significant relationships between element pairs indicated both the presence of metals emitted by motor vehicles and lithophilic elements, presumably from soil particles, resuspended by wind or turbulence generated by traffic. In order to minimize the effects of soil dust contamination and to seek clues to the metal sources, the estimated substrate contribution was subtracted from the raw concentrations of elements in Q. ilex leaves. Normalization for local soil composition confirmed that automotive emissions are the principal source of pollution in Siena. On the basis of a very significant relationship between normalized concentrations of Pb and Ba and the presence of the latter element in diesel and unleaded gasoline, Ba was recognized as a valuable tracer for vehicle emissions, in the place of Pb.
Keywords: accumulative bioindication; Central Italy; Quercus ilex leaves; Siena; trace element pollution; Urban environment

Between-tree variations in leaf Î´ 13 C of Quercus pubescens and Quercus ilex among Mediterranean habitats with different water availability - Damesin, C; Rambal, S; Joffre, R (Oecologia, 1997)
In this study, sun leaf carbon isotope compo- sition (d 13 C) of two co-occurring woody Mediterranean species (Quercus pubescens Willd., a deciduous oak, and Q. ilex L., an evergreen one) was investigated on four sites with dierent water availability. The total range of d 13 C values was 4.4 and 3.1& for Q. pubescens and Q. ilex respectively. The intra-site variability was about 3&. Total mean per species was equal. There were sig- ni®cant dierences among sites, but at each site means of d 13 C were not signi®cantly dierent between species. A simple physiological model predicts no dierence in in- trinsic water-use eciency (WUEi ) between evergreen and deciduous oaks. The relationship between site means of d 13 C and water parameters suggests that there is a leaf functional adjustment with respect to available water resource. No correlation was found between d 13 C and the contents of any mass-based biochemical cons- tituent. Nevertheless there was a signi®cant correlation between d 13 C and leaf mass per area of Q. ilex. For both species, there is also a positive correlation between leaf d 13 C and individual crown area, i.e. a structural char- acteristic at tree level. Causal relations between d 13 C and plant-environment interactions are discussed.
Keywords: carbon isotope composition; Foliar chemical constituents; mediterranean oaks; tree structure; Water availability

Biological and biochemical indicators in derelict soils subject to erosion - García, C; Hernández, T (Soil Biology and Biochemistry, 1997)
n 21 derelict soils from a semi-arid Spanish Mediterranean area, with a lithological sub- strate of Ioams, submitted to a high degree of erosion, several biological and biochemical properties in- dicative of the soil degradation leve1 were determined. The organic matter content of these soils was very low (mean value = 11.8 g kg-‘), approximately one-third of the average value for organic matter content of natura1 soils in the same zone. Biological properties such as basal respiration and biomass C also had low values and were positively correlated with the organic matter content. Low values for de- hydrogenajse and catalase activity were indicative of low biological activity of the degraded soils. A positive correlation was found between the hydrolases related with the N, P, C and S cycles (urease, proteases, fl-glucosidase and arylsulphatase), as wel1 as between these hydrolases and the organic matter content. Principal component analysis showed that ah the variables studied, except catalase and qCOr, had a similar behaviour. There was a negative correlation between many of the properties studied and electrical conductivity, which agreed with the higher degree of biological and biochemical degradation found in gypsiferous soils with a higher salt content. Arylsulphatase and p-glucosidase activity were the hydrolases most affected by soil erosion processes
Keywords: biochemical parameters (PG); Biological indicators; derelict soils; Soil degradation

Biological and biochemical indicators in derelict soils subject to erosion - Garcia, C.; Hernandez, T. (Soil Biology and Biochemistry, 1997)
n 21 derelict soils from a semi-arid Spanish Mediterranean area, with a lithological sub- strate of Ioams, submitted to a high degree of erosion, several biological and biochemical properties in- dicative of the soil degradation leve1 were determined. The organic matter content of these soils was very low (mean value = 11.8 g kg-‘), approximately one-third of the average value for organic matter content of natura1 soils in the same zone. Biological properties such as basal respiration and biomass C also had low values and were positively correlated with the organic matter content. Low values for de- hydrogenajse and catalase activity were indicative of low biological activity of the degraded soils. A positive correlation was found between the hydrolases related with the N, P, C and S cycles (urease, proteases, fl-glucosidase and arylsulphatase), as wel1 as between these hydrolases and the organic matter content. Principal component analysis showed that ah the variables studied, except catalase and qCOr, had a similar behaviour. There was a negative correlation between many of the properties studied and electrical conductivity, which agreed with the higher degree of biological and biochemical degradation found in gypsiferous soils with a higher salt content. Arylsulphatase and p-glucosidase activity were the hydrolases most affected by soil erosion processes
Keywords: biochemical parameters (PG); Biological indicators; derelict soils; Soil degradation

Cambios espaciales de las formaciones forestales mediterráneas ocurridos en los últimos cuarenta años - Regato, P; Castejon, M; TELLA, G; GIMÉNEZ, S; BARRERA, I; ROSSELLO, R ELENA- (II Congreso Forestal Español, 1997)
Partial results obtained fram a Spanish forest fonnation dynamics study are presented. Seven land squares located in different land classes, have been diacranically analyzed using aerial photointerpretation and spatial analysis with G.1.S. techniques. As an overall trend, polarization in forest pattem evolution has been detected: Fragmentation and diversification have occurred in coastal and/or periurban areas, and homogenization and extensification have occurred in inner and remote areas.
Keywords: forest dynamics; landscape ecology; Mediterranean; Spain

Caracterização da avifauna nidificante num montado de azinho Quercus rotundifolia por aplicação do método dos mapas: dois anos de estudo - Almeida, J (Airo, 1997)
Com o objectivo de obter informação de base sobre a composição e estrutura das comunidades de aves dos povoamentos florestais com mais expressão em Portugal, a avifauna nidificante numa parcela de 10ha de montado de azinho foi estudada durante duas épocas de reprodução (1989 e 1990), por aplicação do métod-dos-mapas. Registou-se uma grande estabilidade na composição da comunidade nidificante, assim como no número e traçado dos territórios delineados nos dois anos por aquele método. O número de espécies nidificantes variou entre 13 e 14, a densidade entre 30 e 31 casais/10 ha, a diversidade entre 3,45 e 3,34 e a equiparação entre 0,9 e 0,91
Keywords: Avifauna nidificante; método-dos-mapas (PG); montado

Caracterización de hábitats en los alcornocales andaluces - SÁNCHEZ PALOMARES, O; Carretero Carrero, M Pilar; Carrero, M Pilar Carretero (II Congreso Forestal Español, 1997)
Ecological parameters characterizing 51 cork oak stand sample plots were obtained after their physiographic, climatic and edaphic survey. From those parameters, optimum and marginal habitats have been established for the Andalusian cork oak forests, making possible the analysis of their ecologica1 variation
Keywords: Andalusia; Cork Oak Forest; ecology; habitat; Quereus suber

Chlorophyll fluorescence, stress and survival in populations of Mediterranean grassland species - Figueroa, M. E. (Journal of Vegetation Science, 1997)
Photosynthetic stress in response to a natural episode of frost and seasonal drought was assessed in a ‘dehesa’ grassland of SW Spain with a portable fluorimeter. Chlorophyll fluorescence characteristics of dark-adapted leaves of 11 abundant species of Mediterranean grassland were measured over the course of a growing season from November 1992 to July 1993. Concomitant changes in population size were estimated from censuses of permanent quadrats. There was a general decline in the photochemical efficiency (F v /Fm ) during the growing season and this was particularly evident late in the growing season (spring and early summer) when ambient temperatures were increasing rapidly and rainfall was low; it coincided with the period of most intense mortality for most species. A frost in early March (– 5 °C), when photosynthetically active radiation was relatively high, resulted in a small decrease in F v /Fm that was consistent across many species. The mechanisms of protection in species of Mediterranean grassland appear to be sufficiently effective to avoid damage to PSII for most of the year. For most species there was little evidence of photosystem II damage, as initial fluorescence (F 0 ) usually did not increase. Many of the effects observed were due to a reduction in Fm and thus were consistent with non-photochemical quenching. This could be adaptive in protecting PSII from damage in species that show little evidence of stress. The sharp increase in stress toward the end of the life cycle coincided with the fall in net population size.
Keywords: Drought; Fv/Fm; mortality; Photo-inhibition; photochemical efficiency; Photosystem II

Chlorophyll fluorescence, stress and survival in populations of Mediterranean grassland species - Figueroa, M E (Journal of Vegetation Science, 1997)
Photosynthetic stress in response to a natural episode of frost and seasonal drought was assessed in a ‘dehesa’ grassland of SW Spain with a portable fluorimeter. Chlorophyll fluorescence characteristics of dark-adapted leaves of 11 abundant species of Mediterranean grassland were measured over the course of a growing season from November 1992 to July 1993. Concomitant changes in population size were estimated from censuses of permanent quadrats. There was a general decline in the photochemical efficiency (F v /Fm ) during the growing season and this was particularly evident late in the growing season (spring and early summer) when ambient temperatures were increasing rapidly and rainfall was low; it coincided with the period of most intense mortality for most species. A frost in early March (– 5 °C), when photosynthetically active radiation was relatively high, resulted in a small decrease in F v /Fm that was consistent across many species. The mechanisms of protection in species of Mediterranean grassland appear to be sufficiently effective to avoid damage to PSII for most of the year. For most species there was little evidence of photosystem II damage, as initial fluorescence (F 0 ) usually did not increase. Many of the effects observed were due to a reduction in Fm and thus were consistent with non-photochemical quenching. This could be adaptive in protecting PSII from damage in species that show little evidence of stress. The sharp increase in stress toward the end of the life cycle coincided with the fall in net population size.
Keywords: Drought; Fv/Fm; mortality; Photo-inhibition; photochemical efficiency; Photosystem II

Clasificación ecológica y caracterización selvícola y PRODUCTIVA DEL PARQUE NATURAL DE LOS ALCORNOCALES (CÁDIZ y MÁLAGA) - Torres Álvarez, E; Montero González, G; V ÁZQUEZ PIQUÉ, F J (II Congreso Forestal Español, 1997)
An ecological classification of the Natural Park "Los Alcornocales" (Cádiz and Málaga, Spain) and a silvicultural and productive characterisation are done. The territorial c1assification is assisted by a Geographical Information System. Sixteen Territorial Classes and five classes of cork-oak potentiality are defined and mapped. Using a sample of seventy two plots, the cork-oak forests of this area are silvicultural and productively characterised, according their Territorial Class.
Keywords: Cork; cork-oak; Ecological classification; Geographical inforn1ation system; Potentiali ty; Quercus suber

Climatic discrimination of Mediterranean broad-leaved sclerophyllous and deciduous forests in central Spain - Gavilán, Rosario; Fernández-González, Federico (Journal of Vegetation Science, 1997)
Abstract. Climatic differences between three types of deciduous (Quercus pyrenaica) and three types of sclerophyllous (Quercus rotundifolia) Mediterranean forests in the Spanish Sistema Central were analyzed by means of Canonical Discriminant Analysis and Jancey's Discriminant Analysis, applied in successive steps to data from 252 meteorological stations. Climatic data included temperature and precipitation records as well as bioclimatic indices. Discriminant analysis was applied to broad-leaved sclerophyllous and deciduous forest communities sampled at each meteorological station using phytosociological methods. Annual and seasonal (summer, spring) water availability are the most important factor controlling the distribution of the two physiognomic forest types; southwestern associations of Quercus pyrenaica and Q. rotundifolia differ from their colder homologues by annual and monthly temperatures; western associations were separated from eastern ones in terms of annual and seasonal precipitation gradients. Discriminant analysis was a good technique to explore climatic gradients not shown by other general ordination or classification methods.
Keywords: Bioclimatic indices; climate; Continentality; Discriminant analysis; Summer aridity; Water availability

Climatic discrimination of Mediterranean broad-leaved sclerophyllous and deciduous forests in central Spain - Gavilán, Rosario; Fernández-González, Federico (Journal of Vegetation Science, 1997)
Abstract. Climatic differences between three types of deciduous (Quercus pyrenaica) and three types of sclerophyllous (Quercus rotundifolia) Mediterranean forests in the Spanish Sistema Central were analyzed by means of Canonical Discriminant Analysis and Jancey's Discriminant Analysis, applied in successive steps to data from 252 meteorological stations. Climatic data included temperature and precipitation records as well as bioclimatic indices. Discriminant analysis was applied to broad-leaved sclerophyllous and deciduous forest communities sampled at each meteorological station using phytosociological methods. Annual and seasonal (summer, spring) water availability are the most important factor controlling the distribution of the two physiognomic forest types; southwestern associations of Quercus pyrenaica and Q. rotundifolia differ from their colder homologues by annual and monthly temperatures; western associations were separated from eastern ones in terms of annual and seasonal precipitation gradients. Discriminant analysis was a good technique to explore climatic gradients not shown by other general ordination or classification methods.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Bioclimatic indices; climate; Continentality; Discriminant analysis; Summer aridity; Water availability

Consideraciones paleoambientales del Tardiglaciar y Holoceno inicial en el Levante español: macrorrestos vegetales de El Tossal de la Roca (Vall d'Alcalà, Alicante) - Uzquiano, Paloma; Arnanz, A M (Anales del Jardín Botánico de Madrid, 1997)
Charred macrobotanical remains from El Tossal de la Roca permit a better understanding of the Tardiglacial-Postglacial (Upper Palaeolithic levéis) transition in Valencia región, showing evidence of a supramediterranean environment with Pinus nigra, Juniperus t. phoenicea and Quercus t. faginea. During the early Holocene (Epipaleolithic levéis) Quercus ilex-coccifera is dominant, followed by Quercus t. faginea.
Keywords: Charred plant remains; Early Holocene; Palaeoenvironment; Tardiglacial; Tossal de la Roca; Valencia region

CONTRIBUCIÓN AL ESTUDIO DE LA SECA DE LA ENCINA (Quercus rotundifolia Lam.) EN EL NOROESTE DE LA PROVINCIA DE ALBACETE - MONREAL MONTOYA, J A; GALLETERO BLAZQUEZ, A. CHUMILLAS FERNÁNDEZ, R; SALVADOR ANDRÉS, D (II Congreso Forestal Español, 1997)
This paper is a study of the different hypotheses presented up to the present to try and explain reasons for the withering / drying up of oak trees, a serious problem which is taking a high to11 in our oak forests. Initial and follow-up studies have been carried out in N.W. Albacete on the different conditions that we have then used as parameters. Next, relationships have been established among these parameters and, finally, various conclusions have been reached.
Keywords: Albacete; Oak decline; Quercus rotundifolia

Contribution to the knowledge of the pharmaceutical ethnobotany of La Segarra region (Catalonia, Iberian Peninsula). - Raja, D; Blanché, C; Vallès Xirau, J (Journal of ethnopharmacology, 1997)
An ethnobotanical survey was carried out in the region known as La Segarra, situated at the north east of the Iberian Peninsula, in the inner plains of Catalonia, with an area of 720 km2 and a population of 17000. Working with 29 people, data on uses of 142 species belonging to 54 botanical families were obtained and presented, of which 13 uses corresponding to nine plant species were previously unreported.
Keywords: Catalonia; Ethnobotany; Folk medicine; Medicinal plants

Cork powder waste: an overview - Gil, Luis (Biomass and Bioenergy, 1997)
k powder, the major waste from cork processing industries, is generated throughout the industrial cork process and originates from grinding, cutting and finishing operations. Since there are various types of cork and different industrial operations, different types of cork powders are obtained. These have a high heating value, which make it suitable for energy production as well as other characteristics suitable for other uses as described here
Keywords: Cork; industry wastes; waste characterization; waste utilization

Cork powder waste: an overview - Gil, Luis (Biomass and Bioenergy, 1997)
k powder, the major waste from cork processing industries, is generated throughout the industrial cork process and originates from grinding, cutting and finishing operations. Since there are various types of cork and different industrial operations, different types of cork powders are obtained. These have a high heating value, which make it suitable for energy production as well as other characteristics suitable for other uses as described here
Keywords: Cork; industry wastes; waste characterization; waste utilization

Cork Suberin: A Glyceryl Based Polyester - Graça, José; Pereira, Helena (Holzforschung - International Journal of the Biology, Chemistry, Physics and Technology of Wood, 1997)
Total depolymerization of cork from the cork oak (Quercus suber L.) by using a sodium methoxide catalysed methanolysis solubilized 53.2 % of the material, including 5.2 % of glycerol, 48,0 % of suberinic fatty acids and alcohols and minor amounts of ferulic acid. A very mild depolymerization using calcium oxide treated methanol, which solubilized only 2.0% of the cork material was studied by GC-MS. In the solubilized material, the total amount of aliphatic acids was 43.8 % (including alkanoic acids 4.0%. ω-hydroxyacids 13.2% and α,ω-diacids 26.6%), of 1-alkanols 2.1 % and of monoacylglycenols 32.1%. It was possible to identify 1-monoacylglycerols and 2-monoacylglycerols of alkanoic acids (1,2%), ω-hydroxyacids (3.7 %) and α,ω-diacids (22.8 %). It is proposed that suberin is a glyceryl based polymer and that its insoluble character is given, at least in part, by the cross-linking of dicarboxylic fatty acids with glycerol. The term suberin should be used for this aliphatic polyester component of the cell wall.
Keywords: Cork; Glycerol; Monoacylglycero; Quercus suber; suberin

Cork-oak seedling production : Container capacity and substrate effect on seedling field performance - Costa, F; Silva, E; Moura, S; Almeida, M H; Chambel, M R; Pereira, C (Nursery production and stand establishment of broad leaves to promote sustainable forest management, 1997)
Cork oak is the second forest species in Portugal covering an area of about 721000 ha. In the context of the Common Agriculture Policy (CAP), large areas (ca. 10% of total area) were reforested between 1994-98 with low survival rates due to inappropriate nursery and establishment techniques, as well as the use of unsuitable genetic material. The main purpose of this study was to evaluate the effect of container capacity and substrate in field performance of cork oak seedling with 1 year of age during the first 3 years after plantation. Therefore 3 container capacities were tested (210, 300 and 400 cm3) in combination with 4 types of substrate: composted pine bark, composted pine bark with vermiculite 3:1(v/v), composted pine bark with peat 1:1 (v/v) and peat with vermiculite 3:1 (v/v). With the 300 cm3 container capacity 3 other substrates were also tested: F+H organic layers, F+H organic layers with composted pine bark 1:1 (v/v) and F+H organic layers with peat 1:1 (v/v). A field trial was established in the South of Portugal in April 1998. Just before plantation seedlings morphological characteristics (root and shoot biomass, leaf area, height, stem diameter, root length and root development patterns) were measured and correlated with survival and growth evaluated one, two and three years after plantation. The results showed that after three years in the field only the type of substrate had a highly significant influence in survival and early growth. Container capacity (210, 300 and 400 cm_) did not have an influence on height growth during the first 3 years, just as there was no clear influence on survival rate. Peat with vermiculite (3:1) substrate led to 30% higher survivals than other substrates. Substrate with peat favoured secondary root development (length), which seems to be an advantage in field performance.
Keywords: container capacity; cork-oak seedling; Field performance; substrate

Cork-oak seedling production : Container capacity and substrate effect on seedling field performance - Costa, F.; Silva, E.; Moura, S.; Almeida, M. H.; Chambel, M. R.; Pereira, C. (Nursery production and stand establishment of broad leaves to promote sustainable forest management, 1997)
Cork oak is the second forest species in Portugal covering an area of about 721000 ha. In the context of the Common Agriculture Policy (CAP), large areas (ca. 10% of total area) were reforested between 1994-98 with low survival rates due to inappropriate nursery and establishment techniques, as well as the use of unsuitable genetic material. The main purpose of this study was to evaluate the effect of container capacity and substrate in field performance of cork oak seedling with 1 year of age during the first 3 years after plantation. Therefore 3 container capacities were tested (210, 300 and 400 cm3) in combination with 4 types of substrate: composted pine bark, composted pine bark with vermiculite 3:1(v/v), composted pine bark with peat 1:1 (v/v) and peat with vermiculite 3:1 (v/v). With the 300 cm3 container capacity 3 other substrates were also tested: F+H organic layers, F+H organic layers with composted pine bark 1:1 (v/v) and F+H organic layers with peat 1:1 (v/v). A field trial was established in the South of Portugal in April 1998. Just before plantation seedlings morphological characteristics (root and shoot biomass, leaf area, height, stem diameter, root length and root development patterns) were measured and correlated with survival and growth evaluated one, two and three years after plantation. The results showed that after three years in the field only the type of substrate had a highly significant influence in survival and early growth. Container capacity (210, 300 and 400 cm_) did not have an influence on height growth during the first 3 years, just as there was no clear influence on survival rate. Peat with vermiculite (3:1) substrate led to 30% higher survivals than other substrates. Substrate with peat favoured secondary root development (length), which seems to be an advantage in field performance.
The following values have no corresponding Zotero field: periodical: Nursery production and stand establishment of broad leaves to promote sustainable forest management pub-location: Rome
Keywords: container capacity; cork-oak seedling; Field performance; substrate

CRECIMIENTO RADIAL DEL CORCHO EN LOS ALCORNOCALES ESPAÑOLES: RELACIONES ENTRE ANATOMÍA Y BIOCLIMA. - Fos, S; PÉREZ-RoViRA, P; BARRENO, E (II Congreso Forestal Español, 1997)
A comparative study of the reproduction cork radial growth between the main cork productive areas in Spain is raised: Extremadura-Huelva, Cádiz, Girona and Castellón. The results show that environmental variables bring about significant differences in the annual increments and in the ratio between cork types (late/early cork). The highest average thickness had be en measured in Cádiz (Jerez de la Frontera - 5.587 mm) and the lowest in Castellón (Artana - 1.964 mm). Remaining results yield between 2.963 mm, measured in Sta. Cristina d' Aro (Girona), and 3.566 mm, in Casas de Miravete (Cáceres). These asymmetries are due to the higher early cork development. The most equilibrated corks in the contributions of each cork type are those produced in Cáceres (::::60:40) and Castellón (::::75:25), resisting with those observed in the other areas. The obtained results showed significant correlation with c1imatic (annual average temperature, precipitation) and bioc1imatic (It, Ic) parameters
Keywords: Anatomy; bioc1imatology; Cork; Quercus suber; Radial growth

CRECIMIENTO RADIAL DEL CORCHO EN LOS ALCORNOCALES ESPAÑOLES: RELACIONES ENTRE ANATOMÍA Y BIOCLIMA. - Fos, S.; PÉREZ-RoViRA, P.; Barreno, E. (II Congreso Forestal Español, 1997)
A comparative study of the reproduction cork radial growth between the main cork productive areas in Spain is raised: Extremadura-Huelva, Cádiz, Girona and Castellón. The results show that environmental variables bring about significant differences in the annual increments and in the ratio between cork types (late/early cork). The highest average thickness had be en measured in Cádiz (Jerez de la Frontera - 5.587 mm) and the lowest in Castellón (Artana - 1.964 mm). Remaining results yield between 2.963 mm, measured in Sta. Cristina d' Aro (Girona), and 3.566 mm, in Casas de Miravete (Cáceres). These asymmetries are due to the higher early cork development. The most equilibrated corks in the contributions of each cork type are those produced in Cáceres (::::60:40) and Castellón (::::75:25), resisting with those observed in the other areas. The obtained results showed significant correlation with c1imatic (annual average temperature, precipitation) and bioc1imatic (It, Ic) parameters
The following values have no corresponding Zotero field: periodical: II Congreso Forestal Español pub-location: Pamplona
Keywords: Anatomy; bioc1imatology; Cork; Quercus suber; Radial growth

DEMANDAS SOCIALES, INTERÉS DE LOS PROPIETARIOS E INTERVENCIÓN PÚBLICA EN LOS ESPACIOS NATURALES: EL CASO DE LA DEHESA DE LA COMARCA DE MONFRAGÜE - Mariscal Lorente, Pedro Jesús; Campos Palacín, Pablo (IV Coloquio Hispano-Portugués de Estudios Rurales., 1997)
El creciente interés del público por consumir activamente (valores recreativos actual y futuro) y pasivamente (valor de existencia) los servicios ambientales de los espacios naturales adehesados junto con el continuado intento de ambientalización de la política agraria comunitaria, están produciendo una notable intervención pública hacia el fomento de la gestión conservadora de los recursos naturales y ambientales por parte de los propietarios de dehesas. En este estudio se presentan las preferencias sociales sobre los valores recreativos y de la conservación de la calidad ambiental de las dehesas de Monfragüe manifestadas por la disponibilidad al pago de los visitantes de libre acceso a través de una encuesta de valoración contingente. Se analizan las demandas de compensaciones económicas de los propietarios de dehesas en la comarca de Monfragüe para llevar a cabo mejoras en la conservación de los recursos naturales y los valores ambientales de las dehesas, dichas demandas han sido cuantificadas mediante una encuesta delphi, y se aporta una valoración contingente del auto-consumo anual de servicios ambientales controlados por los propietarios de dehesas. Los resultados de la investigación muestran que el público tiene una relevante disponibilidad al pago por el disfrute y la conservación de los atributos ambientales de la dehesa, que los propietarios aceptan en grados significativos el fomento de una ganadería más extensiva así como otras prácticas agrarias compatibles y favorecedoras de los recursos naturales, como la expansión artificial de los alcornocales y los encinares, siempre que se les recompense por el coste de oportunidad que conllevan y, finalmente, que estos propietarios actualmente auto-consumen anualmente servicios ambientales de sus dehesas por una cuantía que ellos estiman entre el 1% y el 5% del capital total invertido en su explotación adehesada.
The following values have no corresponding Zotero field: periodical: IV Coloquio Hispano-Portugués de Estudios Rurales. issue: i
Keywords: auto-consumo ambiental; demanda de compensaciones; encuesta delphi; prácticas de conservación ambientales; Reforestación de encinas y alcornoques; subvenciones públicas; valoración contingente

DEMANDAS SOCIALES, INTERÉS DE LOS PROPIETARIOS E INTERVENCIÓN PÚBLICA EN LOS ESPACIOS NATURALES: EL CASO DE LA DEHESA DE LA COMARCA DE MONFRAGÜE - Mariscal Lorente, Pedro Jesús; Campos Palacín, Pablo (IV Coloquio Hispano-Portugués de Estudios Rurales., 1997)
El creciente interés del público por consumir activamente (valores recreativos actual y futuro) y pasivamente (valor de existencia) los servicios ambientales de los espacios naturales adehesados junto con el continuado intento de ambientalización de la política agraria comunitaria, están produciendo una notable intervención pública hacia el fomento de la gestión conservadora de los recursos naturales y ambientales por parte de los propietarios de dehesas. En este estudio se presentan las preferencias sociales sobre los valores recreativos y de la conservación de la calidad ambiental de las dehesas de Monfragüe manifestadas por la disponibilidad al pago de los visitantes de libre acceso a través de una encuesta de valoración contingente. Se analizan las demandas de compensaciones económicas de los propietarios de dehesas en la comarca de Monfragüe para llevar a cabo mejoras en la conservación de los recursos naturales y los valores ambientales de las dehesas, dichas demandas han sido cuantificadas mediante una encuesta delphi, y se aporta una valoración contingente del auto-consumo anual de servicios ambientales controlados por los propietarios de dehesas. Los resultados de la investigación muestran que el público tiene una relevante disponibilidad al pago por el disfrute y la conservación de los atributos ambientales de la dehesa, que los propietarios aceptan en grados significativos el fomento de una ganadería más extensiva así como otras prácticas agrarias compatibles y favorecedoras de los recursos naturales, como la expansión artificial de los alcornocales y los encinares, siempre que se les recompense por el coste de oportunidad que conllevan y, finalmente, que estos propietarios actualmente auto-consumen anualmente servicios ambientales de sus dehesas por una cuantía que ellos estiman entre el 1% y el 5% del capital total invertido en su explotación adehesada.
Keywords: auto-consumo ambiental; demanda de compensaciones; encuesta delphi; prácticas de conservación ambientales; Reforestación de encinas y alcornoques; subvenciones públicas; valoración contingente

Determination of the natural mortality age of an holm oak ( Quercus ilex L.) stand in Corsica (Mediterranean Island) - Panaiotis, C; Carcaillet, C; M'Hamedi, M (Acta Oecologica, 1997)
Determination of old forest stand age and forestry history is problematic due to the difficulties which arise in obtaining core samples from trees. In the present paper, the natural mortality age and forestry history of a Corsican holm oak stand are estimated using the methods described below. Firstly, the correlation between stem age estimated from healthy stump counts in fellings and stem diameter is determined using a second order polynomial equation. Secondly, the distribution of stand diameter classes is analyzed by the BHATTACHARYA (1967) method. This method allows the identifica- tion of cohorts as well as the estimation of cohort mean diameters and theoretical tree count numbers. Using cohort mean diameters, we are able to estimate their age and discuss stand forestry history. Finally, the analysis of thirty broken stumps originating from senescent holm oak natural falls, is used to determine the mean natural mortality age of trees bused on their mean diameter. This natural mor- tality is estimated to occur at 170 -+ 46 years of age. The causes of holm oak mortality and the capacity of old stumps to renew the ecosystem are discussed in order to contribute to the conservation and man- agement of these woodland communities.
Keywords: Corsica; Dendrochronology; Forest structure; mediterranean forest; natural mortality; old forest; Quercus ilex

Development and ultrastructure of the endodermis in the primary root of cork oak (Quercus suber) - Verdaguer, Dolors; Molinas, Marisa (Canadian Journal of Botany, 1997)
The endodermis maturation process was studied in the primary root of the cork oak (Quercus suber L.) with emphasis on the chemical nature of the cell wall and on the possible role of tannins. Tannins were found in endodermal and adjacent cortical cells in all maturation stages. We discuss our findings in relation to the previous literature in other woody and herbaceous species. The results of the histochemical tests showed differences in the aliphatic compounds of the suberin between the Casparian strip suberin and the suberin layer deposited in state II cells. Plasmodesmata were present in radial and tangential walls during the entire maturation process. The significance of plasmodesmata and of the suberin deposition pattern is discussed in relation to apoplastic and symplastic transport in roots. Key words: Casparian strip, endodermis, primary root, suberin, Quercus suber L.
doi: 10.1139/b97-087
Keywords: Casparian strip; endoderrnis; primary root; Quercus suber L.; suberin

Distribution of an increasing roe deer population in a fragmented Mediterranean landscape - Tellería, José Luis; Virgós, Emilio (Ecography, 1997)
This paper describes roe deer Capreolus capreolus distribution in central Spain, where the species has spread from the mountains into peripheral agricultural areas In this region, it is more abundant in forest fragments near the mountains than in those further away, in pine and oak woodlands than in sclerophyllous forests, and in forests with open water than in those lacking this resource The paper also analyzes whether habitat quality and geographic location of forests with respect to roe deer source areas are the two basic causes of its distribution, as predicted by some models of the species distribution in fragmented landscapes The results corroborate this hypothesis revealing that roe deer abundance is linked negatively to sclerophyllous forest cover and distance from mountains We conclude that this type of farmland seems to be sub-optimal for roe deer in comparison with forested, moist mountains
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: abundance; Distribution patterns; forest cover; habitat quality (voyant); roe deer

Distribution of an increasing roe deer population in a fragmented Mediterranean landscape - Tellería, José Luis; Virgós, Emilio (Ecography, 1997)
This paper describes roe deer Capreolus capreolus distribution in central Spain, where the species has spread from the mountains into peripheral agricultural areas In this region, it is more abundant in forest fragments near the mountains than in those further away, in pine and oak woodlands than in sclerophyllous forests, and in forests with open water than in those lacking this resource The paper also analyzes whether habitat quality and geographic location of forests with respect to roe deer source areas are the two basic causes of its distribution, as predicted by some models of the species distribution in fragmented landscapes The results corroborate this hypothesis revealing that roe deer abundance is linked negatively to sclerophyllous forest cover and distance from mountains We conclude that this type of farmland seems to be sub-optimal for roe deer in comparison with forested, moist mountains
Keywords: abundance; Distribution patterns; forest cover; habitat quality (voyant); roe deer

Diurnal and seasonal course of monoterpene emissions from Quercus ilex(L.) under natural conditions application of light and temperature algorithms - Bertin, N.; Staudt, M.; Hansen, U.; Seufert, G.; Foster, P.; Fugit, J. L.; Torres, L. (Atmospheric Environment, 1997)
Quercus ilex is a common oak species in the Mediterranean vegetation and a strong emitter of monoterpenes. Since the short-term control of monoterpene emissions from this species involved both temperature and light, the usual exponential function of temperature may not be sufficient to model the diurnal and seasonal emission course. In the frame of the BEMA-project (Biogenic Emissions in the Mediterranean Area), we investigated the tree-to-tree, branch-to-branch, diurnal, and seasonal variability of monoterpene emissions from Q. ibex over one and a half years at Castelporziano (Rome, Italy). In addition, w,: checked the suitability of the model developed for isoprene by Guenther et al. (1991, 1993) to simulate the short- and long-term variations of monoterpene emissions from this particular species. We found that the tree-to-tree variability was rather small compared to the experimental error during air sampling and analysis by diverse laboratories. The branch-to-branch variability was noticeable between sun- and shade-adapted branches only. 80% of total emissions were represented by cc-pinene, B-pinene and sabinene, whose proportions were stable over the year and independent of light exposure. The emission factor (emission rate at 30°C and 1000 ~molphotonm-Zs-l ) estimated by the isoprene model or extrapo- lated from measurements was similar: it was about 22 pggdw -r h-r for sun-exposed branches and 2.3 pggdw.-’ h-r for shade-adapted branches. It was rather stable over the seasons except during leaf development. The diurnal and seasonal emission patterns from Q. ibex were simulated in a satisfying way by Guenther’s algorithms especially if we excluded the laboratory variability. For shade-adapted branches, an emission factor 17 times lower had to be applied, but temperature and light responses were unchanged.
Keywords: Holm oak; index; light and temperature algorithm; Mediterranean vegetation; Modelling; Monoterpene; Quercus ilex

Diurnal and seasonal course of monoterpene emissions from Quercus ilex(L.) under natural conditions application of light and temperature algorithms - Bertin, N; Staudt, M; Hansen, U; Seufert, G; Foster, P; Fugit, J L; Torres, L (Atmospheric Environment, 1997)
Quercus ilex is a common oak species in the Mediterranean vegetation and a strong emitter of monoterpenes. Since the short-term control of monoterpene emissions from this species involved both temperature and light, the usual exponential function of temperature may not be sufficient to model the diurnal and seasonal emission course. In the frame of the BEMA-project (Biogenic Emissions in the Mediterranean Area), we investigated the tree-to-tree, branch-to-branch, diurnal, and seasonal variability of monoterpene emissions from Q. ibex over one and a half years at Castelporziano (Rome, Italy). In addition, w,: checked the suitability of the model developed for isoprene by Guenther et al. (1991, 1993) to simulate the short- and long-term variations of monoterpene emissions from this particular species. We found that the tree-to-tree variability was rather small compared to the experimental error during air sampling and analysis by diverse laboratories. The branch-to-branch variability was noticeable between sun- and shade-adapted branches only. 80% of total emissions were represented by cc-pinene, B-pinene and sabinene, whose proportions were stable over the year and independent of light exposure. The emission factor (emission rate at 30°C and 1000 ~molphotonm-Zs-l ) estimated by the isoprene model or extrapo- lated from measurements was similar: it was about 22 pggdw -r h-r for sun-exposed branches and 2.3 pggdw.-’ h-r for shade-adapted branches. It was rather stable over the seasons except during leaf development. The diurnal and seasonal emission patterns from Q. ibex were simulated in a satisfying way by Guenther’s algorithms especially if we excluded the laboratory variability. For shade-adapted branches, an emission factor 17 times lower had to be applied, but temperature and light responses were unchanged.
Keywords: Holm oak; index; light and temperature algorithm; Mediterranean vegetation; Modelling; Monoterpene; Quercus ilex

Diurnal fluctuations of secondary photooxidants in air and of detoxification systems in the foliage of Mediterranean forest trees - Junkermann, Wolfgang; Polle, A. (Atmospheric Environment, 1997)
s-phase peroxide mixing ratios were measured in the canopy area of a Mediterranean oak/pine fo.rest. Concurrently the activities of cell wall localized peroxidases, which protect leaves from external oxidants, were investigated. The diurnal cycles of peroxidase activity showed a strong decrease when the gas-phase concentration of highly phytotoxic hydroxy hydroperoxides increased. These results suggest that ambient gas-phase mixing ratios of organic peroxides may injure the plants’ oxidative defence system
Keywords: antioxidant protection; organic peroxides; peroxidase activity

Diurnal fluctuations of secondary photooxidants in air and of detoxification systems in the foliage of Mediterranean forest trees - Junkermann, Wolfgang; Polle, A (Atmospheric Environment, 1997)
s-phase peroxide mixing ratios were measured in the canopy area of a Mediterranean oak/pine fo.rest. Concurrently the activities of cell wall localized peroxidases, which protect leaves from external oxidants, were investigated. The diurnal cycles of peroxidase activity showed a strong decrease when the gas-phase concentration of highly phytotoxic hydroxy hydroperoxides increased. These results suggest that ambient gas-phase mixing ratios of organic peroxides may injure the plants’ oxidative defence system
Keywords: antioxidant protection; organic peroxides; peroxidase activity

Ecophysiological studies of Mediterranean plant species at the Castelporziano estate - Manes, Fausto; Seufert, Günther; Vitale, Marcello (Atmospheric Environment, 1997)
e aim of this work was to characterize the eco-physiological performance of the main plant species of the Castelporziano site by single leaf investigations. We measured the leaf gas exchange of Quercus ilex L., Pinus pinea L., Pistacia lentiscus L. and Asphodelus microcarpus L. for several days. Additionally, the xylem water potential of Quercus ibex, Pinus pinea and Pistacia lentiscus was recorded in order to obtain more physiological background information for the discussion of the trace gas emissions. This study indicates significantly different physiological responses to the different environmental condi- tions. In particular, summer conditions (high values of light, air temperature and low xylem water potentials) caused the depression of photosynthesis in Quercus ibex and Pinus pinea but did not affect photosynthesis of Pistacia lentiscus and Asphodelus microcarpus. This should be taken into account when discussing VOC emission rates and fluxes
Keywords: fluorescence; Phenology; photosynthesis; Transpiration; VOCs; Xylem water potential

Edaphic characteristics of Quercus suber woods in Latium - Dowgiallo, G; Testi, a; Pesoli, P; Pignatti, S (Rendiconti Lincei, 1997)
{In this paper the results are reported of a soil survey done in selected sites of Latium un- der the most significant Quercus suber woods (Cytiso-Quercetum suberis Testi, Pignatti and Lucattini 1994) previously studied from a phytosociologicat point of view. After describing the dominant soil type of each area, physical-chemical characteristics have been analysed in order to point out the significance of edaphic factors in the distribution and floristic composition, of the Quereus suber co,noses. Bioclimatic, structural and edaphic features of this vegetation showed a great convergence; among all the parameters examined, AWC resulted to be the most effective one in conditioning the mesophilous character of Quercus suber coenoses growing in Latium. In this respect this type of vegetation shows rather strong affinities with mixed Quercztr cerrz} woods, both in the floristic composition and in the edaphic requirements, as already suggest- ed in the most recent phytosociological studies.
Keywords: Correlation soil-vegetation; Latium; Quercus suber oakwoods; soils

Edaphic characteristics of Quercus suber woods in Latium - Dowgiallo, G.; Testi, A.; Pesoli, P.; Pignatti, S. (Rendiconti Lincei, 1997)
{In this paper the results are reported of a soil survey done in selected sites of Latium un- der the most significant Quercus suber woods (Cytiso-Quercetum suberis Testi, Pignatti and Lucattini 1994) previously studied from a phytosociologicat point of view. After describing the dominant soil type of each area, physical-chemical characteristics have been analysed in order to point out the significance of edaphic factors in the distribution and floristic composition, of the Quereus suber co,noses. Bioclimatic, structural and edaphic features of this vegetation showed a great convergence; among all the parameters examined, AWC resulted to be the most effective one in conditioning the mesophilous character of Quercus suber coenoses growing in Latium. In this respect this type of vegetation shows rather strong affinities with mixed Quercztr cerrz} woods, both in the floristic composition and in the edaphic requirements, as already suggest- ed in the most recent phytosociological studies.
Keywords: Correlation soil-vegetation; Latium; Quercus suber oakwoods; soils

EFECTO DE DISTINTOS TIPOS DE ENVASE, SUSTRATO y GRADOS DE ENDURECIMIENTO EN LA PRODUCCIÓN DE PLANTA DE QUERCUS SUBER L. y QUERCUS ROTUNDIFOLIA LAM. - SUÁREZ, Ma ANGELES; ÁZQUEZ, FRANCISCO V; Baselga, Pilar (II Congreso Forestal Español, 1997)
Different treatments about olm oak (Quercus rotundifolia Lam.) and cork oak (Quercus suber L.) plants' production are comparied. It has been worked with two kinds of containers, three kinds of substratums and two degrees of plants' protection during the cultivation
Keywords: Cork oak; Nursery; Olm oak; Plant's production; Quercus

EFECTOS DE DISTINTOS TRATAMIENTOS EN VIVERO EN EL ARRAIGO Y PRIMER DESARROLLO EN CAMPO DE PLANTAS DE QUERCUS SUBER L. y QUERCUS ROTUNDIFOLIA LAM .. EFECTO DEL PROTECTOR. - Suarez, M Ángeles; VÁzquez, Francisco; Baselga, Pilar; Torres, Enrique; CUEVAS, SERAFÍN (II Congreso Forestal Español, 1997)
The rootting ability and the first developes of cork oak and olm oak seedlings cultivated on different substratums and containers, as well as different harding degrees are comparied. The individual protector's effect is also analyzed.
Keywords: Cork oak; Nursery; Olm oak; Plant's production; Quercus; Reforestation

Efeitos da poda radicular na produçáo de plantas de sobreiro em viveiro (quercus suber l.) - Santos, Maria de Lourdes; PAULINO, ISABEL MARGARIDA ORFÁO (II Congreso Forestal Español, 1997)
The work was accomplished in the Seed Laboratory of National Forestry Station. The aim is to observe, in the nursery plants production, the pruning root effects made at several levels. The seeds provenance are the selected trees. The results permitted to conclude that: • The plants submitted to a radicular pruning at 1/3 and 2/3 present a better thickening and become woody plants; • The plants submitted to a radicular pruning at 1/3 present higher size of aerial parts; • The plants submitted to a radicular pruning at 2/3 present higher rate of secondary roots. K.
The following values have no corresponding Zotero field: periodical: II Congreso Forestal Español pub-location: Pamplona
Keywords: Nursery; Plants; Quercus suber; radicular pruning

Efeitos da poda radicular na produçáo de plantas de sobreiro em viveiro (quercus suber l.) - Santos, Maria de Lourdes; PAULINO, ISABEL MARGARIDA ORFÁO (II Congreso Forestal Español, 1997)
The work was accomplished in the Seed Laboratory of National Forestry Station. The aim is to observe, in the nursery plants production, the pruning root effects made at several levels. The seeds provenance are the selected trees. The results permitted to conclude that: • The plants submitted to a radicular pruning at 1/3 and 2/3 present a better thickening and become woody plants; • The plants submitted to a radicular pruning at 1/3 present higher size of aerial parts; • The plants submitted to a radicular pruning at 2/3 present higher rate of secondary roots. K.
Keywords: Nursery; Plants; Quercus suber; radicular pruning

Effect of habitat and age on variations in volatile organic compound (VOC) emissions from Quercus ilex and Pinus pinea - Street, R A; Owen, S; Duckham, S C (Atmospheric Environment, 1997)
A dynamic branch enclosure was used to measure emission rates of volatile organic compounds (VOCs) under field conditions from two common native Mediterranean species, Quercus ilex and Pinus pinea. In addition to a-pinene, B-pinene, sabinene, limonene and cineole, a suite of lesser known compounds were tentatively identified including cis- and trans-ocimene, cis- and trans-linalool oxide and sabinaketone. Emissions of isoprene from Quercus ilex were insignificant in comparison to those of the monoterpenes and were not detected from Pinus pinea. Variability in emission rates between two habitats, the forest and the dunes, were assessed for Quercus ibex. Temperature sensitivities of emissions and total summed emission rates from Quercus ilex were clearly related to environmental conditions. Emission rates from Pinus pinea showed great variability, but differences between normalised mean emission rates from mature forest and young plantation trees may be significant. Existing emission rate models were found to inadequately describe the observed data.
Keywords: Biogenic emissions; branch enclosure; Mediterranean vegetation; Monoterpene; Pinus pinea; Quercus ilex; VOCs

Effects of germination inhibition on the dynamics of Quercus ilex stands - Li, Junqing; Romane, Francois J (Journal of Vegetation Science, 1997)
Abstract. Germination of Quercus ilex L. in coppice stands of this species in the western Mediterranean Basin was examined and a germination inhibitory process is proposed to explain some germination traits. Germination rate and seedling biomass of Q. ilex were greatly modified by watering acorns with various concentrations of aqueous soil extracts from a Q. ilex coppice stand but also when the acorns were sown in soil from Q. ilex coppice stands. In the aqueous extract experiment, Q. ilex germination and seedling weight both decreased as the aqueous extract concentration increased. In the soil type experiment, Q. ilex soil decreased the Q. ilex germination rate. Comparative studies with Q. pubescens germination (this species, replaced by Q. ilex around 5 000 B.P., is assumed to form the climax vegetation of the region) revealed that Q. pubescens was less sensitive to the aqueous extracts and soils of Q. ilex coppice stands. Inhibition of Q. ilex seed germination could be a major reason for the poor seed regeneration and suggested a possible comeback of Q. pubescens.
Keywords: Allelopathy; Mediterranean vegetation; Quercus pubescens Willd

Effects of germination inhibition on the dynamics of Quercus ilex stands - Li, Junqing; Romane, Francois J. (Journal of Vegetation Science, 1997)
Abstract. Germination of Quercus ilex L. in coppice stands of this species in the western Mediterranean Basin was examined and a germination inhibitory process is proposed to explain some germination traits. Germination rate and seedling biomass of Q. ilex were greatly modified by watering acorns with various concentrations of aqueous soil extracts from a Q. ilex coppice stand but also when the acorns were sown in soil from Q. ilex coppice stands. In the aqueous extract experiment, Q. ilex germination and seedling weight both decreased as the aqueous extract concentration increased. In the soil type experiment, Q. ilex soil decreased the Q. ilex germination rate. Comparative studies with Q. pubescens germination (this species, replaced by Q. ilex around 5 000 B.P., is assumed to form the climax vegetation of the region) revealed that Q. pubescens was less sensitive to the aqueous extracts and soils of Q. ilex coppice stands. Inhibition of Q. ilex seed germination could be a major reason for the poor seed regeneration and suggested a possible comeback of Q. pubescens.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Allelopathy; Mediterranean vegetation; Quercus pubescens Willd

Effects of introduced exotic tree species on Collembola communities: The importance of management techniques - SOUSA, J. P.; Vingada, J. V.; Barrocas, H.; DAGAMA, M. M. (PEDOBIOLOGIA, 1997)
Studies of the impact of the substitution of autochthonous forests by plantations of exotic tree species (a quite common phenomenon in Southern European countries) on soil arthropod communities (mainly Collembola and Acarina) generally deal with the effects of the exotic species per se and disregard the management techniques used. In this study the impact of the introduced Eucalyptus globulus on the Collembola communities of Quercus ilex ballota and Quercus suber stands was analysed. Since the autochthonous tree species are similar (in terms of leaf type and the ability to produce litter) the main objective was to examine the effects of the different management techniques used in the two plantations of Eucalyptus. (i) There is a significant difference in management techniques used in the Eucalyptus plantations leading to differences in habitat configuration: the plantation associated with the Helm-Oak stand is used for cellulose paste production, with periodic removal of the shrub and herbaceous layers; the other plantation, close to the Cork-Oak stand, is not managed at all, presenting an abundant shrub layer. (ii) in both cases, the substitution of the Oak species by Eucalyptus caused a disruption of the Collembola communities, although it was more pronounced in e. ilex ballota vs E. globulus (station 1) than in e. suber vs E. globulus (station 2). The number of individuals, the number of taxa and diversity parameters are in most cases greater under Oak species but more evident in station 1. (iii) Given these results, the influence of the factor `'management technique-habitat configuration'' in analysing and interpreting effects of exotics on soil arthropod communities is discussed.
IX International Colloquium on Apterygota, DUBLIN, IRELAND, 1996IX International Colloquium on Apterygota, DUBLIN, IRELAND, 1996The following values have no corresponding Zotero field: pub-location: VILLENGANG 2, D-07745 JENA, GERMANY publisher: GUSTAV FISCHER VERLAG
Keywords: Collembola community disruption; EUCALYPTUS; Quercus illex; Quercus suber

Effects of introduced exotic tree species on Collembola communities: The importance of management techniques - Sousa, J P; Vingada, J V; Barrocas, H; DaGama, M M (PEDOBIOLOGIA, 1997)
Studies of the impact of the substitution of autochthonous forests by plantations of exotic tree species (a quite common phenomenon in Southern European countries) on soil arthropod communities (mainly Collembola and Acarina) generally deal with the effects of the exotic species per se and disregard the management techniques used. In this study the impact of the introduced Eucalyptus globulus on the Collembola communities of Quercus ilex ballota and Quercus suber stands was analysed. Since the autochthonous tree species are similar (in terms of leaf type and the ability to produce litter) the main objective was to examine the effects of the different management techniques used in the two plantations of Eucalyptus. (i) There is a significant difference in management techniques used in the Eucalyptus plantations leading to differences in habitat configuration: the plantation associated with the Helm-Oak stand is used for cellulose paste production, with periodic removal of the shrub and herbaceous layers; the other plantation, close to the Cork-Oak stand, is not managed at all, presenting an abundant shrub layer. (ii) in both cases, the substitution of the Oak species by Eucalyptus caused a disruption of the Collembola communities, although it was more pronounced in e. ilex ballota vs E. globulus (station 1) than in e. suber vs E. globulus (station 2). The number of individuals, the number of taxa and diversity parameters are in most cases greater under Oak species but more evident in station 1. (iii) Given these results, the influence of the factor `'management technique-habitat configuration'' in analysing and interpreting effects of exotics on soil arthropod communities is discussed.
IX International Colloquium on Apterygota, DUBLIN, IRELAND, 1996
Keywords: Collembola community disruption; EUCALYPTUS; Quercus illex; Quercus suber

El ciclo de biomasa en bosques de frondosas del sur de extremadura. variabilidad espacial del desfronde - TORRES, E; CUEVAS, S; VÁZQUEZ, F Ma; SUÁREZ, Ma A (II Congreso Forestal Español, 1997)
The knowledge of the biomass and nutrients cycle is very important for a suitable forest management. In this paper, four broadleaved species litterfall, during november 1996, is studied in Extremadura (Spain): Castanea sativa Miller, Quercus pyrenaica Willd, Q. rotundifolia Lam and Q. suber L. Litterfall is compared in sorne forests with different maturity. Also, orientation, position and individual tree factors influence is analysed
Keywords: Castanea sativa; Extremadura; litterfall; Quercus pyrenaica; Quercus rotundifolia; Quercus suber

Embriogénesis gamética para obtención de haploides en alcornoque. - Bueno, A.; GÓMEZ, A.; Boscaiu, M.; Manzanera, J. A.; Vicente, O. (II Congreso Forestal Español, 1997)
Inducción of haploid embryos and regeneration of plantlets have been obtained for the first time, in cork oak (Quercus suber L.) by combining a starvation treatment in anther culture with a mild heat shock at 33°C for 5 days, followed by culture at 25°C in a simple agar medium without growth regulator.s. The same conditions had been shown previously to be optimal for embryogenic induction in isolated microspore cultures of several model species such as tobacco and wheat. These results support the notion that stress, particularly sucrose starvation, a heat shock or a combination of both treatments could be the major and general signal responsible for the inhibition of normal gametophytic development of the microspores and for the induction of the alternative embryogenic pathway. A similar approach may be used for the production of haploid and doubled haploids for plant breeding in other species that like most forest trees, are still recalcitrant in anther culture.
The following values have no corresponding Zotero field: periodical: II Congreso Forestal Español pub-location: Pamplona
Keywords: anther culture; Cork oak; Haploid plants; Stress

Embriogénesis gamética para obtención de haploides en alcornoque. - Bueno, A; GÓMEZ, A; Boscaiu, M; Manzanera, J A; Vicente, O (II Congreso Forestal Español, 1997)
Inducción of haploid embryos and regeneration of plantlets have been obtained for the first time, in cork oak (Quercus suber L.) by combining a starvation treatment in anther culture with a mild heat shock at 33°C for 5 days, followed by culture at 25°C in a simple agar medium without growth regulator.s. The same conditions had been shown previously to be optimal for embryogenic induction in isolated microspore cultures of several model species such as tobacco and wheat. These results support the notion that stress, particularly sucrose starvation, a heat shock or a combination of both treatments could be the major and general signal responsible for the inhibition of normal gametophytic development of the microspores and for the induction of the alternative embryogenic pathway. A similar approach may be used for the production of haploid and doubled haploids for plant breeding in other species that like most forest trees, are still recalcitrant in anther culture.
Keywords: anther culture; Cork oak; Haploid plants; Stress

EMISSION OF SHORT CHAINED ORGANIC ACIDS , ALDEHYDES AND MONOTERPENES FROM QUERCUS ILEX L . AND PINUS PINEA L . IN RELATION TO PHYSIOLOGICAL ACTIVITIES , CARBON BUDGET AND EMISSION ALGORITHMS - Kesselmeier, J; Bode, K; Hofmann, U; Mtjller, H; Schafer, L; Wolf, A; Ciccioli, P; Cecinato, A; Frattoni, M; Foster, P; Dutaur, L; Torreq, L (Atmospheric Environment, 1997)
We report on the emission of monoterpenes, short-chained organic acids and aldehydes from Mediterranean oak (Quercus ilex L.) and pine (Pinus pinea L.). All studies were done with dynamic cuvettes enclosing intact branches at the top of the canopy flushed with ambient air. Daily trends are compared with the photosynthetic active radiation (PAR), leaf temperature and the physiological activities of the enclosed branches, i.e. assimilation and transpiration, with special attention on the carbon budget. Oak emits monoterpenes in high amounts, up to 2% of the assimilated carbon. As compared with monoterpenes, short-chained organic acids and aldehydes are of minor importance for oak. However, on a leaf dry-weight basis equal amounts of acids and aldehydes are released from oak and pine. As pine emitted only low amounts of terpenes (below 0.2% of the assimilated carbon) the release of terpenes and oxygenated compounds is of equal importance for this species. A comparison of a modelled light and temperature driven emission with the observed volatile organic compounds (VOC) emissions showed good agreement for monoterpenes as well as for organic acids emitted in the case of oak. For pine only the release of acids showed an adequate relation to the algorithm data, whereas the terpene emissions seemed to be dominated by temperature effects
Keywords: aldehydes; carbon budget; coniferous; deciduous; light; Monoterpenes; oak; organic acids; pine; Pinus pinea L; Plant physiology; Quercus ilex L; Temperature; Volatile Organic Compounds

Endophytic fungi in grasses from semiarid grasslands in Spain - Zabalgogeazcoa, I; Garcia-Ciudad, A; García-Criado, B (NEOTYPHODIUM/GRASS INTERACTIONS, 1997)
Dehesas are savanna-like semiarid grasslands which constitute a traditional, low-input, livestock production system in the Iberian Peninsula. In dehesas, the arboreal stratum is dominated by Quercus species, whereas the pastures are composed by a large number of plant species. More than 1000 species of vascular plants have been catalogued in the dehesas of the province of Salamanca. The grass family is the most important, comprising about 12% of the identified plant species (Hernandez, 1992), and an average of 50% of the herbage dry weight (Corona et al., 1995). Since the middle ages, dehesa pastures have been subjected to grazing pressure from the livestock which was reared on them. The climate of dehesas is of semiarid-mediterranean type, with annual precipitation values averaging about 500 mm (Calabuig, 1992). Since there is evidence that infection by clavicipitaceous endophytes may improve the fitneess of the grass host in situations of water limitation and herbivore grazing, dehesas may constitute an environment where grasses infected by endophytes may be favourably selected. If this were the case, elevated infection rates could be found in host species, and this could be a factor of negative impact in animal production in dehesas. The objective of this study was to made a preliminary survey of the incidence of endophytic fungi in grass species of dehesa pastures.

ENRAIZAMENTO DE ESTACAS DE SOBREIRO (Quercus suber L.): EFEITO DE DIFERENTES FERIDAS E ÁCIDO INDOLBUTÍRICO - Mata, M I S; Ribeiro, M M A; Antunes, A (Simpósio de Propagação Vegetativa de Espécies Lenhosas. Castelo Branco, 18 a 20 Abril de 1996, 1997)
A resposta ao tratamento com AIB e a realização de diferentes feridas foi analisada através de um ensaio de enraizamento de estacas, obtidas a partir de rebentos axilares de jovens sobreiros, durante 3 meses. A aplicação de AIB na base da estaca favoreceu a percentagem de enraizamento. A ferida profunda na base da estaca aumentou a percentagem de formação de callus e a percentagem de estacas enraizadas. Este tratamento juntamente coma aplicação de 0,5% de AIB conduziu a uma percentagem de enraizamento de 20%, ao fim dos 3 meses.
Keywords: AIB; Enraizamento; estacas; feridas; propagação vegetativa; Quercus suber L.

ENSAYO DE DIFERENTES TIPOS DE CONTENEDORES PARA Q.ILEX, P.HALEPENSIS, P.PINASTER Y P.PINEA: RESULTADOS DE VIVERO - DOMÍNGUEZ LERENA, S; HERRERO SIERRA, N; CARRASCO MANZANO, I; OCAÑA BUENO, L; PEÑUELAS RUBIRA, J L (II Congreso Forestal Español, 1997)
The influence of 16 of the most commonly utilised containers on seedling characteristics of Quercus ilex, Pinus pinea, P. halepensis and P. pinaster have been analysed. Studied plant features -height, diameter, shoot and root dry weight, and number of branches- were correlated with container dimensions. Observations on sorne practical problems in several containers and their suitability for forest plant production are given.
Keywords: calidad de planta; desarrollo; envases; sistemas radicales

ENSAYO DE DIFERENTES TIPOS DE CONTENEDORES PARA Q.ILEX, P.HALEPENSIS, P.PINASTER Y P.PINEA: RESULTADOS DE VIVERO - DOMINGUEZ LERENA, S.; HERRERO SIERRA, N.; CARRASCO MANZANO, I.; OCAÑA BUENO, L.; PEÑUELAS RUBIRA, J. L. (II Congreso Forestal Español, 1997)
The influence of 16 of the most commonly utilised containers on seedling characteristics of Quercus ilex, Pinus pinea, P. halepensis and P. pinaster have been analysed. Studied plant features -height, diameter, shoot and root dry weight, and number of branches- were correlated with container dimensions. Observations on sorne practical problems in several containers and their suitability for forest plant production are given.
The following values have no corresponding Zotero field: periodical: II Congreso Forestal Español
Keywords: calidad de planta; desarrollo; envases; sistemas radicales

ENSAYO DE PRODUCCIÓN DE QUERCUS SUBER L. EN VIVERO: CRITERIOS PARA LA EVALUACIÓN DE LA CALIDAD DE LAS PLANTAS - ONCINS, J A; LEITE, C; Chambel, M R; Almeida, M H; FABião, A; CHAVES, M.M.* (II Congreso Forestal Español, 1997)
Seedlings of Quercus suber L. were produced in the Nursery of the Instituto Superior de Agronomia in Lisbon. The experimental design used was a factorial 2x2, with two containers types and two growing media, with five randomised complete blocks. Seedling quality was evaluated by morphological and physiological characteristics and by root electrolyte leakage (R.E.L.). Physiological criteÍ"ia were not sensible enough to detect statistically significant differences between treatments. Through morphological criteria it was possible to <;letect statistically significant differences between growing media. These morphological criteria seem more suitable to determine differences between the plants produced, anyway it is necessary to prove their sensibility in field conditions. K.W.:
Keywords: morphological characteristic; physiological characteristics; Plant production; quality criteria; Quercus suber L.; vitality

ENSAYO DE TRATAMIENTOS HERBICIDAS EN CULTIVO DE TRES ESPECIES FORESTALES (P. halepensis, P. nigra y Q. ilex) EN VIVERO - CARRASCO MANZANO, I.; OCAÑA BUENO, L.; PEÑUELAS RUBIRA, J. L.; DOMINGUEZ LERENA, S. (II Congreso Forestal Español, 1997)
Weeds are one of the problems which more economic costs originates in forest nurseries due to their effect on crop growth. In spite of this, the effect of weeds on forest seedlings and their control in the nursery have not been much studied. In this study we have analysed the ability of five herbicides (Pendimethalin, Propizamide, Napropamide, Oxyflurofen and Simazine) in controlling weeds and their possible harmful effect on two Pinus species (Pinus halepensis, P. nigra ) and Quercus ilex in the nursery. Pendimethalin and Propizamide damaged seriously all tree species while Napropamide and Oxyflourfen did not produce any harmful effect and did not control effectively weeds. Simazine controlled weeds not affecting tree seedlings although it had to be applied periodically to mantain its effect on weeds.
The following values have no corresponding Zotero field: periodical: II Congreso Forestal Español pub-location: Pamplona
Keywords: Herbicides; Nursery

ENSAYO DE TRATAMIENTOS HERBICIDAS EN CULTIVO DE TRES ESPECIES FORESTALES (P. halepensis, P. nigra y Q. ilex) EN VIVERO - CARRASCO MANZANO, I; OCAÑA BUENO, L; PEÑUELAS RUBIRA, J L; DOMÍNGUEZ LERENA, S (II Congreso Forestal Español, 1997)
Weeds are one of the problems which more economic costs originates in forest nurseries due to their effect on crop growth. In spite of this, the effect of weeds on forest seedlings and their control in the nursery have not been much studied. In this study we have analysed the ability of five herbicides (Pendimethalin, Propizamide, Napropamide, Oxyflurofen and Simazine) in controlling weeds and their possible harmful effect on two Pinus species (Pinus halepensis, P. nigra ) and Quercus ilex in the nursery. Pendimethalin and Propizamide damaged seriously all tree species while Napropamide and Oxyflourfen did not produce any harmful effect and did not control effectively weeds. Simazine controlled weeds not affecting tree seedlings although it had to be applied periodically to mantain its effect on weeds.
Keywords: Herbicides; Nursery

ESCORRENT~ A SUPERFICIAL EN LAS VERTIENTES DE UNA CUENCA HIDROGRÁFICA EN EL ECOSISTEMA DEHESA. CUENCA DE GUADALPERAL~ N - Ceballos, Antonio; Schnabel, S. (Geographicalia, 1997)
In a sinall catchrnent under tlie deliesa landuse system overland flow production on slopes is investigated. The obtained results show tliat tl-ie determination of tl-ie tlireshold value for tl-ie generation of runoff is complex. Total precipitation and rnaxim~~m intensity in 10 minutes are the principal factors that explain tl-ie production and generatioii of slope runoff
Keywords: dehesa ecosystem; overland flow; slopes

ESCORRENT~ A SUPERFICIAL EN LAS VERTIENTES DE UNA CUENCA HIDROGRÁFICA EN EL ECOSISTEMA DEHESA. CUENCA DE GUADALPERAL~ N - Ceballos, Antonio; Schnabel, S (Geographicalia, 1997)
In a sinall catchrnent under tlie deliesa landuse system overland flow production on slopes is investigated. The obtained results show tliat tl-ie determination of tl-ie tlireshold value for tl-ie generation of runoff is complex. Total precipitation and rnaxim~~m intensity in 10 minutes are the principal factors that explain tl-ie production and generatioii of slope runoff
Keywords: dehesa ecosystem; overland flow; slopes

Estimation of plant water concentration by the reflectance Water Index WI (R900/R970) - Penuelas, J; Piñol, J; Ogaya, R; Filella, I (International Journal of Remote Sensing, 1997)
Abstract Water Index WI (R900/R970) was used for the estimation of plant water concentration (PWC) by ground-based, reflectance measurements. Reflectance and PWC were measured for adult plants growing in the field throughout an annual cycle and in potted seedlings submitted to progressive desiccation. The species studied were characteristicly Mediterranean: Pinus halepensis, Quercus ilex, Quercus coccifera, Arbutus unedo, Cistus albidus, Cistus monspeliensis, Phillyrea angustifolia, Pistacia lentiscus and Brachypodium retusum . WI was significantly correlated with PWC when all the species were considered together, and with almost all the species considered individually, especially when a wider range of PWC was obtained by extreme dessication of experimental plants. The correlations increased when normalizing WI by NDVI. The wavelength of the trough corresponding to water absorption band tended to shift from 970-980 nm to lower wavelengths 930-950 nm with decreasing PWCs. Infrared measurement of plant temperature and T leaf - T air provided worse assessment of PWC. A simple radiometer measuring plant reflectance at 680, 900, and 970nm could speed up the measurement of PWC, and be useful in wildfire risk evaluation and drought assessment.
doi: 10.1080/014311697217396
Keywords: Mediterranean plant species (voyant); NDVI; plant water concentration (PWC); water index

Estructuras y critérios para la ordenación de "montados" de alter do chao (alentejo) - Moreira Huhn, Elizabeth; Euzabeth, Moreira Huhn (II Congreso Forestal Español, 1997)
An inventory of the " montado" (cork tree forests) has been made, making it possible from that point to determine the desirable (padrón de normalidad) and real (mean values) structures. Following, a comparison with the general· structure of the montado of south Portugal has taken place. Also the structure of the cork tree forest under the influence of different utilizations has been studied. Conclusion: The cork tree forest as an ecosystem of multiple uses lacks management, range management in terms of harmonization of the exploitation of cork in combination with different compatible activities like lifestock, game management (hunting) and others.At the end, management standards have been established for the present case, based upon the principIe of montado sustainability. K.W.
Keywords: management; Montado (cork tree forest); sustainnability

Estudio comparativo de morfología en planta de encina cultivada en distintos envases comerciales - ÁLVAREZ LINAREJOS, L.; RAPP ARRARÁS, I. (II Congreso Forestal Español, 1997)
The aim of the present work is to analize the morfological diferences and its caracterization depending on the container used in nursery production of one year holm oak plants. Six different types of containers -those suitable to be bought in the area were the experiment has taken place- has been used for it. It has been stablished the greatest posible homogeneity in other parameters which influence could have been important such as seeds - which procedence is known-, cultivation media, watering, and microclimate -in greenhouse first and nursery later-. Results for sorne of the factors studied are shown.
The following values have no corresponding Zotero field: periodical: II Congreso Forestal Español issue: 57 pub-location: Pamplona
Keywords: Containers; Holm oak; Nursery; Plant production

Estudio comparativo de morfología en planta de encina cultivada en distintos envases comerciales - ÁLVAREZ LINAREJOS, L; RAPP ARRARÁS, I (II Congreso Forestal Español, 1997)
The aim of the present work is to analize the morfological diferences and its caracterization depending on the container used in nursery production of one year holm oak plants. Six different types of containers -those suitable to be bought in the area were the experiment has taken place- has been used for it. It has been stablished the greatest posible homogeneity in other parameters which influence could have been important such as seeds - which procedence is known-, cultivation media, watering, and microclimate -in greenhouse first and nursery later-. Results for sorne of the factors studied are shown.
Keywords: Containers; Holm oak; Nursery; Plant production

Estudio de la influencia de distintos sustratos de cultivo en el crecimiento y desarrollo en vivero de plantas de ilex l., Q. SUBER L., P. PINA S TER AIT. y P. HALEPENSIS MILL. - Zazo Muncharaz, J; FRANCISCO CASADO, Ma S; TALLÓN MEDRANO, F (II Congreso Forestal Español, 1997)
The influence on various attributes and morphological and anatomical characteristics of seedlings of the mentioned species, of different formulations of growing media commonly used in nurseries, that have fertilized peat as base component and different percentages of pedite, vermiculite, pine bark and sand as ancillary or aeration components, and using the same container, is studied. The obtained results can be applied to propose growing media and cultivation techniques for production of morphological and anatomical quality plants of the mentioned species.
Keywords: Growing medium; Nursery; Plant quality

Estudo de germinação em azinheira (Quercus rotundifolia Lam.) - Ribeiro, M M A; Elvas, P S (I Congresso Florestal Hispano-Luso, 21 a 27 Junho 1997. Pamplona, 1997)
In April 1996 a germination trial took place in Serra da Malcata Natural Reserve nursery. The acorns were collected in Malpica do Tejo holm oak stands, after fruit repining. Treatments included naked root plant production in normal nursery soil and plant production with different other methods: two different containers (plastic bag and plastic pot) with five different media composition (pine bark, peat, normal nursery soil, pine bark with perlite (1:1 v/v) and peat with perlite (1:1 v/v). The number of germinated seeds (G) per treatment and block was first recorded by the end of June and afterwards three times, every three weeks. Last time data was recorded, the following parameters were included: diameter (D) at soil level, height (H) and the leaf area (A), per plant. Percent of germination was better in every treatment using plastic pots, whatever the media used, and the worst results were achieved with the plastic bag/peat and naked root methods. On the other hand, the use of the plastic bag promoted plant loss, avoided with plastic pots. The best-scored treatments for the average plant diameter (D) were the pot/peat (3,26 mm) and bag/pine bark (2,92 mm) methods, and the bag/nursery soil produced the worst result (2,4 mm). The best/worst result in the mean height for plant (H), was obtained with the naked root (10,5 cm)/plastic pot with nursery soil (5,9 cm) method. The leaf area per plant (A) was 52 cm2 for the naked root method, higher then the value of this parameter in every other treatment, except in the bag/pine bark one (45 cm2 ).
Keywords: container; germination; Holm oak; media; naked root; Quercus rotundifolia Lam

European and Mediterranean oaks (Quercus L.; Fagaceae): SEM characterization of the micromorphology of the abaxial leaf surface - Bussotti, Filippo; Grossoni, Paolo (Botanical Journal of the Linnean Society, 1997)
This paper examines micromorphological characteristics (trichomes, waxes, stomata) of the abaxial leaf surface of European and Mediterranean oaks. Observations were performed In-scanning electron microscopy, and the purpose of the investigation was to ascertain whether it is possible to distinguish the different species taxonomically using these features. Several species, as well as some subspecific entities and taxa considered doubtful, were taken into consideration. Subgenera appear to be well-defined: e.g. the subgenus Quercus is characterized by waxes arranged in vertical scales, the subgenera Cenis and Sclerophyllodris by smooth waxes. They differ because the former has markedly elliptical stomata, while the latter two have roundish stomata. The different species are also fairly easy to distinguish, and this fact confirms the taxonomical validity of the parameters we have taken into consideration. In some cases subspecific entities and doublful species do not diflcr at all from the related species, but in others they present such marked variations that it is difficult even to classify them with certainty. The most critical taxonomic groups (i.e. those which include a number of specific and subspecific entities often too difficult to distinguish from each other) are the series Quercus robur – Quercus petraea,– Quercus pubescens and the Quercus faginea,– Quercus Insitanica Quercus canariensis group.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: stomata; taxonomy; Trichomes; waxes

European and Mediterranean oaks (Quercus L.; Fagaceae): SEM characterization of the micromorphology of the abaxial leaf surface - Bussotti, Filippo; Grossoni, Paolo (Botanical Journal of the Linnean Society, 1997)
This paper examines micromorphological characteristics (trichomes, waxes, stomata) of the abaxial leaf surface of European and Mediterranean oaks. Observations were performed In-scanning electron microscopy, and the purpose of the investigation was to ascertain whether it is possible to distinguish the different species taxonomically using these features. Several species, as well as some subspecific entities and taxa considered doubtful, were taken into consideration. Subgenera appear to be well-defined: e.g. the subgenus Quercus is characterized by waxes arranged in vertical scales, the subgenera Cenis and Sclerophyllodris by smooth waxes. They differ because the former has markedly elliptical stomata, while the latter two have roundish stomata. The different species are also fairly easy to distinguish, and this fact confirms the taxonomical validity of the parameters we have taken into consideration. In some cases subspecific entities and doublful species do not diflcr at all from the related species, but in others they present such marked variations that it is difficult even to classify them with certainty. The most critical taxonomic groups (i.e. those which include a number of specific and subspecific entities often too difficult to distinguish from each other) are the series Quercus robur – Quercus petraea,– Quercus pubescens and the Quercus faginea,– Quercus Insitanica Quercus canariensis group.
Keywords: stomata; taxonomy; Trichomes; waxes

Fenofases florales en quercus rotundifolia lam. - Vázquez, F M (II Congreso Forestal Español, 1997)
In this work the floral stages are introduced that it is happened in the masculine and feminine flowering of the holm-oak (Quercus rotundifolia Lam.). In each described stages they incorporate data on the floral morphology: state of development that it reach the catkins, the floral group and the tlowers. Also data of the receptive state in the are inserted feminine tlowers and ripening and viability grade of the grain of ponen and ovule. Finally is represented in a graphic each one of the described stage. K.W.:
Keywords: flowering; holm-oak; Ovule; pollen; Quercus rotundifolia; reproduction; Stages

Fire and late-Holocene expansion of Quercus ilex and Pinus pinaster on Corsica - Carcaillet, Christopher; Barakat, Hala N.; Panaïotis, Christophe; Loisel, Roger (Journal of Vegetation Science, 1997)
Abstract. The natural origin of old Quercus ilex (holm oak) forests on the west coast of Corsica is a matter of dispute. This paper discusses the use of pedoanthracology, especially adapted to approach topics in palaeoecology requiring a high spatial precision. It also shows the importance of fire in vegetation change during the Holocene. Pedoanthracology relies on botanical identification and AMS 14C dating of micro-charcoal found in soil. Three test pits were dug in a forest currently protected within the ‘Man and Biosphere’ program. These pits yielded large quantities of charcoal. There is evidence that Pinus nigra ssp. laricio (laricio pine) and understorey heather species (Ericaceae) played an important role in the vegetation at the beginning of the Subatlantic (ca. 2500 BP). The importance of Pinus pinaster (maritime pine), Quercus ilex and a few mesophilic species increased between 2000 and 1000 BP. Charcoal fragments found in the soil show the role of fire in the vegetation changes recorded. The late expansion of P. pinaster results from a high fire frequency. The hypothesis proposed in the paper suggests that fires destroyed the remaining toxic humus that had accumulated during the millennia which preceded the arrival of Q. ilex to our study sites. The late development of holm oak forest is a combination of the migration of the species and the increase of fire frequency since 2500 BP, most probably resulting from slash-and-burn agriculture.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: charcoal; Evergreen mediterranean forest; Fango valley; human impact; MAB reserve; Quaternary ecology

Fire and late-Holocene expansion of Quercus ilex and Pinus pinaster on Corsica - Carcaillet, Christopher; Barakat, Hala N; Panaïotis, Christophe; Loisel, Roger (Journal of Vegetation Science, 1997)
Abstract. The natural origin of old Quercus ilex (holm oak) forests on the west coast of Corsica is a matter of dispute. This paper discusses the use of pedoanthracology, especially adapted to approach topics in palaeoecology requiring a high spatial precision. It also shows the importance of fire in vegetation change during the Holocene. Pedoanthracology relies on botanical identification and AMS 14C dating of micro-charcoal found in soil. Three test pits were dug in a forest currently protected within the ‘Man and Biosphere’ program. These pits yielded large quantities of charcoal. There is evidence that Pinus nigra ssp. laricio (laricio pine) and understorey heather species (Ericaceae) played an important role in the vegetation at the beginning of the Subatlantic (ca. 2500 BP). The importance of Pinus pinaster (maritime pine), Quercus ilex and a few mesophilic species increased between 2000 and 1000 BP. Charcoal fragments found in the soil show the role of fire in the vegetation changes recorded. The late expansion of P. pinaster results from a high fire frequency. The hypothesis proposed in the paper suggests that fires destroyed the remaining toxic humus that had accumulated during the millennia which preceded the arrival of Q. ilex to our study sites. The late development of holm oak forest is a combination of the migration of the species and the increase of fire frequency since 2500 BP, most probably resulting from slash-and-burn agriculture.
Keywords: charcoal; Evergreen mediterranean forest; Fango valley; human impact; MAB reserve; Quaternary ecology

FORESTACIÓN CON CUATRO ESPECIES (Quercus coccifera L., Q.faginea Lam., Q. rotundifolia y Q. suber L.) DE FRONDOSAS EN EXTREMADURA P.M. - Vázquez, F M; Suárez, M A; TORRES, E; CUEVAS, S (II Congreso Forestal Español, 1997)
The principal species of interest in order to form forests of mediterranean type (not of riverside) in the South half of the Iberian Peninsula are the genus Quercus L ones. In this work the outputs contrasted of development are introduced, 1 root and systems of protection utilized in a mixed afforestation with four species of the cited genus (Q. coccifera L., Q. faginea Lam., Q. rotundifolia Lam., Q. suber L.), in Extremadura (Spain). The analysis of the data offers different strategies in sylviculture for the forest recuperation of the zone in function of the species that utilize
Keywords: Afforestation; coccifera; Extremadura; faginea; Quercus; rotundifolia; suber; sylvicuIture

Growth inhibition of nematophagous and entomopathogenic fungi by leaf litter and soil containing phenols - Lopez-Llorca, L. V.; Olivares-Bernabeu, C. (Mycological Research, 1997)
In a soil survey, nematophagous fungi were recovered less from agar plates sprinkled with forest soil (Quercus ilex subsp. rotundifolia) than from those incubated with agricultural (Citrus orchards) soil. Nematodes were present in all soils. The organic matter was higher in forest soils. Water extracts from forest soils with high levels of phenols, leaf litter and Q. rotundifolia fresh leaves aﬀected the development and growth of common species of nematophagous and entomopathogenic fungi. These results show that phenolics from leaf letter could play an important role in the ecology and biology of these invertebrate pathogens in soil.
Keywords: agricultural soil; entomopathogenic fungi; forest soil; fungal growth (voyant); leaf litter; nematophagous fungi; phenolic compounds; quercus ilex ssp rotundifolia

Growth inhibition of nematophagous and entomopathogenic fungi by leaf litter and soil containing phenols - Lopez-Llorca, L V; Olivares-Bernabeu, C (Mycological Research, 1997)
In a soil survey, nematophagous fungi were recovered less from agar plates sprinkled with forest soil (Quercus ilex subsp. rotundifolia) than from those incubated with agricultural (Citrus orchards) soil. Nematodes were present in all soils. The organic matter was higher in forest soils. Water extracts from forest soils with high levels of phenols, leaf litter and Q. rotundifolia fresh leaves aﬀected the development and growth of common species of nematophagous and entomopathogenic fungi. These results show that phenolics from leaf letter could play an important role in the ecology and biology of these invertebrate pathogens in soil.
Keywords: agricultural soil; entomopathogenic fungi; forest soil; fungal growth (voyant); leaf litter; nematophagous fungi; phenolic compounds; quercus ilex ssp rotundifolia

Highly specific and sensitive non-radioactive molecular identification of Phytophthora cinnamomi - Coelho, A. C.; Cravador, A.; Bollen, A. (Mycological Research, 1997)
In response to the need for a faster, more reliable method for identifying Phytophthora cinnamomi in cork oak soils in Portugal, a simple, fast, sensitive molecular identi®cation method is described. It is based on a colorimetric assay which involves an oligonucleotide capture probe covalently immobilised on microtitration wells, a multi-biotinylated oligonucleotide detection probe and the PCR-ampli®ed target DNA. The target DNA is a 349 bp DNA fragment partially covering the 3«-translated and 3«- untranslated regions of the cinnamomin gene. When the speci®city of the PCR reaction was evaluated in vitro using isolates of P. cinnamomi and eight other Phytophthora species, including the related P. cambivora, it was speci®c to P. cinnamomi. When 30 isolates of P. cinnamomi from oak roots in southern Portugal were assayed, 26 gave a strong positive response. The assay has a sensitivity of about 2±5 genome equivalents of P. cinnamomi. The reason for the negative response of four isolates remains unclear.
Keywords: Cork oak soils; Iidentification method; phytophthora cinnamomi

Highly specific and sensitive non-radioactive molecular identification of Phytophthora cinnamomi - Coelho, A C; Cravador, A; Bollen, A (Mycological Research, 1997)
In response to the need for a faster, more reliable method for identifying Phytophthora cinnamomi in cork oak soils in Portugal, a simple, fast, sensitive molecular identi®cation method is described. It is based on a colorimetric assay which involves an oligonucleotide capture probe covalently immobilised on microtitration wells, a multi-biotinylated oligonucleotide detection probe and the PCR-ampli®ed target DNA. The target DNA is a 349 bp DNA fragment partially covering the 3«-translated and 3«- untranslated regions of the cinnamomin gene. When the speci®city of the PCR reaction was evaluated in vitro using isolates of P. cinnamomi and eight other Phytophthora species, including the related P. cambivora, it was speci®c to P. cinnamomi. When 30 isolates of P. cinnamomi from oak roots in southern Portugal were assayed, 26 gave a strong positive response. The assay has a sensitivity of about 2±5 genome equivalents of P. cinnamomi. The reason for the negative response of four isolates remains unclear.
Keywords: Cork oak soils; Iidentification method; phytophthora cinnamomi

The impact of grazing on forage quality of the herbaceous vegetation in the Mamora cork oak forest, Morocco - Alami, M Mejjati; Bedell, T E; Sharrow, S H; Berkat, O (African Journal of Range & Forage Science, 1997)
This research was conducted in the Mamora cork oak forest of Morocco to describe the impacts of sheep grazing (no use, 35% use, 70% use) in March, April, May and June of 1987 and 1988 on seasonal changes in forage quality of the herbaceous vegetation. The study showed that trends in herbage quality were related mainly to plant maturity. As more species mature, forage quality declines and falls below animal nutritional requirements, especially for young animals. With declining forage quality, the manager has the option of moving stock to areas of less-mature forage, supplementing the forage or modifying the demand placed upon it.
doi: 10.1080/10220119.1997.9647913
Keywords: crude protein; IVOMD; Mediterranean-type climate; minerals; time of grazing

The impact of grazing on forage quality of the herbaceous vegetation in the Mamora cork oak forest, Morocco - Alami, M. Mejjati; Bedell, T. E.; Sharrow, S. H.; Berkat, O. (African Journal of Range & Forage Science, 1997)
This research was conducted in the Mamora cork oak forest of Morocco to describe the impacts of sheep grazing (no use, 35% use, 70% use) in March, April, May and June of 1987 and 1988 on seasonal changes in forage quality of the herbaceous vegetation. The study showed that trends in herbage quality were related mainly to plant maturity. As more species mature, forage quality declines and falls below animal nutritional requirements, especially for young animals. With declining forage quality, the manager has the option of moving stock to areas of less-mature forage, supplementing the forage or modifying the demand placed upon it.
doi: 10.1080/10220119.1997.9647913doi: 10.1080/10220119.1997.9647913The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: crude protein; IVOMD; Mediterranean-type climate; minerals; time of grazing