Flammability assessment of Mediterranean forest fuels - Dimitrakopoulos, A P; Papaioannou, K K (Fire Technology, 2001)
The time-to-ignition of variousdominant Mediterranean forest fuelswasmeasured during laboratory tests, in order to develop a relative ﬂammability classiﬁcation and determine the moisture of extinction of these fuels. The tests were performed with an ignition apparatusmanufactured according to the ISO standards(ISO 5657-1986E) and under a wide gradient of fuel moisture contents, ranging from air-dry to fresh foliage. Moisture content was the single most signiﬁcant factor that affected fuel ﬂammability. Regression modelswere developed between the time-to-ignition and the moisture content valuesof all the fuels tested, and subsequently, were used for the relative ﬂammability ranking of these fuels. Fuel moisture of extinction was assessed to have a threshold value ranging from 40% to more than 140% o.d.w. for the species tested. The ﬂammability ranking of natural fuels can be useful in fuel hazard assessment and ﬁre danger rating, thus facilitating the judicial ﬁre management planning in wildlandsand at the rural-urban interface.
Keywords: flammability; ignitability; Mediterranean; natural fuels; wildland fires

Flammability assessment of Mediterranean forest fuels - Dimitrakopoulos, A. P.; Papaioannou, K. K. (Fire Technology, 2001)
The time-to-ignition of variousdominant Mediterranean forest fuelswasmeasured during laboratory tests, in order to develop a relative ﬂammability classiﬁcation and determine the moisture of extinction of these fuels. The tests were performed with an ignition apparatusmanufactured according to the ISO standards(ISO 5657-1986E) and under a wide gradient of fuel moisture contents, ranging from air-dry to fresh foliage. Moisture content was the single most signiﬁcant factor that affected fuel ﬂammability. Regression modelswere developed between the time-to-ignition and the moisture content valuesof all the fuels tested, and subsequently, were used for the relative ﬂammability ranking of these fuels. Fuel moisture of extinction was assessed to have a threshold value ranging from 40% to more than 140% o.d.w. for the species tested. The ﬂammability ranking of natural fuels can be useful in fuel hazard assessment and ﬁre danger rating, thus facilitating the judicial ﬁre management planning in wildlandsand at the rural-urban interface.
Keywords: flammability; ignitability; Mediterranean; natural fuels; wildland fires

The foraging ecology of red deer (Cervus elaphus) in a Mediterranean environment: is a larger body size advantageous? - Bugalho, M N; Milne, J a.; Racey, P a. (Journal of Zoology, 2001)
In Mediterranean environments browse is expected to be a major component of the diet of red deer Cervus elaphus during the summer when most grasses senesce. In this study the hypothesis is tested that, if browse is an essential food resource at this time, the sex with the larger body size may have a greater physical ability to reach the tree canopy and include a higher proportion of browse in its diet. The organic matter digestibility (OMD) and composition of the diet of a population of red deer males and females were measured between July and September, in 1996 and 1997, in an area of Portugal with a Mediterranean type of climate, using the n-alkane technique. Direct observations of animals browsing on tree canopies and shrubs were made also during the same period. The OMD of the diet was signi®cantly different between sexes and between years and was higher in males than females both in 1996 (means sem for males and females, 0.65 and 0.58 0.026, respectively) and 1997 (means for males and females, 0.59 and 0.48 0.045, respectively). The proportion of cork oak Quercus suber in the diet was also signi®cantly different between sexes and between years, with males having a higher proportion of cork oak in their diets in 1996 (males and females, 0.30 and 0.16 0.037, respectively) and 1997 (males and females, 0.41 and 0.23 0.064, respectively). A signi®cantly lower proportion of the herbage layer was found in the diet of males in 1996 (males and females, 0.46 and 0.64 0.048) but not in 1997. The number of observations of males browsing on tree canopies was signi®cantly higher than females. It is concluded that there are differences between sexes in the composition and quality of the diet and that a larger body size may confer advantages in situations where browse is an essential food resource.
Keywords: body-size; browse; cervus elaphus; diet composition; Mediterranean

The foraging ecology of red deer (Cervus elaphus) in a Mediterranean environment: is a larger body size advantageous? - Bugalho, M. N.; Milne, J. a; Racey, P. a (Journal of Zoology, 2001)
In Mediterranean environments browse is expected to be a major component of the diet of red deer Cervus elaphus during the summer when most grasses senesce. In this study the hypothesis is tested that, if browse is an essential food resource at this time, the sex with the larger body size may have a greater physical ability to reach the tree canopy and include a higher proportion of browse in its diet. The organic matter digestibility (OMD) and composition of the diet of a population of red deer males and females were measured between July and September, in 1996 and 1997, in an area of Portugal with a Mediterranean type of climate, using the n-alkane technique. Direct observations of animals browsing on tree canopies and shrubs were made also during the same period. The OMD of the diet was signi®cantly different between sexes and between years and was higher in males than females both in 1996 (means sem for males and females, 0.65 and 0.58 0.026, respectively) and 1997 (means for males and females, 0.59 and 0.48 0.045, respectively). The proportion of cork oak Quercus suber in the diet was also signi®cantly different between sexes and between years, with males having a higher proportion of cork oak in their diets in 1996 (males and females, 0.30 and 0.16 0.037, respectively) and 1997 (males and females, 0.41 and 0.23 0.064, respectively). A signi®cantly lower proportion of the herbage layer was found in the diet of males in 1996 (males and females, 0.46 and 0.64 0.048) but not in 1997. The number of observations of males browsing on tree canopies was signi®cantly higher than females. It is concluded that there are differences between sexes in the composition and quality of the diet and that a larger body size may confer advantages in situations where browse is an essential food resource.
Keywords: body-size; browse; cervus elaphus; diet composition; Mediterranean

Forecasted stability of Mediterranean evergreen species considering global changes - Gratani, L; Bombelli, A (GLOBAL CHANGE AND PROTECTED AREAS, 2001)
Plant communities of the Mediterranean climate Regions are exposed to high temperatures, high radiation and water stress during summer, they are dominated by evergreen sclerophyllous species and drought semi deciduous species. To define the adaptive strategies, anatomical and morphological leaf traits of Quercus ilex L., Phillyrea latifolia L. (typical evergreen sclerophyllous species) and Cistus incanus L., (a drought semi deciduous species), growing in the Mediterranean maquis along Pome's coast line (Italy) were analysed. The typical evergreen sclerophyllous species have long leaf life span (from 1 to 4 years), steeper leaf inclination (average 56 degrees), higher specific leaf mass (average 21.3 mg cm(-2)) and the highest leaf thickness (average 324 mum). The semi deciduous species have a lower leaf life span (from 4 to 8 months), a lower leaf inclination (44 degrees +/- 13 degrees), a lower specific leaf mass (14.7 +/-1.5 mg cm(-2)) and a lower leaf thickness (244 +/- 15 mum). The more xeromorphyc species (Q. ilex and P. latifolia) may be at a competitive advantage considering the forecasted air temperature increase in the Mediterranean basin. Increasing drought stress may in fact determine a shortening of leaf life span that may prove to be critical for C. incanus. Knowledge of plant response to stress factors is important in the perspective of climatic changes.
Meeting on Global Change and Protected Areas, LAQUILA, ITALY, SEP, 1999
Keywords: C. incanus; leaf life span; P. latifolia; Q. ilex

Forecasted stability of Mediterranean evergreen species considering global changes - GRATANI, L.; Bombelli, A. (GLOBAL CHANGE AND PROTECTED AREAS, 2001)
Plant communities of the Mediterranean climate Regions are exposed tohigh temperatures, high radiation and water stress during summer, they are dominated by evergreen sclerophyllous species and drought semi deciduous species. To define the adaptive strategies, anatomical and morphological leaf traits of Quercus ilex L., Phillyrea latifolia L. (typical evergreen sclerophyllous species) and Cistus incanus L., (a drought semi deciduous species), growing in the Mediterranean maquis along Pome's coast line (Italy) were analysed. The typical evergreen sclerophyllous species have long leaf life span (from 1 to 4 years), steeper leaf inclination (average 56 degrees), higher specific leaf mass (average 21.3 mg cm(-2)) and the highest leaf thickness (average 324 mum). The semi deciduous species have a lower leaf life span (from 4 to 8 months), a lower leaf inclination (44 degrees +/- 13 degrees), a lower specific leaf mass (14.7 +/-1.5 mg cm(-2)) and a lower leaf thickness (244 +/- 15 mum). The more xeromorphyc species (Q. ilex and P. latifolia) may be at a competitive advantage considering the forecasted air temperature increase in the Mediterranean basin. Increasing drought stress may in fact determine a shortening of leaf life span that may prove to be critical for C. incanus. Knowledge of plant response to stress factors is important in the perspective of climatic changes.
Meeting on Global Change and Protected Areas, LAQUILA, ITALY, SEP, 1999Meeting on Global Change and Protected Areas, LAQUILA, ITALY, SEP, 1999The following values have no corresponding Zotero field: periodical: GLOBAL CHANGE AND PROTECTED AREAS pub-location: PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS
Keywords: Q. ilex; P. latifolia; C. incanus; leaf life span

Frequent cytoplasmic exchanges between oak species that are not closely related: Quercus suber and Q. ilex in Morocco - Belahbib, N; Pemonge, M.-H. H; Ouassou, A; Sbay, H; Kremer, A; Petit, R J (Molecular Ecology, 2001)
Chloroplast (cp) and mitochondrial (mt) DNA variation were studied in 97 populations of cork oak (Quercus suber) in Morocco; in 31 of these populations, holm oak (Quercus ilex), a clearly distinct species, also occurred and was compared with Q. suber. Three cpDNA and one mtDNA primer pairs were used in the survey, each in combination with one restriction enzyme. Six haplotypes belonging to two very divergent lineages were detected; one lineage predominates in each species, and is probably ancestral, as inferred from comparisons with other oak species. In the mixed-species populations, cytoplasmic genomes were frequently shared across species, as indicated by an introgression ratio of 0.63. This index is a new measure of the propensity of species to share locally genetic markers, varying from zero (complete differentiation) to one (no differentiation). By contrast, more closely related deciduous oak species (Q. robur, Q. petraea and Q. pubescens) have introgression ratios varying from 0.82 to 0.97. The introgression events appear to have been more frequent in the direction Q. ilex (female) × Q. suber (male), a finding which seems attributable to the flowering phenology of these two species. This asymmetry may have favoured immigration of Q. suber beyond its main range, in regions already colonized by Q. ilex. There, rare hybridization and further introgression through long distance pollen flow have established populations that are morphologically indistinguishable from Q. suber but that have cytoplasmic genomes originating from the local Q. ilex populations.
Keywords: Chloroplast; Chloroplast: genetics; cpDNA; DNA; Evolution; Genetic; Genetic Markers; Genetic Variation; Genetic: genetics; geographical structure; Haplotypes; Hybridization; introgression; Mitochondrial; Mitochondrial: genetics; Models; Molecular; Morocco; mtDNA; PCR–RFLP; Quercus; Quercus: genetics; Trees; Trees: genetics

Frequent cytoplasmic exchanges between oak species that are not closely related: Quercus suber and Q. ilex in Morocco - Belahbib, N.; Pemonge, M.-H. H.; Ouassou, A.; Sbay, H.; Kremer, A.; Petit, R. J. (Molecular Ecology, 2001)
Chloroplast (cp) and mitochondrial (mt) DNA variation were studied in 97 populations of cork oak (Quercus suber) in Morocco; in 31 of these populations, holm oak (Quercus ilex), a clearly distinct species, also occurred and was compared with Q. suber. Three cpDNA and one mtDNA primer pairs were used in the survey, each in combination with one restriction enzyme. Six haplotypes belonging to two very divergent lineages were detected; one lineage predominates in each species, and is probably ancestral, as inferred from comparisons with other oak species. In the mixed-species populations, cytoplasmic genomes were frequently shared across species, as indicated by an introgression ratio of 0.63. This index is a new measure of the propensity of species to share locally genetic markers, varying from zero (complete differentiation) to one (no differentiation). By contrast, more closely related deciduous oak species (Q. robur, Q. petraea and Q. pubescens) have introgression ratios varying from 0.82 to 0.97. The introgression events appear to have been more frequent in the direction Q. ilex (female) × Q. suber (male), a finding which seems attributable to the flowering phenology of these two species. This asymmetry may have favoured immigration of Q. suber beyond its main range, in regions already colonized by Q. ilex. There, rare hybridization and further introgression through long distance pollen flow have established populations that are morphologically indistinguishable from Q. suber but that have cytoplasmic genomes originating from the local Q. ilex populations.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd accession-num: 11555243
Keywords: Chloroplast; Chloroplast: genetics; cpDNA; DNA; Evolution; Genetic; Genetic Markers; Genetic Variation; Genetic: genetics; geographical structure; Haplotypes; Hybridization; introgression; Mitochondrial; Mitochondrial: genetics; Models; Molecular; Morocco; mtDNA; PCR–RFLP; Quercus; Quercus: genetics; Trees; Trees: genetics

Identificação e Quantificação por DAD-HPLC, da Fracção Fenólica Contida em Folhas de Quercus suber L. - Evaristo, Isabel Maria; Leitão, Maria Cecília (Silva Lusitana, 2001)
In this study, an analytical method has been developed for the determination of phenolic compounds since they are related with disease and pests plant resistance mechanisms. The components of the hydrolysed extract (gallic acid, ellagic acid, catechin, epicatechin, caffeic acid, p-coumaric acid and ferulic acid) have been resolved and identified by DAD-HPLC based on their retention times and spectral data. For quantifications, the external standard method was used.
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: avoir un rôle important; caffeic acid; car ces; catechin; dans la présente étude; défense des; des feuilles de chêne; détermination des composés phénoliques; ferulic acid; gallic acid; liège; méthode analytique pour la; on a developpé une; p-coumaric acid; Quercus Suber L; résumé; substances sont susceptibles d; sur les mécanismes de

Identificação e Quantificação por DAD-HPLC, da Fracção Fenólica Contida em Folhas de Quercus suber L. - Evaristo, Isabel Maria; Leitão, Maria Cecília (Silva Lusitana, 2001)
In this study, an analytical method has been developed for the determination of phenolic compounds since they are related with disease and pests plant resistance mechanisms. The components of the hydrolysed extract (gallic acid, ellagic acid, catechin, epicatechin, caffeic acid, p-coumaric acid and ferulic acid) have been resolved and identified by DAD-HPLC based on their retention times and spectral data. For quantifications, the external standard method was used.
Keywords: avoir un rôle important; caffeic acid; car ces; catechin; dans la présente étude; défense des; des feuilles de chêne; détermination des composés phénoliques; ferulic acid; gallic acid; liège; méthode analytique pour la; on a developpé une; p-coumaric acid; Quercus Suber L; résumé; substances sont susceptibles d; sur les mécanismes de

Identification of an endophytic Nodulisporium sp from Quercus ilex in central Spain as the anamorph of Biscogniauxia mediterranea by rDNA sequence analysis and effect of different ecological factors on distribution of the fungus - Collado, J.; Platas, G.; Pelaez, F. (MYCOLOGIA, 2001)
A study of fungal endophytes from aerial parts of Quercus ilex ssp. ballota was carried out on 32 specimens sampled at three forests in Central Spain. Trunk bark, fresh leaves, and healthy and decaying twigs were surveyed. A Nodulisporium sp. was frequently recorded among the isolates. Sequence analysis of the internal transcribed spacer (ITS) region of the rDNA (including the 5.8S rRNA gene) was used for the identification of this fungus. The comparison and phylogenetic analysis of the sequences from several representatives of this endophytic species and a group of xylariaceous fungi with Nodulisporium-like anamorphs revealed that the endophytic Nodulisporium sp. was conspecific with the phytopathogenic species Biscogniauxia mediterranea (equivalent to Hypoxylon mediterraneum). Significant differences were found between the isolation frequencies of the fungus, relative to the geographical origin of the samples. Also, the fungus was more frequent on samples collected in the autumn, as compared to those collected in the spring. The greatest degree of colonization was observed in twigs, while in leaves the fungus was present in significantly lower amounts. The relative frequency of this species in bark increased in the higher parts of the trunk. Tissue preference analysis revealed that this fungal species is exclusively located in bark, being absent from xylem of living twigs. The relative abundance of the fungus in decaying twigs was remarkably higher than in healthy twigs.
The following values have no corresponding Zotero field: pub-location: PUBLICATIONS DEPT, BRONX, NY 10458 USA publisher: NEW YORK BOTANICAL GARDEN
Keywords: Distribution patterns; fungal endophytes; Hypoxylon mediterraneum; ITS sequences; Periconiella-like; Xylariaceae

Identification of an endophytic Nodulisporium sp from Quercus ilex in central Spain as the anamorph of Biscogniauxia mediterranea by rDNA sequence analysis and effect of different ecological factors on distribution of the fungus - Collado, J; Platas, G; Pelaez, F (MYCOLOGIA, 2001)
A study of fungal endophytes from aerial parts of Quercus ilex ssp. ballota was carried out on 32 specimens sampled at three forests in Central Spain. Trunk bark, fresh leaves, and healthy and decaying twigs were surveyed. A Nodulisporium sp. was frequently recorded among the isolates. Sequence analysis of the internal transcribed spacer (ITS) region of the rDNA (including the 5.8S rRNA gene) was used for the identification of this fungus. The comparison and phylogenetic analysis of the sequences from several representatives of this endophytic species and a group of xylariaceous fungi with Nodulisporium-like anamorphs revealed that the endophytic Nodulisporium sp. was conspecific with the phytopathogenic species Biscogniauxia mediterranea (equivalent to Hypoxylon mediterraneum). Significant differences were found between the isolation frequencies of the fungus, relative to the geographical origin of the samples. Also, the fungus was more frequent on samples collected in the autumn, as compared to those collected in the spring. The greatest degree of colonization was observed in twigs, while in leaves the fungus was present in significantly lower amounts. The relative frequency of this species in bark increased in the higher parts of the trunk. Tissue preference analysis revealed that this fungal species is exclusively located in bark, being absent from xylem of living twigs. The relative abundance of the fungus in decaying twigs was remarkably higher than in healthy twigs.
Keywords: Distribution patterns; fungal endophytes; Hypoxylon mediterraneum; ITS sequences; Periconiella-like; Xylariaceae

ilex subsp. ballota) DE MONTE BAJO TRAS DISTINTAS INTENSIDADES DE RESALVEO SEIS AÑOS DESPUÉS DEL FUEGO. RESULTADOS PRELIMINARES - GONZÁLEZ-OCHOA, A I; Lopez, F; DE LAS HERAS, J (III Congreso Forestal Español, 2001)
In a post-fire coppice forest of Quercus ilex different thinning intensities (0%, 53%, 88% and 100%) were carried out in order to evaluate their effects on the dynamic of the forest. The following spring after treatments, there were not significative differences for no thinning intensity on diameter relative growth but, on the contrary, there were differences for height relative growth between control plots and 88% thinning intensity. The higher resprouting percentage is reached for the treatment of 88% thinning intensity, while the lowest is registered in the control plots. Finally, the specific leaf area is higher for resprouters in control plots than in the treated ones. K.W.:
Keywords: Coppice forest; resprouting; thinning

INCIDENCIA DE LA MANCHA AMARILLA SOBRE LA CALIDAD DEL CORCHO - GONZALEZ-ADRADOS, J R; GARCIA-VALLEJO, M C; De laVEGA, R; GONZÁLEZ-HERNÁNDEZ, F (III Congreso Forestal Español, 2001)
A brief survey is presented about the state-of-the-art of the influence over cork quality of the so called "yellow stain", a cork anomaly related to non-desired taints in wine. Data coming from an inquiry to the industry on this topic are presented, showing the importance of the problem. A bibliographical search on the mechanical, chemical, and microbiological characterization of cork presenting this defect has also been done. Final results show the changes in the industrial processes and the techniques that are being studied to obtain the cork quality level requested by the wineries
Keywords: Cork; Quality; yellow stain

Inflación del capital natural de la dehesa: hipótesis sobre la naturaleza caótica de la seca de los Quercus DENTRO DEL PROCESO DE LA SENESCENCIA FOLIAR - CUEVAS, S; TORRES, E; VÁZQUEZ, F.Mª.; López Arias, M; HERNÁNDEZ, A (III Congreso Forestal Español Congreso, 2001)
“Dehesa” is a gap forest yielding as an ecological-economic system (money-borrowed), poor soils (money-lender) upheld during optimal stopping millenia. Have supported multiple antropogenic nutrition disturbances during chaotic and resource routine affecting oak root uptake. Shoot nutrient odyssey is represented by cobweb model as price (nitrogen) evolution working by-product quantity (biomass). This trial evaluates cork oak (Quercus suber L.) and holm oak (Quercus rotundifolia Lam.) harvest basic sustainability (HBS) or nitrogen leaf redemption, southern Extremadura situated, evaluating ecological economic orientor for ecosystem. Defective HBS management hypothesis is expound in the absence of forest management, leading to sickly phenomenon on forest health as oak decline. Parallelly, HBS is proposed as an cork quality indirect index. Leaf senescence fork leads to physiological imbalance and, in some final cases, whole canopy defoliation (tie break). K.W.: Cobweb model, Oak decline, Renewal, Optimal stopping Dehesa, Nitrogen.
Keywords: Cobweb model; nitrogen; Oak decline; Optimal stopping Dehesa; Renewal

Inflación del capital natural de la dehesa: hipótesis sobre la naturaleza caótica de la seca de los Quercus DENTRO DEL PROCESO DE LA SENESCENCIA FOLIAR - CUEVAS, S.; Torres, E.; VÁZQUEZ, F. Mª; López Arias, M.; HERNÁNDEZ, A. (III Congreso Forestal Español Congreso, 2001)
“Dehesa” is a gap forest yielding as an ecological-economic system (money-borrowed), poor soils (money-lender) upheld during optimal stopping millenia. Have supported multiple antropogenic nutrition disturbances during chaotic and resource routine affecting oak root uptake. Shoot nutrient odyssey is represented by cobweb model as price (nitrogen) evolution working by-product quantity (biomass). This trial evaluates cork oak (Quercus suber L.) and holm oak (Quercus rotundifolia Lam.) harvest basic sustainability (HBS) or nitrogen leaf redemption, southern Extremadura situated, evaluating ecological economic orientor for ecosystem. Defective HBS management hypothesis is expound in the absence of forest management, leading to sickly phenomenon on forest health as oak decline. Parallelly, HBS is proposed as an cork quality indirect index. Leaf senescence fork leads to physiological imbalance and, in some final cases, whole canopy defoliation (tie break). K.W.: Cobweb model, Oak decline, Renewal, Optimal stopping Dehesa, Nitrogen.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español Congreso pub-location: Granada
Keywords: Cobweb model; nitrogen; Oak decline; Optimal stopping Dehesa; Renewal

INFLUENCIA DE LA "MANCHA AMARILLA" SOBRE LA COMPOSICIÓN QUÍMICA DEL CORCHO Y LA PRESENCIA DE TCA - García Vallejo, M. C.; Varea, S.; Cadahia, E.; Fernández de Simón, B. (III Congreso Forestal Español, 2001)
The anomaly of cork known as "yellow stain" has been considered as the main responsible for the presence, in some cork stoppers, of 2,4,6-trichloroanisole (TCA), compound that confers the "cork taint" to wine. In this Communication, a comparative study on the chemical composition of cork (suberin, waxes, polyphenols, holocellulose and lignin) and on the presence of chloroanisoles and chlorophenols is carried out with samples of healthy cork and cork affected with that anomaly. The cork with "yellow stain" differed from the healthy cork because of the presence of TCA and the low content of tannins.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español issue: 1995 pub-location: Granada
Keywords: chemical composition; Cork; yellow stain

INFLUENCIA DE LA "MANCHA AMARILLA" SOBRE LA COMPOSICIÓN QUÍMICA DEL CORCHO Y LA PRESENCIA DE TCA - García Vallejo, M C; Varea, S; Cadahía, E; Fernández de Simón, B (III Congreso Forestal Español, 2001)
The anomaly of cork known as "yellow stain" has been considered as the main responsible for the presence, in some cork stoppers, of 2,4,6-trichloroanisole (TCA), compound that confers the "cork taint" to wine. In this Communication, a comparative study on the chemical composition of cork (suberin, waxes, polyphenols, holocellulose and lignin) and on the presence of chloroanisoles and chlorophenols is carried out with samples of healthy cork and cork affected with that anomaly. The cork with "yellow stain" differed from the healthy cork because of the presence of TCA and the low content of tannins.
Keywords: chemical composition; Cork; yellow stain

Influencia del clima en el crecimiento longitudinal y radial de Q. ilex ssp. ballota L. y Q. faginea Lam. EN EL SISTEMA IBERICO ARAGONES - Corcuera, L.; Camarero, J. J.; GIL-PELEGRÍN, E. (III Congreso Forestal Español, 2001)
Climate influence (precipitation and temperature) on primary growth (annual growth length) and secondary growth (ring width and ring surface) of Quercus ilex ssp. ballota L. (evergreen and diffuse-porous species) and Q. faginea Lam. (decidious and ring-porous species) is studied. Samples were taken from a coppice in Sierra de Santa Cruz, Cubel, Zaragoza. Both species show lesser longitudinal and radial growth in drought years. A positive and significant relationship between precipitation and secondary growth and a negative and significant relationship between high summer temperatures and secondary growth were observed. Primary and secondary growth in 1993 and previous years mirror foliage desiccation of Q. ilex in 1993.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español issue: 1 pub-location: Granada
Keywords: climate; primary growth; Q. faginea; Q. ilex ssp. ballota; secondary growth

Influencia del clima en el crecimiento longitudinal y radial de Q. ilex ssp. ballota L. y Q. faginea Lam. EN EL SISTEMA IBERICO ARAGONES - Corcuera, L; CAMARERO, J J; Gil-Pelegrín, E (III Congreso Forestal Español, 2001)
Climate influence (precipitation and temperature) on primary growth (annual growth length) and secondary growth (ring width and ring surface) of Quercus ilex ssp. ballota L. (evergreen and diffuse-porous species) and Q. faginea Lam. (decidious and ring-porous species) is studied. Samples were taken from a coppice in Sierra de Santa Cruz, Cubel, Zaragoza. Both species show lesser longitudinal and radial growth in drought years. A positive and significant relationship between precipitation and secondary growth and a negative and significant relationship between high summer temperatures and secondary growth were observed. Primary and secondary growth in 1993 and previous years mirror foliage desiccation of Q. ilex in 1993.
Keywords: climate; primary growth; Q. faginea; Q. ilex ssp. ballota; secondary growth

Internal remobilization of carbohydrates, lipids, nitrogen and phosphorus in the Mediterranean evergreen oak Quercus ilex - Cherbuy, Bénédicte; Joffre, Richard; Gillon, Dominique; Rambal, Serge (Tree Physiology, 2001)
Remobilization of internal resources is an important mechanism enabling plants to be partly independent of external nutrient availability. We assessed resource remobilization during the growing period in woody and foliar tissues of leafy branches of mature evergreen Mediterranean oak (Quercus ilex L.) at three field sites. We compared nonstructural carbohydrates, lipids, nitrogen and phosphorus pools in leaves and stems before bud burst (March) and at the end of the growing period (July). We also experimentally defoliated leafy branches to determine the storage function of old leaves. Changes in pools of carbon compounds in leaves and stems during spring and in response to defoliation indicated that foliar and woody tissues could provide carbon to support shoot growth. Independently of stem age, soluble sugar and lipid pools decreased significantly during spring. Changes in leaf pools between March and July involved all compounds measured except starch and were accompanied by a 5%; decrease in mean leaf biomass. During the same period, 15%; of the nitrogen and 25%; of the phosphorus were removed from leaves. In contrast, woody tissues did not remobilize nitrogen or phosphorus. Our results support earlier hypotheses that leaves of evergreen species have a primary role in resource remobilization.
10.1093/treephys/21.1.9
Keywords: defoliation; Growth; nutrient storage; resource remobilization

Internal remobilization of carbohydrates, lipids, nitrogen and phosphorus in the Mediterranean evergreen oak Quercus ilex - Cherbuy, Bénédicte; Joffre, Richard; Gillon, Dominique; Rambal, Serge (Tree Physiology, 2001)
Remobilization of internal resources is an important mechanism enabling plants to be partly independent of external nutrient availability. We assessed resource remobilization during the growing period in woody and foliar tissues of leafy branches of mature evergreen Mediterranean oak (Quercus ilex L.) at three field sites. We compared nonstructural carbohydrates, lipids, nitrogen and phosphorus pools in leaves and stems before bud burst (March) and at the end of the growing period (July). We also experimentally defoliated leafy branches to determine the storage function of old leaves. Changes in pools of carbon compounds in leaves and stems during spring and in response to defoliation indicated that foliar and woody tissues could provide carbon to support shoot growth. Independently of stem age, soluble sugar and lipid pools decreased significantly during spring. Changes in leaf pools between March and July involved all compounds measured except starch and were accompanied by a 5%; decrease in mean leaf biomass. During the same period, 15%; of the nitrogen and 25%; of the phosphorus were removed from leaves. In contrast, woody tissues did not remobilize nitrogen or phosphorus. Our results support earlier hypotheses that leaves of evergreen species have a primary role in resource remobilization.
10.1093/treephys/21.1.910.1093/treephys/21.1.9
Keywords: defoliation; Growth; nutrient storage; resource remobilization

Isolation and functional analysis of a cDNA encoding a myrcene synthase from holm oak (Quercus ilex L.) - Fischbach, Robert J.; Zimmer, Wolfgang; Schnitzler, Jörg-Peter (European Journal of Biochemistry, 2001)
An 859-bp cDNA segment of a terpene synthase gene was amplified by PCR from the evergreen sclerophyllous holm oak (Quercus ilex L.) using heterologous primers for conserved regions of terpene synthase genes (TPS) in dicotyledonous plants. Based on the sequence of this segment, homologous primers were designed for amplification by RACE-PCR of a cDNA segment carrying the monoterpene synthase gene myrS. The gene encodes a protein of 597 amino acids including an N-terminal putative plastid transit peptide. The gene without the segment encoding the transit peptide was cloned by PCR into a bacterial expression vector. Expression in Escherichia coli yielded an active monoterpene synthase, which converted geranyl diphosphate (GDP) predominantly into the acyclic monoterpene myrcene and to a very small extent into cyclic monoterpenes. Sequence comparison with previously cloned monoterpene synthases revealed that the myrcene synthase from Q. ilex belongs to the TPSb subfamily.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: functional expression; geranyl diphosphate; monoterpene synthases; myrcene synthase; Quercus ilex

Isolation and functional analysis of a cDNA encoding a myrcene synthase from holm oak (Quercus ilex L.) - Fischbach, Robert J; Zimmer, Wolfgang; Schnitzler, Jörg-Peter (European Journal of Biochemistry, 2001)
An 859-bp cDNA segment of a terpene synthase gene was amplified by PCR from the evergreen sclerophyllous holm oak (Quercus ilex L.) using heterologous primers for conserved regions of terpene synthase genes (TPS) in dicotyledonous plants. Based on the sequence of this segment, homologous primers were designed for amplification by RACE-PCR of a cDNA segment carrying the monoterpene synthase gene myrS. The gene encodes a protein of 597 amino acids including an N-terminal putative plastid transit peptide. The gene without the segment encoding the transit peptide was cloned by PCR into a bacterial expression vector. Expression in Escherichia coli yielded an active monoterpene synthase, which converted geranyl diphosphate (GDP) predominantly into the acyclic monoterpene myrcene and to a very small extent into cyclic monoterpenes. Sequence comparison with previously cloned monoterpene synthases revealed that the myrcene synthase from Q. ilex belongs to the TPSb subfamily.
Keywords: functional expression; geranyl diphosphate; monoterpene synthases; myrcene synthase; Quercus ilex

Land use, biodiversity conservation, and rural development in the dehesas of Cuatro Lugares, Spain - Plieninger, T.; Wilbrand, C. (Agroforestry Systems, 2001)
Dehesas are an agrosilvopastoral system that has enhanced the maintenance of an extraordinarily high biodiversity. The traditional use is characterized by mixed livestock raising at low stocking densities, employment of hardy regional breeds and an elaborated maintenance and exploitation of holm oaks. Livestock production has traditionally been accompanied by arable systems with long rotations and closed nutrient cycles without external inputs of fodder, fertilizers and agro-chemicals. Modern trends are a specialization toward lamb and beef production and the employment of intensive techniques like freerange grazing at high stocking levels or crossbreeding with high-performance breeds. A model income statement shows that livestock create an income of 49.91 US$ per ewe per year on an average basis. The central problem for the continuity of the dehesas is the gradual decay of the tree canopy. Intensification of agricultural production and the abandonment of traditional grazing practices additionally threaten biodiversity within the dehesas. The authors suggest the foundation of a biosphere reserve in Cuatro Lugares as a framework for a sustainable development of the dehesas.
Keywords: economic output; Grazing; livestock; Mediterranean; pastoralism; Quercus ilex; rangeland

Land use, biodiversity conservation, and rural development in the dehesas of Cuatro Lugares, Spain - Plieninger, T; Wilbrand, C (Agroforestry Systems, 2001)
Dehesas are an agrosilvopastoral system that has enhanced the maintenance of an extraordinarily high biodiversity. The traditional use is characterized by mixed livestock raising at low stocking densities, employment of hardy regional breeds and an elaborated maintenance and exploitation of holm oaks. Livestock production has traditionally been accompanied by arable systems with long rotations and closed nutrient cycles without external inputs of fodder, fertilizers and agro-chemicals. Modern trends are a specialization toward lamb and beef production and the employment of intensive techniques like freerange grazing at high stocking levels or crossbreeding with high-performance breeds. A model income statement shows that livestock create an income of 49.91 US$ per ewe per year on an average basis. The central problem for the continuity of the dehesas is the gradual decay of the tree canopy. Intensification of agricultural production and the abandonment of traditional grazing practices additionally threaten biodiversity within the dehesas. The authors suggest the foundation of a biosphere reserve in Cuatro Lugares as a framework for a sustainable development of the dehesas.
Keywords: economic output; Grazing; livestock; Mediterranean; pastoralism; Quercus ilex; rangeland

Leaves of Quercus ilex L. as biomonitors of PAHs in the air of Naples (Italy) - Alfani, Anna; Maisto, Giulia; Vittoria Prati, Maria; Baldantoni, Daniela (Atmospheric Environment, 2001)
Polycyclic aromatic hydrocarbons (PAHs)were determined by the GC-MS chromatography in the leaves of Quercus ilex L., an evergreen Mediterranean oak, to monitor the degree of pollution in the urban area of Naples compared to remote areas. Leaf samples were collected in July 1998 from four urban parks, six roadsides and two sites in remote areas. The total PAH contents in Q. ilex leaves ranged from 106.6 in a control site to 4607.5 ng/g d.w. along a road with a high tra$c #ow. The mean concentration factors (urban/control)were 3.8 for the parks and 15 for the roads. The contribution of carcinogenic PAHs (benz[a]anthracene, benzo[b]#uoranthene, benzo[k]#uoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, indeno[1,2,3-c,d]pyrene)was higher in urban area and di!ered according to the site, ranging from 6.7% to 21.3%. The total PAH burden in control sites was dominated by the low molecular weight PAHs, whilst along the urban roads #uoranthene, pyrene and benz[a]anthracene among the measured PAHs showed the highest values. PAHs were positively correlated (P(0.01)to trace metals measured in a previous study.
Keywords: biomonitoring; leaves; polycyclic aromatic hydrocarbons; Quercus ilex L; rural and urban areas

Leaves of Quercus ilex L. as biomonitors of PAHs in the air of Naples (Italy) - Alfani, Anna; Maisto, Giulia; Vittoria Prati, Maria; Baldantoni, Daniela (Atmospheric Environment, 2001)
Polycyclic aromatic hydrocarbons (PAHs)were determined by the GC-MS chromatography in the leaves of Quercus ilex L., an evergreen Mediterranean oak, to monitor the degree of pollution in the urban area of Naples compared to remote areas. Leaf samples were collected in July 1998 from four urban parks, six roadsides and two sites in remote areas. The total PAH contents in Q. ilex leaves ranged from 106.6 in a control site to 4607.5 ng/g d.w. along a road with a high tra$c #ow. The mean concentration factors (urban/control)were 3.8 for the parks and 15 for the roads. The contribution of carcinogenic PAHs (benz[a]anthracene, benzo[b]#uoranthene, benzo[k]#uoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, indeno[1,2,3-c,d]pyrene)was higher in urban area and di!ered according to the site, ranging from 6.7% to 21.3%. The total PAH burden in control sites was dominated by the low molecular weight PAHs, whilst along the urban roads #uoranthene, pyrene and benz[a]anthracene among the measured PAHs showed the highest values. PAHs were positively correlated (P(0.01)to trace metals measured in a previous study.
Keywords: biomonitoring; leaves; polycyclic aromatic hydrocarbons; Quercus ilex L; rural and urban areas

Leeuwenhoek's observations on the anatomy of bark - Baas, P. (HOLZFORSCHUNG, 2001)
Leeuwenhoek's letter to the Royal Society of 27 March 1705, dealing with the anatomy of bark of cherry, birch, cinnamon, lime and cork oak is reviewed. It contains many detailed observations and illustrations of, i.a., ray dilatation, various types of phloem sclerenchyma, and annual rings in cork. This is another example of Leeuwenhoek's importance as an early plant anatomist.
The following values have no corresponding Zotero field: pub-location: GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY publisher: WALTER DE GRUYTER & CO
Keywords: biohistory; Cork; fibres; phloem; sclereids

Leeuwenhoek's observations on the anatomy of bark - Baas, P (HOLZFORSCHUNG, 2001)
Leeuwenhoek's letter to the Royal Society of 27 March 1705, dealing with the anatomy of bark of cherry, birch, cinnamon, lime and cork oak is reviewed. It contains many detailed observations and illustrations of, i.a., ray dilatation, various types of phloem sclerenchyma, and annual rings in cork. This is another example of Leeuwenhoek's importance as an early plant anatomist.
Keywords: biohistory; Cork; fibres; phloem; sclereids

LIMITACIONES A LA AUTORREGENERACIÓN DE LA ENCINA EN DEHESAS Y MONTES DE SIERRA MORENA. PREDACIÓN DE FRUTOS M. - LEIVA, M. J.; FERNÁNDEZ-ALÉS, R. (III Congreso Forestal Español, 2001)
We study acorn predation by insects, ungulates and small vertebrates in Mediterranean savannah-like forests and shrublands. The higher activity of rodents that we found in shrublands than in savannah-like forests, likely contributes to oak regeneration in these ecosystems as these animals can acts as disperser of acorns. Acorn predation by insects and ungulates were not significantly different among the two types of ecosystems.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: Predispersive and postdispersive acorn predation

Mediterranean natural forest living at elevated carbon dioxide: soil biological properties and plant biomass growth - Moscatelli, M. C.; Fonck, M.; De Angelis, P.; Larbi, H.; Macuz, A.; Rambelli, A.; Grego, S. (Soil Use and Management, 2001)
Abstract. Biomass productivity and soil microbial responses to long-term CO2 enrichment have been investigated in a Mediterranean natural forest ecosystem. Several biochemical parameters have been measured on soil samples taken from six open top chambers (OTCs), enclosing clumps of natural Mediterranean woody vegetation including: Quercus ilex L., Phillyrea angustifolia L., Pistacia lentiscus L. and Myrtus communis L. The CO2 concentration of the air inside the OTCs was either ambient or ambient plus 350 μmol mol–1 (c. 710 ppm as mean daily value). Microbial C biomass, microbial respiration, dehydrogenase, β-glucosidase, acid phosphatase and protease activities, inorganic N and soluble P, were tested in order to evaluate soil microbial size and activity. Statistically correlated seasonal patterns have been identified in some biochemical parameters in response to climatic conditions, soil nutritional status and the physiology of the vegetative cover. In situ soil respiration and above- and below-ground productivity were also measured. Microbial responses to CO2 enrichment were observed only at the beginning of the study and a general progressive reduction of the CO2 effect was recorded as monitoring continued. These results are in agreement with data from literature regarding similar studies on natural complex communities.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Carbon dioxide; Forests; Mediterranean Region; microbial activities; roots; Soil; Soil enzymes

Mediterranean natural forest living at elevated carbon dioxide: soil biological properties and plant biomass growth - Moscatelli, M C; Fonck, M; De Angelis, P; Larbi, H; Macuz, A; Rambelli, A; Grego, S (Soil Use and Management, 2001)
Abstract. Biomass productivity and soil microbial responses to long-term CO2 enrichment have been investigated in a Mediterranean natural forest ecosystem. Several biochemical parameters have been measured on soil samples taken from six open top chambers (OTCs), enclosing clumps of natural Mediterranean woody vegetation including: Quercus ilex L., Phillyrea angustifolia L., Pistacia lentiscus L. and Myrtus communis L. The CO2 concentration of the air inside the OTCs was either ambient or ambient plus 350 μmol mol–1 (c. 710 ppm as mean daily value). Microbial C biomass, microbial respiration, dehydrogenase, β-glucosidase, acid phosphatase and protease activities, inorganic N and soluble P, were tested in order to evaluate soil microbial size and activity. Statistically correlated seasonal patterns have been identified in some biochemical parameters in response to climatic conditions, soil nutritional status and the physiology of the vegetative cover. In situ soil respiration and above- and below-ground productivity were also measured. Microbial responses to CO2 enrichment were observed only at the beginning of the study and a general progressive reduction of the CO2 effect was recorded as monitoring continued. These results are in agreement with data from literature regarding similar studies on natural complex communities.
Keywords: Carbon dioxide; Forests; Mediterranean Region; microbial activities; roots; Soil; Soil enzymes

Metropolitan area of Rome: an integrated vegetation study by remote sensing and field data - Giannini, M.; Anselmi, S.; Melini, S.; Allegrini, A.; Manes, F. (Remote Sensing and Data Fusion over Urban Areas, IEEE/ISPRS Joint Workshop 2001, 2001)
The objective of this work is to assess the impact of environmental stresses, both natural (water stress, due to summer dryness typical of the Mediterranean climate) and anthropogenic (atmospheric pollution), on the vegetation in sites of great naturalistic value and under strong anthropic pressure in the Rome metropolitan area. The species <e1>Q</e1>uercus ilex L<e1>.</e1> (holm oak), an evergreen oak, has been studied through ecophysiological measurements performed in the field and Landsat TM images relating to the Rome metropolitan area. The results obtained show a greater degree of structural and functional alteration in individual holm oaks within the urban area compared with those in the protected areas outside of the central zone. In particular, in 1993 the main stress factor for vegetation is attributable to climatic conditions, whereas in 1998 ozone atmospheric concentration caused an evident alteration of the parameters studied
The following values have no corresponding Zotero field: periodical: Remote Sensing and Data Fusion over Urban Areas, IEEE/ISPRS Joint Workshop 2001
Keywords: Environmental stresses; metropolitan area; multiscale approach; Vegetation

Metropolitan area of Rome: an integrated vegetation study by remote sensing and field data - Giannini, M; Anselmi, S; Melini, S; Allegrini, A; Manes, F (Remote Sensing and Data Fusion over Urban Areas, IEEE/ISPRS Joint Workshop 2001, 2001)
The objective of this work is to assess the impact of environmental stresses, both natural (water stress, due to summer dryness typical of the Mediterranean climate) and anthropogenic (atmospheric pollution), on the vegetation in sites of great naturalistic value and under strong anthropic pressure in the Rome metropolitan area. The species <e1>Q</e1>uercus ilex L<e1>.</e1> (holm oak), an evergreen oak, has been studied through ecophysiological measurements performed in the field and Landsat TM images relating to the Rome metropolitan area. The results obtained show a greater degree of structural and functional alteration in individual holm oaks within the urban area compared with those in the protected areas outside of the central zone. In particular, in 1993 the main stress factor for vegetation is attributable to climatic conditions, whereas in 1998 ozone atmospheric concentration caused an evident alteration of the parameters studied
Keywords: Environmental stresses; metropolitan area; multiscale approach; Vegetation

Micorrización de plantas de PINUS HALEPENSIS, PINUS PINASTER Y QUERCUS ILEX SUBSP. BALLOTA PARA REPOBLACIÓN DE ZONAS INCENDIADAS DE ESCASA REGENERACIÓN NATURAL. - GÓMEZ-SÁNCHEZ, E; GONZÁLEZ-OCHOA, A I; TORRES, P; DE LAS HERAS, J; SIMARRO, E (III Congreso Forestal Español, 2001)
In order to obtain plant of good quality for afforestation of burned zones, seedlings inoculation has been carried out in nursery with different species of ectomycorrhizal fungi, using different inoculation techniques. The inoculated seedlings belong to three Mediterranean tree species with high colonizer capability of burned zones: Pinus halepensis, Pinus pinaster and Quercus ilex subsp. ballota. All of them were produced in container. The fungi used were: Lactarius deliciosus, L. sanguifluus, Suillus bellinii, S. collinitus, S. mediterraneensis and Pisolithus tinctorius for pine species; and Tuber melanosporum in the case of holm-oak. For Pinus inoculation it was made mycelial slurries and spore suspensions. For Quercus inoculation it was produced spore suspension. The experiment was carried out in two different nurseries, and it was evaluated the seedling heights and the mycorrhization percentage obtained using several parameters. Our results let optimize the application of mycorrhizal techniques in nurseries in order to produced mycorrhized plants with commercial aims.
Keywords: ectomycorrhizal fungi; Inoculation; mediterranean burned forests

Morphometric and biochemical contributions to the structuration and systematics of the Holm oak Quercus ilex L. specific complex - Lebreton, P; Barbero, M; Quezel, P (ACTA BOTANICA GALLICA, 2001)
The ecological amplitude and the biological variability of the Holm oak are such that any systematic characterization is hazardous. This study, conducted from eleven origins representative of the Western Mediterranean area, is novel by its pluridisciplinary and statistical approach. Chemical (foliar flavonoids) and morphometric data (dry weight, lengthening, veins of the leaves) support the same conclusion that the ``variability{''} of the Holm oak is structured by Ford sensu polymorphism. The distinction between ilex and rotundifolia remains pertinent from a first order perspective, but the second taxon should also be sub-divided into two distinct entities, the first in the Iberian peninsula, the other in North Africa. We consider the Holm oak as a specific complex comprising three taxa: ilex L.; rotundifolia emend. and maghrebiana subsp. nov. Although the Pyrenees constituted a barrier between ilex and rotundifolia, hybridisations and mutual introgressions doubtless explain certain abnormalities in Catalonia and Languedoc, A primarily morphometric determination key is proposed, though to be entirely rigorous only a population-based and multivariate-based approach, with inclusion of the biochemical parameters, can hope to address with sufficiently subtlety a problem of this complexity.
Keywords: Holm oak; Polymorphism; systematics

Non-steady-state modelling of water transfer in a Mediterranean evergreen canopy - Lhomme, J. P.; Rocheteau, A.; OURCIVAL, J. M.; Rambal, S. (Agricultural and Forest Meteorology, 2001)
A model simulating the diurnal pattern of water transfer within a Holm oak (Quercus ilex) canopy in Mediterranean conditions has been designed. It combines a non-steady-state hydraulic model with a transpiration model. The hydraulic model includes a reservoir represented by a capacitance, a soil–plant hydraulic resistance and a storage hydraulic resistance connected to the capacitance. It simulates the diurnal variation of water uptake and storage ﬂow from the diurnal course of transpiration used as input. The transpiration model is based upon the Penman–Monteith equation and a Jarvis-type representation of the stomatal resistance (i.e., a minimum stomatal resistance multiplied by the product of independent stress functions). Simultaneous measurements of canopy evaporation by an eddy covariance system and water uptake from the soil by sap ﬂow measurements have allowed one to calibrate and validate the model. The capacitance has been found to be equal to 0.17 mm MPa−1 (with a storage hydraulic resistance of about 2 MPa h mm−1 ), generating a time lag of about 1 h between the transpiration rate and the water uptake from the soil. The hydraulic model correctly represents the experimental data. The transpiration model provides reasonable estimates, but with a signiﬁcant scatter. The combined model simulates the diurnal variation of water uptake, storage ﬂow and transpiration rate directly from environmental variables, but in this latter case, the storage ﬂow is estimated with a rather poor accuracy
Keywords: Capacitance; Holm oak; Hydraulic resistance; Non-steady-state model; stomatal resistance; Transpiration; Water storage; Water uptake

Photosynthesis, Soluble and Structural Carbon Compounds in Two Mediterranean Oak Species (Quercus pubescens and Q. ilex) after Lifetime Growth at Naturally Elevated CO2 Concentrations - Blaschke, L.; Schulte, M.; Raschi, A.; Slee, N.; Rennenberg, H.; Polle, A. (Plant Biology, 2001)
Abstract: To study physiological responses of mature forest trees to elevated CO2 after lifetime growth under elevated atmospheric CO2 concentrations (pCO2), photosynthesis, Rubisco content, foliar concentrations of soluble sugars and starch, sugar concentrations in transport tissues (phloem and xylem), structural biomass, and lignin in leaves and branches were investigated in 30- to 50-year-old Quercus pubescens and Q. ilex trees grown at two naturally elevated CO2 springs in Italy. Ribulose-1,5-bisphosphate carboxylase/oxygenase content was decreased in Q. pubescens grown under elevated CO2 concentrations, but not in Q. ilex. Photosynthesis was consistently higher in Q. pubescens grown at elevated CO2 as compared with “control” sites, whereas the response in Q. ilex was less pronounced. Stomatal conductance was lower in both species leading to decreased transpiration and increased instantaneous water use efficiency in Q. pubescens. Overall mean sugar + starch concentrations of the leaves were not affected by elevated pCO2, but phloem exudates contained higher concentrations of soluble sugars. This finding suggests increased transport to sinks. Qualitative changes in major carbon-bearing compounds, such as structural biomass and lignins, were only found in bark but not in other tissues. These results support the concept that the maintenance of increased rates of photosynthesis after long-term acclimation to elevated pCO2 provides a means of optimization of water relations under arid climatic conditions but does not cause an increase in aboveground carbon sequestration per unit of tissue in Mediterranean oak species.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Carbohydrate; climate change; Elevated CO2; Lignin; photosynthesis; Rubisco

Photosynthesis, Soluble and Structural Carbon Compounds in Two Mediterranean Oak Species (Quercus pubescens and Q. ilex) after Lifetime Growth at Naturally Elevated CO2 Concentrations - Blaschke, L; Schulte, M; Raschi, A; Slee, N; Rennenberg, H; Polle, A (Plant Biology, 2001)
Abstract: To study physiological responses of mature forest trees to elevated CO2 after lifetime growth under elevated atmospheric CO2 concentrations (pCO2), photosynthesis, Rubisco content, foliar concentrations of soluble sugars and starch, sugar concentrations in transport tissues (phloem and xylem), structural biomass, and lignin in leaves and branches were investigated in 30- to 50-year-old Quercus pubescens and Q. ilex trees grown at two naturally elevated CO2 springs in Italy. Ribulose-1,5-bisphosphate carboxylase/oxygenase content was decreased in Q. pubescens grown under elevated CO2 concentrations, but not in Q. ilex. Photosynthesis was consistently higher in Q. pubescens grown at elevated CO2 as compared with “control” sites, whereas the response in Q. ilex was less pronounced. Stomatal conductance was lower in both species leading to decreased transpiration and increased instantaneous water use efficiency in Q. pubescens. Overall mean sugar + starch concentrations of the leaves were not affected by elevated pCO2, but phloem exudates contained higher concentrations of soluble sugars. This finding suggests increased transport to sinks. Qualitative changes in major carbon-bearing compounds, such as structural biomass and lignins, were only found in bark but not in other tissues. These results support the concept that the maintenance of increased rates of photosynthesis after long-term acclimation to elevated pCO2 provides a means of optimization of water relations under arid climatic conditions but does not cause an increase in aboveground carbon sequestration per unit of tissue in Mediterranean oak species.
Keywords: Carbohydrate; climate change; Elevated CO2; Lignin; photosynthesis; Rubisco

Possibilité de contrôle automatique de la qualité du liège par vision artificielle - Benkirane, Hatim; Benslimane, Rachid; Hachmi, M'Hamed; Sesbou, Ahmed (Ann. For. Sci., 2001)
The quality control often requires some visual inspection systems for defects detection in industrial production. In such application, those systems offer more reliability and lower processing time than a human operator. So this paper aims to introduce an automatic procedure to quality control of cork bits used for quality estimation of cork stacks, which is based on digital image analysis techniques. This procedure tries to quantify defects density of cork bit and to classify them in different quality classes. Experimental results are presented in order to evaluate the performance of the proposed automatic procedure.
Keywords: Classification; cork quality control; defect quantification; digital image; visual system

Possibilité de contrôle automatique de la qualité du liège par vision artificielle - Benkirane, Hatim; Benslimane, Rachid; Hachmi, M'Hamed; Sesbou, Ahmed (Ann. For. Sci., 2001)
The quality control often requires some visual inspection systems for defects detection in industrial production. In such application, those systems offer more reliability and lower processing time than a human operator. So this paper aims to introduce an automatic procedure to quality control of cork bits used for quality estimation of cork stacks, which is based on digital image analysis techniques. This procedure tries to quantify defects density of cork bit and to classify them in different quality classes. Experimental results are presented in order to evaluate the performance of the proposed automatic procedure.
Keywords: Classification; cork quality control; defect quantification; digital image; visual system

Predicting heating values of lignocellulosics and carbonaceous materials from proximate analysis - Cordero, T; Marquez, F; Rodriguez-Mirasol, J; Rodriguez, J J (Fuel, 2001)
A simple equation based on proxymate analysis (volatile matter and fixed carbon contents) is presented which allows calculation of the higher heating value of lignocellulosic as well as the charcoals resulting from their carbonization. The equation has been tested with different lignocellulosic wastes and chars obtained from carbobization at different temperatures. Derivations from the experimental heating values fall in most cases below 2%. A comparison is presented with some equationsfrom the literature based on proximate, ultimate and chemical analysis data. As a general conclusion the equation proposed in this paper leads to comparableand in many cases more accurate predictions of heating valus and has the advantage of being applicable to a wide range of carbonaceous materials, requiring only a simple, rapid and cheap proximate analysis of the samples
Keywords: charcoal; heating value calculation; lignocellulosics

Predicting heating values of lignocellulosics and carbonaceous materials from proximate analysis - Cordero, T.; Marquez, F.; Rodriguez-Mirasol, J.; Rodriguez, J. J. (Fuel, 2001)
A simple equation based on proxymate analysis (volatile matter and fixed carbon contents) is presented which allows calculation of the higher heating value of lignocellulosic as well as the charcoals resulting from their carbonization. The equation has been tested with different lignocellulosic wastes and chars obtained from carbobization at different temperatures. Derivations from the experimental heating values fall in most cases below 2%. A comparison is presented with some equationsfrom the literature based on proximate, ultimate and chemical analysis data. As a general conclusion the equation proposed in this paper leads to comparableand in many cases more accurate predictions of heating valus and has the advantage of being applicable to a wide range of carbonaceous materials, requiring only a simple, rapid and cheap proximate analysis of the samples
Keywords: charcoal; heating value calculation; lignocellulosics

PROCESADO DE LABORATORIO PARA LA OBTENCIÓN DE LOS PARAMETROS CARACTERISTICOS DEL CORCHO EN PLANCHA - González, F; GONZÁLEZ, J R; de la Vega, R; Cristóbal, A (III Congreso Forestal Español, 2001)
We enumerate a register of trials and laboratory operations to process pluggings from probes and cork planks in general. We also set the cheracteristic parameter before and after heating and the formula to calculate them is shown
Keywords: Characteristic parameter; Cork; Quality

Propagação Vegetativa por Estacaria do Sobreiro (Quercus suber L.) - Cordeiro, Sonia; Moreira, Carmen; Ferreira, R. P.; Carvalho, J. P. F.; Pinto, T. M. S.; Pereira, J. M. G. Torres (Silva Lusitana, 2001)
The PAMAF-IED 8110 (1997-2000) project, was used to verify the rhizogenic capacity of Quercus suber, throughout the study of rhizogenic behaviour of different kinds of propagule considering several rooting factors. Due to the preliminary state of statistical data analysis, these conclusions are at an early stage, consisting only in first indications to a later definition of the best combination of "propagule x rooting factors"
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: propagule; Quercus Suber L; rooting factors

Propagação Vegetativa por Estacaria do Sobreiro (Quercus suber L.) - Cordeiro, Sonia; Moreira, Carmen; Ferreira, R P; Carvalho, J P F; Pinto, T M S; Pereira, J M G Torres (Silva Lusitana, 2001)
The PAMAF-IED 8110 (1997-2000) project, was used to verify the rhizogenic capacity of Quercus suber, throughout the study of rhizogenic behaviour of different kinds of propagule considering several rooting factors. Due to the preliminary state of statistical data analysis, these conclusions are at an early stage, consisting only in first indications to a later definition of the best combination of "propagule x rooting factors"
Keywords: propagule; Quercus Suber L; rooting factors

REFORESTACIÓN DE TIERRAS AGRARIAS CON ENCINA Y COSCOJA. UN CASO EN TOLEDO - BARREDA, A.; SOBRINI, I. (III Congreso Forestal Español Congreso, 2001)
The Holm Oak (Quercus ilex) and the Kermes Oak (Quercus coccifera), both together, are being used successfuly in the dry Spain in the afforestations made under the Afforestation of Agricultural Land European Program, since 1993. We study a 1998/1999 afforestation of a farm in Toledo, in two pieces of 50 ha. each, until that moment dedicated to dry farming grain crops. The slopeswere between 0 and 10%, with sandy soils. All the farm presents high density of small game species. The results obtained, with less than 8% faults after two years, under conditions of little rain in 1998/99, and very dry summer in 2000, answer for the afforestation method employed, and permit us recomend it for other farms.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español Congreso pub-location: Granada
Keywords: Agricultural land; dry regions; Holm oak; Kermes Oak

REFORESTACIÓN DE TIERRAS AGRARIAS CON ENCINA Y COSCOJA. UN CASO EN TOLEDO - BARREDA, A; SOBRINI, I (III Congreso Forestal Español Congreso, 2001)
The Holm Oak (Quercus ilex) and the Kermes Oak (Quercus coccifera), both together, are being used successfuly in the dry Spain in the afforestations made under the Afforestation of Agricultural Land European Program, since 1993. We study a 1998/1999 afforestation of a farm in Toledo, in two pieces of 50 ha. each, until that moment dedicated to dry farming grain crops. The slopeswere between 0 and 10%, with sandy soils. All the farm presents high density of small game species. The results obtained, with less than 8% faults after two years, under conditions of little rain in 1998/99, and very dry summer in 2000, answer for the afforestation method employed, and permit us recomend it for other farms.
Keywords: Agricultural land; dry regions; Holm oak; Kermes Oak

Relaciones hídricas en procedencias de QUERCUS SUBER L. - Castro, L.; Aranda, I.; Gil, L.; Pardos, J. A. (III Congreso Forestal Español Congreso, 2001)
Response to drought was studied in 5 provenances of cork oak, which are representative of the ecogeographic range of the species. The variation of several water parameters was analysed in 2000 from the beginning of the summer to the first rainy period. Predawn water potential (ψama) was measured on 5 dates on 6 plants per provenance. On the same plants, pressure-volume curves were carried out on twigs from the spring flushing. Several parameters related to responses to drought were estimated: osmotic potential at full turgor (ψπ 100) and at the loss turgor point (ψπ 0), relative water content at zero turgor (CHR0) and elastic modulus at maximum turgor (εmax). Afterwards osmotic and elastic adjustments were evaluated, and the response to drought was separated of the influence of other factor such as phenology. When the water parameters were analysed, there were not significant differences among provenances, meanwhile the differences among dates were highly significant. A decrease in ψπ 100 and an increase of tissue rigidity (εmax) were observed during the period of water stress. The response to drought overlapped with variations due to ontogenic factors.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español Congreso
Keywords: Cork oak; osmotic adjustment; pressure-volume curves; water potential

Relaciones hídricas en procedencias de QUERCUS SUBER L. - Castro, L; Aranda, I; Gil, L; Pardos, J A (III Congreso Forestal Español Congreso, 2001)
Response to drought was studied in 5 provenances of cork oak, which are representative of the ecogeographic range of the species. The variation of several water parameters was analysed in 2000 from the beginning of the summer to the first rainy period. Predawn water potential (ψama) was measured on 5 dates on 6 plants per provenance. On the same plants, pressure-volume curves were carried out on twigs from the spring flushing. Several parameters related to responses to drought were estimated: osmotic potential at full turgor (ψπ 100) and at the loss turgor point (ψπ 0), relative water content at zero turgor (CHR0) and elastic modulus at maximum turgor (εmax). Afterwards osmotic and elastic adjustments were evaluated, and the response to drought was separated of the influence of other factor such as phenology. When the water parameters were analysed, there were not significant differences among provenances, meanwhile the differences among dates were highly significant. A decrease in ψπ 100 and an increase of tissue rigidity (εmax) were observed during the period of water stress. The response to drought overlapped with variations due to ontogenic factors.
Keywords: Cork oak; osmotic adjustment; pressure-volume curves; water potential

Response to fire of a predominantly transient seed bank in a Mediterranean weedy pasture (eastern-central Spain) - FERRANDIS, Pablo; HERRANZ, José M.; MARTÍNEZ-SÁNCHEZ, Juan J. (Ecoscience, 2001)
L'impact du feu sur la viabilité du réservoir total de graines du sol dans un pâturage méditérranéen, dominé par des herbes provenant de terrains arables, de même que sur son rétablissement pendant la première année après-feu, a été étudié. Des échantillons de sol ont été prélevés séparément en tranches de 0-2 cm et de 2-5 cm d'épaisseur, et leur contenu en graines a été évalué par la méthode d'émergence des plantules. De plus, des dénombrements de plantules émergentes ont été effectués sur le terrain au cours du printemps suivant le feu. L'analyse d'échantillons provenant d'un site non brûlé a révélé que les plantes annuelles (83 % des espèces, 86 % des graines) et les mauvaises herbes (50 % des espèces, 30 % des graines) étaient une composante majeure du réservoir de graines. Le réservoir de graines de la majorité des espèces (85 %) s'est accumulé dans la couche superficielle du sol, indiquant sa nature transitoire. Le feu a fortement réduit la densité et la richesse en espèces du réservoir de graines, tel qu'attendu pour une réserve de graines principalement transitoire d'une communauté qui n'a pas été exposée à un régime de feux récurrent au cours de son histoire évolutive. Une augmentation de la densité et de la richesse spécifique du réservoir de graines a été observée un an après le feu notamment dans les couches supérieures du sol. Le rétablissement s'est déroulé de deux façons : i) par une production de graines in situ à partir de graines ayant survécu au feu et germé et ii) par une invasion de graines disséminées par le vent provenant de la végétation adjacente non brûlée. La première a été réalisée par des espèces à graines relativement grosses selon une dispersion à faible distance. La seconde a été réalisée par des espèces anémochores et/ou à petites graines. Nous en concluons que l'habileté des communautés de mauvaises herbes de répondre au feu est basée sur la nature colonisatrice et envahissante des espèces. Les conséquences possibles pour l'utilisation du feu dans l'aménagement de telles communautés sont discutées
Keywords: disturbance history; Quercus faginea "dehesa"; seed bank recovery; seed invasion; weeds

Response to fire of a predominantly transient seed bank in a Mediterranean weedy pasture (eastern-central Spain) - FERRANDIS, Pablo; HERRANZ, José M; MARTÍNEZ-SÁNCHEZ, Juan J (Ecoscience, 2001)
L'impact du feu sur la viabilité du réservoir total de graines du sol dans un pâturage méditérranéen, dominé par des herbes provenant de terrains arables, de même que sur son rétablissement pendant la première année après-feu, a été étudié. Des échantillons de sol ont été prélevés séparément en tranches de 0-2 cm et de 2-5 cm d'épaisseur, et leur contenu en graines a été évalué par la méthode d'émergence des plantules. De plus, des dénombrements de plantules émergentes ont été effectués sur le terrain au cours du printemps suivant le feu. L'analyse d'échantillons provenant d'un site non brûlé a révélé que les plantes annuelles (83 % des espèces, 86 % des graines) et les mauvaises herbes (50 % des espèces, 30 % des graines) étaient une composante majeure du réservoir de graines. Le réservoir de graines de la majorité des espèces (85 %) s'est accumulé dans la couche superficielle du sol, indiquant sa nature transitoire. Le feu a fortement réduit la densité et la richesse en espèces du réservoir de graines, tel qu'attendu pour une réserve de graines principalement transitoire d'une communauté qui n'a pas été exposée à un régime de feux récurrent au cours de son histoire évolutive. Une augmentation de la densité et de la richesse spécifique du réservoir de graines a été observée un an après le feu notamment dans les couches supérieures du sol. Le rétablissement s'est déroulé de deux façons : i) par une production de graines in situ à partir de graines ayant survécu au feu et germé et ii) par une invasion de graines disséminées par le vent provenant de la végétation adjacente non brûlée. La première a été réalisée par des espèces à graines relativement grosses selon une dispersion à faible distance. La seconde a été réalisée par des espèces anémochores et/ou à petites graines. Nous en concluons que l'habileté des communautés de mauvaises herbes de répondre au feu est basée sur la nature colonisatrice et envahissante des espèces. Les conséquences possibles pour l'utilisation du feu dans l'aménagement de telles communautés sont discutées
Keywords: disturbance history; Quercus faginea "dehesa"; seed bank recovery; seed invasion; weeds

The role of landscape structure in species richness distribution of birds, amphibians, reptiles and lepidopterans in Mediterranean landscapes - Atauri, J A; Lucio, J V De (Landscape ecology, 2001)
The parameters referring to landscape structure are essential in any evaluation for conservation because of the relationship that exists between the landscape structure and the ecological processes. This paper presents a study of the relationships between landscape structure and species diversity distribution (estimated in terms of richness of birds, amphibians, reptiles and butterﬂies) in the region of Madrid, Spain. The results show that the response of species richness to landscape heterogeneity varies depending on the group of species considered. For birds and lepidopterans, the most important factor affecting the distribution of richness of species is landscape heterogeneity, while other factors, such as the speciﬁc composition of land use, play a secondary role at this scale. On the other hand, richness of amphibians and reptiles is more closely related to the abundance of certain land-use types. The study highlights the importance of heterogeneity in Mediterranean landscapes as a criterion for landscape planning and for deﬁnition of management directives in order to maintain biodiversity
Keywords: diversity distribution; landscape ecology; landscape heterogeneity; species richness distribution

The role of landscape structure in species richness distribution of birds, amphibians, reptiles and lepidopterans in Mediterranean landscapes - Atauri, J. A.; Lucio, J. V. De (Landscape ecology, 2001)
The parameters referring to landscape structure are essential in any evaluation for conservation because of the relationship that exists between the landscape structure and the ecological processes. This paper presents a study of the relationships between landscape structure and species diversity distribution (estimated in terms of richness of birds, amphibians, reptiles and butterﬂies) in the region of Madrid, Spain. The results show that the response of species richness to landscape heterogeneity varies depending on the group of species considered. For birds and lepidopterans, the most important factor affecting the distribution of richness of species is landscape heterogeneity, while other factors, such as the speciﬁc composition of land use, play a secondary role at this scale. On the other hand, richness of amphibians and reptiles is more closely related to the abundance of certain land-use types. The study highlights the importance of heterogeneity in Mediterranean landscapes as a criterion for landscape planning and for deﬁnition of management directives in order to maintain biodiversity
Keywords: diversity distribution; landscape ecology; landscape heterogeneity; species richness distribution

Selección de rodales selectos de alcornoque (Quercus suber) EN ANDALUCÍA Angel - Carrasco, Angel; Campayo, Pablo; Sanchez, Mª Felisa (III Congreso Forestal Español, 2001)
La Consejería de Medio Ambiente de la Junta de Andalucía, a través de la empresa pública EGMASA, como medio propio, ha desarrollado una metodología para evaluar la selección de rodales selectos de alcornoque (Quercus suber) en Andalucía. En primer lugar se consideran unos requisitos o criterios generales que debe cumplir una masa de alcornocal para poder optar a formar parte de la relación de rodales selectos. Los parámetros considerados son: Calidad productiva, Aislamiento, Pureza, Número de pies por hectárea y Estado sanitario, es decir, aquellos que mayor influencia genética van a tener sobre la calidad de las nuevas plantas de alcornoque. En segundo lugar, se hace una valoración de cada rodal. Para ello, se han definido unos índices de tal forma que el valor suma de estos sirve para diferenciar como mejores aquellos de mayor puntuación. Los índices definidos son: Indice de Calidad de Corcho, Índice Morfológico e Índice sanitario. La sumaserá el valor definitivo por el que se evalúa el rodal, considerándose como rodales selectos aquellos que superen el valor medio de cada Región de Procedencia
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: Andalucía; calidad; Quercus suber; selecto

Selección de rodales selectos de alcornoque (Quercus suber) EN ANDALUCÍA Angel - Carrasco, Angel; Campayo, Pablo; Sanchez, Mª Felisa (III Congreso Forestal Español, 2001)
La Consejería de Medio Ambiente de la Junta de Andalucía, a través de la empresa pública EGMASA, como medio propio, ha desarrollado una metodología para evaluar la selección de rodales selectos de alcornoque (Quercus suber) en Andalucía. En primer lugar se consideran unos requisitos o criterios generales que debe cumplir una masa de alcornocal para poder optar a formar parte de la relación de rodales selectos. Los parámetros considerados son: Calidad productiva, Aislamiento, Pureza, Número de pies por hectárea y Estado sanitario, es decir, aquellos que mayor influencia genética van a tener sobre la calidad de las nuevas plantas de alcornoque. En segundo lugar, se hace una valoración de cada rodal. Para ello, se han definido unos índices de tal forma que el valor suma de estos sirve para diferenciar como mejores aquellos de mayor puntuación. Los índices definidos son: Indice de Calidad de Corcho, Índice Morfológico e Índice sanitario. La sumaserá el valor definitivo por el que se evalúa el rodal, considerándose como rodales selectos aquellos que superen el valor medio de cada Región de Procedencia
Keywords: Andalucía; calidad; Quercus suber; selecto

SSR Markers for Quercus suber Tree Identification and Embryo Analysis - GÓMEZ, A; Pintos, B; Aguiriano, E; Manzanera, J A; Bueno, M A (Journal of Heredity, 2001)
Three Quercus simple sequence repeat (SSR) markers were amplified by polymerase chain reaction (PCR) from nuclear DNA extracts of trees and in vitro-induced haploid embryos from anther cultures of Quercus suber L. These markers were sufficiently polymorphic to identify 10 of 12 trees located in two Spanish natural areas. The same loci have been analyzed in anther-derived haploid embryos showing the parental tree allele segregation. All the alleles were present in the haploid progeny. The presence of diverse alleles in embryos derived from the same anther demonstrated that they were induced on multiple microspores or pollen grains and they were not clonally propagated. Also, diploid cultures and mixtures of haploid-diploid tissues were obtained. The origin of such cultures, either somatic or gametic, was elucidated by SSR markers. All the embryos showed only one allele, corroborating a haploid origin. Allelic composition of the haploid progeny permitted parental identification among all analyzed trees.
10.1093/jhered/92.3.292
Keywords: haploid embryos; identification (PG); Quercus suber; SSR markers

Structure and floristic diversity in permanent monitoring plots in forest ecosystems of Tuscany - Chiarucci, A; Dominicis, V De; Wilson, J B (Forest Ecology and Management, 2001)
The sampling method is described which is used for the sampling of plant species richness and cover in a monitoring project on forest ecosystems in Tuscany (named MONITO). Species richness is sampled through a nested plot design, with plot size ranging from 1 to 2500 m 2 , whereas species abundance is estimated in 100 m 2 plots. This sampling design is simple to install and to manage through time. Species diversity can be monitored not just at one single spatial scale but at many scales, and species±area relations can also be calculated. The analyses of the data that were collected produced the ®rst available data on species richness in relation to plot size for Tuscan forest ecosystems, indeed for any Italian forests. The Arrhenius Power function and the General Root models showed the best ®t. Turkey oak (Quercus cerris) woods located on slightly acidic soil were found to be the forest ecosystems with the highest species richness, con®rming and quantifying well-established ¯oristic- phytosociological knowledge. Habitat heterogeneity, measured by plot ¯oristic resemblance, showed how the Turkey oak woods were the most heterogeneous at the smaller spatial scales, but not at larger ones
Keywords: forest ecosystem monitoring; habitat-heterogeneity; Permanent plots; species; species diversity; species-area relations

Structure and floristic diversity in permanent monitoring plots in forest ecosystems of Tuscany - Chiarucci, A.; Dominicis, V. De; Wilson, J. B. (Forest Ecology and Management, 2001)
The sampling method is described which is used for the sampling of plant species richness and cover in a monitoring project on forest ecosystems in Tuscany (named MONITO). Species richness is sampled through a nested plot design, with plot size ranging from 1 to 2500 m 2 , whereas species abundance is estimated in 100 m 2 plots. This sampling design is simple to install and to manage through time. Species diversity can be monitored not just at one single spatial scale but at many scales, and species±area relations can also be calculated. The analyses of the data that were collected produced the ®rst available data on species richness in relation to plot size for Tuscan forest ecosystems, indeed for any Italian forests. The Arrhenius Power function and the General Root models showed the best ®t. Turkey oak (Quercus cerris) woods located on slightly acidic soil were found to be the forest ecosystems with the highest species richness, con®rming and quantifying well-established ¯oristic- phytosociological knowledge. Habitat heterogeneity, measured by plot ¯oristic resemblance, showed how the Turkey oak woods were the most heterogeneous at the smaller spatial scales, but not at larger ones
Keywords: forest ecosystem monitoring; habitat-heterogeneity; Permanent plots; species; species diversity; species-area relations

Susceptibility of hepatic tissue of Iberian pigs is enhanced by free-range feeding and reduced by vitamin E supplementation - López Bote, C. J.; Rey, A. I. (Nutrition Research, 2001)
The effect of feeding system (free-range vs conﬁnement) and the supplementation of concentrated feed with vitamin E and copper was investigated. Dietary copper supplementation (100 mg/kg) increased the hepatic concentration of copper in hepatic tissue (P , 0.05), reaching similar concentrations than pigs fed under free-range conditions. Free-range feeding produced higher concentration of a-tocopherol than those from pigs fed in conﬁnement with the basal level of vitamin E, but lower values than pigs fed supplemented levels, which may be attributed to the relative high concentration of a-tocopherol in the grass. Liver samples from pigs under free-range conditions showed higher susceptibility to lipid oxidation than pigs produced in conﬁnement and fed mixed diets. No signiﬁcant effect of copper was observed in hepatic tissue oxidation, but vitamin E supplementation markedly decreased oxidation
Keywords: a-tocopherol; copper; fatty acid; liver; pig

Testing the conservation of Quercus spp. microsatellites in the cork oak, Q-suber L. - Hornero, J; Gallego, F J; Martinez, I; TORIBIO, M (SILVAE GENETICA, 2001)
The transferability of microsatellite (SSR) loci from Quercus spp. to cork oak (Quercus suber L.) was investigated. Semi-automated analysis of fluorescently-labelled PCR fragments was used to test 24 primer sets developed for Q. myrsinifolia BLUME, Q. petraea (MAT7.) LIEB. and Q. robur L. in 41 cork oak trees from four stands covering the main area of distribution of the species in Spain. Successful cross-species events occurred for 13 loci (54%). Two of them were monomorphic and another two appeared as multilocus. High levels of genetic variability were detected both for the number of alleles, 62 (7.5 per polymorphic locus, with a maximum number of 19 in locus ssrQpZAG110) and for the expected heterozygosity (mean H-E = 0.648). These results were much higher than those previously reported by other authors using allozyme loci. The usefulness of the. SSR loci successfully amplified for studies on population genetics of cork oak is discussed.
Keywords: Cork oak; Fagaceae; microsatellites; Quercus suber

Thermogravimetric analysis of Mediterranean plant species - a. P. Dimitrakopoulos (Journal of Analytical and Applied Pyrolysis, 2001)
Twelve dominant Mediterranean plant species were subjected to thermogravimetric analysis (TGA) in air medium, in order to study their thermal degradation process and assess their potential combustibility as natural fuels. Statistically signiﬁcant differences were observed among the values of the pyrolytic parameters of the species analyzed. The mean volatilization rate values resulted in meaningful ranking of the species into vegetation types of similar combustibility, as veriﬁed by observations during actual wildﬁres. The use of TGA as a method for assessing the combustibility of individual plant species seems justiﬁed
Keywords: combustibility; lignocellulosic materials; Mediterranean; natural fuels; pyrolysis; thermogravimetric analysis; wildland fires

Thermogravimetric analysis of Mediterranean plant species - a.P. Dimitrakopoulos (Journal of Analytical and Applied Pyrolysis, 2001)
Twelve dominant Mediterranean plant species were subjected to thermogravimetric analysis (TGA) in air medium, in order to study their thermal degradation process and assess their potential combustibility as natural fuels. Statistically signiﬁcant differences were observed among the values of the pyrolytic parameters of the species analyzed. The mean volatilization rate values resulted in meaningful ranking of the species into vegetation types of similar combustibility, as veriﬁed by observations during actual wildﬁres. The use of TGA as a method for assessing the combustibility of individual plant species seems justiﬁed
Keywords: combustibility; lignocellulosic materials; Mediterranean; natural fuels; pyrolysis; thermogravimetric analysis; wildland fires

Tipología de sistemas adehesados* - Escribano, M.; Rodríguez de Ledesma, A.; Mesías, F. J.; Pulido, F. (Archivos de Zootecnia, 2001)
This work analyzes a a group of livestock farms in semiarid grazing areas in Spain. The surface sample studied adds up to 80.000 hectares. The results are expressed according to the livestock prevalence of the farms. INTRODUCCIÓN

Tipología de sistemas adehesados* - Escribano, M; Rodriguez de Ledesma, A; Mesías, F J; Pulido, F (Archivos de Zootecnia, 2001)
This work analyzes a a group of livestock farms in semiarid grazing areas in Spain. The surface sample studied adds up to 80.000 hectares. The results are expressed according to the livestock prevalence of the farms. INTRODUCCIÓN

Towards the dehesa total income accounting: theory and operative Monfragüe study cases - Campos, P.; Rodriguez, Y.; Caparros, A. (Investigación Agraria: Sistemas y Recursos Forestales, 2001)
There has been, from the beginning of the 1970s, a controversial debate on the income measurement of natural resource exploitation and sustainability both commercial and environmental of their economic resources. Treeless pastures and woodlands have been the focus of less research than has timber forestland. Up to today, institutional timber forestland accounting proposals have not integrated non-excludable and other non-market benefits into total income measurement of forestland. This paper shows a complete accounting system that can incorporate any economic benefit and cost that could accrue from active and passive uses of forestland, whether or not the economic effects are the result of on-site and off-site land uses. An application to the Spanish dehesas at Monfragüe area gives a tentative total income measurement under this new accounting proposal. The dehesa woodland study represents one of the most complex forestland uses system.
Keywords: Commercial income; Dehesa; Environmental income; Forestland accounting; Total income

Towards the dehesa total income accounting: theory and operative Monfragüe study cases - Campos, P; Rodriguez, Y; Caparros, A (Investigación Agraria: Sistemas y Recursos Forestales, 2001)
There has been, from the beginning of the 1970s, a controversial debate on the income measurement of natural resource exploitation and sustainability both commercial and environmental of their economic resources. Treeless pastures and woodlands have been the focus of less research than has timber forestland. Up to today, institutional timber forestland accounting proposals have not integrated non-excludable and other non-market benefits into total income measurement of forestland. This paper shows a complete accounting system that can incorporate any economic benefit and cost that could accrue from active and passive uses of forestland, whether or not the economic effects are the result of on-site and off-site land uses. An application to the Spanish dehesas at Monfragüe area gives a tentative total income measurement under this new accounting proposal. The dehesa woodland study represents one of the most complex forestland uses system.
Keywords: Commercial income; Dehesa; Environmental income; Forestland accounting; Total income

The use of near infrared reflectance spectroscopy to study chemical changes in the leaf litter consumed by saprophagous invertebrates - Gillon, D; David, J F (SOIL BIOLOGY & BIOCHEMISTRY, 2001)
Chemical changes in holm oak leaf litter that was consumed by the millipede Glomeris marginata were studied using near infrared reflectance spectroscopy. Compared to leaf litter, faecal pellets were significantly richer in lignin and poorer in nitrogen and readily assimilable constituents. The C:N ratio was significantly higher in the faeces. A NIRS-predicted index of litter decomposability was found to be lower in the faeces than in uneaten litter. (C) 2001 Elsevier Science Ltd. All rights reserved.
Keywords: leaf litter chemistry; near infrared reflectance spectroscopy; soil macrofauna

UTILIZACION DE ESPECIES AUTOCTONAS PARA RECUPERACION DE SUELOS DEGRADADOS ENMENDADOS CON LODOS RESIDUALES - GASCÓ, G; ALONSO, J; MARTINEZ IÑIGO, M J; LOBO, M C (III Congreso Forestal Español, 2001)
The objective of this study was to analyse if composted sewage sludges could be used to amend degraded soils. Two different treatments were applied to Nerium oleander L. and Quercus ilex L (120 Tons/Ha. y 60 Tons/Ha) in a greenhouse with controled conditions. Both heavy metals and nutrients soil contents were analysed to study the influence of the compost in soil properties. Moreover, the effect of the residue in physiological and nutritive plants properties were evaluated.
Keywords: composted sewage sludge; degraded soils; Heavy metals; Nerium oleander L.; Quercus ilex L.

UTILIZACION DE ESPECIES AUTOCTONAS PARA RECUPERACION DE SUELOS DEGRADADOS ENMENDADOS CON LODOS RESIDUALES - GASCÓ, G.; ALONSO, J.; MARTINEZ IÑIGO, M. J.; LOBO, M. C. (III Congreso Forestal Español, 2001)
The objective of this study was to analyse if composted sewage sludges could be used to amend degraded soils. Two different treatments were applied to Nerium oleander L. and Quercus ilex L (120 Tons/Ha. y 60 Tons/Ha) in a greenhouse with controled conditions. Both heavy metals and nutrients soil contents were analysed to study the influence of the compost in soil properties. Moreover, the effect of the residue in physiological and nutritive plants properties were evaluated.
The following values have no corresponding Zotero field: periodical: III Congreso Forestal Español pub-location: Granada
Keywords: composted sewage sludge; degraded soils; Heavy metals; Nerium oleander L.; Quercus ilex L.

VARIABILIDAD DE LOS PARAMETROS CARACTERÍSTICOS DEL CORCHO EN PLANCHA CON LA ALTURA DE EXTRACCIÓN - González, F; GONZÁLEZ, J R; GARCIA DE CECA, J L; GONZÁLEZ, M (III Congreso Forestal Español, 2001)
135 cork sample planks have been gotten from 15 trees ready to uncork. Planks were taken from 5 different heights and 2 orientations. 12 variables have been measured and studied from them. The following variables show a decrease in their values with the extraction height: Yearly average growth in thickness and superficial density before and after boiling. Two groups based on the sampling average height of 130 cm can be made with the following variables: thickness expansion, visual quality and coefficient of porosity. With few exceptions, the quality index (QI) shows a bigger commercial value for the cork coming from the upper part of the debarking height
Keywords: Characteristic parameter; Cork; Quality

Variability of cork from Portuguese Quercus suber studied by solid-state 13C-NMR and FTIR spectroscopies - Lopes, M. H.; Barros, A. S.; Pascoal Neto, C.; Rutledge, D.; Delgadillo, I.; Gil, A. M. (Biopolymers, 2001)
A new approach is presented for the study of the variability of Portuguese reproduction cork using solid-state 13C-NMR spectroscopy and photoacoustic (PAS) FTIR (FTIR-PAS) spectroscopy combined with chemometrics. Cork samples were collected from 12 different geographical sites, and their 13C-cross-polarization with magic angle spinning (CP/MAS) and FTIR spectra were registered. A large spectral variability among the cork samples was detected by principal component analysis and found to relate to the suberin and carbohydrate contents. This variability was independent of the sample geographical origin but significantly dependent on the cork quality, thus enabling the distinction of cork samples according to the latter property. The suberin content of the cork samples was predicted using multivariate regression models based on the 13C-NMR and FTIR spectra of the samples as reported previously. Finally, the relationship between the variability of the 13C-CP/MAS spectra with that of the FTIR-PAS spectra was studied by outer product analysis. This type of multivariate analysis enabled a clear correlation to be established between the peaks assigned to suberin and carbohydrate in the FTIR spectrum and those appearing in the 13C-CP/MAS spectra. © 2001 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 62: 268–277, 2001
The following values have no corresponding Zotero field: publisher: John Wiley & Sons, Inc.
Keywords: 13C-cross-polarization with magic angle spinning; chemometrics; Cork; outer product analysis; photoacoustic FTIR; Quercus suber Linnaeus

Variation in cork production of the cork oak between two consecutive cork harvests - Costa, a; Oliveira, A C (Forestry, 2001)
The variation in the cork produced by individual trees (Quercus suber L.) in three distinct locations, Mora, Alcácer do Sal and Benavente, is characterized by measurements made during two consecutive harvests of cork in the same trees. Particular emphasis is given to the variability in the weight of cork produced by individual trees and its mean caliper for the two strippings in each region. A good linear correlation between the tree circumference after the first stripping and the weight of the cork produced 9 years later as well as a poor linear correlation between the first variable and the caliper of the cork produced 9 years later is reported. A cork oak diameter curve is presented for each region, considering their two radial growths: the wood growth, which is cumulative, and the cork growth, which is the 9‐year growth.
10.1093/forestry/74.4.337
Keywords: Cork Production; Growth (PG); stripping; variability

Variation in cork production of the cork oak between two consecutive cork harvests - Costa, A.; Oliveira, A. C. (Forestry, 2001)
The variation in the cork produced by individual trees (Quercus suber L.) in three distinct locations, Mora, Alcácer do Sal and Benavente, is characterized by measurements made during two consecutive harvests of cork in the same trees. Particular emphasis is given to the variability in the weight of cork produced by individual trees and its mean caliper for the two strippings in each region. A good linear correlation between the tree circumference after the first stripping and the weight of the cork produced 9 years later as well as a poor linear correlation between the first variable and the caliper of the cork produced 9 years later is reported. A cork oak diameter curve is presented for each region, considering their two radial growths: the wood growth, which is cumulative, and the cork growth, which is the 9‐year growth.
10.1093/forestry/74.4.33710.1093/forestry/74.4.337
Keywords: Cork Production; Growth (PG); stripping; variability

Volatile organic compounds (vocs) emitted from 40 mediterranean plant species:: Voc speciation and extrapolation to habitat scale - Owen, S M; Boissard, Christophe; Hewitt, C N (Atmospheric Environment, 2001)
Forty native Mediterranean plant species were screened for emissions of the C5 and C10 hydrocarbons, isoprene and monoterpenes, in ﬁve diﬀerent habitats. A total of 32 compounds were observed in the emissions from these plants. The number of compounds emitted by diﬀerent plant species varied from 19 (Quercus ilex) to a single compound emission, usually of isoprene. Emission rates were normalised to generate emission factors for each plant species for each sampling event at standard conditions of temperature and light intensity. Plant species were categorised according to their main emitted compound, the major groups being isoprene, a-pinene, linalool, and limonene emitters. Estimates of habitat ﬂuxes for each emitted compound were derived from the contributing plant species’ emission factors, biomass and ground cover. Emissions of individual compounds ranged from 0.002 to 505 g ha 1 h 1 (camphene from garrigue in Spain in autumn and isoprene from riverside habitats in Spain in late spring; respectively). Emissions of isoprene ranged from 0.3 to 505 g ha 1 h 1 (macchia in Italy in late spring and autumn; and riverside in Spain in late spring; respectively) and a-pinene emissions ranged from 0.51 to 52.92 g ha 1 h 1 (garrigue in Spain in late spring; and forest in France in autumn; respectively). Habitat ﬂuxes of most compounds in autumn were greater than in late spring, dominated by emissions from Quercus ilex, Genista scorpius and Quercus pubescens. This study contributes to regional emission inventories and will be of use to tropospheric chemical modellers
Keywords: biogenic voc speciation; branch enclosure; extrapolation to regional scale; isoprene emissions; Mediterranean vegetation; monoterpene emissions; volatile organic compounds flux

Within-tree variation in transpiration in isolated evergreen oak trees: evidence in support of the pipe model theory - Infante, Juan Manuel; Mauchamp, André; Fernández-Alés, Rocío; Joffre, Richard; Rambal, Serge (Tree Physiology, 2001)
Within-tree variation in sap flow density (SFD) was measured in two isolated evergreen oak (Quercus ilex L.) trees growing in an oak savannah (dehesa) in southwest Spain. Sap flow was estimated by the constant heating method. Three sensors were installed in the trunk of each tree in three orientations: northeast (NE), northwest (NW) and south (S). Sap flow density was monitored continuously from May 18 to September 27, 1993. Daily values of SFD ranged between 500 and 4500 mm3 mm−2 day−1. There were significant differences in SFD between orientations; SFD was higher in the NE and NW orientations than in the S orientation. These differences were noted on both a daily and seasonal time scale, and were less pronounced on cloudy days and at the end of the drought period, when SFD was relatively low. Our results support the idea that branches of trees can be viewed as a collection of small independent plants.
10.1093/treephys/21.6.409
Keywords: Dehesa; oak savannah; Quercus ilex; sap flow den- sity; water use

The aero-aquatic Helicodendron microsporum n. sp from Mallorca, Spain - Abdullah, S. K.; Cano, J.; Descals, E.; Guarro, J. (MYCOLOGICAL RESEARCH, 2000)
A new aero-aquatic helicosporous hyphomycete, Helicodendron microsporum, is described and illustrated from decaying leaves submerged in a small artificial pond surrounded by Quercus ilex and Pinus halepensis in Mallorca, Spain. It is characterized by branched conidiophores with chains of hyaline conidia eventually forming white clusters which do not break up even at maturity. It also has small conidia (8-10 mu m diam.) consisting of a 2-2.5 mu m thick filament which coils 1.5-2 times counter-clockwise. The main characters of the species are compared with 14 similar hyalosporous Helicodendron species.
APSAPSThe following values have no corresponding Zotero field: pub-location: 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA publisher: CAMBRIDGE UNIV PRESS
Keywords: deaying leaves; hyphomycete; Pinus halepensis; Quercus ilex; Spain

The aero-aquatic Helicodendron microsporum n. sp from Mallorca, Spain - Abdullah, S K; Cano, J; Descals, E; Guarro, J (MYCOLOGICAL RESEARCH, 2000)
A new aero-aquatic helicosporous hyphomycete, Helicodendron microsporum, is described and illustrated from decaying leaves submerged in a small artificial pond surrounded by Quercus ilex and Pinus halepensis in Mallorca, Spain. It is characterized by branched conidiophores with chains of hyaline conidia eventually forming white clusters which do not break up even at maturity. It also has small conidia (8-10 mu m diam.) consisting of a 2-2.5 mu m thick filament which coils 1.5-2 times counter-clockwise. The main characters of the species are compared with 14 similar hyalosporous Helicodendron species.
APS
Keywords: deaying leaves; hyphomycete; Pinus halepensis; Quercus ilex; Spain

Annual variations of phenoloxidase activities in an evergreen oak litter: influence of certain biotic and abiotic factors - Criquet, S.; Farnet, A. M.; Tagger, S.; Petit, J. Le (Soil Biology and Biochemistry, 2000)
This study concerns ligninolysis phenomena occurring over 13 months in forest litter. Evergreen oak (Quercus ilex L.) litter was taken as a model because Quercus ilex L. is the most abundant tree species in forests of the French Mediterranean area. Several biotic and abiotic factors potentially involved in transformations of polyphenolic compounds, were measured between October 1997 and October 1998. These factors were: global fungal micro¯ora, the fungi producing phenoloxidases (PO+ ), the activities of several phenoloxidases, hydrosoluble phenols, and temperature, humidity and pH of the litter. Results showed that the annual dynamics of fungi and phenoloxidase activities appear to be seasonal, i.e. that these biotic factors such as, were optimal in autumn. A multiple regression analysis showed that there was no correlation between biotic factors such as, fungal populations and phenoloxidase activity and abiotic factors such as, temperature, humidity and pH. Laccases were the preponderant phenoloxidase activities during the year, while those of Mn-peroxidases only appeared in the autumn of 1997. Other phenoloxidases, lignin-peroxidases and tyrosinases were never detected. Interactions between laccases and humic substances were also investigated. Adsorption of laccases on humic substances leads to a shift in the optimal temperature activity of these enzymes from 50 to 308C. Activities of laccases also shifted towards more acidic values when laccases were not adsorbed on humic substances. Nevertheless, the optimal pH was the same (5.7) whether laccases were adsorbed or not to humic substances. Electrophoresis analysis showed little variations in the number of phenoloxidase isoenzymes. Indeed, laccases showed three isoenzymes during the year (Rf 0.23, 0.34 and 0.43). Only one isoform of Mn-peroxidase, with an Rf 0.21, was detected in the litter
Keywords: fungi; humic substances; laccase; litter; peroxidase

Annual variations of phenoloxidase activities in an evergreen oak litter: influence of certain biotic and abiotic factors - Criquet, S; Farnet, A M; Tagger, S; Petit, J Le (Soil Biology and Biochemistry, 2000)
This study concerns ligninolysis phenomena occurring over 13 months in forest litter. Evergreen oak (Quercus ilex L.) litter was taken as a model because Quercus ilex L. is the most abundant tree species in forests of the French Mediterranean area. Several biotic and abiotic factors potentially involved in transformations of polyphenolic compounds, were measured between October 1997 and October 1998. These factors were: global fungal micro¯ora, the fungi producing phenoloxidases (PO+ ), the activities of several phenoloxidases, hydrosoluble phenols, and temperature, humidity and pH of the litter. Results showed that the annual dynamics of fungi and phenoloxidase activities appear to be seasonal, i.e. that these biotic factors such as, were optimal in autumn. A multiple regression analysis showed that there was no correlation between biotic factors such as, fungal populations and phenoloxidase activity and abiotic factors such as, temperature, humidity and pH. Laccases were the preponderant phenoloxidase activities during the year, while those of Mn-peroxidases only appeared in the autumn of 1997. Other phenoloxidases, lignin-peroxidases and tyrosinases were never detected. Interactions between laccases and humic substances were also investigated. Adsorption of laccases on humic substances leads to a shift in the optimal temperature activity of these enzymes from 50 to 308C. Activities of laccases also shifted towards more acidic values when laccases were not adsorbed on humic substances. Nevertheless, the optimal pH was the same (5.7) whether laccases were adsorbed or not to humic substances. Electrophoresis analysis showed little variations in the number of phenoloxidase isoenzymes. Indeed, laccases showed three isoenzymes during the year (Rf 0.23, 0.34 and 0.43). Only one isoform of Mn-peroxidase, with an Rf 0.21, was detected in the litter
Keywords: fungi; humic substances; laccase; litter; peroxidase

Biochemical and molecular characterization of a laccase from Marasmius quercophilus - Dedeyan, B; Klonowska, A; Tagger, S; Tron, T; Iacazio, G; Gil, G; Le petit, J (APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2000)
The basidiomycete Marasmius quercophilus is commonly found during autumn on the decaying litter of the evergreen oak (Quercus ilex L.), a plant characteristic of Mediterranean forest. This white-rot fungus colonizes the leaf surface with rhizomorphs, causing a total bleaching of the leaf. In synthetic liquid media, this white-rot fungus has strong laccase activity. From a three-step chromatographic procedure, we purified a major isoform to homogeneity, The gene encodes a monomeric glycoprotein of approximately 63 kDa, with a 3.6 isoelectric point, that contains 12% carbohydrate, Spectroscopic analysis of the purified enzyme (UV/visible and electron paramagnetic resonance, atomic absorption) confirmed that it belongs to the ``blue copper oxidase{''} family. With syringaldazine as the substrate, the enzyme's pH optimum was 4.5, the optimal temperature was 75 degrees C, and the K-m was 7.1 mu M. The structural gene, lac1, was cloned and sequenced. This gene encodes a 517-amino-acid protein 99% identical to a laccase produced by PM1, an unidentified basidiomycete previously isolated from wastewater from a paper factory in Spain. This similarity may be explained by the ecological distribution of the evergreen oak in Mediterranean forest.
Keys: APS
Keywords: Basidiomycete; litter; Marasmius quercophilus; mediterranean forest; Quercus ilex L.; structural genes

Biochemical and molecular characterization of a laccase from Marasmius quercophilus - Dedeyan, B.; Klonowska, A.; Tagger, S.; Tron, T.; Iacazio, G.; Gil, G.; Le petit, J. (APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2000)
The basidiomycete Marasmius quercophilus is commonly found during autumn on the decaying litter of the evergreen oak (Quercus ilex L.), a plant characteristic of Mediterranean forest. This white-rot fungus colonizes the leaf surface with rhizomorphs, causing a total bleaching of the leaf. In synthetic liquid media, this white-rot fungus has strong laccase activity. From a three-step chromatographic procedure, we purified a major isoform to homogeneity, The gene encodes a monomeric glycoprotein of approximately 63 kDa, with a 3.6 isoelectric point, that contains 12% carbohydrate, Spectroscopic analysis of the purified enzyme (UV/visible and electron paramagnetic resonance, atomic absorption) confirmed that it belongs to the ``blue copper oxidase{''} family. With syringaldazine as the substrate, the enzyme's pH optimum was 4.5, the optimal temperature was 75 degrees C, and the K-m was 7.1 mu M. The structural gene, lac1, was cloned and sequenced. This gene encodes a 517-amino-acid protein 99% identical to a laccase produced by PM1, an unidentified basidiomycete previously isolated from wastewater from a paper factory in Spain. This similarity may be explained by the ecological distribution of the evergreen oak in Mediterranean forest.
Keys: APSKeys: APSThe following values have no corresponding Zotero field: pub-location: 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA publisher: AMER SOC MICROBIOLOGY
Keywords: Basidiomycete; litter; Marasmius quercophilus; mediterranean forest; Quercus ilex L.; structural genes

Caractérisation de la croissance et de la qualité du liège dans une région de production - Ferreira, Alexandra; Lopes, Fernando; Pereira, Helena (Ann. For. Sci., 2000)
Cork growth and quality were characterised in 5 cork oak stands within the production area of the Sado basin (Alcácer do Sal, Portugal) based on a field sampling on 40 trees/stand. Cork thickness was on average 33.8 mm, with 75% of the samples in the commercial classes above 27 mm suitable for production of stoppers. Porosity measured by image analysis was 4.6% on average. Between tree and between stand variability of cork quality was large. The annual average cork growth for a production cycle with 8 complete growth years was 4.1 mm, being highest during the years following cork extraction and decreasing during the cycle. For this region, a production cycle of 9 years is adequate for raw-material industrial requirements. The results show the importance of between tree variability in growth and especially in quality.
Keywords: Cork; Growth; Porosity; Quality; variability

Caractérisation de la croissance et de la qualité du liège dans une région de production - Ferreira, Alexandra; Lopes, Fernando; Pereira, Helena (Ann. For. Sci., 2000)
Cork growth and quality were characterised in 5 cork oak stands within the production area of the Sado basin (Alcácer do Sal, Portugal) based on a field sampling on 40 trees/stand. Cork thickness was on average 33.8 mm, with 75% of the samples in the commercial classes above 27 mm suitable for production of stoppers. Porosity measured by image analysis was 4.6% on average. Between tree and between stand variability of cork quality was large. The annual average cork growth for a production cycle with 8 complete growth years was 4.1 mm, being highest during the years following cork extraction and decreasing during the cycle. For this region, a production cycle of 9 years is adequate for raw-material industrial requirements. The results show the importance of between tree variability in growth and especially in quality.
Keywords: Cork; Growth; Porosity; Quality; variability

Characterization of cork growth and quality in one region of production. - Ferreira, A; Lopes, F; Pereira, H (ANNALS OF FOREST SCIENCE, 2000)
Cork growth and quality were characterised in 5 cork oak stands within the production area of the Sado basin (Alcacer do Sal, Portugal) based on a field sampling on 40 trees/stand. Cork thickness was on average 33.8 mm, with 75% of the samples in the commercial classes above 27 mm suitable for production of stoppers. Porosity measured by image analysis was 4.6% on average. Between toe and between stand variability of cork quality was large. The annual average cork growth for a production cycle with 8 complete growth years was 4.1 mm, being highest during the years following cork extraction and decreasing during the cycle. For this region, a production cycle of 9 years is adequate for raw-material industrial requirements. The results show the importance of between tree variability in growth and especially in quality.
Keywords: Cork; Growth; Porosity; Quality; variability

Characterization of cork growth and quality in one region of production. - Ferreira, A.; Lopes, F.; Pereira, H. (ANNALS OF FOREST SCIENCE, 2000)
Cork growth and quality were characterised in 5 cork oak stands within the production area of the Sado basin (Alcacer do Sal, Portugal) based on a field sampling on 40 trees/stand. Cork thickness was on average 33.8 mm, with 75% of the samples in the commercial classes above 27 mm suitable for production of stoppers. Porosity measured by image analysis was 4.6% on average. Between toe and between stand variability of cork quality was large. The annual average cork growth for a production cycle with 8 complete growth years was 4.1 mm, being highest during the years following cork extraction and decreasing during the cycle. For this region, a production cycle of 9 years is adequate for raw-material industrial requirements. The results show the importance of between tree variability in growth and especially in quality.
The following values have no corresponding Zotero field: pub-location: 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE publisher: EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
Keywords: Cork; Growth; Porosity; Quality; variability

A checklist approach to evaluate the contribution of organic farms to landscape quality - Kuiper, Juliëtte (Agriculture, Ecosystems & Environment, 2000)
Criteria need to be developed to evaluate the cultural environment of European rural landscapes. The goal is to evaluate and encourage the contribution of organic farming to sustainable landscape quality. Two sets of criteria were used to evaluate the quality of the cultural environment, non-expert and expert values. The non-expert values consisted of criteria for the appreciation of the present local landscape by users and inhabitants. These criteria were derived from psychological principles (Coeterier, 1996). The expert values for landscape assessment were derived from physiognomy, geography and landscape architecture. These criteria require specialized knowledge essential in understanding the cultural history of at least the regional landscape and in landscape planning. The criteria were derived from a reﬂection of landscape plans at different scale levels (Kuiper, 1998). This reﬂection resulted in planning objectives based on the following three criteria: diversity; coherence; and continuity. Diversity refers to the diversity of landscape components as an expression of the relationships between land use and abiotic features; coherence refers to coherence among landscape components as an expression of the relationships between sites (hydrology, ecology and infrastructure); continuity refers to temporal relationships of land use and spatial arrangement from the past to the future. These three criteria are interrelated and inseparable. The need for ecological quality as well as aesthetic quality within the rural landscape is seen as a step forward in cultural development. To make EU regulations based on planning objectives seems premature at present. A checklist was established based on the criteria mentioned and was formulated in such a way as to compare an organic farm with a conventional farm in the same landscape unit. The checklist was implemented on organic and adjacent conventional farms in nine regions of Europe. In this article a large farm was considered in the Dehesa landscape in Andalusia and small farms were considered in the fringe of Lisboa, in the Netherlands and on Crete. The two sets of criteria proved able to include all the arguments named during the evaluation of the contribution of organic farms to landscape quality
Keywords: diversity and coherence; landscape quality; organic farms

Comparative photochemical and phenomorphological responses to winter stress of an evergreen ( Quercus ilex L.) and a semi-deciduous ( Cistus albidus - Oliveira, G; Penuelas, J (Acta Oecologica, 2000)
The impact of winter stress on plants from a Mediterranean area was evaluated through comparison of photosystem II (PS II) efficiencies and phenomorphological characteristics of two Mediterranean woody species – Quercus ilex (evergreen) and Cistus albidus (semi-deciduous). The studies were carried out in NE Spain, at two sites with different mean winter temperatures. The results showed that reductions of the efficiency of PS II may occur in Mediterranean plant communities during winter, and are especially remarkable on colder days. The extent and duration of the decrease in PS II efficiency (photoinhibition) depended not only on the climatic conditions, but also on the site, on the species considered and on the position of leaves in the plant canopy. Increased photoinhibition at the colder site was only clear for C. albidus. Nevertheless, the efficiencies of PS II were always higher in C. albidus than in Q. ilex. Phenological patterns, morphology and leaf inclination may protect C. albidus leaves from potentially photoinhibitory conditions in winter. Morphological and structural photoprotection is apparently not so well developed in Q. ilex, which probably relies more on increased protection at the photochemical level of its long-lived leaves. As has been reported in relation to summer-drought stress, Q. ilex has possibly developed a strategy of tolerance to photoinhibition, whereas C. albidus relies preferentially on avoidance features
Keywords: Chlorophyll ﬂuorescence; evergreens; leaf characteristics; Mediterranean winter; Phenology; photoinhibition; semi-deciduous

Comparative stem-growth rates of Mediterranean trees under background and naturally enhanced ambient CO2 concentrations - Tognetti, Roberto; Cherubini, Paolo; Innes, John L (New Phytologist, 2000)
Ring widths of five Mediterranean forest tree species (Arbutus unedo, Fraxinus ornus, Quercus cerris, Quercus ilex and Quercus pubescens) growing close to a natural source of CO2 in Tuscany, Italy and at a nearby control site were compared. At the CO2-enriched site, trees have been growing for decades under elevated CO2 concentrations. They originated from parent trees that also grew under elevated CO2 in natural conditions, and they have been continuously exposed to elevated CO2 throughout their growth. Tree-ring series from each of the species were prepared. Assigning calendar dates to rings was difficult but possible, and ring-width series were built for all species. The ring-width data were analysed using a two-sided t-test to assess if there was a difference between the radial growth at the CO2-enriched site and the control site. The cumulative basal area at the same cambial age at both sites was also compared using a Wilcoxon test. Radial growth of trees at the CO2-enriched site was not significantly different from growth at the control site. For each species, year by year, radial growth at the CO2-enriched site was tested against the control site and significant differences were found in only a few years; these differences were not synchronous with extreme climatic events. The expected increase in above-ground productivity, as one of the ecosystem responses to increasing CO2 during drought stress, was not observed in this Mediterranean woody plant community, despite being water-limited. Other resource limitations, such as low nutrient availability (common in the Mediterranean region), may have counteracted the positive effect of elevated CO2 under drought stress, or trees may have acclimated to the high CO2.
Keywords: Arbutus unedo (strawberry tree); Carbon Sequestration; Dendroecology; Mediterranean trees; natural CO2 springs; Quercus ilex (holm oak); tree rings; water stress

Comparative stem-growth rates of Mediterranean trees under background and naturally enhanced ambient CO2 concentrations - Tognetti, Roberto; Cherubini, Paolo; INNES, JOHN L. (New Phytologist, 2000)
Ring widths of five Mediterranean forest tree species (Arbutus unedo, Fraxinus ornus, Quercus cerris, Quercus ilex and Quercus pubescens) growing close to a natural source of CO2 in Tuscany, Italy and at a nearby control site were compared. At the CO2-enriched site, trees have been growing for decades under elevated CO2 concentrations. They originated from parent trees that also grew under elevated CO2 in natural conditions, and they have been continuously exposed to elevated CO2 throughout their growth. Tree-ring series from each of the species were prepared. Assigning calendar dates to rings was difficult but possible, and ring-width series were built for all species. The ring-width data were analysed using a two-sided t-test to assess if there was a difference between the radial growth at the CO2-enriched site and the control site. The cumulative basal area at the same cambial age at both sites was also compared using a Wilcoxon test. Radial growth of trees at the CO2-enriched site was not significantly different from growth at the control site. For each species, year by year, radial growth at the CO2-enriched site was tested against the control site and significant differences were found in only a few years; these differences were not synchronous with extreme climatic events. The expected increase in above-ground productivity, as one of the ecosystem responses to increasing CO2 during drought stress, was not observed in this Mediterranean woody plant community, despite being water-limited. Other resource limitations, such as low nutrient availability (common in the Mediterranean region), may have counteracted the positive effect of elevated CO2 under drought stress, or trees may have acclimated to the high CO2.
The following values have no corresponding Zotero field: publisher: Cambridge University Press
Keywords: Arbutus unedo (strawberry tree); Carbon Sequestration; Dendroecology; Mediterranean trees; natural CO2 springs; Quercus ilex (holm oak); tree rings; water stress

Composition of Suberin Extracted upon Gradual Alkaline Methanolysis of Quercus suber L. Cork - Lopes, Marta H.; Gil, Ana M.; Silvestre, Armando J. D.; Neto, Carlos Pascoal (Journal of Agricultural and Food Chemistry, 2000)
The monomeric composition of suberin extracts obtained by gradual alkaline methanolysis of Quercus suber cork was determined by gas chromatography?mass spectrometry (GC-MS). Results show that 1-alkanols and alkanoic and α,?-alkanedioic acids are preferentially removed upon mild alkaline conditions, whereas mid-chain-modified ?-hydroxyalkanoic acids are preferentially removed under stronger alkaline conditions. Saturated ?-hydroxyalkanoic acids are found to be abundant in all suberin extracts. These results are consistent with two distinct suberin fractions with different locations in cork cell walls and/or esterification degrees. It is proposed that these fractions correlate with the two main suberin peaks in the solid state 13C NMR spectra of cork and suberin extracts. Quantitative GC-MS analysis showed that suberin monomers comprise ?30% (w/w) of the suberin extracts, the remaining comprising nonvolatile structures with high Mn values, as measured by vapor pressure osmometry. The presence of a large fraction of high molecular weight aliphatic structures in suberin extracts is supported by the corresponding NMR spectra. Keywords: Suberin; cork; Quercus suber L.; GC-MS; NMR; alkaline methanolysis
doi: 10.1021/jf9909398doi: 10.1021/jf9909398The following values have no corresponding Zotero field: publisher: American Chemical Society
Keywords: Alkaline methanolysis; Cork; GC-MS; NMR; Quercus suber L.; suberin

Conservation strategy of a nature reserve in Mediterranean ecosystems: the effects of protection from grazing on biodiversity - Verdú, J R; Crespo, M B; Galante, Eduardo (Biodiversity and Conservation, 2000)
Protection of natural areas has caused the elimination of traditional grazing activity on many occasions. As a result, in Mediterranean ecosystems a loss of biodiversity is usually related to a decrease of grassland and grassland–bush mosaic areas. In order to establish relationships between land use and the relative importance of each type of habitat in terms of species richness and endemicity, the Font Roja Natural Park in Alicante Province (SE Iberian Peninsula) was studied. Four sites were selected representing the four different existing habitats: a wooded area (holm-oak forest), a dense shrubland, a dense grassland, and a grassland–shrubland mosaic area. In each site, the species composition of vegetation and dung beetle fauna were analysed. The results showed that the highest diversity and endemicity, for plants and beetles, were concentrated in the dense grasslands and the grassland–shrubland mosaic. Thus, controlled grazing activity of sheep and goats which maintained a diverse variegated landscape would favour the historical sustenance of the biodiversity of Mediterranean ecosystems, as that would allow a remarkable diversity of habitats with higher conservation levels of existing species richness and endemicity. Therefore, we propose a reintroduction of traditional grazing of sheep and goats throughout ecological, cultural and economical measures, which would include guidelines and regulations, set out to boost an integrated rural policy.
Keywords: dung beetles; endemicity; impact; management; vascular plants

Conservation strategy of a nature reserve in Mediterranean ecosystems: the effects of protection from grazing on biodiversity - Verdú, J. R.; Crespo, M. B.; Galante, Eduardo (Biodiversity and Conservation, 2000)
Protection of natural areas has caused the elimination of traditional grazing activity on many occasions. As a result, in Mediterranean ecosystems a loss of biodiversity is usually related to a decrease of grassland and grassland–bush mosaic areas. In order to establish relationships between land use and the relative importance of each type of habitat in terms of species richness and endemicity, the Font Roja Natural Park in Alicante Province (SE Iberian Peninsula) was studied. Four sites were selected representing the four different existing habitats: a wooded area (holm-oak forest), a dense shrubland, a dense grassland, and a grassland–shrubland mosaic area. In each site, the species composition of vegetation and dung beetle fauna were analysed. The results showed that the highest diversity and endemicity, for plants and beetles, were concentrated in the dense grasslands and the grassland–shrubland mosaic. Thus, controlled grazing activity of sheep and goats which maintained a diverse variegated landscape would favour the historical sustenance of the biodiversity of Mediterranean ecosystems, as that would allow a remarkable diversity of habitats with higher conservation levels of existing species richness and endemicity. Therefore, we propose a reintroduction of traditional grazing of sheep and goats throughout ecological, cultural and economical measures, which would include guidelines and regulations, set out to boost an integrated rural policy.
Keywords: dung beetles; endemicity; impact; management; vascular plants

Constraints and trade-offs in Mediterranean plant communities: The case of holm oak-Aleppo pine forests - Zavala, M A; ESPELTA, J M; RETANA, J (The Botanical Review, 2000)
In this paper we review those aspects that are relevant to the development of a mechanistic ecological theory to account for the structure and dynamics of Mediterranean forests, focus- ing our attention on mixed forests of holm oak (Quercus ilex L.), a shade-tolerant, slow- growing species that resprouts vigorously after disturbance, and Aleppo pine (Pinus halepen- sis M.), a fast-growing, nonresprouting, shade-intolerant species. The main objectives of this report are: to introduce some of the primary features of these forests, showing their structural complexity and historical peculiarities; to show that much of this complexity can be concep- tually reduced to two main factors of variation, soil-moisture gradients and a complex inter- action of historical management and disturbance regimes; and to contrast the unique features of Mediterranean systems with other communities that have inspired generalization in ecol- ogy. Plants in Mediterranean-climate regions must face several environmental constraints dur- ing their life cycle: water limitation, competition for light, and a complex set of disturbance regimes, mainly fire, herbivory, and human exploitation. The response of co-occurring spe- cies to a given set of environmental constraints depends on a combination of physiological and morphological traits. In holm oak-Aleppo pine forests, the lower limit of distribution along a soil-moisture gradient appears to be controlled by dry-season water stress on seedling performance, and the upper limit seems to be controlled by shade tolerance relative to com- petitors. The processes that generate and maintain these patterns are related to the responses of the two species to the water and light environments that result from interacting gradients of disturbance and resource availability. The dynamics of mixed holm oak-Aleppo pine forests may be represented along two major environmental axes: water availability and light intensity; namely, time since last disturbance. At the regional scale, the presence of holm oak and Aleppo pine is expected to be driven mainly by the precipitation regime, with the proportion of Aleppo pine in- creasing toward the driest border and with holm oak being the dominant species in areas with higher precipitation. Changes of dominance of holm oak and Aleppo pine also re- spond to water availability at the local scale. In this case, variations between species de- pend on different factors in a complex way, because reduced soil-moisture levels may re- sult either from low precipitation or from topography and edaphic features. The dynamics of holm oak-Aleppo pine forests are also determined by temporal changes in canopy clo- sure; that is, forest recovery after disturbance. In this case, the proportion of Aleppo pine would increase in recently disturbed stands (i.e., with high light intensity reaching the for- est floor), whereas regeneration of holm oak would be dominant under partially closed canopies. Theories of forest dynamics developed in humid regions may apply only poorly to Medi- terranean plant communities, where vegetation change is qualitatively or quantitatively dif- ferent. Thus, succession in temperate forests appears to be driven by differences in light availability and shade tolerance; but in Mediterranean plant communities, water limitation is of greater importance for the distribution of forest species. In Mediterranean landscapes the interaction of life-history strategies with changing environments is difficult to infer from observational and experimental studies. A mechanistic approach, in which competi- tion or plant performance is measured as a function of resource availability, seems more feasible. The idea should be to develop multispeeies models calibrated specifically for Mediterranean forests in a combined program of modeling, field research, and experimenta- tion.
Keywords: Aleppo pine; disturbance regimes; forest dynamics; holm oak (voyant); light intensity; mediterranean plant-communities; Water availability

Constraints and trade-offs in Mediterranean plant communities: The case of holm oak-Aleppo pine forests - Zavala, M. A.; Espelta, J. M.; Retana, J. (The Botanical Review, 2000)
In this paper we review those aspects that are relevant to the development of a mechanistic ecological theory to account for the structure and dynamics of Mediterranean forests, focus- ing our attention on mixed forests of holm oak (Quercus ilex L.), a shade-tolerant, slow- growing species that resprouts vigorously after disturbance, and Aleppo pine (Pinus halepen- sis M.), a fast-growing, nonresprouting, shade-intolerant species. The main objectives of this report are: to introduce some of the primary features of these forests, showing their structural complexity and historical peculiarities; to show that much of this complexity can be concep- tually reduced to two main factors of variation, soil-moisture gradients and a complex inter- action of historical management and disturbance regimes; and to contrast the unique features of Mediterranean systems with other communities that have inspired generalization in ecol- ogy. Plants in Mediterranean-climate regions must face several environmental constraints dur- ing their life cycle: water limitation, competition for light, and a complex set of disturbance regimes, mainly fire, herbivory, and human exploitation. The response of co-occurring spe- cies to a given set of environmental constraints depends on a combination of physiological and morphological traits. In holm oak-Aleppo pine forests, the lower limit of distribution along a soil-moisture gradient appears to be controlled by dry-season water stress on seedling performance, and the upper limit seems to be controlled by shade tolerance relative to com- petitors. The processes that generate and maintain these patterns are related to the responses of the two species to the water and light environments that result from interacting gradients of disturbance and resource availability. The dynamics of mixed holm oak-Aleppo pine forests may be represented along two major environmental axes: water availability and light intensity; namely, time since last disturbance. At the regional scale, the presence of holm oak and Aleppo pine is expected to be driven mainly by the precipitation regime, with the proportion of Aleppo pine in- creasing toward the driest border and with holm oak being the dominant species in areas with higher precipitation. Changes of dominance of holm oak and Aleppo pine also re- spond to water availability at the local scale. In this case, variations between species de- pend on different factors in a complex way, because reduced soil-moisture levels may re- sult either from low precipitation or from topography and edaphic features. The dynamics of holm oak-Aleppo pine forests are also determined by temporal changes in canopy clo- sure; that is, forest recovery after disturbance. In this case, the proportion of Aleppo pine would increase in recently disturbed stands (i.e., with high light intensity reaching the for- est floor), whereas regeneration of holm oak would be dominant under partially closed canopies. Theories of forest dynamics developed in humid regions may apply only poorly to Medi- terranean plant communities, where vegetation change is qualitatively or quantitatively dif- ferent. Thus, succession in temperate forests appears to be driven by differences in light availability and shade tolerance; but in Mediterranean plant communities, water limitation is of greater importance for the distribution of forest species. In Mediterranean landscapes the interaction of life-history strategies with changing environments is difficult to infer from observational and experimental studies. A mechanistic approach, in which competi- tion or plant performance is measured as a function of resource availability, seems more feasible. The idea should be to develop multispeeies models calibrated specifically for Mediterranean forests in a combined program of modeling, field research, and experimenta- tion.
Keywords: Aleppo pine; disturbance regimes; forest dynamics; holm oak (voyant); light intensity; mediterranean plant-communities; Water availability

Contribution to the karyomorphology of some species of the genus Quercus - D'Emerico, S; Paciolla, C; Tommasi, F (SILVAE GENETICA, 2000)
In order to contribute to the knowledge of the taxonomic relationships between some species of the Quercus genus, the karyomorphology of 4 species (Quercus ilex L., Q, suber L., Q. robur L, and Q. pubescens WILLD.) was carried out. The somatic chromosome number 2n=24 was found in all taxa examined. An evident differentiation in karyotype structure of Q. ilex compared to other previous studied species has been found. Quercus suber, Q. robur and Q. pubescens possess moderately asymmetrical karyotypes. Q. suber differs from other species of the subgenus Cerris on the basis of karyological data showing similarities with Q, robur and Q. pubescens.
Keywords: B. pubescens; karyotype; Q. robur; Q. suber; Quercus ilex

Contribution to the karyomorphology of some species of the genus Quercus - D'Emerico, S.; Paciolla, C.; Tommasi, F. (SILVAE GENETICA, 2000)
In order to contribute to the knowledge of the taxonomic relationships between some species of the Quercus genus, the karyomorphology of 4 species (Quercus ilex L., Q, suber L., Q. robur L, and Q. pubescens WILLD.) was carried out. The somatic chromosome number 2n=24 was found in all taxa examined. An evident differentiation in karyotype structure of Q. ilex compared to other previous studied species has been found. Quercus suber, Q. robur and Q. pubescens possess moderately asymmetrical karyotypes. Q. suber differs from other species of the subgenus Cerris on the basis of karyological data showing similarities with Q, robur and Q. pubescens.
The following values have no corresponding Zotero field: pub-location: FINKENHOFSTRASSE 21, W-6000 FRANKFURT, GERMANY publisher: SAUERLANDERS VERLAG
Keywords: B. pubescens; karyotype; Q. robur; Q. suber; Quercus ilex

Cork - Gil, Luis; Moiteiro, Cristina (Ullmann's Encyclopedia of Industrial Chemistry, 2000)
The article contains sections titled: 1.Introduction1.1.Definition and Origin1.2.History1.3.Morphology1.3.1.Microscopic Aspects1.3.2.Macroscopic Aspects1.4.Chemical Composition1.4.1.Suberin1.4.2.Lignin1.4.3.Polysaccharides1.4.4.Waxes1.4.5.Tannins1.4.6.Other Components1.5.Physical and Mechanical Properties2.Cork Extraction3.Production of Cork Based Products3.1.Disks and Cork Stoppers3.2.Granulates and Broken3.3.Composition Cork3.3.1.Floor and Wall Coverings3.3.2.Agglomerated Disks and Cork Stoppers3.3.3.Corkrubber3.4.Insulation Corkboard3.5.Other Specific Products4.Uses4.1.Stoppers4.2.Civil Construction4.3.Industrial Applications4.4.Automotive Industry4.5.Other Specific Uses5.Quality and Standardization5.1.Standardization and Testing5.2.Quality in Cork Production6.Economic Aspects6.1.Forestall Production6.2.Personnel and Companies6.3.Consumption of Products and Markets6.4.Producers7.Environmental and Toxicological Aspects7.1.Industrial Wastes7.2.Recycling and Treatments7.3.Emissions8.Legal Aspects
Keywords: composition (voyant); Cork; insulation; products; stoppers

Cork - Gil, Luis; Moiteiro, Cristina (Ullmann's Encyclopedia of Industrial Chemistry, 2000)
The article contains sections titled: 1.Introduction1.1.Definition and Origin1.2.History1.3.Morphology1.3.1.Microscopic Aspects1.3.2.Macroscopic Aspects1.4.Chemical Composition1.4.1.Suberin1.4.2.Lignin1.4.3.Polysaccharides1.4.4.Waxes1.4.5.Tannins1.4.6.Other Components1.5.Physical and Mechanical Properties2.Cork Extraction3.Production of Cork Based Products3.1.Disks and Cork Stoppers3.2.Granulates and Broken3.3.Composition Cork3.3.1.Floor and Wall Coverings3.3.2.Agglomerated Disks and Cork Stoppers3.3.3.Corkrubber3.4.Insulation Corkboard3.5.Other Specific Products4.Uses4.1.Stoppers4.2.Civil Construction4.3.Industrial Applications4.4.Automotive Industry4.5.Other Specific Uses5.Quality and Standardization5.1.Standardization and Testing5.2.Quality in Cork Production6.Economic Aspects6.1.Forestall Production6.2.Personnel and Companies6.3.Consumption of Products and Markets6.4.Producers7.Environmental and Toxicological Aspects7.1.Industrial Wastes7.2.Recycling and Treatments7.3.Emissions8.Legal Aspects
The following values have no corresponding Zotero field: periodical: Ullmann's Encyclopedia of Industrial Chemistry electronic-resource-num: 10.1002/14356007.f07_f01
Keywords: composition (voyant); Cork; insulation; products; stoppers

Cork suberin as an additive in offset lithographic printing inks - Cordeiro, N; Blayo, A; Belgacem, N M; Gandini, A; Pascoal Neto, C; LeNest, J.-F (Industrial Crops and Products, 2000)
Suberin oligomers, isolated from cork (Quercus suber L.), were used as additives in ‘Waterless’ and vegetable-oil ink formulations, in the range of 2–10% w:w. The rheological behaviour of the suberin oligomers as well as of the inks, with and without suberin, were investigated as a function of temperature. It was shown that the addition of suberin induces a decrease of viscosity of both inks. The tack of pristine inks, suberin oligomers and their mixtures were determined at different temperatures: the variation of this parameter as a function of time provided information about the drying kinetics of these formulations. The tack of the ‘Waterless’ ink was found to increase with the introduction of suberin, whereas that of vegetable-oil based counterparts decreased. All the trends observed were interpreted in terms of the differences in composition between the two types of inks. Preliminary printing tests were carried out with the various suberin-containing inks
Keywords: Additive; Quercus suber L.; rheological properties; suberin; Tack; Vegetable oil-based ink; Viscosity; Waterless ink

Cork suberin as an additive in offset lithographic printing inks - Cordeiro, N.; Blayo, A.; Belgacem, N. M.; Gandini, A.; Pascoal Neto, C.; LeNest, J.-F. (Industrial Crops and Products, 2000)
Suberin oligomers, isolated from cork (Quercus suber L.), were used as additives in ‘Waterless’ and vegetable-oil ink formulations, in the range of 2–10% w:w. The rheological behaviour of the suberin oligomers as well as of the inks, with and without suberin, were investigated as a function of temperature. It was shown that the addition of suberin induces a decrease of viscosity of both inks. The tack of pristine inks, suberin oligomers and their mixtures were determined at different temperatures: the variation of this parameter as a function of time provided information about the drying kinetics of these formulations. The tack of the ‘Waterless’ ink was found to increase with the introduction of suberin, whereas that of vegetable-oil based counterparts decreased. All the trends observed were interpreted in terms of the differences in composition between the two types of inks. Preliminary printing tests were carried out with the various suberin-containing inks
Keywords: Additive; Quercus suber L.; rheological properties; suberin; Tack; Vegetable oil-based ink; Viscosity; Waterless ink

Crystallization and preliminary x-ray diffraction analysis of beta-cinnamomin, an elicitin secreted by the phytopathogenic fungus Phytophthora cinnamomin. - Archer, M; RODRIGUES, M L; Aurélio, M; Biemans, R; Cravador, A; Carrondo, M a (Acta crystallographica. Section D, Biological crystallography, 2000)
Cinnamomin (CIN) belongs to a family of 10 kDa proteins designated as elicitins. Some of these proteins induce a hypersensitive response in diverse plant species, leading to resistance against fungal and bacterial plant pathogens. CIN was crystallized by the vapour-diffusion method using either ammonium sulfate or polyethyleneglycol (PEG) as precipitants in solutions buffered at around pH 7. These crystals are isomorphous and belong to the triclinic space group, with unit-cell parameters a = 31.69, b = 36. 99, c = 44.09 A, alpha = 76.86, beta = 84.41, gamma = 80.26 degrees. A frozen crystal diffracted X-rays beyond 1.45 A resolution on a synchrotron-radiation source.
Keywords: Beta-cinnamomin; Elicitins; Phytopathogenic fungi

Crystallization and preliminary x-ray diffraction analysis of beta-cinnamomin, an elicitin secreted by the phytopathogenic fungus Phytophthora cinnamomin. - Archer, M.; Rodrigues, M. L.; Aurélio, M.; Biemans, R.; Cravador, A.; Carrondo, M. a (Acta crystallographica. Section D, Biological crystallography, 2000)
Cinnamomin (CIN) belongs to a family of 10 kDa proteins designated as elicitins. Some of these proteins induce a hypersensitive response in diverse plant species, leading to resistance against fungal and bacterial plant pathogens. CIN was crystallized by the vapour-diffusion method using either ammonium sulfate or polyethyleneglycol (PEG) as precipitants in solutions buffered at around pH 7. These crystals are isomorphous and belong to the triclinic space group, with unit-cell parameters a = 31.69, b = 36. 99, c = 44.09 A, alpha = 76.86, beta = 84.41, gamma = 80.26 degrees. A frozen crystal diffracted X-rays beyond 1.45 A resolution on a synchrotron-radiation source.
The following values have no corresponding Zotero field: accession-num: 10713528
Keywords: Beta-cinnamomin; Elicitins; Phytopathogenic fungi

Effect of polyethylene glycol on in vitro degradability of nitrogen and microbial protein synthesis from tannin-rich browse and herbaceous legumes - Getachew, G.; Makkar, H. P. S.; Becker, K. (BRITISH JOURNAL OF NUTRITION, 2000)
Determination of microbial degradability of N is important in formulating a sound supplementation strategy for efficient utilisation of basal as well as supplementary diet components. In vitro degradability of N (IVDN) from tannin-containing browses (Acacia cyanophylla, Acacia albida, Acioa barteri and Quercus ilex) and two herbaceous legumes (Desmodium intortum andDesmodium uncinatum) was determined using the in vitro gas-production method coupled with NH3-N measurement in the presence and absence of a tannin-binding agent (polyethylene glycol (PEG), molecular mass 6000). Addition of PEG to tannin-containing feeds significantly (P < 0.05) increased in vitro gas and short-chain fatty acid (SCFA) production, and IVDN. The use of PEG as a tannin-binding agent increased IVDN from 28 to 59, 32 to 72, 19 to 40, 32 to 73, 40 to 80, and 26 to 77 % in A. cyanophylla, A. albida, A. barteri, D. intortum, D. uncinatum and Q. ilexrespectively. There was significant correlation between total phenolic compounds (total phenol, TP; total tannin, TT) in leguminous forages and percentage increase in IVDN on addition of PEG (P < 0.05; R-2 0.70 and 0.82 for TP and TT respectively). The difference in IVDN observed in the absence and presence of PEG indicates the amount of protein protected from degradation in the rumen by tannins. When measured after 24 h incubation, tannin-containing feeds incubated in absence of PEG resulted in higher microbial protein synthesis than in the presence of PEG. Addition of PEG significantly (P < 0.05) reduced the efficiency of microbial protein synthesis expressed as mu mol purine/mmol SCFA.
The following values have no corresponding Zotero field: pub-location: C/O PUBLISHING DIVISION, WALLINGFORD OX10 8DE, OXON, ENGLAND publisher: C A B INTERNATIONAL
Keywords: microbial protein synthesis; Polyethylene glycol; protein degradability; Tannins

Effect of polyethylene glycol on in vitro degradability of nitrogen and microbial protein synthesis from tannin-rich browse and herbaceous legumes - Getachew, G; Makkar, H P S; Becker, K (BRITISH JOURNAL OF NUTRITION, 2000)
Determination of microbial degradability of N is important in formulating a sound supplementation strategy for efficient utilisation of basal as well as supplementary diet components. In vitro degradability of N (IVDN) from tannin-containing browses (Acacia cyanophylla, Acacia albida, Acioa barteri and Quercus ilex) and two herbaceous legumes (Desmodium intortum andDesmodium uncinatum) was determined using the in vitro gas-production method coupled with NH3-N measurement in the presence and absence of a tannin-binding agent (polyethylene glycol (PEG), molecular mass 6000). Addition of PEG to tannin-containing feeds significantly (P < 0.05) increased in vitro gas and short-chain fatty acid (SCFA) production, and IVDN. The use of PEG as a tannin-binding agent increased IVDN from 28 to 59, 32 to 72, 19 to 40, 32 to 73, 40 to 80, and 26 to 77 % in A. cyanophylla, A. albida, A. barteri, D. intortum, D. uncinatum and Q. ilexrespectively. There was significant correlation between total phenolic compounds (total phenol, TP; total tannin, TT) in leguminous forages and percentage increase in IVDN on addition of PEG (P < 0.05; R-2 0.70 and 0.82 for TP and TT respectively). The difference in IVDN observed in the absence and presence of PEG indicates the amount of protein protected from degradation in the rumen by tannins. When measured after 24 h incubation, tannin-containing feeds incubated in absence of PEG resulted in higher microbial protein synthesis than in the presence of PEG. Addition of PEG significantly (P < 0.05) reduced the efficiency of microbial protein synthesis expressed as mu mol purine/mmol SCFA.
Keywords: microbial protein synthesis; Polyethylene glycol; protein degradability; Tannins

Effects of environmental stress on forest crown condition in Europe. Part II: Estimation of stress induced by meteorology and air pollutants - Leeuwen, E. P. Van; Hendriks, KCMA (Water, Air, & Soil Pollution, 2000)
In order to assess the relationship between environmental stress and crown condition of forest trees monitored since 1986 in Europe, estimates of stress factors, including temperature stress, drought stress and air pollution stress, were derived with the best data, methods and models currently available. This paper presents information on the methods used to derive such stress factors, and on the overall ranges, the temporal trends, the spatial distribution and the reliability of the calculated stress factors. The temperature stress indices did not show much temporal variation between 1985 to 1995. As expected spatial patterns were north-south orientated, going from colder northern regions to warmer southern regions. The calculated relative transpiration showed a more complex pattern, coinciding to a large extend with patterns of rainfall and temperature. Potential acid deposition decreased between 1986 and 1992, but remained fairly constant after 1992. The strong decrease was mainly the result of the decrease in SOx deposition, and to a small decrease in NOy deposition. Highest levels of the S and N deposition were calculated in Central and Western Europe. Base cation deposition was largest in coastal areas and in southern Europe. This is mainly due to soil dust, Sahara dust and sea salt. Base cation deposition can compensate almost entirely for the potential inputs in the south of Europe, whereas in central Europe it equalled about 25% of the potential acid input. A comparison between site speciﬁc modelled deposition and deposition derived from throughfall data showed that the total acid deposition is usually overestimated by the model, whereas the total nitrogen deposition is underestimated, especially at plots with high nitrogen loads. There is, however, a signiﬁcant correlation between measured and modelled data for all S and N deposition, thus allowing their use in a statistical analyses.
Keywords: acidity; air pollution; ammonia; atmospheric deposition; Base cations; deposition model; Drought; nitrogen oxides; Ozone; sulphur; temperature stress; water balance

Effects of environmental stress on forest crown condition in Europe. Part IV: statistical analysis of relationships - Klap, J M; Voshaar, J H Oude (Water, Air, & Soil …, 2000)
Site-speciﬁc estimates for various environmental stress factors were related with measured crown condition data at a systematic 16 16 km2 grid over Europe, according to previously stated hypotheses, using a multiple regression approach, including interactions, and lagged effects of stress factors. Methodological differences among countries accounted for >30% of the variation in defoliation. Nevertheless, crown condition was found to vary naturally with tree age, altitude, drought stress and, most likely, also pathogenic fungi and insects. Signiﬁcant impacts of air pollution (speciﬁcally ozone but also NOx , SOx and acid deposition) were found at regional levels in parts of central Europe, particularly for deciduous species. Impacts seemed less signiﬁcant for conifers, especially for spruce, but this might be affected by confounding effects or strong correlations between (a harsh) climate and (low) atmospheric deposition in the area where spruce predominates. National studies indicate that ozone and acid deposition can have a signiﬁcant effect on the defoliation of spruce as well. We conclude that while forest condition varies naturally, continued emissions will contribute further to forest decline in the long term.
Keywords: acid deposition; air pollution; correlative study; critical load; defoliation; Fagus sylvatica; forest vitality; meteorological stress; picea abies; Pinus sylvestris; Quercus ilex; Quercus petraea; Quercus robur

Egg-size variation in Algerian populations of the Blue Tit (Parus caeruleus ultramarinus): Effects of altitude and habitat - Chabi, Y; Benyacoub, S; Banbura, J (REVUE D ECOLOGIE-LA TERRE ET LA VIE, 2000)
Egg-size, as a component of life history, is expected to be traded-off with other components and, consequently, to display a pattern of variation between different habitats and altitudes. Relevant data being very scarcely available for just a few bird species caused us to study interhabitat and interaltitude variation in egg dimensions and mass in the Blue Tit Parus caeruleus ultramarinus, taking the advantage of the occurrence of this species in a variety of habitats and at different altitudes in North Africa (north-eastern Algeria). In 1991-1993 we selected 6 study sites representing two types of habitat (rich deciduous forests dominated by Alnus glutinosa and Quercus faginea vs poor evergreen forests of Quercus suber) at three elevations (30 m asl, 500 m als and 900-1 000 m asl). We analysed both multiple response variables characterizing egg dimensions and individual egg traits. Eggs turned out to differ between altitudes (the lowest elevation against the two higher ones) but did not differ between habitats. They also display relatively high within-clutch repeatabilities, 0.6 on average for all traits. Egg traits were not significantly correlated with clutch-size within study stations, but the analysis of a bivariate response variable composed of egg volume and clutch-size suggested that these components of life history were negatively linked. Moreover, this bivariate response variable differed both between habitats and altitudes.
Keywords: birds; calcium; egg sizes; habitat contrast; shelled snails; tits

Ericoid mycorrhizal fungi are common root associates of a Mediterranean ectomycorrhizal plant (Quercus ilex) - Bergero, R; Perotto, S; Girlanda, M; Vidano, G; Luppi, a M (Molecular Ecology, 2000)
Mycorrhiza samples of neighbouring Quercus ilex and Erica arborea plants collected in a postcutting habitat were processed to see whether plants differing in mycorrhizal status harbour the same root endophytes. Three experiments were performed in parallel: (i) isolation, identification and molecular characterization of fungi from surface-sterilized roots of both plant species; (ii) re-inoculation of fungal isolates on axenic E. arborea and Q. ilex seedlings; (iii) direct inoculation of field-collected Q. ilex ectomycorrhizas onto E. arborea seedlings. About 70 and 150 fungal isolates were obtained from roots of Q. ilex and E. arborea, respectively. Among them, Oidiodendron species and five cultural morphotypes of sterile isolates formed typical ericoid mycorrhizas on E. arborea in vitro. Fungi with such mycorrhizal ability were derived from both host plants. Isolates belonging to one of these morphotypes (sd9) also exhibited an unusual pattern of colonization, with an additional extracellular hyphal net. Ericoid mycorrhizas were also readily obtained by direct inoculation of E. arborea seedlings with Q. ilex ectomycorrhizal tips. Polymerase chain–restriction fragment length polymorphism and random amplified polymorphic DNA analyses of the shared sterile morphotypes demonstrate, in the case of sd9, the occurrence of the same genet on the two host plants. These results indicate that ericoid mycorrhizal fungi associate with ectomycorrhizal roots, and the ecological significance of this finding is discussed.
Keywords: DNA; ectomycorrhizas; Erica arborea; ericoid fungi; fungi; Fungi: genetics; Fungi: isolation & purification; Fungi: physiology; Genetic; Mediterranean ecosystem; Mediterranean Region; Molecular Sequence Data; Plant Diseases; Plant Diseases: microbiology; Plant Roots; Plant Roots: microbiology; Polymorphism; Quercus ilex; Restriction Fragment Length; Ribosomal Spacer; Trees; Trees: microbiology

Ericoid mycorrhizal fungi are common root associates of a Mediterranean ectomycorrhizal plant (Quercus ilex) - Bergero, R.; Perotto, S.; Girlanda, M.; Vidano, G.; Luppi, a M. (Molecular Ecology, 2000)
Mycorrhiza samples of neighbouring Quercus ilex and Erica arborea plants collected in a postcutting habitat were processed to see whether plants differing in mycorrhizal status harbour the same root endophytes. Three experiments were performed in parallel: (i) isolation, identification and molecular characterization of fungi from surface-sterilized roots of both plant species; (ii) re-inoculation of fungal isolates on axenic E. arborea and Q. ilex seedlings; (iii) direct inoculation of field-collected Q. ilex ectomycorrhizas onto E. arborea seedlings. About 70 and 150 fungal isolates were obtained from roots of Q. ilex and E. arborea, respectively. Among them, Oidiodendron species and five cultural morphotypes of sterile isolates formed typical ericoid mycorrhizas on E. arborea in vitro. Fungi with such mycorrhizal ability were derived from both host plants. Isolates belonging to one of these morphotypes (sd9) also exhibited an unusual pattern of colonization, with an additional extracellular hyphal net. Ericoid mycorrhizas were also readily obtained by direct inoculation of E. arborea seedlings with Q. ilex ectomycorrhizal tips. Polymerase chain–restriction fragment length polymorphism and random amplified polymorphic DNA analyses of the shared sterile morphotypes demonstrate, in the case of sd9, the occurrence of the same genet on the two host plants. These results indicate that ericoid mycorrhizal fungi associate with ectomycorrhizal roots, and the ecological significance of this finding is discussed.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd accession-num: 11050558
Keywords: DNA; ectomycorrhizas; Erica arborea; ericoid fungi; fungi; Fungi: genetics; Fungi: isolation & purification; Fungi: physiology; Genetic; Mediterranean ecosystem; Mediterranean Region; Molecular Sequence Data; Plant Diseases; Plant Diseases: microbiology; Plant Roots; Plant Roots: microbiology; Polymorphism; Quercus ilex; Restriction Fragment Length; Ribosomal Spacer; Trees; Trees: microbiology

Estimating species-based community integrity under global warming, with special reference to the western Mediterranean region - Box, E O; Choi, J N (PHYTOCOENOLOGIA, 2000)
Climate-based estimates of the fitness of the main structural elements of several western Mediterranean plant communities were used to estimate potential community integrity and its consequent vulnerability under a global-change scenario involving warming but no net drying. Results for a simple Quercus ilex community suggest expansion northward and inland under warming but with significant loss of area currently covered by the community. The data for estimating such changes in potential community integrity and areal coverage can be readily obtained from climatic envelope models. Mapping can be done by interpolation or by pixel-based GIS methods.
Keywords: climatic envelope; community integrity; global war

Estimating species-based community integrity under global warming, with special reference to the western Mediterranean region - Box, E. O.; Choi, J. N. (PHYTOCOENOLOGIA, 2000)
Climate-based estimates of the fitness of the main structural elementsof several western Mediterranean plant communities were used to estimate potential community integrity and its consequent vulnerability under a global-change scenario involving warming but no net drying. Results for a simple Quercus ilex community suggest expansion northward and inland under warming but with significant loss of area currently covered by the community. The data for estimating such changes in potential community integrity and areal coverage can be readily obtained from climatic envelope models. Mapping can be done by interpolation or by pixel-based GIS methods.
The following values have no corresponding Zotero field: pub-location: JOHANNESSTR 3A, D-70176 STUTTGART, GERMANY publisher: GEBRUDER BORNTRAEGER
Keywords: climatic envelope; community integrity; global war

Factors affecting the distribution of Red-legged Partridges Alectoris rufa in an agricultural landscape of southern Portugal - Borralho, R; Stoate, C; Araújo, M (Bird Study, 2000)
The main factors affecting the spring distribution of Red-legged Partridges Alectoris rufa were evaluated in a 1550-km2 landscape of southern Portugal, where different arable systems and hunting regimes were implemented. Partridge surveys were performed in April 1995 along 90, 250-m transects. Partridge locations and a number of environmental variables were incorporated and manipulated in a vector-based GIS. A multivariate logistic model of partridge detection was fitted using forward stepwise selection, and was validated using a jack-knife approach. The probability of detecting Red-legged Partridges within the landscape was positively affected by game management, structural diversity of cover, proportion of olive tree groves and wheat fields along the transects. Conservation implications of the results and research priorities are discussed.
doi: 10.1080/00063650009461190
Keywords: agricultural landscape; distribution (voyant); game management; Red-legged partridge

Factors affecting the distribution of Red-legged Partridges Alectoris rufa in an agricultural landscape of southern Portugal - Borralho, R.; Stoate, C.; Araújo, M. (Bird Study, 2000)
The main factors affecting the spring distribution of Red-legged Partridges Alectoris rufa were evaluated in a 1550-km2 landscape of southern Portugal, where different arable systems and hunting regimes were implemented. Partridge surveys were performed in April 1995 along 90, 250-m transects. Partridge locations and a number of environmental variables were incorporated and manipulated in a vector-based GIS. A multivariate logistic model of partridge detection was fitted using forward stepwise selection, and was validated using a jack-knife approach. The probability of detecting Red-legged Partridges within the landscape was positively affected by game management, structural diversity of cover, proportion of olive tree groves and wheat fields along the transects. Conservation implications of the results and research priorities are discussed.
doi: 10.1080/00063650009461190doi: 10.1080/00063650009461190The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: agricultural landscape; distribution (voyant); game management; Red-legged partridge

Floristic relationship between scrubland and grassland patches in the Mediterranean landscape of the Iberian Peninsula - Ramirez-Sanz, L; Casado, M A; Miguel, J M De (Plant Ecology, 2000)
In the rural Mediterranean landscape, mosaics of patches of sclerophyllous scrubland and semi-natural grasslands are frequent. The plant communities of these patches, which are physiognomically easy to recognise, are very heterogeneous. The objective of this paper is to determine whether the patches of scrub-grassland represent an integrated response unit of the vegetation with regard to the physical environment (climatic, geographical and edaphic factors) and human use, or whether, on the contrary, this is an independent response. In order to do this a total of 50 sampling sites where scrubland and grassland patches were in contact were studied along a 370 km E-W mesoclimatic gradient from central Spain to Portugal (Iberian Peninsula). Two distinct zones, the east and the west halves of the study area, were identiﬁed according to the plant communities. Within each of these zones, each type of patch responded to the previously mentioned factors, differentially and independently. This determined a general lack of inter-community association or ﬂoristic correlation between scrub and grassland plant communities in contact. The spatial association is a random process probably related to the particular human management realised on every scrubland and grassland patch. The scrub–grassland pattern, which is characteristic of the Mediterranean landscape, does not represent an integrated response unit of the vegetation to a given environment, but rather the sum of the independent responses to the environment of the two patches in contact.
Keywords: environmental gradient; inter-community association; mediterranean scrubland; rural landscape; spatial association; therophyte grasslands

Floristic relationship between scrubland and grassland patches in the Mediterranean landscape of the Iberian Peninsula - Ramirez-Sanz, L.; Casado, M. A.; Miguel, J. M. De (Plant Ecology, 2000)
In the rural Mediterranean landscape, mosaics of patches of sclerophyllous scrubland and semi-natural grasslands are frequent. The plant communities of these patches, which are physiognomically easy to recognise, are very heterogeneous. The objective of this paper is to determine whether the patches of scrub-grassland represent an integrated response unit of the vegetation with regard to the physical environment (climatic, geographical and edaphic factors) and human use, or whether, on the contrary, this is an independent response. In order to do this a total of 50 sampling sites where scrubland and grassland patches were in contact were studied along a 370 km E-W mesoclimatic gradient from central Spain to Portugal (Iberian Peninsula). Two distinct zones, the east and the west halves of the study area, were identiﬁed according to the plant communities. Within each of these zones, each type of patch responded to the previously mentioned factors, differentially and independently. This determined a general lack of inter-community association or ﬂoristic correlation between scrub and grassland plant communities in contact. The spatial association is a random process probably related to the particular human management realised on every scrubland and grassland patch. The scrub–grassland pattern, which is characteristic of the Mediterranean landscape, does not represent an integrated response unit of the vegetation to a given environment, but rather the sum of the independent responses to the environment of the two patches in contact.
Keywords: environmental gradient; inter-community association; mediterranean scrubland; rural landscape; spatial association; therophyte grasslands

Forests of the Mediterranean region: gaps in knowledge and research needs - Scarascia-Mugnozza, Giseppe; Oswald, Helfried; Piussi, Pietro; Radoglou, Kalliopi (Forest Ecology and Management, 2000)
Mediterranean forests are characterised by a remarkable set of features that make them naturally and aesthetically attractive, on the one hand, but also quite fragile, on the other, therefore calling for careful strategies for their conservation and management. An exceptionally large variation of environmental conditions characterises the Mediterranean countries, where the environment can limit forest growth and succession but can also give rise, more often than it is supposed, to lush, mesic forest ecosystems, similar to those of central Europe. Moreover, Mediterranean forests contain an ample, plant and animal biological diversity, exempli®ed by the large number of tree species as compared to Nordic forests, and by their relatively high genetic variability due to the survival of many conifer and broadleaf species in southern European refuges, during the glacial periods. Another peculiar aspect of this region is the long-lasting manipulation of trees, forests and landscapes, since ancient times, with the diffusion all over the Mediterranean basin of such species as Pinus pinea, Cupressus sempervirens, Castanea sativa, and Quercus suber. The harsh and unpredictable climate, the dif®cult socio-economic conditions and the history of over-exploitation of the Mediterranean forests require that a scienti®cally sound conservation strategy and a locally-tailored sustainable management should be implemented. In particular, the need for identifying those silvicultural and management strategies appropriate for southern European forests should be stressed. Obviously, this consideration will have important effects on the de®nition of criteria for sustainability and eco-certi®cation. Also, social issues should be considered key factors for effective forest conservation in the Mediterranean region, otherwise it will be impossible to control forest ®res and landscape degradation. Based on these considerations a number of research priorities are discussed, with special consideration to possible impacts that global change may have on Mediterranean forest ecosystems.
Keywords: Biodiversity; forest ecosystems; Mediterranean Region; silviculture; sustainable management

Forests of the Mediterranean region: gaps in knowledge and research needs - Scarascia-Mugnozza, Giseppe; Oswald, Helfried; Piussi, Pietro; Radoglou, Kalliopi (Forest Ecology and Management, 2000)
Mediterranean forests are characterised by a remarkable set of features that make them naturally and aesthetically attractive, on the one hand, but also quite fragile, on the other, therefore calling for careful strategies for their conservation and management. An exceptionally large variation of environmental conditions characterises the Mediterranean countries, where the environment can limit forest growth and succession but can also give rise, more often than it is supposed, to lush, mesic forest ecosystems, similar to those of central Europe. Moreover, Mediterranean forests contain an ample, plant and animal biological diversity, exempli®ed by the large number of tree species as compared to Nordic forests, and by their relatively high genetic variability due to the survival of many conifer and broadleaf species in southern European refuges, during the glacial periods. Another peculiar aspect of this region is the long-lasting manipulation of trees, forests and landscapes, since ancient times, with the diffusion all over the Mediterranean basin of such species as Pinus pinea, Cupressus sempervirens, Castanea sativa, and Quercus suber. The harsh and unpredictable climate, the dif®cult socio-economic conditions and the history of over-exploitation of the Mediterranean forests require that a scienti®cally sound conservation strategy and a locally-tailored sustainable management should be implemented. In particular, the need for identifying those silvicultural and management strategies appropriate for southern European forests should be stressed. Obviously, this consideration will have important effects on the de®nition of criteria for sustainability and eco-certi®cation. Also, social issues should be considered key factors for effective forest conservation in the Mediterranean region, otherwise it will be impossible to control forest ®res and landscape degradation. Based on these considerations a number of research priorities are discussed, with special consideration to possible impacts that global change may have on Mediterranean forest ecosystems.
Keywords: Biodiversity; forest ecosystems; Mediterranean Region; silviculture; sustainable management

Fumigation with exogenous monoterpenes of a non-isoprenoid-emitting oak (Quercus suber): monoterpene acquisition, translocation, and effect on the photosynthetic properties at high temperatures - Delfine, Sebastiano; Csiky, Olav; Seufert, Guenther; Loreto, Francesco (New Phytologist, 2000)
We tested if fumigation with exogenous monoterpenes might induce thermotolerance in leaves of an oak species (Quercus suber) which does not form and emit isoprenoids. To understand if exogenous monoterpene fumigation results in internal accumulation of monoterpenes, a physical method of monoterpene extraction was used. The internal content of monoterpenes increased in concert with increasing fumigation doses. This unambiguously demonstrated acquisition of exogenous monoterpenes. We exposed fumigated Q. suber leaves to two cycles of increasing temperatures from 35 to 55°C at 5°C steps. When leaves were exposed to a low dose of exogenous monoterpenes, yielding an internal content similar to that endogenously formed in the leaves of the monoterpene- emitter Q. ilex, no clear improvement in thermotolerance was found. When leaves were exposed to a high dose of exogenous monoterpenes, yielding an internal content of about ®ve fold the endogenous pool of Q. ilex, but comparable with the expected content following stress-induced stomatal closure, photosynthesis inhibition at high temperatures was attenuated. This eﬀect was observed only at temperatures !45°C during the ®rst cycle, but at all temperatures between 35 and 55°C when plants were exposed to two cycles of high temperatures. Monoterpenes were still found in the leaves of Q. suber 12 h after ending the fumigation. Monoterpenes were also found in non-fumigated leaves distant up to 45 cm from the fumigated leaves. If monoterpenes make the photosynthetic apparatus more resistant to high temperatures, the eﬀect might not be limited to the fumigated leaves and might be persistent after fumigation.
Keywords: isoprenoid emission; Monoterpenes; photosynthesis; Quercus suber; thermotolerance

Fumigation with exogenous monoterpenes of a non-isoprenoid-emitting oak (Quercus suber): monoterpene acquisition, translocation, and effect on the photosynthetic properties at high temperatures - Delfine, Sebastiano; Csiky, Olav; Seufert, Guenther; Loreto, Francesco (New Phytologist, 2000)
We tested if fumigation with exogenous monoterpenes might induce thermotolerance in leaves of an oak species (Quercus suber) which does not form and emit isoprenoids. To understand if exogenous monoterpene fumigation results in internal accumulation of monoterpenes, a physical method of monoterpene extraction was used. The internal content of monoterpenes increased in concert with increasing fumigation doses. This unambiguously demonstrated acquisition of exogenous monoterpenes. We exposed fumigated Q. suber leaves to two cycles of increasing temperatures from 35 to 55°C at 5°C steps. When leaves were exposed to a low dose of exogenous monoterpenes, yielding an internal content similar to that endogenously formed in the leaves of the monoterpene- emitter Q. ilex, no clear improvement in thermotolerance was found. When leaves were exposed to a high dose of exogenous monoterpenes, yielding an internal content of about ®ve fold the endogenous pool of Q. ilex, but comparable with the expected content following stress-induced stomatal closure, photosynthesis inhibition at high temperatures was attenuated. This eﬀect was observed only at temperatures !45°C during the ®rst cycle, but at all temperatures between 35 and 55°C when plants were exposed to two cycles of high temperatures. Monoterpenes were still found in the leaves of Q. suber 12 h after ending the fumigation. Monoterpenes were also found in non-fumigated leaves distant up to 45 cm from the fumigated leaves. If monoterpenes make the photosynthetic apparatus more resistant to high temperatures, the eﬀect might not be limited to the fumigated leaves and might be persistent after fumigation.
Keywords: isoprenoid emission; Monoterpenes; photosynthesis; Quercus suber; thermotolerance

Grazing alone is not enough to maintain landscape diversity in the Montseny Biosphere Reserve - Bartolomé, J; Franch, J (Agriculture, Ecosystems & Environment, 2000)
Conservative land-use over the past few decades has converted the Montseny Biosphere Reserve (Spain) from the original open, patchy landscape to almost continuous woodland. Small ruminant grazing is virtually the only major remaining utilisation activity yet little is known about its role in the changing vegetation of the Reserve. This study was undertaken to determine the effects of current grazing practice on its main vegetation components. Three ﬂocks, composed of sheep and goats, that graze yearlong on three separate ranges in the Reserve were selected for study. The ranges represent the wooded slopes and the shrubby upland (altiplano) in the area. Biomass consumption by the ﬂocks was estimated by calculation of normative requirements for observed production and the botanical composition of the livestock diets over a whole annual cycle was determined by micro-histological analysis of the faeces. Production of herbaceous vegetation was determined by clipping sample quadrats, the production of the woody vegetation was derived from previous work in the Reserve. It was found that grazing removed a very small proportion of the dominant Holm oak (Quercus ilex) on the slopes, and a moderate fraction of the shrubby and herbaceous vegetation on the altiplano. Only the heath tree (Erica arborea), an edible shrub in the woodlands, was relatively heavily grazed. It is concluded that grazing alone is not enough to maintain the open, diverse landscape with its many natural values. As in other northern Mediterranean countries, under-utilisation of these woodlands is becoming a serious problem that is also increasing the ﬁre hazard. Maintaining landscape diversity in the region is a complex challenge that land managers should recognise
Keywords: calluna vulgaris; Erica arborea; mediterranean rangeland; Quercus ilex; small ruminants

Grazing alone is not enough to maintain landscape diversity in the Montseny Biosphere Reserve - Bartolomé, J.; Franch, J. (Agriculture, Ecosystems & Environment, 2000)
Conservative land-use over the past few decades has converted the Montseny Biosphere Reserve (Spain) from the original open, patchy landscape to almost continuous woodland. Small ruminant grazing is virtually the only major remaining utilisation activity yet little is known about its role in the changing vegetation of the Reserve. This study was undertaken to determine the effects of current grazing practice on its main vegetation components. Three ﬂocks, composed of sheep and goats, that graze yearlong on three separate ranges in the Reserve were selected for study. The ranges represent the wooded slopes and the shrubby upland (altiplano) in the area. Biomass consumption by the ﬂocks was estimated by calculation of normative requirements for observed production and the botanical composition of the livestock diets over a whole annual cycle was determined by micro-histological analysis of the faeces. Production of herbaceous vegetation was determined by clipping sample quadrats, the production of the woody vegetation was derived from previous work in the Reserve. It was found that grazing removed a very small proportion of the dominant Holm oak (Quercus ilex) on the slopes, and a moderate fraction of the shrubby and herbaceous vegetation on the altiplano. Only the heath tree (Erica arborea), an edible shrub in the woodlands, was relatively heavily grazed. It is concluded that grazing alone is not enough to maintain the open, diverse landscape with its many natural values. As in other northern Mediterranean countries, under-utilisation of these woodlands is becoming a serious problem that is also increasing the ﬁre hazard. Maintaining landscape diversity in the region is a complex challenge that land managers should recognise
Keywords: calluna vulgaris; Erica arborea; mediterranean rangeland; Quercus ilex; small ruminants

Haploid origin of cork oak anther embryos detected by enzyme and RAPD gene markers. - Bueno, M A; Agundez, M D (International Journal of Plant Sciences, 2000)
Examines the haploid origin of cork oak anther embryos using enzyme and RAPD gene marker analysis. Exploration of the gene coding of shikimate dehydrogenase; Factor influencing the non-identification of another genotypes by isozyme analysis; Implication of detected banding patterns for the existence of multiple microspore origins.
Keywords: Cork oak; Haploid; Quercus suber; RAPD markers

Haploid origin of cork oak anther embryos detected by enzyme and RAPD gene markers. - Bueno, M. A.; Agundez, M. D. (International Journal of Plant Sciences, 2000)
Examines the haploid origin of cork oak anther embryos using enzyme and RAPD gene marker analysis. Exploration of the gene coding of shikimate dehydrogenase; Factor influencing the non-identification of another genotypes by isozyme analysis; Implication of detected banding patterns for the existence of multiple microspore origins.
Keywords: Cork oak; Haploid; Quercus suber; RAPD markers

Herbivore dunging and endozoochorous seed deposition in a Mediterranean dehesa - Malo, J. E.; Jimenez, B.; Suarez, F. (JOURNAL OF RANGE MANAGEMENT, 2000)
Spatial patterns of herbivore defecation within grazing systems are important as they directly affect pasture growth and composition. These effects are partially linked to seed dispersal in dung, a little studied process. This paper focuses on: (1) quantification of dung and seeds deposited by herbivores in a Mediterranean grazing system, and (ii) analysis of the spatial variability of dung and seeds deposited within and among plant communities. We carried out year-long monthly quantifications of the depositions of rabbit (Oryctolagus cuniculus), fallow deer (Dama dama), red deer (Cervus elaphus), and cow (Bos taurus) dung to 32 plots distributed in Quercus rotundifolia Lam. and Fraxinus angustifolia Vahl woodlands, mixed scrub, and Cistus ladanifer L. scrub. We also quantified the germinable seed content of dung. The results revealed differences (p < 0.05) in dung deposition, varying (i) among the 4 species, (ii) within species (except for the red deer) among plant communities, and (iii) within plant communities. An average of 735 seeds/m(2) were returned to the soil via dung, with the highest numbers in open woodlands (870-1,888 seeds/m(2)) and the lowest numbers in scrubs (83-315 seeds/m(2)). Cows dispersed the most seeds (68%), followed by red deer (20%), rabbits (7%), and fallow deer (5%). Spatial variability in deposition led to accumulations of up to several thousand seeds at points covered by the dung. The effect of seed input to the seed bank and on vegetation may be low at large and medium-sized spatial scales, but it can be very important at small scales and for colonization processes.
The following values have no corresponding Zotero field: pub-location: 445 UNION BLVD, STE 230, LAKEWOOD, CO 80228-1259 USA publisher: SOC RANGE MANAGEMENT
Keywords: dispersal; dung; endozoochory; herbivores; Mediterranean pastures; Spatial pattern

Herbivore dunging and endozoochorous seed deposition in a Mediterranean dehesa - Malo, J E; Jimenez, B; Suarez, F (JOURNAL OF RANGE MANAGEMENT, 2000)
Spatial patterns of herbivore defecation within grazing systems are important as they directly affect pasture growth and composition. These effects are partially linked to seed dispersal in dung, a little studied process. This paper focuses on: (1) quantification of dung and seeds deposited by herbivores in a Mediterranean grazing system, and (ii) analysis of the spatial variability of dung and seeds deposited within and among plant communities. We carried out year-long monthly quantifications of the depositions of rabbit (Oryctolagus cuniculus), fallow deer (Dama dama), red deer (Cervus elaphus), and cow (Bos taurus) dung to 32 plots distributed in Quercus rotundifolia Lam. and Fraxinus angustifolia Vahl woodlands, mixed scrub, and Cistus ladanifer L. scrub. We also quantified the germinable seed content of dung. The results revealed differences (p < 0.05) in dung deposition, varying (i) among the 4 species, (ii) within species (except for the red deer) among plant communities, and (iii) within plant communities. An average of 735 seeds/m(2) were returned to the soil via dung, with the highest numbers in open woodlands (870-1,888 seeds/m(2)) and the lowest numbers in scrubs (83-315 seeds/m(2)). Cows dispersed the most seeds (68%), followed by red deer (20%), rabbits (7%), and fallow deer (5%). Spatial variability in deposition led to accumulations of up to several thousand seeds at points covered by the dung. The effect of seed input to the seed bank and on vegetation may be low at large and medium-sized spatial scales, but it can be very important at small scales and for colonization processes.
Keywords: dispersal; dung; endozoochory; herbivores; Mediterranean pastures; Spatial pattern

Holocene climatic changes in the Western Mediterranean, from south-east France to south-east Spain - Jalut, Guy; Esteban Amat, Augustin; Bonnet, Louis; Gauquelin, Thierry; Fontugne, Michel (Palaeogeography, Palaeoclimatology, Palaeoecology, 2000)
Holocene climatic changes along coastal regions from south-east France to south-east Spain were studied using pollen ratios. Comparing modern pollen rain, vegetation and climate along selected transects from the Atlantic Ocean to the Mediterranean, we obtained threshold values of two diVerent ratios corresponding to the diVerent climatic conditions along the transects. These pollen ratios and threshold values were employed to characterize the Holocene climatic changes from nine Mediterranean coastal sites. The results were compared with data from marine and continental pollen sequences distributed in the western Mediterranean basin, and with additional regional data independent of human activity: lake-level ﬂuctuations, alpine glacier advance and retreat chronology, 14C anomaly and cooling phases in Eastern France and Central Europe. The role of anthropogenic activities and climate on the changes in vegetation is discussed. Six major changes in vegetation cover were identiﬁed. They correspond to aridiﬁcation phases that occurred around 9500–9000 yr BP (10 900–9700 cal BP), 7500–7000 yr BP (8400–7600 cal BP), 4500–4000 yr BP (5300–4200 cal BP), 3700–3300 yr BP (4300–3400 cal BP), 2600–1900 yr BP (2850–1730 cal BP) and 1300–1000 yr BP (1300–750 cal BP). These arid episodes were regional responses to more global climatic changes and determined the changes in the vegetation cover. Humans undoubtedly enhanced the vegetation changes, but none the less had to adapt to these new climatic conditions.
Keywords: climatic changes; holocene vegetation; human impact; pollen data; western Mediterranean

Host specificity in fungal endophytic populations of Quercus ilex and Quercus faginea from Central Spain - Collado, J; Platas, G; Pelaez, F (NOVA HEDWIGIA, 2000)
A comparative study of the endophytic fungal assemblages of Quercus ilex subsp. ballota and Quercus faginea subsp. faginea was carried out on 10 trees growing in a Mediterranean forest in Central Spain. Endophytes from bark, twigs and fresh leaves were isolated from both tree species. As observed for other taxonomically related hosts, a certain overlapping between the endophytic mycoflora in both Quercus species was found. The most frequent fungus in both host species was Pyrenochaeta sp., an anamorph of Dothideales. Nevertheless, a certain degree of host specificity in fungal endophytic infection was detected, when the frequencies of the most commonly isolated endophytes were statistically analysed. The tree species affects significantly the distribution of almost all the fungi with isolation frequencies equal or higher than 2%. Moreover, some dominant fungal taxa could be isolated only from a particular host (Q. ilex or Q. faginea). A cluster analysis of the trees computed on the base of the similarity of their whole of fungal populations confirmed that there is an evident influence of the host species on the composition of the fungal assemblages of the trees. However, this effect does not appear to be always the main determinant of the composition of the fungal assemblages analysed.
Keywords: fungal endophytes; Quercus faginea; Quercus ilex

Host specificity in fungal endophytic populations of Quercus ilex and Quercus faginea from Central Spain - Collado, J.; Platas, G.; Pelaez, F. (NOVA HEDWIGIA, 2000)
A comparative study of the endophytic fungal assemblages of Quercus ilex subsp. ballota and Quercus faginea subsp. faginea was carried out on 10 trees growing in a Mediterranean forest in Central Spain. Endophytes from bark, twigs and fresh leaves were isolated from both tree species. As observed for other taxonomically related hosts, a certain overlapping between the endophytic mycoflora in both Quercus species was found. The most frequent fungus in both host species was Pyrenochaeta sp., an anamorph of Dothideales. Nevertheless, a certain degree of host specificity in fungal endophytic infection was detected, when the frequencies of the most commonly isolated endophytes were statistically analysed. The tree species affects significantly the distribution of almost all the fungi with isolation frequencies equal or higher than 2%. Moreover, some dominant fungal taxa could be isolated only from a particular host (Q. ilex or Q. faginea). A cluster analysis of the trees computed on the base of the similarity of their whole of fungal populations confirmed that there is an evident influence of the host species on the composition of the fungal assemblages of the trees. However, this effect does not appear to be always the main determinant of the composition of the fungal assemblages analysed.
The following values have no corresponding Zotero field: pub-location: JOHANNESSTR 3A, D-70176 STUTTGART, GERMANY publisher: GEBRUDER BORNTRAEGER
Keywords: fungal endophytes; Quercus faginea; Quercus ilex

IDENTIFICACIÓN Y DESCRIPCIÓN DE LAS ECTOMICORRIZAS ZONA QUEMADA Y UNA ZONA SIN ALTERAR DEL CARRASCAL DE NAZAR ( NAVARRA ) - Román, D. E.; Miguel, M. D. E. (Publicaciones de Biología, Universidad de Navarra, Serie Botánica, 2000)
Since 1998, a field study has been undertaken in a Quercus ilex L. subsp. ballota (Desf.) Samp. forest located in Nazar (Navarra, Spain). This study aims to establish a qualitative and quantitative comparison between the ectomycorrhizal morphotypes which have been collected, described and identified in a burned site and in a non- disturbed one within this forest. Thus, this study aims to contribute to the knowledge of the ectomycorrhizae associated with evergreen oak in field conditions, because most of the studies on evergreen oak ectomycorrhizae are related to truffle growing or artificial mycorrhization in the nursery.
Keywords: Ectomycorrhizae; fire; identification; morphology; Quercus ilex; Tuber melanosporum

IDENTIFICACIÓN Y DESCRIPCIÓN DE LAS ECTOMICORRIZAS ZONA QUEMADA Y UNA ZONA SIN ALTERAR DEL CARRASCAL DE NAZAR ( NAVARRA ) - Román, D E; Miguel, M D E (Publicaciones de Biología, Universidad de Navarra, Serie Botánica, 2000)
Since 1998, a field study has been undertaken in a Quercus ilex L. subsp. ballota (Desf.) Samp. forest located in Nazar (Navarra, Spain). This study aims to establish a qualitative and quantitative comparison between the ectomycorrhizal morphotypes which have been collected, described and identified in a burned site and in a non- disturbed one within this forest. Thus, this study aims to contribute to the knowledge of the ectomycorrhizae associated with evergreen oak in field conditions, because most of the studies on evergreen oak ectomycorrhizae are related to truffle growing or artificial mycorrhization in the nursery.
Keywords: Ectomycorrhizae; fire; identification; morphology; Quercus ilex; Tuber melanosporum

Influence of weather on cork-ring width - Caritat, Antònia; Gutiérrez, Emilia; Molinas, Marisa (Tree Physiology, 2000)
Ring-width series of cork from Quercus suber L. trees growing at two sites in Extremadura (southwestern Spain) were analyzed in relation to monthly precipitation and temperature, and to climatic indices combining both variables. Ring width of cork showed strong positive correlations with precipitation, especially during the fall and winter. Moderately low temperatures were favorable for cork growth, except in winter and during the onset of phellogen activity. We conclude that drought or temperature, or both, can limit cork growth during the annual drought period.
10.1093/treephys/20.13.893
Keywords: climatic variability; cork growth; cork-ring chro- nology; dendroclimatology; phellogen activity; Quercus suber

Influence of weather on cork-ring width - Caritat, Antònia; Gutiérrez, Emilia; Molinas, Marisa (Tree Physiology, 2000)
Ring-width series of cork from Quercus suber L. trees growing at two sites in Extremadura (southwestern Spain) were analyzed in relation to monthly precipitation and temperature, and to climatic indices combining both variables. Ring width of cork showed strong positive correlations with precipitation, especially during the fall and winter. Moderately low temperatures were favorable for cork growth, except in winter and during the onset of phellogen activity. We conclude that drought or temperature, or both, can limit cork growth during the annual drought period.
10.1093/treephys/20.13.89310.1093/treephys/20.13.893
Keywords: climatic variability; cork growth; cork-ring chro- nology; dendroclimatology; phellogen activity; Quercus suber

Leaf morphology and macronutrients in broadleaved trees in central Italy - Bussotti, Filippo; Borghini, Francesca; Celesti, Carlo; Leonzio, Claudio; Bruschi, Piero (Trees, 2000)
As part of an intensive monitoring programme (MON.I.TO, Intensive Monitoring of Forests in Tuscany), a 3-year survey was carried out, which included three tree species (beech, Fagus sylvatica L.; Turkey oak, Quercus cerris L.; holm-oak, Quercus ilex L.) located at six different sites. Leaves were sampled annually and analysed for nutrient concentrations (nitrogen, sulphur, phosphorus, magnesium, calcium, potassium and sodium) and morphological parameters (leaf area, dry weight, leaf mass per area, leaf thickness and leaf density). Results indicated considerable interannual variation of all the parameters. Differences between sampling sites indicated that, of all parameters measured, leaf mass per area could explain best the differences in field performance under conditions of stress. In fact, leaf mass per area was greater in the drier sites or when sea salt deposition occurred. Nevertheless, the variation of leaf mass per area over the 3 years did not reflect the differences in rainfall. Higher leaf mass per area was accompanied by lower concentrations of phosphorus and nitrogen, which could be a dilution effect due to an increase of structural carbon compounds in sclerophyllous leaves, as revealed by the total foliar content of these elements. Leaf mass per area as a measure of sclerophylly reached very high values among mesophile vegetation. Long-range transport of sea salt from coastal areas to mountain areas was mirrored in sodium concentrations of leaves.
Keywords: Fagus sylvatica; macronutrients; Quercus cerris; Quercus ilex; sclerophylly

Leaf morphology and macronutrients in broadleaved trees in central Italy - Bussotti, Filippo; Borghini, Francesca; Celesti, Carlo; Leonzio, Claudio; Bruschi, Piero (Trees, 2000)
As part of an intensive monitoring programme (MON.I.TO, Intensive Monitoring of Forests in Tuscany), a 3-year survey was carried out, which included three tree species (beech, Fagus sylvatica L.; Turkey oak, Quercus cerris L.; holm-oak, Quercus ilex L.) located at six different sites. Leaves were sampled annually and analysed for nutrient concentrations (nitrogen, sulphur, phosphorus, magnesium, calcium, potassium and sodium) and morphological parameters (leaf area, dry weight, leaf mass per area, leaf thickness and leaf density). Results indicated considerable interannual variation of all the parameters. Differences between sampling sites indicated that, of all parameters measured, leaf mass per area could explain best the differences in field performance under conditions of stress. In fact, leaf mass per area was greater in the drier sites or when sea salt deposition occurred. Nevertheless, the variation of leaf mass per area over the 3 years did not reflect the differences in rainfall. Higher leaf mass per area was accompanied by lower concentrations of phosphorus and nitrogen, which could be a dilution effect due to an increase of structural carbon compounds in sclerophyllous leaves, as revealed by the total foliar content of these elements. Leaf mass per area as a measure of sclerophylly reached very high values among mesophile vegetation. Long-range transport of sea salt from coastal areas to mountain areas was mirrored in sodium concentrations of leaves.
Keywords: Fagus sylvatica; macronutrients; Quercus cerris; Quercus ilex; sclerophylly

Leaf temperature effects on gas exchange in Quercus ilex L. growing under field conditions - Gratani, Loretta (Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2000)
ABSTRACT Gas exchange temperature dependence in Quercus ilex shrubs growing in the Mediterranean maquis was analysed. The gas exchange trend was monitored during the year: photosynthetic activity (A net) reached the highest average rates in early spring and autumn (12.5 µmol m-2s-1 was the absolute maximum A net measured) and the lowest rates were monitored in the middle of June. There was a good correlation (r = 0.72) between A net and g s (A net = 4.1246 ln g s + 4316; P < 0.01), indicating that stomatal control of CO2 diffusion plays an important role in controlling photosynthetic activity. Leaf temperature allowing the highest photosynthetic and stomatal conductance rates of Quercus ilex were in the range 17.5 ? 29°C. A net and gs dropped below half its maximum value when leaf temperatures were below 11.5°C and above 35.7°C. Transpiration rates (E) were strongly related to leaf temperature; E increased as leaf temperature increased and the highest E rates were monitored in June, despite a 46% decrease in g s. Leaf water loss from transpiration, during the drought period, could result in leaf water stress which would exacerbate heat effects on photosynthesis. During summer, the increase in leaf temperatures decreased g s which in turn decreased A net. Consequently, stomatal control in Quercus ilex may be considered as an adaptive strategy during drought.
doi: 10.1080/11263500012331350295
Keywords: Leaf temperature; photosynthetic activity; Quercus ilex; Stomatal conductance

The Lichen Genus Usnea On Quercus Suber In Iberian Cork-Oak Forests - Fos, Simón; Clerc, Philippe (The Lichenologist, 2000)
Fifteen species of Usnea are recorded from Iberian cork-oak forests: U. ceratina, U. cornuta, U. dasaea, U. esperantiana, U. ﬂammea, U. fulvoreagens, U. glabrata, U. hirta, U. mutabilis, U. rubicunda, U. subcornuta, U. subﬂoridana, U. subscabrosa, U. substerilis and U. wasmuthii. A key for these species is provided. Details of morphology, chemistry, distribution, ecology and taxonomy are discussed. Usnea dasaea is reported as new to the Iberian Peninsula. New chemotypes of U. fulvoreagens (with squamatic acid) and U. wasmuthii (with psoromic acid) have been identiﬁed. Distribution maps of U. dasaea and U. subcornuta in Europe are presented. A new combination, Usnea subﬂoridana subsp. praetervisa (Asahina) P. Clerc, is proposed
Keywords: characterization; lichens; quercus suber (PG); usnea

Light energy dissipation in Quercus ilex resprouts after fire - Fleck, I; Aranda, X; El Omari, B; Permanyer, J; Abadía, A; Hogan, K P (AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY, 2000)
Holm oak (Quercus ilex) plants that have resprouted after fire have higher photosynthetic capacity than control plants in intact vegetation. In this study, branches detached from forest plants were fed with dithiothreitol (DTT) in the laboratory to inhibit zeaxanthin production and thus reduce the dissipation of light energy as heat. This allowed us to test the hypothesis that plants with greater photosynthetic capacity, and therefore greater photochemical sink strength, would suffer a lower reduction in photochemical efficiency under stressful conditions. Greater rates of photochemistry in resprouts, which exhibited increased photosynthesis (A), leaf conductance (g), quantum yield of PSII (Delta F/F-m') and photochemical quenching (q(P)), were related to lower non-radiative dissipation of excess energy as indicated by 1 - (F-v'/F-m'). However, the fraction of energy remaining of that used in photochemistry or dissipated thermally in the PSII antennae was similar in resprouts and controls and was not affected by DTT, especially under high irradiance conditions. Zeaxanthin involvement in PSII protection operated in resprouts and controls since DTT induced the same kind of response (NPQ decrease) but was lower in resprouts. These chlorophyll fluorescence results suggest the participation of some additional mechanism for energy dissipation. Light capture characteristics of the photosynthetic apparatus did not differ between resprouts and controls, and leaf age did not play a determining role in the differences observed.
APS
Keywords: DTT; photochemical sink; Quercus ilex

Light energy dissipation in Quercus ilex resprouts after fire - Fleck, I.; Aranda, X.; El Omari, B.; Permanyer, J.; Abadia, A.; Hogan, K. P. (AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY, 2000)
Holm oak (Quercus ilex) plants that have resprouted after fire have higher photosynthetic capacity than control plants in intact vegetation. In this study, branches detached from forest plants were fed with dithiothreitol (DTT) in the laboratory to inhibit zeaxanthin production and thus reduce the dissipation of light energy as heat. This allowed us to test the hypothesis that plants with greater photosynthetic capacity, and therefore greater photochemical sink strength, would suffer a lower reduction in photochemical efficiency under stressful conditions. Greater rates of photochemistry in resprouts, which exhibited increased photosynthesis (A), leaf conductance (g), quantum yield of PSII (Delta F/F-m') and photochemical quenching (q(P)), were related to lower non-radiative dissipation of excess energy as indicated by 1 - (F-v'/F-m'). However, the fraction of energy remaining of that used in photochemistry or dissipated thermally in the PSII antennae was similar in resprouts and controls and was not affected by DTT, especially under high irradiance conditions. Zeaxanthin involvement in PSII protection operated in resprouts and controls since DTT induced the same kind of response (NPQ decrease) but was lower in resprouts. These chlorophyll fluorescence results suggest the participation of some additional mechanism for energy dissipation. Light capture characteristics of the photosynthetic apparatus did not differ between resprouts and controls, and leaf age did not play a determining role in the differences observed.
APSAPSThe following values have no corresponding Zotero field: pub-location: 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA publisher: C S I R O PUBLISHING
Keywords: DTT; photochemical sink; Quercus ilex

Litter quality and decomposition in a CO2-enriched Mediterranean forest ecosystem - Angelis, Paolo De (Plant and Soil, 2000)
Six large open top chambers were installed to test the effect of atmospheric [CO2] enrichment on clumps of natural Mediterranean vegetation starting from early spring 1992. To study the impact of [CO2] enrichment on litter decomposition, leaves of three woody species (Quercus ilex L., Phillyrea angustifolia L. and Pistacia lentiscus L.) were collected from the forest ﬂoor and subsequently incubated in situ over a two-year period. The initial slope of the exponential function, describing mass loss, indicated that there was a small negative effect of elevated [CO2] on the decomposition rate of all the species. All regressions were signiﬁcant. The decrease of decomposition rate is particularly notable during the initial stages of decomposition, when the differences of quality parameters, lignin/N and C/N were larger. This study points out that a decrease of decomposition rate may occur under elevated [CO2] conditions; if this effect is coupled to an increase of primary production, there will be a net rise of C-storage in the soils of forest ecosystems. Forest soils may, therefore, represent a potentially increasing sink for this excess carbon.
Keywords: decomposition rates; elevated [CO2]; litter quality; mediterranean forest; Quercus ilex

Litter quality and decomposition in a CO2-enriched Mediterranean forest ecosystem - Angelis, Paolo De (Plant and Soil, 2000)
Six large open top chambers were installed to test the effect of atmospheric [CO2] enrichment on clumps of natural Mediterranean vegetation starting from early spring 1992. To study the impact of [CO2] enrichment on litter decomposition, leaves of three woody species (Quercus ilex L., Phillyrea angustifolia L. and Pistacia lentiscus L.) were collected from the forest ﬂoor and subsequently incubated in situ over a two-year period. The initial slope of the exponential function, describing mass loss, indicated that there was a small negative effect of elevated [CO2] on the decomposition rate of all the species. All regressions were signiﬁcant. The decrease of decomposition rate is particularly notable during the initial stages of decomposition, when the differences of quality parameters, lignin/N and C/N were larger. This study points out that a decrease of decomposition rate may occur under elevated [CO2] conditions; if this effect is coupled to an increase of primary production, there will be a net rise of C-storage in the soils of forest ecosystems. Forest soils may, therefore, represent a potentially increasing sink for this excess carbon.
Keywords: decomposition rates; elevated [CO2]; litter quality; mediterranean forest; Quercus ilex

Methanolysis of bark suberins: analysis of glycerol and acid monomers - Graça, J; Pereira, Helena (Phytochemical Analysis, 2000)
The depolymerization and subsequent analysis of cork suberins from the outer barks of Pseudotsuga menziesii and Quercus suber was performed using a simpliﬁed methanolysis procedure. The amount of sodium methoxide catalyst was maintained at 20–30 mM and the methanolysis mixture was submitted to trimethylsilyl derivatisation and used directly for gas chromatographic analysis, allowing simultaneous quantiﬁcation of glycerol and long-chain monomers. Response factors for glycerol, ferulic acid and one saturated homologue representing each of the suberinic families (i.e. the 1-alkanols, 1-alkanoic acids, vhydroxyacids and a,v-diacids) were determined. Effective depolymerization of suberin was checked using the infrared specta of the residues after methanolysis. Glycerol is a major constituent of the suberins from P. menziesii (26% of total) and from Q. suber (14%). In both suberins, a,v-diacids are dominant, i.e. 54% of the long-chain monomers in P. menziesii (mostly saturated C16-C22 homologues and the C18 unsaturated diacid), and 53% in Q. suber (mostly the C18 unsaturated diacid and mid-chain oxygenated (epoxide and vic-diol) derivatives). In P. menziesii epoxyacids are absent. The importance of glycerol and a,v-diacids as suberin monomers supports a polymeric structure based on their successive esteriﬁcation.
Keywords: Cork; Glycerol; Methanolysis; monomer composition; Pseudotsuga menziesii; Quercus suber; suberin

Modelling habitat selection of Common Cranes Grus grus wintering in Portugal using multiple logistic regression - FRANCO, ALDINA M A; BRITO, JOSÉ C; ALMEIDA, JULIA (Ibis, 2000)
Predictive models of habitat suitability for the Common Crane Grus grus in a wintering area of southern Portugal were derived using logistic multiple regression and Geographic Information Systems. The study area was characterized by landscape variables and surveyed uniformly for the presence of cranes. The most important variables were distance to roosts, to open Holm Oak woods and to villages, and the occurrence of unpaved roads, shrubby vegetation, slope and orchards. Two models were built, the second having one variable fewer than the first. The selection of the best model was based on statistical and biological criteria. Crane distribution was negatively related to: distance to open Holm Oak Quercus rotundifolia woods and roosts. Additionally, unsuitable vegetation and orchard areas are avoided. In these areas movement is difficult, food availability is reduced and the risk of predation increased. We also found that villages and roads were avoided; disturbance is a significant factor for this species. Some management guidelines are proposed for the area: (1) maintenance of open Holm Oak woodlands, (2) incentives to avoid the abandonment of traditional agriculture and pastoral use of the area, which would lead to an increase of shrubby vegetation areas, (3) preservation of suitable roosting places and (4) management of new patches of forest and orchards.
Keywords: Common Crane; habitat suitability models; holm oak woodlands (voyant); wintering habitats

Modelling habitat selection of Common Cranes Grus grus wintering in Portugal using multiple logistic regression - FRANCO, ALDINA M. A.; BRITO, JOSÉ C.; ALMEIDA, JULIA (Ibis, 2000)
Predictive models of habitat suitability for the Common Crane Grus grus in a wintering area of southern Portugal were derived using logistic multiple regression and Geographic Information Systems. The study area was characterized by landscape variables and surveyed uniformly for the presence of cranes. The most important variables were distance to roosts, to open Holm Oak woods and to villages, and the occurrence of unpaved roads, shrubby vegetation, slope and orchards. Two models were built, the second having one variable fewer than the first. The selection of the best model was based on statistical and biological criteria. Crane distribution was negatively related to: distance to open Holm Oak Quercus rotundifolia woods and roosts. Additionally, unsuitable vegetation and orchard areas are avoided. In these areas movement is difficult, food availability is reduced and the risk of predation increased. We also found that villages and roads were avoided; disturbance is a significant factor for this species. Some management guidelines are proposed for the area: (1) maintenance of open Holm Oak woodlands, (2) incentives to avoid the abandonment of traditional agriculture and pastoral use of the area, which would lead to an increase of shrubby vegetation areas, (3) preservation of suitable roosting places and (4) management of new patches of forest and orchards.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Common Crane; habitat suitability models; holm oak woodlands (voyant); wintering habitats

Mycorrhization of vitroplants raised from somatic embryos of cork oak (Quercus suber L.) - Dı́ez, Jesús; Manjón, José Luis; Kovács, Gabor M; Celestino, Cristina; Toribio, Mariano (Applied Soil Ecology, 2000)
The technique described herein allows in vitro ectomycorrhizal synthesis in Quercus suber vitroplants raised from somatic embryos with Pisolithus tinctorius and Scleroderma polyrhizum strains. Only strains of this species coming from fruit bodies collected in Quercus suber stands (strain QS241 and strain QS247) formed ectomycorrhizas, and hence these species seem to exhibit host adaptation. The in vitro mycorrhization facilitated the development of secondary roots and the ex vitro weaning of cork oak vitroplants.
Keywords: Cork oak; ectomycorrhizas; Mycorrhization; Somatic embryogenesis

Mycorrhization of vitroplants raised from somatic embryos of cork oak (Quercus suber L.) - Dı́ez, Jesús; Manjón, José Luis; Kovács, Gabor M.; Celestino, Cristina; Toribio, Mariano (Applied Soil Ecology, 2000)
The technique described herein allows in vitro ectomycorrhizal synthesis in Quercus suber vitroplants raised from somatic embryos with Pisolithus tinctorius and Scleroderma polyrhizum strains. Only strains of this species coming from fruit bodies collected in Quercus suber stands (strain QS241 and strain QS247) formed ectomycorrhizas, and hence these species seem to exhibit host adaptation. The in vitro mycorrhization facilitated the development of secondary roots and the ex vitro weaning of cork oak vitroplants.
Keywords: Cork oak; ectomycorrhizas; Mycorrhization; Somatic embryogenesis

An NMR microscopy study of water absorption in cork - Gil, A M; Lopes, M H; Pascoal Neto, C; Callaghan, P T (Journal of Materials Science, 2000)
NMR Microscopy is used to measure the imbibition of water into natural cork, extractives-free cork and desuberised cork. The results clearly indicate that suberin is the key constituent which determines the ability of cork to resist water uptake. Furthermore, a particular suberin with distinct spectral properties as viewed by 13C NMR is shown to be the component responsible for cork resistance to water absorption. Laser confocal microscopy suggests that this function is associated with the role of suberin in preserving cell wall structure but the highly hydrophobic nature of suberin may also play an important role. The NMR microscopy study shows that the water absorbed by natural cork, after soaking for three days, is confined to the lenticels, narrow channels on the order of 1000 to 1500 μm in diameter. One incidental outcome is the observation of a clear down-field shift in NMR frequency for water near the cut transverse surfaces of the cork, an effect~associated with susceptibility inhomogeneity.
Keywords: 13C NMR; cell structure (voyant); Cork; suberin; WATER ABSORPTION

Observations sur la dynamique du développement du Diplodia mutila Fr. apud Mont. sur le chêne-liège, Quercus suber L., au Maroc - El-Badri, Naïma; Abadie, Michel (Cryptogamie Mycologie, 2000)
Mamora forest in Rabat (Morocco) was a wide forest of cork oak which is rapidly disappearing. This crisis is caused by both human exploitation and overgrazing by animals. This situation is also affected by the existence of harmful insects and parasitic fungi. One of the most common species is Diplodia mutila Fr. apud Mont. (group of Coelomycetes) anamorph of Botryosphaeria stevensii Shoem., which causes withering and cankers on trunks and branches. The electron microscope observations on pycnosporogenesis and the study of the relation plant-host-pathogen show the structure and the biological cycle of Diplodia mutila, the endophytic and the systemic development of the pathogen and the irreversible damage on the plant host. This study is a contribution to the research on cork-oak forest protection.
Keywords: decline; Diplodia mutila Fr. apud Mont.; FOREST; Mamora; Morocco; pathology; Quercus suber L.; ultrastructure

Observations sur la dynamique du développement du Diplodia mutila Fr. apud Mont. sur le chêne-liège, Quercus suber L., au Maroc - El-Badri, Naïma; Abadie, Michel (Cryptogamie Mycologie, 2000)
Mamora forest in Rabat (Morocco) was a wide forest of cork oak which is rapidly disappearing. This crisis is caused by both human exploitation and overgrazing by animals. This situation is also affected by the existence of harmful insects and parasitic fungi. One of the most common species is Diplodia mutila Fr. apud Mont. (group of Coelomycetes) anamorph of Botryosphaeria stevensii Shoem., which causes withering and cankers on trunks and branches. The electron microscope observations on pycnosporogenesis and the study of the relation plant-host-pathogen show the structure and the biological cycle of Diplodia mutila, the endophytic and the systemic development of the pathogen and the irreversible damage on the plant host. This study is a contribution to the research on cork-oak forest protection.
Keywords: decline; Diplodia mutila Fr. apud Mont.; FOREST; Mamora; Morocco; pathology; Quercus suber L.; ultrastructure

Past distribution and ecology of the cork oak (Quercus suber) in the Iberian Peninsula: a pollen-analytical approach - Carrión, J. S.; Parra, I.; Navarro, C.; Munuera, M. (Diversity and Distributions, 2000)
This study presents pollen-analytical data from continental and offshore Iberian Peninsula sites that include pollen curves of Quercus suber, to provide information on the past distribution and ecology of the cork oak (Q. suber). Results centre on a new pollen record of Navarrés (Valencia, eastern Spain), which shows that the cork oak survived regionally during the Upper Pleistocene and was important during a mid-Holocene replacement of a local pine forest by Quercus-dominated communities. This phenomenon appears linked to the recurrence of ﬁre and reinforces the value of the cork oak for reforestation programmes in ﬁre-prone areas. In addition to Navarrés, other Late Quaternary pollen sequences (Sobrestany, CasablancaAlmenara, Padul, SU 8103, SU8113, 8057B) suggest last glacial survival of the cork oak in southern and coastal areas of the Peninsula and North Africa. Important developments also occur from the Late Glacial to the middle Holocene, not only in the west but also in the eastern Peninsula. It is suggested that, in the absence of human inﬂuence, Q. suber would develop in non-monospeciﬁc forests, sharing the arboreal stratum both with other sclerophyllous and deciduous Quercus and Pinus species
Keywords: Cork oak; historical biogeography; iberian peninsula; palaeoecology; pollen.

Past distribution and ecology of the cork oak (Quercus suber) in the Iberian Peninsula: a pollen-analytical approach - Carrión, J S; Parra, I; Navarro, C; Munuera, M (Diversity and Distributions, 2000)
This study presents pollen-analytical data from continental and offshore Iberian Peninsula sites that include pollen curves of Quercus suber, to provide information on the past distribution and ecology of the cork oak (Q. suber). Results centre on a new pollen record of Navarrés (Valencia, eastern Spain), which shows that the cork oak survived regionally during the Upper Pleistocene and was important during a mid-Holocene replacement of a local pine forest by Quercus-dominated communities. This phenomenon appears linked to the recurrence of ﬁre and reinforces the value of the cork oak for reforestation programmes in ﬁre-prone areas. In addition to Navarrés, other Late Quaternary pollen sequences (Sobrestany, CasablancaAlmenara, Padul, SU 8103, SU8113, 8057B) suggest last glacial survival of the cork oak in southern and coastal areas of the Peninsula and North Africa. Important developments also occur from the Late Glacial to the middle Holocene, not only in the west but also in the eastern Peninsula. It is suggested that, in the absence of human inﬂuence, Q. suber would develop in non-monospeciﬁc forests, sharing the arboreal stratum both with other sclerophyllous and deciduous Quercus and Pinus species
Keywords: Cork oak; historical biogeography; iberian peninsula; palaeoecology; pollen.

Photosynthesis as a temperature indicator in Quercus ilex L. - Gratani, L; Pesoli, P; Crescente, M F; Aichner, K; LARCHER, W (Global and Planetary Change, 2000)
Net photosynthesis Pn , stomatal conductance gs , leaf temperature LT , transpiration rate . . . . E and in vivo chlorophyll fluorescence were monitored February 1996–February 1997 in Quercus ilex plants growing in the climax area Rome and . in the Garda lake region. Photosynthetic activity is an appropriate temperature-dependent functional trait linked to plant metabolism and performance. We employed photosynthesis as a stress temperature indicator. Regression analysis showed that in such regional climatic conditions, net photosynthetic rates were primarily correlated with temperature. The introduction of rainfall in the function did not significantly improve the theoretical prevision, in the range of temperature and rainfall analysed. The favourable leaf temperatures allowing 90–100% of the highest photosynthetic rates were 14–288C, decreasing over 50% when leaf temperature were respectively below 68C and over 378C: the low potential photochemical efficiency of 0.71 PSII Fv . rFm at Castelporziano during summer, confirmed the state of stress. Transpiration rates remained high with the increase of leaf temperature in summer, in spite of the 46% decrease of stomatal conductance. Nevertheless, this decrease allowed the maintenance of acceptable Pn rates in stressful conditions. The potential productivity of Q. ilex lied on high peaks of activity during periods of lower evaporative demand and a rapid stomatal response to an increase in air temperature and soil water deficit. Although it is difficult to forecast Q. ilex productivity and plant structure, we may hypothesize its future presence in the Mediterranean Basin by the capability of vegetative activity in a wide range of temperatures, the high stomatal control in stressful conditions, the high plasticity index and water use efficiency WUE .
Keywords: climatic change; in vivo chlorophyll fluorescence; photosynthesis; Quercus ilex; Temperature

Pollen viability as a bio-indicator of air quality - Iannotti, Orietta; Mincigrucci, Gianfranco; Bricchi, Emma; Frenguelli, Giuseppe (Aerobiologia, 2000)
Many air pollutants cause plant deterioration. In this study pollen viability was used as bio-indicator of air quality. The study was carried out in the city of Perugia where road trafﬁc is the most important cause of air pollution. Three areas, with different intensity of road trafﬁc (very high, medium and absent) but all characterized by the presence of the same plant species, were selected. Eight species were studied: Hedera helix L., Convolvulus sepium L., Cynodon dactylon (L.) Pers., Quercus ilex L., Dactylis glomerata L., Parietaria diffusa M. et K., Daucus carota L. and Tilia cordata Miller. The pollen of these species was treated with TTC (2, 3, 5 Tryphenil-Tetrazolium-Chloride) staining solution and viability was then estimated by light microscopy. The results showed that the pollen viability was inversely proportioned with pollution. The highest difference in pollen viability between the areas was registered in Tilia cordata. Quercus ilex instead showed that there was no difference in pollen viability between the three different areas. Parietaria diffusa showed a particular behaviour; the highest pollen viability percentage was in polluted areas. The statistical analysis (ANOVA) showed that the main source of variability of the pollen viability depends on the plant but also the site and the interaction between plant and site were very important with a high signiﬁcant level (p < 0.0001).
Keywords: air quality; bio-indicator; perugia; pollen; viability

Quantitation of aliphatic suberin in Quercus suber L. cork by FTIR spectroscopy and solid-state 13C-NMR spectroscopy - Lopes, M. H.; Neto, C. Pascoal; Barros, A. S.; Rutledge, D.; Delgadillo, I.; Gil, A. M. (Biopolymers, 2000)
This work determined that the percentage of suberin in cork may be found by solid-state 13C cross polarization/magic angle spinning (CP/MAS) NMR spectroscopy and by FTIR with photoacoustic detection (FTIR-PAS) spectroscopy. A linear relationship is found between the suberin content measured through CP/MAS spectral areas and that measured gravimetrically. Furthermore, application of a partial least squares (PLS1) regression model to the NMR and gravimetric data sets clearly correlates the two sets, enabling suberin quantification with 90% precision. Suberin quantitation by FTIR-PAS spectroscopy is also achieved by a PLS1 regression model, giving 90% accurate estimates of the percentage of suberin in cork. Therefore, 13C-CP/MAS NMR and FTIR-PAS proved to be useful and accurate noninvasive techniques to quantify suberin in cork, thus avoiding the traditional time consuming and destructive chemical methods. © 2000 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 57: 344–351, 2000
The following values have no corresponding Zotero field: publisher: John Wiley & Sons, Inc.
Keywords: 13 C-cross polarization/ magic angle spinning; Cork; FTIR spectroscopy with photoacoustic detection; multivariate calibration; quantitation; Quercus suber L.; solid-state NMR; suberin

Quantitative Assessment of Polycyclic Aromatic Hydrocarbons from Corkwaste Combustion Emissions - Cabañas, Aracel; Sáez, Felicia; González, Alberto; Escalada, Ricardo (Journal of Agricultural Engineering Research, 2000)
Cork is a natural raw material obtained from the cork oak (Quercus suber). The corkwaste is a potential source of polycyclic aromatic hydrocarbons (PAHs) due to its high content of volatile compounds. A sampling method was developed for the measurement of polycyclic aromatic hydrocarbons emissions in a pilot bubbling #uidized bed combustion. This method has been designed to assess simultaneously the PAH contained in the gas phase and in the particulate matter. The samples were analysed on a gas chromatography coupled to a mass spectrometer to identify and quantify PAH compounds. The mass-selective detector was run in the selected ion monitoring mode. This study shows that lower molecular weight PAH were present predominantly in the gas phase, whereas high weight PAHs were retained in the particulate phase. As there is an existing relationship between the emission of CO and polycyclic aromatic hydrocarbons, the control and assessment of both compounds have been performed.
Keywords: Cork waste; Fluidized bed combustion (PG); GC-MS; Polycyclic aromatic hydrocarbons (PAHs)

Quantitative Assessment of Polycyclic Aromatic Hydrocarbons from Corkwaste Combustion Emissions - Cabañas, Aracel; Sáez, Felicia; González, Alberto; Escalada, Ricardo (Journal of Agricultural Engineering Research, 2000)
Cork is a natural raw material obtained from the cork oak (Quercus suber). The corkwaste is a potential source of polycyclic aromatic hydrocarbons (PAHs) due to its high content of volatile compounds. A sampling method was developed for the measurement of polycyclic aromatic hydrocarbons emissions in a pilot bubbling #uidized bed combustion. This method has been designed to assess simultaneously the PAH contained in the gas phase and in the particulate matter. The samples were analysed on a gas chromatography coupled to a mass spectrometer to identify and quantify PAH compounds. The mass-selective detector was run in the selected ion monitoring mode. This study shows that lower molecular weight PAH were present predominantly in the gas phase, whereas high weight PAHs were retained in the particulate phase. As there is an existing relationship between the emission of CO and polycyclic aromatic hydrocarbons, the control and assessment of both compounds have been performed.
Keywords: Cork waste; Fluidized bed combustion (PG); GC-MS; Polycyclic aromatic hydrocarbons (PAHs)

Relationship between leaf life-span and photosynthetic activity of Quercus ilex in polluted urban areas (Rome). - Gratani, L; Crescente, M F; Petruzzi, M (Environmental pollution (Barking, Essex : 1987), 2000)
Anatomical, morphological and physiological leaf traits of Quercus ilex in response to different traffic levels (high traffic level, type A sites; average traffic level, type B sites; control sites, type C sites) were analysed in Rome. Superficial leaf deposits were analysed comparing unwashed and washed leaf samples. Washing lowered Pb 61% in A, 54% in B and 27% in C. Sr, Fe, Cu, Zn and Al showed the same trend as Pb. The higher photosynthetic activity of 1-year-old leaves (Pn=7.0+/-2.9 micromol m(-2 )s(-1), average value) in A sites with respect to B sites (6.7+/-2.4 micromol m(-2 )s(-1)) and C sites (6.7+/-1.8 micromol m(-2 )s(-1)) seems to be related to higher stomatal conductance (g(s)=0.13+/-0.06 mol m(-2 )s(-1)), higher total chlorophyll content (Chl=1.57 mg g(-1)) and higher leaf thickness (L(T)=218.9 microm), particularly palisade parenchyma thickness (109.4 microm). Q. ilex showed, on average, 95% of 1-year-old leaves and rarely 2-year-old leaves in A and B sites; 77% 1-year leaves, 20% previous-year leaves and sporadic 3-year leaves in C sites. The enhanced leaf senescence in A sites is compensated by a stimulated shoot production (18% higher with respect to C sites); 25% increased specific leaf area seems to be compensatory growth occurring in order to increase the size of the assimilatory area. The inverse trend of leaf life-span and Pn seems to be Q. ilex' adaptive strategy in polluted areas.
Keywords: chlorophyll content; leaf life-span; leaf thickness; Net photosynthesis; shoot production; traffic level

Removal of toxic metals from solution by leaf, stem and root phytomass of Quercus ilex L. (holly oak). - Prasad, M. N.; Freitas, H. (Environmental pollution (Barking, Essex : 1987), 2000)
Increased consciousness for safeguarding the aqueous environment has prompted a search for alternative technologies for the removal of toxic metal ions from aqueous solutions. In this regard, a wide variety of biomass is being considered as adsorbents of heavy metals for treatment of industrial and domestic wastewaters as well as natural waters, including drinking water. In the present investigation, the potential of Quercus ilex phytomass from stem, leaf and root as an adsorbent of chromium (Cr), nickel (Ni), copper (Cu), cadmium (Cd) and lead (Pb) at ambient temperature was investigated. The metal uptake capacity of the root for different metals was found to be in the order: Ni>Cd>Pb>Cu>Cr; stem Ni>Pb>Cu>Cd>Cr; and leaf Ni>Cd>Cu>Pb>Cr. The highest amount adsorbed was Ni (root>leaf>stem). Data from this laboratory demonstrated that Ni is sequestered mostly in the roots, where concentrations can be as high as 428.4 ng/g dry wt., when 1-year-old seedlings were treated with Ni (2000 mg/l) in pot culture experiments, compared to 7.63 ng/g dry wt., control (garden and greenhouse soil) topsoil where Ni was present in trace amounts. This proves that the root biomass of Q. ilex has the capacity for complexing Ni. Cr exhibited the least adsorption values for all the three types of phytomass compared to other metals. The trend of adsorption of the phytomass was similar for Ni and Cd, i.e. root>leaf>stem. Desorption with 10 mM Na(4) EDTA was effective (55-90%) and, hence, there exists the possibility of recycling the phytomass. The biosorption results of recycled phytomass suggest that the selected adsorbents are re-usable. The advantages and potential of the Q. ilex phytomass as a biofilter of toxic trace metals, the scope and need for enhancing the efficiency of the Q. ilex phytomass as an adsorbent of metals are presented.
The following values have no corresponding Zotero field: accession-num: 15092842
Keywords: Biosorption; cadmium; chromium; copper; desorption; lead; Nickel; phytomass; Quercus ilex; root; stem

Removal of toxic metals from solution by leaf, stem and root phytomass of Quercus ilex L. (holly oak). - Prasad, M N; Freitas, H (Environmental pollution (Barking, Essex : 1987), 2000)
Increased consciousness for safeguarding the aqueous environment has prompted a search for alternative technologies for the removal of toxic metal ions from aqueous solutions. In this regard, a wide variety of biomass is being considered as adsorbents of heavy metals for treatment of industrial and domestic wastewaters as well as natural waters, including drinking water. In the present investigation, the potential of Quercus ilex phytomass from stem, leaf and root as an adsorbent of chromium (Cr), nickel (Ni), copper (Cu), cadmium (Cd) and lead (Pb) at ambient temperature was investigated. The metal uptake capacity of the root for different metals was found to be in the order: Ni>Cd>Pb>Cu>Cr; stem Ni>Pb>Cu>Cd>Cr; and leaf Ni>Cd>Cu>Pb>Cr. The highest amount adsorbed was Ni (root>leaf>stem). Data from this laboratory demonstrated that Ni is sequestered mostly in the roots, where concentrations can be as high as 428.4 ng/g dry wt., when 1-year-old seedlings were treated with Ni (2000 mg/l) in pot culture experiments, compared to 7.63 ng/g dry wt., control (garden and greenhouse soil) topsoil where Ni was present in trace amounts. This proves that the root biomass of Q. ilex has the capacity for complexing Ni. Cr exhibited the least adsorption values for all the three types of phytomass compared to other metals. The trend of adsorption of the phytomass was similar for Ni and Cd, i.e. root>leaf>stem. Desorption with 10 mM Na(4) EDTA was effective (55-90%) and, hence, there exists the possibility of recycling the phytomass. The biosorption results of recycled phytomass suggest that the selected adsorbents are re-usable. The advantages and potential of the Q. ilex phytomass as a biofilter of toxic trace metals, the scope and need for enhancing the efficiency of the Q. ilex phytomass as an adsorbent of metals are presented.
Keywords: Biosorption; cadmium; chromium; copper; desorption; lead; Nickel; phytomass; Quercus ilex; root; stem

Seasonal patterns of terpene content and emission from seven Mediterranean woody species in field conditions - Llusia, J.; Penuelas, J. (AMERICAN JOURNAL OF BOTANY, 2000)
The seasonal pattern of terpene content and emission by seven Mediterranean woody species was studied under field conditions. Emission rates were normalized at 30 degrees C and 1000 mu mol.m(-2).s(-1) PFD (photosynthetic photon Aux density). Bupleurum fruticosum, Pinus halepensis, and Cistus albidus stored large amounts of terpenes (0.01-1.77% \{[\}dry matter]) with maximum values in autumn and minimum values in spring. They emitted large amounts of terpenes (2-40 mu g.g DM-1.h(-1)), but with no clear seasonal trend except for Cistus albidus, which had maximum values in spring and minimum values in autumn. The nonstoring species Arbutus unedo, Erica arborea, Quercus coccifera and Quercus ilex also emitted large amounts of terpenes (0-40 mu g.g DM-1.h(-1)) and also tended to present maximum emission rates in spring, although this trend was significant only for A. unedo. At the seasonal scale, emission rates did not follow changes in photosynthetic rates; instead, they mostly followed changes in temperature. From autumn to spring, the least volatile monoterpenes such as limonene were emitted at highest rates, whereas the most volatile monoterpenes such as ol-pinene and P-pinene were the most emitted in summer. The monoterpene emission rates represented a greater percentage of the photosynthetic carbon fixation in summer (from 0.51% in Arbutus unedo to 5.64% in Quercus coccifera) than in the rest of the seasons. All these seasonality trends must be considered when inventorying and modeling annual emission rates in Mediterranean ecosystems.
The following values have no corresponding Zotero field: pub-location: OHIO STATE UNIV-DEPT BOTANY 1735 NEIL AVE, COLUMBUS, OH 43210 USA publisher: BOTANICAL SOC AMER INC
Keywords: alpha-pinene; limonene; mediterranean woody species; photosynthetic rate; relative humidity; Seasonality; Temperature; terpene emission and storage; volatility

Seasonal variation of foraging niches in a guild of passerine birds in a cork-oak woodland - Almeida, J.; Granadeiro, J. P. (ARDEA, 2000)
Spatial foraging niches of a pariform guild in a cork-oak woodland were examined during winter and spring. Niche structure was described in terms of the niche dimensions foraging substrate, foraging height and part of tree, and seasonal changes in niche breadth and overlap were examined. Considering the difficulties of dealing with the multidimensionality of Hutchinson's niche concept, we adopted a multivariate approach and identified the most important factors for spatial segregation. Significant differences between winter and spring utilisation of the foraging dimensions were found for the guild as a whole. At the species level, however, no major seasonal differences in the utilisation of foraging dimensions were found. No consistent seasonal trend occurred in terms of niche size or niche overlap. Multivariate analysis showed that the guild structure is basically the same in winter or spring, with Little influence of species that are present in only one of the two seasons. These results suggest that there is no food shortage in winter for the pariform guild in this woodland. The niche dimensions related with tree structure and foraging substrate appeared to be the most important ones in species segregation.
The following values have no corresponding Zotero field: pub-location: C/O PAUL STARMANS, OUDE ARNHEMSEWEG 261, 3705 BD ZEIST, NETHERLANDS publisher: NEDERLANDSE ORNITHOLOGISCHE UNIE
Keywords: community ecology; cork-oak woodland; guild; niche; passerines

Seasonal variation of foraging niches in a guild of passerine birds in a cork-oak woodland - Almeida, J; Granadeiro, J P (ARDEA, 2000)
Spatial foraging niches of a pariform guild in a cork-oak woodland were examined during winter and spring. Niche structure was described in terms of the niche dimensions foraging substrate, foraging height and part of tree, and seasonal changes in niche breadth and overlap were examined. Considering the difficulties of dealing with the multidimensionality of Hutchinson's niche concept, we adopted a multivariate approach and identified the most important factors for spatial segregation. Significant differences between winter and spring utilisation of the foraging dimensions were found for the guild as a whole. At the species level, however, no major seasonal differences in the utilisation of foraging dimensions were found. No consistent seasonal trend occurred in terms of niche size or niche overlap. Multivariate analysis showed that the guild structure is basically the same in winter or spring, with Little influence of species that are present in only one of the two seasons. These results suggest that there is no food shortage in winter for the pariform guild in this woodland. The niche dimensions related with tree structure and foraging substrate appeared to be the most important ones in species segregation.
Keywords: community ecology; cork-oak woodland; guild; niche; passerines

Soil microbial activity as a biomarker of degradation and remediation processes - Pascual, J. a; Garcia, C.; Hernandez, T.; Moreno, J. L.; Ros, M. (Soil Biology and Biochemistry, 2000)
Several organic matter fractions together with biological and biochemical parameters were measured in a range of intensively farmed soils in SE Spanish Mediterranean region, which had been abandoned (i.e. not used in agriculture) for different periods of time. These soils were compared with adjacent natural soils that had never been used for agriculture. There was a general decline of total organic carbon (TOC), extractable humic substances, water-soluble carbon (WSC) and carbohydrates, microbial biomass and respiration with the time elapsed since abandonment. There was also a decline in plant cover in the abandoned soils. When a degraded soil was amended with municipal solid waste at rates of 6.5 and 26 kg m 22 as a potential means of remediation, TOC, humic substances, WSC, microbial biomass and respiration rates signi®cantly increased but only at the higher rate of amendment. Plant cover was signi®cantly enhanced by both rates of the amendments and was still present 10 years after the amendment. These data con®rm that agricultural soil abandonment leads to soil degradation and that the addition of urban waste could be a suitable technique with which to restore their quality
Keywords: dehydrogenase; hydrolases; organic matter; soil remediation

Soil microbial activity as a biomarker of degradation and remediation processes - Pascual, J.a; García, C; Hernández, T; Moreno, J L; Ros, M (Soil Biology and Biochemistry, 2000)
Several organic matter fractions together with biological and biochemical parameters were measured in a range of intensively farmed soils in SE Spanish Mediterranean region, which had been abandoned (i.e. not used in agriculture) for different periods of time. These soils were compared with adjacent natural soils that had never been used for agriculture. There was a general decline of total organic carbon (TOC), extractable humic substances, water-soluble carbon (WSC) and carbohydrates, microbial biomass and respiration with the time elapsed since abandonment. There was also a decline in plant cover in the abandoned soils. When a degraded soil was amended with municipal solid waste at rates of 6.5 and 26 kg m 22 as a potential means of remediation, TOC, humic substances, WSC, microbial biomass and respiration rates signi®cantly increased but only at the higher rate of amendment. Plant cover was signi®cantly enhanced by both rates of the amendments and was still present 10 years after the amendment. These data con®rm that agricultural soil abandonment leads to soil degradation and that the addition of urban waste could be a suitable technique with which to restore their quality
Keywords: dehydrogenase; hydrolases; organic matter; soil remediation

Soil nitrogen heterogeneity in a Dehesa ecosystem - Gallardo, A.; Rodriguez-Saucedo, J. J. (Plant and Soil, 2000)
The Dehesa are savannah-like ecosystems that occupy extensive areas in the mediterranean regions of Southern Spain and Portugal. The changes in the soil nitrogen (N) potential mineralisation rate, microbial biomass-N and available mineral N in soils were studied over 1 year in a Dehesa ecosystem, in the SW of Spain. The temporal variability of soil samples was compared by using the coefficient of variation of samples taken on a monthly basis. Spatial variability of the soil samples was measured by comparing the variograms generated with geostatistical techniques. The potential N mineralisation reached a maximum in the spring and summer samples, and a minimum in the autumn. However, the soil NHC 4 , NO 3 and microbial biomass-N showed maximum levels in winter, compared with minimum levels in the spring and summer. The potential mineralisation rate showed a higher temporal variability in the samples taken under tree canopies, due to highest maximum and similar minimum levels reached during the sampling period. The potential mineralisation rate, microbial biomass-N and soil mineral N were higher under the tree canopies than in the open grassland. The spatial distribution of the soil organicmatter and available NHC 4 was strongly influenced by tree canopy size. The semivariograms were adjusted to a spherical model, indicating a maximum NHC 4 variability at a certain distance from the tree crown diameter. The same was not the case for the spatial distribution of the soil NO 3 from the tree crown. Our results indicate that the tree component of a Dehesa ecosystem is a major influence in the spatial and temporal heterogeneity of soils.
Keywords: Dehesa; geostatistics; grassland; Quercus ilex; soil heterogeneity; soil nitrogen

Soil nitrogen heterogeneity in a Dehesa ecosystem - Gallardo, A; Rodriguez-Saucedo, J J (Plant and Soil, 2000)
The Dehesa are savannah-like ecosystems that occupy extensive areas in the mediterranean regions of Southern Spain and Portugal. The changes in the soil nitrogen (N) potential mineralisation rate, microbial biomass-N and available mineral N in soils were studied over 1 year in a Dehesa ecosystem, in the SW of Spain. The temporal variability of soil samples was compared by using the coefficient of variation of samples taken on a monthly basis. Spatial variability of the soil samples was measured by comparing the variograms generated with geostatistical techniques. The potential N mineralisation reached a maximum in the spring and summer samples, and a minimum in the autumn. However, the soil NHC 4 , NO 3 and microbial biomass-N showed maximum levels in winter, compared with minimum levels in the spring and summer. The potential mineralisation rate showed a higher temporal variability in the samples taken under tree canopies, due to highest maximum and similar minimum levels reached during the sampling period. The potential mineralisation rate, microbial biomass-N and soil mineral N were higher under the tree canopies than in the open grassland. The spatial distribution of the soil organicmatter and available NHC 4 was strongly influenced by tree canopy size. The semivariograms were adjusted to a spherical model, indicating a maximum NHC 4 variability at a certain distance from the tree crown diameter. The same was not the case for the spatial distribution of the soil NO 3 from the tree crown. Our results indicate that the tree component of a Dehesa ecosystem is a major influence in the spatial and temporal heterogeneity of soils.
Keywords: Dehesa; geostatistics; grassland; Quercus ilex; soil heterogeneity; soil nitrogen

Spatial pattern of Quercus ilex and Quercus pubescens recruitment in Pinus halepensis dominated woodlands - Lookingbill, T. R.; Zavala, M. A. (Journal of Vegetation Science, 2000)
Abstract. European Mediterranean landscapes have undergone changes in structure in recent years as a result of widespread agricultural land abandonment and cessation of silvicultural regimes. Studies concerning the regeneration dynamics of dominant forest species have become critical to the prediction of future landscape trends in these changing forest stands. Quercus ilex (holm oak) and Q. pubescens (downy oak) are considered to be the terminal point of secondary succession in extensive areas of the Mediterranean region. Recent studies, however, have suggested the existence of recruitment bottlenecks in oak genet populations as a result of current management regimes. In this study, we present evidence of the successful establishment of Q. ilex and Q. pubescens in Pinus halepensis (Aleppo pine) woodlands. We investigate the distribution patterns and spatial relationships among oak recruits and resident pines. Established P. halepensis is randomly distributed throughout the study area. Oak seedlings are positively associated with pine trees, suggesting that P. halepensis individuals provide safe sites for oak genet recruitment. We show that spatial patterns of recruitment are in agreement with the general model of spatial segregation described for other Mediterranean plant communities, with seeder species colonizing large openings after disturbance, followed by a more aggregated recruitment of resprouter species.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: mediterranean forest; Monte Carlo simulation; Nearest neighbour analysis; Nurse effect; Ripley's K-analysis; spatial analysis; succession

Spectral editing of 13C cp/MAS NMR spectra of complex systems: application to the structural characterisation of cork cell walls. - Lopes, M H; Sarychev, A; Neto, C P; Gil, A M (Solid state nuclear magnetic resonance, 2000)
A mathematical method of obtaining 13C CP/MAS subspectra of single components of a complex system is presented and applied to three- and four-component systems. The method is based on previously reported work that exploits different proton relaxation properties for different domains of an heterogeneous system. However, unlike the original method that obtained subspectra through a trial-and-error approach, the method here presented solves the problem mathematically, thus avoiding the time-consuming and non-rigorous trial-and-error step. The method is applied to mixtures of three and four polymers and to a more complex system: cork cell walls. As expected, as the number of components increases, the sharing of relaxation properties between different components is increasingly probable, either due to incidental coincidence of relaxation times or to specific interactions and intimate mixing of compounds. While this hinders the calculation of the subspectra of single chemical components, it may provide useful information about inter-component interactions. This possibility was demonstrated by the application of this method to cork cell walls. Both three-component and four-component approaches showed that three domains exist in cork cell walls: carbohydrate/lignin matrix, mobile suberin close to (probably bonded to) lignin groups (about 42% w/w) and hindered suberin close to (probably bonded to) carbohydrate-OCH2O groups (about 4% w/w).
Keywords: 13CCPrMAS NMR; Cork; Polymer; Quercus suber L.; Relaxation; Spectral editing

Spectral editing of 13C cp/MAS NMR spectra of complex systems: application to the structural characterisation of cork cell walls. - Lopes, M. H.; Sarychev, A.; Neto, C. P.; Gil, a M. (Solid state nuclear magnetic resonance, 2000)
A mathematical method of obtaining 13C CP/MAS subspectra of single components of a complex system is presented and applied to three- and four-component systems. The method is based on previously reported work that exploits different proton relaxation properties for different domains of an heterogeneous system. However, unlike the original method that obtained subspectra through a trial-and-error approach, the method here presented solves the problem mathematically, thus avoiding the time-consuming and non-rigorous trial-and-error step. The method is applied to mixtures of three and four polymers and to a more complex system: cork cell walls. As expected, as the number of components increases, the sharing of relaxation properties between different components is increasingly probable, either due to incidental coincidence of relaxation times or to specific interactions and intimate mixing of compounds. While this hinders the calculation of the subspectra of single chemical components, it may provide useful information about inter-component interactions. This possibility was demonstrated by the application of this method to cork cell walls. Both three-component and four-component approaches showed that three domains exist in cork cell walls: carbohydrate/lignin matrix, mobile suberin close to (probably bonded to) lignin groups (about 42% w/w) and hindered suberin close to (probably bonded to) carbohydrate-OCH2O groups (about 4% w/w).
The following values have no corresponding Zotero field: accession-num: 10868562
Keywords: 13CCPrMAS NMR; Cork; Polymer; Quercus suber L.; Relaxation; Spectral editing

Temporal and spatial variation in C, N, S and trace element contents in the leaves of Quercus ilex within the urban area of Naples. - Alfani, a; Baldantoni, D.; Maisto, G.; Bartoli, G.; Virzo De Santo, A. (Environmental pollution (Barking, Essex : 1987), 2000)
This paper presents a comparative analysis of the concentrations of C, N and S and several trace elements (Fe, Mn, Na, Zn, Cu, V, Pb, Ni, Cr, Cd) in leaves of Quercus ilex, an evergreen oak, collected in the urban area of Naples in 1989 and 1996. The samplings were carried out from 25 urban sites (roads with different traffic flows as well as urban and suburban parks) and from two remote areas as controls. Relative to 1989, the values measured in 1996 denote a strong decrement of S, Fe, Na, Pb, and Cr, with the exception of S in control sites. By contrast, C, N and Cd contents were higher in 1996 than in 1989. Cu and Ni showed a conspicuous increment in control sites as well as in urban sites facing the sea and in the parks, while in all the other urban sites these elements decreased remarkably. No significant difference was found in the leaf contents of Mn, Zn and V measured in 1989 relative to 1996. Both in 1989 and 1996 the contents of N, S, Fe, Na, Cu, Pb, V, Ni, Cr and Cd were significantly higher in leaves from urban sites than in the controls, reflecting the high degree of contamination of the urban area. Concentration factors expressed as the ratio of road/control values for most of the elements were still very high in leaves collected in 1996, though remarkably lower than in 1989.
The following values have no corresponding Zotero field: accession-num: 15092919
Keywords: air pollution biomonitoring; leaf elemental analysis; no x; so 2; Trace Elements

Temporal and spatial variation in C, N, S and trace element contents in the leaves of Quercus ilex within the urban area of Naples. - Alfani, a; Baldantoni, D; Maisto, G; Bartoli, G; Virzo de Santo, A (Environmental pollution (Barking, Essex : 1987), 2000)
This paper presents a comparative analysis of the concentrations of C, N and S and several trace elements (Fe, Mn, Na, Zn, Cu, V, Pb, Ni, Cr, Cd) in leaves of Quercus ilex, an evergreen oak, collected in the urban area of Naples in 1989 and 1996. The samplings were carried out from 25 urban sites (roads with different traffic flows as well as urban and suburban parks) and from two remote areas as controls. Relative to 1989, the values measured in 1996 denote a strong decrement of S, Fe, Na, Pb, and Cr, with the exception of S in control sites. By contrast, C, N and Cd contents were higher in 1996 than in 1989. Cu and Ni showed a conspicuous increment in control sites as well as in urban sites facing the sea and in the parks, while in all the other urban sites these elements decreased remarkably. No significant difference was found in the leaf contents of Mn, Zn and V measured in 1989 relative to 1996. Both in 1989 and 1996 the contents of N, S, Fe, Na, Cu, Pb, V, Ni, Cr and Cd were significantly higher in leaves from urban sites than in the controls, reflecting the high degree of contamination of the urban area. Concentration factors expressed as the ratio of road/control values for most of the elements were still very high in leaves collected in 1996, though remarkably lower than in 1989.
Keywords: air pollution biomonitoring; leaf elemental analysis; no x; so 2; Trace Elements

Water stress responses of seedlings of four Mediterranean oak species - Fotelli, M N; Radoglou, K M; Constantinidou, H.-I. A (Tree Physiology, 2000)
Effects of water stress on phenology, growth, stomatal activity and water status were assessed from April to November 1996 in 2-year-old seedlings of Quercus frainetto Ten. (Quercus conferta Kit.), Quercus pubescens Willd., Quercus macrolepis Kotschy (Quercus aegilops auct.) and Quercus ilex L. growing in containers in northern Greece. All four species developed more than 50% of their total leaf area before the beginning of June—an adaptation to arid climates. Well-irrigated plants tended to develop greater individual leaf area, number of leaves per plant, total plant leaf area, height and root:shoot ratios than water-stressed plants, but the difference between treatments was not significant for any parameter in any species. Quercus macrolepis appeared to be the most drought-tolerant of the four species. It maintained the highest number of leaves of the smallest size and increased the proportion of fine roots during drought. In all species, drought caused significant decreases in stomatal conductance and predawn and midday water potentials from mid-July until the end of August, when the lowest soil water content and highest mean daily air temperatures and midday leaf temperatures occurred; however, the responses were species-specific. Among the four species, Quercus macrolepis sustained the highest stomatal conductance despite very low water potentials, thus overcoming drought by means of desiccation tolerance. Quercus ilex decreased stomatal conductance even before severe water stress occurred, thereby avoiding dessication during drought. Quercus pubescens had the highest water potential despite a high stomatal conductance, indicating that its leaf water status was independent of stomatal activity. Quercus frainetto was the least drought-resistant of the four species. During drought it developed very low water potentials despite markedly reduced stomatal aperture.
10.1093/treephys/20.16.1065
Keywords: Growth; Phenology; Quercus; Stomatal conductance; water potential

Weichselian palynological records from southern Europe: correlation and chronology - Allen, Judy R M; Huntley, Brian (Quaternary International, 2000)
The high resolution, independently dated palynostratigraphic record from Lago Grande di Monticchio spanning the last 101,530 calendar years provides a basis for re-evaluating the correlations between palaeoenvironmental events in Europe during the last glacial as well as a means to determine their chronology. The interstadial events recorded from various localities throughout Europe are combined into a single scheme of correlations and a chronological framework is suggested. This provides a basis for assessing the evolution of the vegetation and environmental patterns across Europe during the last glacial, revealing a general tendency for the latitudinal climatic gradient to have been steeper than it has been during the Holocene. The vegetation has also generally been subject to greater moisture de"ciency, either because of prevailing climatic conditions or as a re#ection of the lower atmospheric concentration of CO 2 . The scheme of correlations is shown to be capable of being extended beyond Europe, not only to marine and ice-core records from the North Atlantic region, but also to a palynological record from north-west North America.
Keywords: chronology; interstadial; Last Glacial (voyante); Monticchio

Abundance, biomass and functional structure of the saprophagous macrofauna in the litter and soil of Mediterranean oak forests - David, J F (PEDOBIOLOGIA, 1999)
The saprophagous macrofauna (macroarthropods, gastropods, earthworms) was sampled in five Mediterranean forests of southern France: two helm oak (Quercus ilex) sites on limestone, two downy oak (Q. pubescens) sites on limestone and a helm oak site on schist. The total biomass was high, ranging from 52.1 to 113.1 g fresh mass m(-2). Classification of species into functional groups (epigeic, epi-anecic, anecic and endogeic) showed that the four groups were well represented in this region. However, the density and biomass of epigeic macroarthropods (mainly millipedes) were significantly higher at the helm oak sites on limestone (186 ind. m(-2); 9.6 g m(-2)) than at the other sites. In contrast, the density and biomass of epi-anecic earthworms (Lumbricus spp.) were higher at the downy oak: sites on limestone (13 ind. m(-2); 16.7 g m(-2)). Anecic earthworms (Aporrectodea and Scherotheca spp.) were dominant in terms of biomass at all sites (overall mean 56.6 g m(-2)). Although the results are consistent with possible competitive interactions between epigeic macroarthropods and epi-anecic earthworms, they also show a high degree of coexistence between both of these groups and anecic earthworms. The study provides an insight into the possible responses of the macrofauna of N-W Europe to climate change towards warmer and drier conditions. There is potential for maintenance of all the functional groups that take part in the formation of forest mull.
Keywords: earthworms; functional group; soil macroarthropods

Acclimatation of the roe deer (Capreolus capreolus L.) introduced in a supramediterranean habitat and its occupation of space - Maillard, D; Gaudin, J C; Reudet, D; Boutin, J M (REVUE D ECOLOGIE-LA TERRE ET LA VIE, 1999)
In 1988 and 1989, we captured 74 roe deer (Capreolus capreolus) in the Chize National Reserve in France and transferred them to the Monts de Vaucluse. Thirteen individuals were followed by radio-tracking during two years. The study area, a supramediterranean habitat dominated by Quercus humilis and Quercus ilex covered 40,000 ha. The instrumented deer were located daily during the three first months, the longest time required to settle on a home range, and once a week thereafter. These data allowed us to calculate survival rates and size of home ranges. The mean survival rate during the first year after the introduction was 85 %. Except for one adult male and one adult female, all radio-equipped deer established their home range within 3 km of the release site. The time required for definitive establishment on a home range varied from 45 to 85 days after release. The mean area prospected before settling on a home range was greater for adults (n = 5) than for juveniles (n = 6) (2,240 ha vs. 478 ha). Conversely, the mean home range size after the period of prospection was greater for juveniles (n = 6) than for adults (n = 4) (823 ha vs. 342 ha). If capture, transport and release are carried out under good conditions, the roe deer can adapt to the Mediterranean climate and habitat.
APS
Keywords: Chize National Reserve; Quercus humilis; Quercus ilex; roe deer

Afinidades bióticas entre encinares ibéricos en función de sus taxocenosis de acrídidos (Insecta, Orthoptera). - Presa, J J; Clemente, M E; HERNÁNDEZ, A; García, M D (Boln. Asoc. esp. Ent., 1999)
Orthopterocenosis from eight oak forests of the Iberian Peninsula are analyzed and compared. Two groups of biotopes are stablished: iberian-atlantic and iberian-mediterranean. Carrascal of Font Roja is excluded and reamins isolated, with a very low similarity index value with the other oak forests, because its peculiar characteristics. Use of orthopterocenosis in order to characterize specific biotopes is proposed
Keywords: holm oak forests (PG); orthopterocenosis

Agriculture and landscape in Portugal - Firmino, Ana (Landscape and Urban Planning, 1999)
Landscape is the result of a dynamic process, which changes either due to natural causes or due to human impact. Therefore, we cannot expect landscapes to stay unchangeable, although some are evolving more quickly than others. Portugal is a mosaic of landscapes, partly because of different climatic conditions and orographic and morphologic genesis but also because of the impact of human activity, especially in agriculture. This article deals with the impacts of this sector on the landscapes, the consequences of which can be found not only in the ecosystems but also in the daily life of the people, in their jobs, in the abandonment of the land and in the change of mentality, related to the inadequate national policies and the overestimation of short-term economic pro®t
Keywords: agri-environmental measures; Environment; Portugal

Agriculture and landscape in Portugal - Firmino, Ana (Landscape and Urban Planning, 1999)
Landscape is the result of a dynamic process, which changes either due to natural causes or due to human impact. Therefore, we cannot expect landscapes to stay unchangeable, although some are evolving more quickly than others. Portugal is a mosaic of landscapes, partly because of different climatic conditions and orographic and morphologic genesis but also because of the impact of human activity, especially in agriculture. This article deals with the impacts of this sector on the landscapes, the consequences of which can be found not only in the ecosystems but also in the daily life of the people, in their jobs, in the abandonment of the land and in the change of mentality, related to the inadequate national policies and the overestimation of short-term economic pro®t
Keywords: agri-environmental measures; Environment; Portugal

Altitudinal differences in UV absorbance, UV reflectance and related morphological traits of Quercus ilex and Rhododendron ferrugineum in the Mediterranean region - Filella, Iolanda; Penuelas, Josep (Plant Ecology, 1999)
We studied the variations in different physiological parameters associated with UV-B radiation defense: UV-B radiation absorbance, UV-visible spectral reﬂectance, carotenoids concentration, leaf thickness, SLW (speciﬁc leaf weigth) and trichome density in Quercus ilex growing at 200 and 1200 m and Rhododendron ferrugineum growing at 2200 m. We examined the role of these parameters as protection mechanisms in an altitudinal gradient of increasing UV radiation in northern Catalonia and in sun and shade leaves. The concentration of UV-B radiation absorbing pigments was 15% higher in sun leaves of Q. ilex at 1200 m than in those from 200 m altitude. Sun leaves of R. ferrugineum presented concentrations three times higher than those of Q. ilex. Reﬂectance ranged between 5% (in the region 300–400 nm) and 12% (in the region 280–300 nm). The variation of reﬂectance with altitude followed an inverse trend respect to absorbance in the 280–300 nm region, with higher values the lower the altitude, but in the 300–400 nm region, reﬂectance of the lower site was the lowest. In both species and altitudes sun leaves presented higher concentrations of UV-B radiation absorbing pigments and UV reﬂectance than shade leaves. Quercus ilex trees of the higher location presented higher NDPI (Normalized Difference Pigment Reﬂectance Index) values, indicating higher carotenoids/chlorophylla ratio. Actual measurements of carotenoid/chlorophyll a ratio conﬁrmed this pattern. The photochemical reﬂectance index (PRI) presented higher values the higher the location indicating lower photosynthetic radiation-use efﬁciency. Speciﬁc leaf weight (SLW) and leaf thickness were larger in Q. ilex trees of higher location than in those of lower location. In both sites, sun leaves also presented larger SLW values than shade leaves. Adaxial leaf hair density in sun leaves was signiﬁcantlly higher in the lower location. UV absorption and linked morphological traits (SLW, leaf thickness measured in Q. ilex) presented the larger differences among studied plants at different altitudes and seem to be the dominant UV protecting mechanisms.
Keywords: Altitude; carotenoids/chlorophyll a ratio; leaf hair density; Mediterranean Region; ndpi; pri; Quercus ilex; rhododendron ferrugineum; slw; Thickness; uv absorbing compounds; uv reflectance

Altitudinal differences in UV absorbance, UV reflectance and related morphological traits of Quercus ilex and Rhododendron ferrugineum in the Mediterranean region - Filella, Iolanda; Penuelas, Josep (Plant Ecology, 1999)
We studied the variations in different physiological parameters associated with UV-B radiation defense: UV-B radiation absorbance, UV-visible spectral reﬂectance, carotenoids concentration, leaf thickness, SLW (speciﬁc leaf weigth) and trichome density in Quercus ilex growing at 200 and 1200 m and Rhododendron ferrugineum growing at 2200 m. We examined the role of these parameters as protection mechanisms in an altitudinal gradient of increasing UV radiation in northern Catalonia and in sun and shade leaves. The concentration of UV-B radiation absorbing pigments was 15% higher in sun leaves of Q. ilex at 1200 m than in those from 200 m altitude. Sun leaves of R. ferrugineum presented concentrations three times higher than those of Q. ilex. Reﬂectance ranged between 5% (in the region 300–400 nm) and 12% (in the region 280–300 nm). The variation of reﬂectance with altitude followed an inverse trend respect to absorbance in the 280–300 nm region, with higher values the lower the altitude, but in the 300–400 nm region, reﬂectance of the lower site was the lowest. In both species and altitudes sun leaves presented higher concentrations of UV-B radiation absorbing pigments and UV reﬂectance than shade leaves. Quercus ilex trees of the higher location presented higher NDPI (Normalized Difference Pigment Reﬂectance Index) values, indicating higher carotenoids/chlorophylla ratio. Actual measurements of carotenoid/chlorophyll a ratio conﬁrmed this pattern. The photochemical reﬂectance index (PRI) presented higher values the higher the location indicating lower photosynthetic radiation-use efﬁciency. Speciﬁc leaf weight (SLW) and leaf thickness were larger in Q. ilex trees of higher location than in those of lower location. In both sites, sun leaves also presented larger SLW values than shade leaves. Adaxial leaf hair density in sun leaves was signiﬁcantlly higher in the lower location. UV absorption and linked morphological traits (SLW, leaf thickness measured in Q. ilex) presented the larger differences among studied plants at different altitudes and seem to be the dominant UV protecting mechanisms.
Keywords: Altitude; carotenoids/chlorophyll a ratio; leaf hair density; Mediterranean Region; ndpi; pri; Quercus ilex; rhododendron ferrugineum; slw; Thickness; uv absorbing compounds; uv reflectance

Análisis del área foliar del alcornoque en relación con tratamientos silvo-pastorales - Caritat, A. I.; Molinas, M. I.; Vilar, I. P.; Masson, L. (Scientia gerundensis, 1999)
The fluctuations showed by ecophysiologic parameters, like leaf area and leaf area indices, in relation to silvo-pastoral treatments can be used to evaluate the effects of these treatments on o&-cork forests. Leaf area shows a close relation to production and is a good indicator of the physiological state of the plants. Leaf area, leaf area indices and specific leaf weight have been studied in four cork-oak wood stations in relation to shrub clearing and grazing treat- ments. Leaf parameters have been measured using a computer image analysis system. We found that, in general, leaf average area is increased by silvo-pastotal treatments, apparently in order to recover the wasted canopy and in answer to nutrient supply. On the other hand, leaf area index decreases after treatments because of the leaf biomass lost, but the fast apical growth showed by cork-trees in treated plots points to a quick recovery of this parameter when an appropiate tree density is reached.
Keywords: cork-oak; Grazing; leaf area; leaf index; shrub cleareing; silvo-pastoral treatments

Análisis del área foliar del alcornoque en relación con tratamientos silvo-pastorales - Caritat, A I; Molinas, M I; Vilar, I P; Masson, L (Scientia gerundensis, 1999)
The fluctuations showed by ecophysiologic parameters, like leaf area and leaf area indices, in relation to silvo-pastoral treatments can be used to evaluate the effects of these treatments on o&-cork forests. Leaf area shows a close relation to production and is a good indicator of the physiological state of the plants. Leaf area, leaf area indices and specific leaf weight have been studied in four cork-oak wood stations in relation to shrub clearing and grazing treat- ments. Leaf parameters have been measured using a computer image analysis system. We found that, in general, leaf average area is increased by silvo-pastotal treatments, apparently in order to recover the wasted canopy and in answer to nutrient supply. On the other hand, leaf area index decreases after treatments because of the leaf biomass lost, but the fast apical growth showed by cork-trees in treated plots points to a quick recovery of this parameter when an appropiate tree density is reached.
Keywords: cork-oak; Grazing; leaf area; leaf index; shrub cleareing; silvo-pastoral treatments

Antimutagenicity of a suberin extract from Quercus suber cork. - Krizková, L; Lopes, M H; Polónyi, J; Belicová, a; Dobias, J; Ebringer, L (Mutation research, 1999)
The possible protective effect of a suberin extract from Quercus suber cork on acridine orange (AO)-, ofloxacin- and UV radiation-induced mutagenicity (bleaching activity) in Euglena gracilis was examined. To our knowledge, the present results are the first attempt to analyse suberin in relation to mutagenicity of some chemicals. Suberin exhibits a significant dose-dependent protective effect against AO-induced mutagenicity and the concentration of 500 micrograms/ml completely eliminates the Euglena-bleaching activity of AO. The mutagenicity of ofloxacin is also significantly reduced in the presence of suberin (125, 250 and 500 micrograms/ml). However, the moderate protective effect of suberin on UV radiation-induced mutagenicity was observed only at concentrations 500 and 1000 micrograms/ml. Our data shows that suberin extract from Q. suber cork possess antimutagenic properties and can be included in the group of natural antimutagens acting in a desmutagenic manner.
Keywords: Acridine Orange; Acridine Orange: toxicity; Animals; Antimutagenic Agents; Antimutagenic Agents: pharmacology; Euglena gracilis; Euglena gracilis: drug effects; Euglena gracilis: genetics; Euglena gracilis: radiation effects; Lipids; Membrane Lipids; Membrane Lipids: pharmacology; Mutagenicity Tests; Mutagenicity Tests: methods; Mutagens; Mutagens: toxicity; Ofloxacin; Ofloxacin: toxicity; Plant Extracts; Plant Extracts: pharmacology; Plant Shoots; Plant Shoots: chemistry; Spectrophotometry, Ultraviolet; Superoxides; Superoxides: metabolism; Trees; Trees: chemistry; Ultraviolet Rays

APLICACION DEL ANALISIS DE IMAGENES AL ESTUDIO DE PARÁMETROS MORFOMETRICOS DEL CORCHO - Campos, M; Molinas, M (Scientia gerundensis, 1999)
In this work we propose a method to study cork quality from little samples throug the analy- sis of images. This method has aplications in all studies that need cork quality determination. The digital analysis of images is an apropiate option due to makes morphometry automati- cally and it allows a quick manipulation of the results. It is a fast and objective method because allows the comparative study between a high number of samples; so it could be pos- sible to compare populations or individual in order to study the influence of some ambiental or getnetic factors and have another aproach to three's selection. Here we describe an digital analysis program based on IMAGE 1.41 VDMi software for Macintosh developed to measu- re severa1 cork morphometric parameters.
Keywords: Cork quality; image analysis; methodology; morphometry; Quercus suber

APLICACION DEL ANALISIS DE IMAGENES AL ESTUDIO DE PARÁMETROS MORFOMETRICOS DEL CORCHO - Campos, M.; Molinas, M. (Scientia gerundensis, 1999)
In this work we propose a method to study cork quality from little samples throug the analy- sis of images. This method has aplications in all studies that need cork quality determination. The digital analysis of images is an apropiate option due to makes morphometry automati- cally and it allows a quick manipulation of the results. It is a fast and objective method because allows the comparative study between a high number of samples; so it could be pos- sible to compare populations or individual in order to study the influence of some ambiental or getnetic factors and have another aproach to three's selection. Here we describe an digital analysis program based on IMAGE 1.41 VDMi software for Macintosh developed to measu- re severa1 cork morphometric parameters.
Keywords: Cork quality; image analysis; methodology; morphometry; Quercus suber

Apoplastic Solute Concentrations of Organic Acids and Mineral Nutrients in the Leaves of Several Fagaceae - Gabriel, Reinhard; Kesselmeier, Jürgen (Plant and Cell Physiology, 1999)
Ion chromatographic methods determined organic acids and main nutrient minerals in the apoplastic solution from leaves of several Fagaceae (Quercus ilex L., Quercus cerris L., Quercus virgiliana (Ten.) Ten, and Fagus sylvatica L.). The anions of organic acids found in high amounts (250 to 650 μM) were quinate, malate, and oxalate. Lactate, pyruvate, formate and acetate were detected in relatively low amounts with concentrations between 20 and 200 μM. The total concentration of organic acids in the apoplastic sap ranged between 1.5 and 2 mM. The total concentration of inorganic cations (K+, Mg2+, NH4+, Ca2+, Na+) and anions (C1−, NO3−, SO2−4 and PO3−4) in the apoplastic sap varied between 5 and 10 mM, and 0.35 and 1.8 mM, respectively. We conclude that the concentration of organic acid ions in the leaf apoplast depends mainly on the exchange with the leaf cells and is influenced by the electrochemical gradient between the symplast and the apoplast in relation to the water potential of the leaf. The determination of formate and acetate in the apoplastic compartment of leaves lend weight to the argument that the production of these acids by trees is a important emission source to the atmosphere.
Keywords: Anions; Apoplast; cations; Fagaceae; leaf; organic acids

Apoplastic Solute Concentrations of Organic Acids and Mineral Nutrients in the Leaves of Several Fagaceae - Gabriel, Reinhard; Kesselmeier, Jürgen (Plant and Cell Physiology, 1999)
Ion chromatographic methods determined organic acids and main nutrient minerals in the apoplastic solution from leaves of several Fagaceae (Quercus ilex L., Quercus cerris L., Quercus virgiliana (Ten.) Ten, and Fagus sylvatica L.). The anions of organic acids found in high amounts (250 to 650 μM) were quinate, malate, and oxalate. Lactate, pyruvate, formate and acetate were detected in relatively low amounts with concentrations between 20 and 200 μM. The total concentration of organic acids in the apoplastic sap ranged between 1.5 and 2 mM. The total concentration of inorganic cations (K+, Mg2+, NH4+, Ca2+, Na+) and anions (C1−, NO3−, SO2−4 and PO3−4) in the apoplastic sap varied between 5 and 10 mM, and 0.35 and 1.8 mM, respectively. We conclude that the concentration of organic acid ions in the leaf apoplast depends mainly on the exchange with the leaf cells and is influenced by the electrochemical gradient between the symplast and the apoplast in relation to the water potential of the leaf. The determination of formate and acetate in the apoplastic compartment of leaves lend weight to the argument that the production of these acids by trees is a important emission source to the atmosphere.
Keywords: Anions; Apoplast; cations; Fagaceae; leaf; organic acids

Belowground biodiversity in a Mediterranean landscape: relationships between saprophagous macroarthropod communities and vegetation structure - DAVID, J. F.; Devernay, S. (Biodiversity and …, 1999)
Millipedes and woodlice were sampled at 27 sites in a mosaic landscape in order to establish the extent to which the macroarthropod community changed with dierent plant for- mations. Multivariate analyses conducted on abundance data for ten species revealed four main types of macroarthropod communities. This classi®cation was highly correlated with vegetation structure and particularly the degree of openness of the sites. Communities dominated by Om- matoiulus rutilans (Julidae) occurred in open grassland; those dominated by Glomeris marginata (Glomeridae) plus Porcellio gallicus (Porcellionidae) were found at the least open sites, with a high oak cover; communities with a high proportion of the endemic glomerid Glomeris annulata oc- curred in semi-open sites with a substantial cover of shrubs. Species diversity was signi®cantly higher at the semi-open sites, this being interpreted as an edge eect. Population density and biomass were lower at wooded sites. In the context of a regional trend towards woodland ex- pansion, the results are discussed from the viewpoint of conserving the pool of millipede and woodlouse species and of maintaining the abundance of saprophagous macroarthropods in the region's ecosystems.
Keywords: diplopoda; habitat preferences; Isopoda; Mediterranean Region; vegetation changes

Belowground biodiversity in a Mediterranean landscape: relationships between saprophagous macroarthropod communities and vegetation structure - David, J F; Devernay, S (Biodiversity and …, 1999)
Millipedes and woodlice were sampled at 27 sites in a mosaic landscape in order to establish the extent to which the macroarthropod community changed with dierent plant for- mations. Multivariate analyses conducted on abundance data for ten species revealed four main types of macroarthropod communities. This classi®cation was highly correlated with vegetation structure and particularly the degree of openness of the sites. Communities dominated by Om- matoiulus rutilans (Julidae) occurred in open grassland; those dominated by Glomeris marginata (Glomeridae) plus Porcellio gallicus (Porcellionidae) were found at the least open sites, with a high oak cover; communities with a high proportion of the endemic glomerid Glomeris annulata oc- curred in semi-open sites with a substantial cover of shrubs. Species diversity was signi®cantly higher at the semi-open sites, this being interpreted as an edge eect. Population density and biomass were lower at wooded sites. In the context of a regional trend towards woodland ex- pansion, the results are discussed from the viewpoint of conserving the pool of millipede and woodlouse species and of maintaining the abundance of saprophagous macroarthropods in the region's ecosystems.
Keywords: diplopoda; habitat preferences; Isopoda; Mediterranean Region; vegetation changes

Biodiversity of woody species in oak woodlands of southern Spain and northern Morocco - MARAÑÓN, T; Ajbilou, R; Ojeda, F; Arroyo, J (Forest Ecology and Management, 1999)
Three biodiversity parameters ± species richness, endemic species richness and taxonomic singularity ± have been evaluated for the woody understorey of oak woodlands on sandstone-derived substrates, on both sides of the Strait of Gibraltar. There is a similarity in ¯oristic composition and ecological distribution of woody plant communities across the Strait. Nevertheless, we have detected signi®cant differences. These include a general reduction in species richness, number of endemic species and taxonomic singularity (at the community level), and a greater abundance of widespread, generalist species, on the southern side (Moroccan) communities, as compared to the north (Spanish ones). We interpret these differences as partly caused by the contrasting management of woodlands, with higher slashing and browsing pressure in Morocco.
Keywords: Cork oak; diversity; Mediterranean woodlands; Quercus; Species richness; strait of gibraltar

Biogenic volatile organic compounds (VOC): An overview on emission, physiology and ecology - Kesselmeier, J; Staudt, M (JOURNAL OF ATMOSPHERIC CHEMISTRY, 1999)
This overview compiles the actual knowledge of the biogenic emissions of some volatile organic compounds (VOCs), i.e., isoprene, terpenes, alkanes, alkenes, alcohols, esters, carbonyls, and acids. We discuss VOC biosynthesis, emission inventories, relations between emission and plant physiology as well as temperature and radiation, and ecophysiological functions. For isoprene and monoterpenes, an extended summary of standard emission factors, with data related to the plant genus and species, is included. The data compilation shows that we have quite a substantial knowledge of the emission of isoprene and monoterpenes, including emission rates, emission regulation, and biosynthesis. The situation is worse in the case of numerous other compounds (other VOCs or OVOCs) being emitted by the biosphere. This is reflected in the insufficient knowledge of emission rates and biological functions. Except for the terpenoids, only a limited number of studies of OVOCs are available; data are summarized for alkanes, alkenes, carbonyls, alcohols, acids, and esters. In addition to closing these gaps of knowledge, one of the major objectives for future VOC research is improving our knowledge of the fate of organic carbon in the atmosphere, ending up in oxidation products and/or as aerosol particles.
Keywords: acids; alkanes; alkenes; carbonyls; ecology; emission; emission inventories; Esters; isoprene; nonmethane hydrocarbons; oxygenated compounds; physiology; review; terpenes; Volatile Organic Compounds

Biomass, nutrient content, litterfall and nutrient return to the soil in Mediterranean oak forests - Rapp, Maurice; Santa Regina, Ignacio; Rico, Mercedes; Gallego, Humberto Antonio (Forest Ecology and Management, 1999)
We estimated above-ground biomass, nutrient content, litterfall and nutrient return to the soil in deciduous and evergreen Quercus pyrenaica Will., Quercus lanuginosa Lamk and evergreen Quercus ilex L. oak forests, respectively, near Salamanca (Spain) and Montpellier (France). The calculated biomass ranged from 64 to 121 Mg ha ÿ1 . Perennial material (trunks and branches) represented 96±97% in the four Spanish Q. pyrenaica stands and 93% in the French Q. lanuginosa and Q. ilex stands. Q. pyrenaica had higher P, Mg, Fe and Mn contents than the other two species from southern France. In contrast, these latter species had higher N and Ca concentrations. All of these differences were related to soil nutrient availability, especially Ca, Mg, P, Fe and Mn. Comparison of the chemical composition of leaves on trees with that of leaf litter indicated retention and translocation of N, P and K from leaves to perennial biomass and recycling of Ca and Mg from trees to the soil
Keywords: forest biomass; forest ecosystems; litterfall; Q. ilex; Q. lanuginosa; Q. pyrenaica

Biomass, nutrient content, litterfall and nutrient return to the soil in Mediterranean oak forests - Rapp, Maurice; Santa Regina, Ignacio; Rico, Mercedes; Gallego, Humberto Antonio (Forest Ecology and Management, 1999)
We estimated above-ground biomass, nutrient content, litterfall and nutrient return to the soil in deciduous and evergreen Quercus pyrenaica Will., Quercus lanuginosa Lamk and evergreen Quercus ilex L. oak forests, respectively, near Salamanca (Spain) and Montpellier (France). The calculated biomass ranged from 64 to 121 Mg ha ÿ1 . Perennial material (trunks and branches) represented 96±97% in the four Spanish Q. pyrenaica stands and 93% in the French Q. lanuginosa and Q. ilex stands. Q. pyrenaica had higher P, Mg, Fe and Mn contents than the other two species from southern France. In contrast, these latter species had higher N and Ca concentrations. All of these differences were related to soil nutrient availability, especially Ca, Mg, P, Fe and Mn. Comparison of the chemical composition of leaves on trees with that of leaf litter indicated retention and translocation of N, P and K from leaves to perennial biomass and recycling of Ca and Mg from trees to the soil
Keywords: forest biomass; forest ecosystems; litterfall; Q. ilex; Q. lanuginosa; Q. pyrenaica

Bird communities of highway verges: Influence of adjacent habitat and roadside management - Meunier, Francis D; Verheyden, Christophe; Jouventin, Pierre (Acta Oecologica, 1999)
We have investigated the effects of landscape traversed and roadside structure on the use of highway verges by birds. Three contrasted landscapes were chosen in terms of human land use and vegetation structure: an intensive farmland, a pine plantation, and a matoral. The roadside sections varied in vegetation structure, width and profile. We recorded birds present in roadsides and adjacent habitats by transect counts over all seasons. Roadside bird species appeared for a great part similar to those of adjacent habitats. However, diversity and abundance in verges did not depend on that of adjacent habitats. Woody roadsides were compararable to hedges, as trees (and shrubs) in verges enhanced species richness and abundance of birds in the farmland and woodland sites. Width and profile of verges had less influence. In all sites, typical species of the habitat traversed partly avoided roadsides. On the contrary, numerous species associated with ‘rare’ habitats in one site preferred roadsides, provided that verge vegetation contrasted with the dominant habitat. It is concluded that birds responses to highways can vary greatly with landscape traversed and verge vegetation. Highway verges could be favorable to birds, if they constitute a complementary habitat to the dominant habitat within a landscape
Keywords: Biodiversity; bird communities; landscape; linear structure; roadside

The breakdown of leaves of poplar and holm oak in three Moroccan streams : effect of burial in the sediment - Naamane, B; Chergui, H; Pattee, E (Annales de Limnologie - International Journal of Limnology, 1999)
Weight loss of leaves of Populus nigra and Quercus ilex was observed in coarse-mesh bags exposed in three watercourses and their sediment (-30 and -50 cm) near the city of Fes. The watercourses were: Oued Sebou (a river), Oued Sidi-Harazem (issuing from a warm spring), and Ain Chkef (a cold spring). Weight loss was faster at the surface than within the sediment. Weight loss was faster in poplar than in the tough holm oak leaves. At all levels, weight loss was fastest in Oued Sebou where the water flowed faster both at the surface and within the coarser sediment. It was slowest in the cold spring. Thus the influence of leaf texture, current velocity, and temperature were stressed
Keywords: burial; decomposition; Holm oak; Poplar; watercourse

Breeding performance of the Blue Tit Parus caeruleus in a patchy Mediterranean landscape - Catalan, R M; Haeger, J F (REVUE D ECOLOGIE-LA TERRE ET LA VIE, 1999)
This study compares reproductive strategy and breeding success of Parus caeruleus in a helm-oak (Quercus rotundifolia) forest and a pine plantation (Pinus pinea and P. pinaster) in the southern Iberian Peninsula. During the breeding period, an asymmetric flow of individuals takes place from the helm-oak forest to the pine plantation. This flow is favoured by nestboxes where Blue tits can lay their eggs. During the winter, a large part of the population moves back from the pine plantation to the helm-oak forest. Breeding pair density was much higher in the helm-oak forest than in the pine plantation. This may bt accounted for by the poorer quality of the resources available in the pine plantation which birds try to compensate for with larger breeding territories. Breeding density and most life-history traits examined (timing of breeding, clutch site, egg size, number of fledglings and fledgling weight) were similar in both habitats, as a result of the phenotypic plasticity of this species. Although breeding success was similar in both habitats, recruitment of new individuals per unit area was higher in the helm-oak forest. The consequences of pine plantations, as a form of forestry management, on species conservation is discussed.
APS
Keywords: breeding success; Holm oak; iberian peninsula; Parus caeruleus; Pinus pinaster; Pinus pinea; Quercus ilex; reproductive strategies

Caracterización de los quesos artesanos extremeños: Una aproximación desde el punto de vista del consumidor - Pulido García, Francisco; Mesías Díaz, Francisco Javier; Rodríguez de Ledesma Vega, Antonio; Coleto Martímez, J M; Gallardo Díaz, Juan; Escribano Sánchez, Miguel (Simposio Internacional. Caracterización de los productos ganaderos de la dehesa, 1999)
En Extremadura existen quesos artesanos de cabra y oveja muy apreciados por los consumidores pero que, en el aspecto productivo y a pesar de los esfuerzos realizados desde todos los ámbitos, adolecen de una completa caracterización. En esta comunicación, y a partir de los datos de una encuesta a consumidores realizada dentro del proyecto de investigación del Programa Sectorial de I+D del MAPA “La comercialización de los quesos en Extremadura”, se procede a una caracterización de los distintos tipos de quesos artesanos extremeños, incidiendo en aspectos como su conocimiento, la apreciación de su naturalidad y sabor, precio, etc. Con ello se obtiene una imagen de estos productos que contribuirá a mejorar su posicionamiento y su comercialización.
Keywords: encuestas a consumidores; quesos artesanos de cabra y oveja

Changes in use and landscape preferences on the agricultural-livestock landscapes of the central Iberian Peninsula (Madrid, Spain) - Gómez-Limón, J; Fernández, J V L (Landscape and urban planning, 1999)
The abandonment of traditional uses over the last 60 years of the dehesa landscapes of the central Iberian Peninsula is leading to an increase in trees and bushes and to a big change in the structure of these landscapes. We studied one of these cases, comparing four different points in time of the ecological succession (years: 1930, 1957, 1995 and 2010) which were from photorealistic simulations represented by digitally treated photographs. Different groups of users (livestock farmers, managers and recreationists) have different landscape preferences. The livestock farmers tend to prefer open landscapes, in comparison to the recreationists and managers who show a preference for landscapes with denser vegetation. These differences could be related to certain cultural components or expectations with regard to uses on these landscapes. The relationships between landscape preferences, expected uses on the territory and environmental goods and services should be taken into account in the context of an environmental planning involving participation and democracy.
Keywords: changes in use; Landscape management; landscape preferences; visual simulation

Comparative Analysis of the Lignins of Cork from Quercus suber L. and Wood from Eucalyptus globulus L. by Dry Hydrogen Iodide Cleavage - Akim, L G; Cordeiro, N; Pascoal Neto, C; Gandini, A (Lignin: Historical, Biological, and Materials Perspectives, 1999)
Lignin from cork (Quercus suber L.) was isolated by two procedures: organosolv extraction and dioxane-water (9:1) extraction in presence of HCl. These lignins were characterized using a mild hydrogen iodide-cleavage method followed by 1H NMR and GPC analysis. The results were compared with those for eucalyptus lignins (Eucalyptus globulus) isolated by the same procedures. The method used provided syringyl/guaiacyl ratios for the linear parts of the macromolecules and the degrees of crosslinking. The prevalence of guaiacyl units was demonstrated for cork lignin. Syringyl units were found to be minor components and present mainly in the linear parts of macromolecules. p-Hydroxyphenyl units were mainly condensed. Cork lignin was found to be significantly more cross-linked than eucalyptus lignin.
doi:10.1021/bk-2000-0742.ch014
Keywords: cross-linking (PG); Eucalyptus globulus; Lignin; Quercus suber