<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>7</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">ALADOS, C L</style></author><author><style face="normal" font="default" size="100%">ELAICH, A</style></author><author><style face="normal" font="default" size="100%">PAPANASTASIS, V P</style></author><author><style face="normal" font="default" size="100%">OZBEK, H</style></author><author><style face="normal" font="default" size="100%">Freitas, H</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Kepner, William G</style></author><author><style face="normal" font="default" size="100%">Rubio, Jose L</style></author><author><style face="normal" font="default" size="100%">Mouat, David A</style></author><author><style face="normal" font="default" size="100%">Pedrazzini, Fausto</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">MONITORING TOOLS TO ASSESS VEGETATION SUCCESSIONAL REGRESSION AND PREDICT CATASTROPHIC SHIFTS AND DESERTIFICATION IN MEDITERRANEAN RANGELAND ECOSYSTEMS</style></title><secondary-title><style face="normal" font="default" size="100%">Desertification in the Mediterranean Region a Security Issue</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">disturbance</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Grazing</style></keyword><keyword><style  face="normal" font="default" size="100%">matorral (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">Spatial pattern</style></keyword><keyword><style  face="normal" font="default" size="100%">Vegetation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">Submitted</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer Netherlands</style></publisher><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The relationship between grazing intensity and ecosystem performance is complex and can depend on the prevailing ecological conditions. Previous studies have revealed that, in traditional grazing ecosystems, grazing can reduce ecosystem diversity in poor soils, but increase diversity and productivity in rich ecosystems subject to moderate grazing pressure. We are interested in detecting long-term structural changes or drift in an ecosystem before it is too late to prevent irreversible degradation. We analyzed vegetation spatial patterns and complexities of four Mediterranean communities: Tihmadit Region (Middle Atlas, Morocco), Camiyayla (Namrum) Region (Taurus Mountain, Turkey), Sykia Region (south of the Sithonia Peninsula, Greece), and Cabo de Gata Nijar Natural Park, Spain. Grazing disturbance was most intense near shelter and water points, which lead to gradients in soil surface disruption, compaction, and changes in the composition and cover of perennial vegetation. Dense matorral was more resistant to species loss than were moderately dense and scattered matorral, and grassland. Information fractal dimension decreased as we moved from a dense matorral to a discontinuous matorral, and increased as we moved to a more scattered matorral and to a grassland, which resulted in two opposing processes (interaction declining with ecosystem development, and immigration increasing with degradation) in a common pattern, i.e., small patches homogeneously distributed in the landscape. Characteristic species of the natural vegetation declined in frequency and organization in response to higher grazing disturbance, while species of disturbed areas exhibited the opposite trend. Overall, the spatial organization of the characteristic plants of each community decreased with increasing vegetation degradation, with the intensity of the trend being related to the species’ sensitivity to grazing. Developmental instability analyses of key species were used to determine the sensitivity of dominant key species to grazing pressure. Palatable species, which are better adapted to being eaten, such as Periploca laevigata, Phillyrea latifolia and Genista pseudopilosa, were able to resist moderate grazing pressure, while species of disturbed, grazed sites did not change developmental instability in response to increasing grazing pressure, such as Thymus hyemalis, Teucrium lusitanicum and Cistus monspeliensis. The usefulness of these monitoring tools in preventing land degradation is discussed.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Faria, Nuno</style></author><author><style face="normal" font="default" size="100%">Rabaça, João E.</style></author><author><style face="normal" font="default" size="100%">Morales, Manuel B.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Linking plant composition and arthropod abundance to establish little bustard breeding requirements in pastureland dominated landscapes</style></title><secondary-title><style face="normal" font="default" size="100%">Biodiversity and Conservation</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acrididae</style></keyword><keyword><style  face="normal" font="default" size="100%">Fabaceae</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Microhabitat selection</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant richness</style></keyword><keyword><style  face="normal" font="default" size="100%">Tetrax tetrax</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s10531-012-0300-8http://www.springerlink.com/index/10.1007/s10531-012-0300-8</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">21</style></volume><pages><style face="normal" font="default" size="100%">2109 - 2125</style></pages><isbn><style face="normal" font="default" size="100%">1053101203008</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Most research on steppe bird habitat selection has been focused on the effects of management regimes or vegetation structure. However, much less is known on how plant composition is related with steppe bird occurrence. We investigated microhabitat of little bustard territorial males and females during the nesting and chick-rearing season in areas with dominance of pastureland focusing on plant composition. We searched for relationships between preferred vegetation and arthropod abundance in order to identify the contribution of different vegetation typologies in providing essential trophic resources for the species. Surveys of little bustards were made using car and foot transects. Plant composition was obtained within a 50 9 50 cm square at four sampling replicates and arthropod availability was sampled using a sweep net. Statistical procedures were conducted in three steps: (1) analysis of variance was used to identify at univariate level the plant composition and arthropod variables that were signiﬁcantly related with both male and female occurrence sites; (2) principal components analysis was performed using the variables with signiﬁcant results at univariate level; (3) model averaging on generalized linear and mixed models was applied to evaluate the selection probability of each principal component. The species occurs in sites with high ﬂoristic richness and high abundance of Fabaceae species, although plant composition differs from male to female sites. These variables were found to be crucial to provide higher abundances of arthropods, notably of Acrididea, Formicidae and some groups of Coleoptera which are decisive for the selection of displaying or female breeding sites.</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ricarte, Antonio</style></author><author><style face="normal" font="default" size="100%">Ángeles Marcos-García, M</style></author><author><style face="normal" font="default" size="100%">Moreno, Claudia E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Assessing the effects of vegetation type on hoverfly (Diptera: Syrphidae) diversity in a Mediterranean landscape: implications for conservation</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Insect Conservation</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">alpha beta and gamma diversity</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">national park</style></keyword><keyword><style  face="normal" font="default" size="100%">scrubland</style></keyword><keyword><style  face="normal" font="default" size="100%">Spain</style></keyword><keyword><style  face="normal" font="default" size="100%">woodland</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">865-877</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Understanding the responses of insects to ecological variables provides information that is fundamental for their conservation. The present study took place in three different landscapes (three plots of 10 9 10 km each) in a typical Mediterranean ecosystem of a Spanish national park. Each landscape included three vegetation types, grasslands, scrublands, and woodlands, and was characterised by a dominant vegetation type. Our objectives were: (1) to assess how important the inﬂuence of the dominant vegetation type and the vegetation type of sites are on hoverﬂy (Diptera: Syrphidae) diversity at landscape scale; (2) to assess whether scrublands are contributing to the loss of hoverﬂy diversity in an ecosystem with a long history of human use. In order to achieve these goals, we compared hoverﬂy diversity among sampling sites by prospecting all three diversity levels, alpha, beta and gamma, at each landscape. We sampled adult hoverﬂies at 18 sites located in different vegetation types within the three landscapes. No evidence was found that demonstrated an effect of the dominant vegetation type on alpha or beta diversity of sites, but the vegetation type of sites did have an affect. The highest species richness was found in woodland sites, particularly in the grassland-dominated landscape. At each landscape, beta diversity among sampling sites contributed more to gamma diversity than alpha diversity did. Our results highlight the need to focus on the conservation of woodland remnants of grassland-dominated landscape and scrubland-dominated landscape in order to preserve a large proportion of the biodiversity of Caban˜eros hoverﬂies, as well as on the maintenance of the mosaic landscape, which is linked to high beta diversity, typical in many Mediterranean ecosystems. We emphasise the importance of open clearings in the vast mass of scrubland in the scrubland-dominated landscape in order to provide extra resources for the hoverﬂies.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bartolomé, Jordi</style></author><author><style face="normal" font="default" size="100%">Plaixats, Josefina</style></author><author><style face="normal" font="default" size="100%">Fanlo, Rosario</style></author><author><style face="normal" font="default" size="100%">Boada, Martí</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Conservation of isolated Atlantic heathlands in the Mediterranean region: effects of land-use changes in the Montseny biosphere reserve (Spain)</style></title><secondary-title><style face="normal" font="default" size="100%">Biological Conservation</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">calluna vulgaris</style></keyword><keyword><style  face="normal" font="default" size="100%">fire</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Grazing</style></keyword><keyword><style  face="normal" font="default" size="100%">landscape</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0006320704002721http://linkinghub.elsevier.com/retrieve/pii/S0006320704002721</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">122</style></volume><pages><style face="normal" font="default" size="100%">81 - 88</style></pages><isbn><style face="normal" font="default" size="100%">3493581149</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In the Mediterranean region, cycles of controlled burning combined with continuous grazing appear to have been an effective tool for maintaining isolated Calluna vulgaris heathlands in the form in which they occur in many places in the Atlantic region. Changes in land use and management of the mosaic of extensively exploited heathland and associated grassland over recent decades, such as bringing land into cultivation followed by its abandonment and the prohibition of fires has resulted in a process of transformation into new shrub communities with lower biodiversity. In the Mediterranean region, these changes are similar to those described in the Atlantic area, but encroachment occurs faster and could lead ultimately to afforestation by Mediterranean woodland.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bartolomé, Jordi</style></author><author><style face="normal" font="default" size="100%">Plaixats, Josefina</style></author><author><style face="normal" font="default" size="100%">Fanlo, Rosario</style></author><author><style face="normal" font="default" size="100%">Boada, Martí</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Conservation of isolated Atlantic heathlands in the Mediterranean region: effects of land-use changes in the Montseny biosphere reserve (Spain)</style></title><secondary-title><style face="normal" font="default" size="100%">Biological Conservation</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">calluna vulgaris</style></keyword><keyword><style  face="normal" font="default" size="100%">fire</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Grazing</style></keyword><keyword><style  face="normal" font="default" size="100%">landscape</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><volume><style face="normal" font="default" size="100%">122</style></volume><pages><style face="normal" font="default" size="100%">81-88</style></pages><isbn><style face="normal" font="default" size="100%">3493581149</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In the Mediterranean region, cycles of controlled burning combined with continuous grazing appear to have been an effective tool for maintaining isolated Calluna vulgaris heathlands in the form in which they occur in many places in the Atlantic region. Changes in land use and management of the mosaic of extensively exploited heathland and associated grassland over recent decades, such as bringing land into cultivation followed by its abandonment and the prohibition of fires has resulted in a process of transformation into new shrub communities with lower biodiversity. In the Mediterranean region, these changes are similar to those described in the Atlantic area, but encroachment occurs faster and could lead ultimately to afforestation by Mediterranean woodland.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gallardo, A</style></author><author><style face="normal" font="default" size="100%">Rodriguez-Saucedo, J J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil nitrogen heterogeneity in a Dehesa ecosystem</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and Soil</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">geostatistics</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">soil heterogeneity</style></keyword><keyword><style  face="normal" font="default" size="100%">soil nitrogen</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><volume><style face="normal" font="default" size="100%">222</style></volume><pages><style face="normal" font="default" size="100%">71-82</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gallardo, A.</style></author><author><style face="normal" font="default" size="100%">Rodriguez-Saucedo, J. J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil nitrogen heterogeneity in a Dehesa ecosystem</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and Soil</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">geostatistics</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">soil heterogeneity</style></keyword><keyword><style  face="normal" font="default" size="100%">soil nitrogen</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/J1335844428H6726.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">222</style></volume><pages><style face="normal" font="default" size="100%">71 - 82</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ruano-Ramos, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Interannual variations of nutrient concentrations in botanical fractions from extensively managed grasslands</style></title><secondary-title><style face="normal" font="default" size="100%">Animal Feed Science …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">correlation</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Interannual variations</style></keyword><keyword><style  face="normal" font="default" size="100%">Mineral content</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><volume><style face="normal" font="default" size="100%">66</style></volume><pages><style face="normal" font="default" size="100%">257-269</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We studied interannual variations in the concentrations of N, P, K, Ca, Mg, Na, Mn, Fe, Cu, and Zn in botanical fractions from semi-natural grassland in central-western Spain. Herbage samples were collected at the ripening stage at the end of May over a 4-year period (1987, 1988, 1989 and 1991) and classified into: grasses, legumes and forbs. There was an increase in N, P and K contents from 1987 until 1991. The interannual differences in Ca, Mn, Cu and Zn concentra- tions showed no clear trends. However, the sampling year had no significant effect on Mg and Na contents. Grasses generally exhibited significant lower nutrient contents than legumes and forbs. Forbs had N, Ca, Mg and Cu concentrations midway between those of grasses and legumes, and higher P, K, Fe and Zn contents than legumes. The P, Mg, and Na contents in the three botanical fractions were inadequate for feeding livestock. However, the K, Mn, and Fe contents in the three botanical groups and the Ca, Cu, and Zn contents in legumes and forbs were within recommended ranges for cattle. The N contents were only adequate in legumes. These and forbs appear to be most suitable for cattle feeding on account of their mineral contents</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">GARCIACRIADO, B</style></author><author><style face="normal" font="default" size="100%">GARCIACIUDAD, A</style></author><author><style face="normal" font="default" size="100%">PEREZCORONA, M E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">PREDICTION OF BOTANICAL COMPOSITION IN GRASSLAND HERBAGE SAMPLES BY NEAR-INFRARED REFLECTANCE SPECTROSCOPY</style></title><secondary-title><style face="normal" font="default" size="100%">JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BOTANICAL COMPOSITION</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">NEAR</style></keyword><keyword><style  face="normal" font="default" size="100%">prediction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1991</style></year></dates><publisher><style face="normal" font="default" size="100%">JOHN WILEY &amp; SONS LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD</style></pub-location><volume><style face="normal" font="default" size="100%">57</style></volume><pages><style face="normal" font="default" size="100%">507-515</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Near infrared reflectance spectroscopy (NIRS) was evaluated as a method&lt;br/&gt;to predict the botanical composition of seminatural grassland in&lt;br/&gt;`dehesa' systems. Samples of herbaceous biomass were harvested over&lt;br/&gt;four consecutive years, determining in each-by manual separation-the&lt;br/&gt;proportion by weight of the following taxonomic groups: grasses,&lt;br/&gt;legumes and the rest of the families in a single block ('others'). &lt;br/&gt;After reconstructing the natural samples they were analysed by NIRS. &lt;br/&gt;One set of samples (calibration set) was selected for the development of&lt;br/&gt;the equations, assaying different mathematical treatments (log 1/R,&lt;br/&gt;first derivative and second derivative). The ranges of coefficients of&lt;br/&gt;multiple determination and standard errors of calibration, respectively,&lt;br/&gt;for the various components were: grasses, 0.86 to 0.92 and 6.66 to&lt;br/&gt;9.14; legumes, 0.77 to 0.81 and 6.82 to 7.43; and `others', 0.85 to 0.88&lt;br/&gt;and 8.17 to 9.54. The remaining samples not included in the development&lt;br/&gt;of the NIRS equations (prediction set) were used for the purposes of&lt;br/&gt;validating the best equations. Standard errors of performance were: &lt;br/&gt;grasses, 6.12; legumes, 7.56 and `others', 7.70.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Joffre, R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Plant and soil nitrogen dynamics in mediterranean grasslands: a comparison of annual and perennial grasses</style></title><secondary-title><style face="normal" font="default" size="100%">Oecologia</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Annual</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrogen mineralization</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen uptake</style></keyword><keyword><style  face="normal" font="default" size="100%">Perennial</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1990</style></year></dates><volume><style face="normal" font="default" size="100%">85</style></volume><pages><style face="normal" font="default" size="100%">142-149</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The predominance of annual species in the rangelands of southwestern Spain is not due only to climatic factors but is also strongly influenced by grazing management. Manipulating the grazing system in an experimental plot gave a vegetation structure with patches of annual grasses (mainly Vulpia ssp. and Bromus hordeaceus) and patches of perennial grasses (mainly Phalaris aquatica). This vegetation change allowed us to test the hypothesis that life-cycle differences between annual and perennial grasses affect soil nitrogen availability and plant uptake. Nitrogen availability, measured by in situ incubation, and nitrogen uptake were measured through the growing period (October to June). Amounts of in situ mineralized nitrogen over the whole growth phase were more important for soils supporting perennials (37 ppm) than for soils supporting annuals (27 ppm). The difference between the mineral nitrogen produced in situ and the mineral nitrogen accumulated during the same time in the soil allowed an estimation of the maximum mineral nitrogen quantity which can be taken up by the vegetation during each incubation period. The quantities accumulated over the year were 47 and 38 ppm (or 103 and 83 kg/ha) for soils supporting perennials and annuals respectively. For the same period, amounts of nitrogen immobilized in biomass production were 90 and 70 kg/ha for perennials and annuals respectively. During the autumn, a large proportion of mineral nitrogen was leached from soils supporting annual plants which had only just commenced germination. By contrast, the ability to use mineral nitrogen as soon as autumn rains occurred gave a competitive advantage to the perennial species, but only if they were protected from grazing during this period. The higher mineralization and use of this nitrogen reserve by perennials indicates that they made more efficient use of nitrogen resources than annuals, and validate the initial hypothesis.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Castro, Isabel</style></author><author><style face="normal" font="default" size="100%">Sterling, Agustina</style></author><author><style face="normal" font="default" size="100%">Galiano, E F</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Multi-species pattern analysis of Mediterranean pastures in three stages of ecological succession</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean pasture</style></keyword><keyword><style  face="normal" font="default" size="100%">pattern analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">principal components analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">succession</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1986</style></year></dates><volume><style face="normal" font="default" size="100%">68</style></volume><pages><style face="normal" font="default" size="100%">37-42</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Multi-species patterns were analyzed in three stages of ecological succession in oligotrophic pastures in Central Spain using a new method of analysis. The method is based on plotting the species coordinates of principal components analysis undertaken at different block sizes. It allows the detection of any heterogenei- ty present and reveals both microtopographical and macrotopographical trends in species patterns.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pablo, C L</style></author><author><style face="normal" font="default" size="100%">Peec, B</style></author><author><style face="normal" font="default" size="100%">Galiano, E F</style></author><author><style face="normal" font="default" size="100%">Nicolas, J P</style></author><author><style face="normal" font="default" size="100%">Pineda, F D</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Space-time variability in mediterranean pastures analyzed with diversity parameters</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">diversity</style></keyword><keyword><style  face="normal" font="default" size="100%">geomorphology</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">spatial organization</style></keyword><keyword><style  face="normal" font="default" size="100%">succession</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1982</style></year></dates><volume><style face="normal" font="default" size="100%">50</style></volume><pages><style face="normal" font="default" size="100%">113-125</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Different parameters of diversity and spatial niche amplitude (Pielou, 1975, Pineda et aL, 1981 b) have been used to describe the spatial organization of mediterranean grasslands in Central Spain. A slope sampled by 480 contiguous 8 X 8 cm quadrats proved to have a homogeneous floristic distribution when it was divided into 160 parts and maximum heterogeneity when divided into 4 sectors. These sectors corresponded to different geomorphological zones of the slope. The complexity of vegetation distribution on the slope was reflected by differences in organization - measured by diversity parameter A = H ( P / E ) / l o g a N (number of plots) between the parts obtained by division. The presence of low-entropy species - specialists - and high entropy species - generalists - was related to the different scales of slope organization. The spatial distribu- tion of plants was compared for different successional stages. Multivariate analysis of sampling plots confirmed previously identified organizational characteristics and clarified the nature of transitions between communities of different floristic composition or structure.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pineda, F D</style></author><author><style face="normal" font="default" size="100%">Nicolas, J P</style></author><author><style face="normal" font="default" size="100%">Rou, A</style></author><author><style face="normal" font="default" size="100%">Galiano, E F</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Ecological succession in oligotrophic pastures of central Spain</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Central Spain</style></keyword><keyword><style  face="normal" font="default" size="100%">correspondence analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">geomorphology</style></keyword><keyword><style  face="normal" font="default" size="100%">grassland</style></keyword><keyword><style  face="normal" font="default" size="100%">slope</style></keyword><keyword><style  face="normal" font="default" size="100%">succession</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1981</style></year></dates><volume><style face="normal" font="default" size="100%">44</style></volume><pages><style face="normal" font="default" size="100%">165-176</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The dynamics of oligotrophic pastures were analyzed in the area of El Pardo (Central Spain), and related with geomorphological features and time elapsed since the last ploughing. A sampling of the area was carried out regarding these two factors. The data were subjected to correspondence analysis, which showed the progressive replacement of species related to succession, variation along slopes, with a tight interaction between both phenomena. The correspondence between vegetation change and slope geomorphology is closer as succession progresses.</style></abstract></record></records></xml>