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International audience; Aim In the alpine life zone, plant diversity is strongly determined by local topography and microclimate. We assessed the extent to which aspect and its relatedness to temperature affect plant species diversity, and the colonization and disappearance of species on alpine summits on a pan-European scale. Location Mountain summits in Europe's alpine life zone. Methods Vascular plant species and their percentage cover were recorded in permanent plots in each cardinal direction on 123 summits in 32 regions across Europe. For a subset from 17 regions, resurvey data and 6-year soil temperature series were available. Differences in temperature sum and Shannon index as well as species richness, colonization and disappearance of species among cardinal directions were analysed using linear mixed-effects and generalised mixed-effects models, respectively. Results Temperature sums were higher in east- and south-facing aspects than in the north-facing ones, while the west-facing ones were intermediate; differences were smallest in northern Europe. The patterns of temperature sums among aspects were consistent among years. In temperate regions, thermal differences were reflected by plant diversity, whereas this relationship was weaker or absent on Mediterranean and boreal mountains. Colonization of species was positively related to temperature on Mediterranean and temperate mountains, whereas disappearance of species was not related to temperature. Main conclusions Thermal differences caused by solar radiation determine plant species diversity on temperate mountains. Advantages for plants on eastern slopes may result from the combined effects of a longer diurnal period of radiation due to convection cloud effects in the afternoon and the sheltered position against the prevailing westerly winds. In northern Europe, long summer days and low sun angles can even out differences among aspects. On Mediterranean summits, summer drought may limit species numbers on the warmer slopes. Warmer aspects support a higher number of colonization events. Hence, aspect can be a principal determinant of the pace of climate-induced migration processes.

Pure and mixed high-mountain pine forest vegetation of the Gredos range (central Spain) was studied using 57 relevés and multivariate analyses (hierarchical cluster analysis and detrended correspondence analysis). Classification of the relevés resulted in 7 vegetation units, 3 of which were ranked as associations and only one as subassociation. DCA diagrams of relevés and taxa indicated that floristic differentiation was attributed mainly to factors such as altitude. Differential taxa of vegetation units were chosen based on their phi coefficient values. The statistic discrimination of some of these vegetation units has allowed us to propose a new association and a new subassociation of other community described in a previous paper.

Deciduous forests occur widely in central-western Europe as far south as the Iberian Peninsula. In this area dominated by a Mediterranean-type climate, the marcescent endemic Quercus pyrenaica Willd. serves as an indicator of the southern limit of broad-leaved forests. Its distribution area extends from southwest France to northeast Morocco, occupying—at least potentially—large areas of the peninsula and thus covering a wide variety of environments and ecological niches that we will attempt to identify. Different community types will also be identified, based on current classifications and the latest analysis of these forests. Their uniqueness, the current situation of global change, and real threats to their conservation and existence, have made their study a pressing concern.

Biurrun, Idoia/0000-0002-1454-0433; Rojo, Maria Pilar Rodriguez/0000-0001-5449-9386; Ermakov, Nikolai/0000-0001-7550-990X; De Sanctis, Michele/0000-0002-7280-6199; Svenning, Jens-Christian/0000-0002-3415-0862; Virtanen, Risto/0000-0002-8295-8217; Agrillo, Emiliano/0000-0003-2346-8346; Onyshchenko, Viktor/0000-0001-9079-7241; Marceno, Corrado/0000-0003-4361-5200; Willner, Wolfgang/0000-0003-1591-8386; Fernandez-Gonzalez, Federico/0000-0003-1234-4065; Jansen, Florian/0000-0002-0331-5185; Swacha, Grzegorz/0000-0002-6380-2954; Dengler, Jurgen/0000-0003-3221-660X; Guarino, Riccardo/0000-0003-0106-9416; Sopotlieva, Desislava/0000-0002-9281-7039; Venanzoni, Roberto/0000-0002-7768-0468; Chytry, Milan/0000-0002-8122-3075; Kuzemko, Anna/0000-0002-9425-2756; Danihelka, Jiri/0000-0002-2640-7867; Kuzemko, Anna/0000-0002-9425-2756; Venanzoni, Roberto/0000-0002-7768-0468; Gavilan, Rosario G./0000-0002-1022-445X; Jansen, Florian/0000-0002-0331-5185; Wohlgemuth, Thomas/0000-0002-4623-0894; Svenning, Jens-Christian/0000-0002-3415-0862; Sibik, Jozef/0000-0002-5949-862X; Casella, Laura/0000-0003-2550-3010; Lenoir, Jonathan/0000-0003-0638-9582; Attorre, Fabio/0000-0002-7744-2195; Kacki, Zygmunt/0000-0002-2241-1631; Jandt, Ute/0000-0002-3177-3669; Carni, Andraz/0000-0002-8909-4298; Jirousek, Martin/0000-0002-4293-478X; GARCIA-MIJANGOS, ITZIAR/0000-0002-6642-7782; Campos, Juan Antonio/0000-0001-5992-2753; Fanelli, Giuliano/0000-0002-3143-1212; Haveman, Rense/0000-0001-9127-4549; Acic, Svetlana/0000-0001-6553-3797; De Bie, Els/0000-0001-7679-743X; Font, Xavier/0000-0002-7253-8905; Moeslund, Jesper Erenskjold/0000-0001-8591-7149; Martynenko, Vasiliy/0000-0002-9071-3789; Jimenez-Alfaro, Borja/0000-0001-6601-9597; Ejrnaes, Rasmus/0000-0003-2538-8606; Carlon Ruiz, Luis/0000-0003-3442-8710; Angelini, Pierangela/0000-0002-5321-9757; Silc, Urban/0000-0002-3052-699X; Landucci, Flavia/0000-0002-6848-0384; Ewald, Jorg/0000-0002-2758-9324; Dziuba, Tetiana/0000-0001-8621-0890 WOS: 000368074600018 The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional vegetation-plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their corresponding names on a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 027 376 vegetation plots, 82% of them with geographic coordinates, from 57 countries. EVA provides a unique data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database. Czech Science Foundation (Centre of Excellence PLADIAS) [14-36079G] Our major thanks go to thousands of European vegetation scientists of several generations who collected the original vegetation-plot data in the field, published them or made their unpublished data available to others, and to those who spent myriad hours digitizing data and managing the contributing databases. EVA data management has been partly funded by the Czech Science Foundation (Centre of Excellence PLADIAS, 14-36079G).

Global warming is creating the need to incorporate a considerable amount of knowledge on diversity and functionality into management plans, but this is not always an easy task. We have developed an approach that includes the analysis of biodiversity measures and their relation with physiographic or soil parameters, for use in forestry management plans in Hoyocasero (central Spain). Considering the richness in forest plants and according to their morphological and functional traits, we grouped the species present under the canopy into four groups. Then we have calculated their richness and biodiversity indices and for the set of plants as a whole. The species groups showed differences in richness and diversity indices for the two forest types in the study, while the set of plants as a whole was not sensitive enough to detect variations in the quality of the floristic species. The use of diversity indices applied to particular species groups proved to be a useful method of defining levels of forest quality. This methodology has enabled us to establish that the pinewood is in a better state of conservation than the oakwood.

The aim of this study is to investigate distribution patterns of species occurring at definite spatial scales and to address the main ecological factors that structure a Mediterranean high mountain grassland community. Following the protocols of the GLORIA long-term study, four summits were sampled during the year 2006 and 2007 in Sierra de Guadarrama (Spain). The data recorded on two of those summits were analysed for spatial pattern of species, interspecific associations and environmental relationships were determined from the recorded data. This was done by multivariate analyses (ordinations), SADIE analyses (distance indices) and Pearson χ2 test, respectively. Results showed that chamaephyte species were more abundant in less disturbed situations whilst caespitose hemicryptophyte species and mosses were more abundant in disturbed ones. High mountain species were more abundant in less disturbed situations. Higher spatial heterogeneity was detected on northern and eastern slopes, which could be related to the increased environmental severity of northern exposures and to the greater intensity of the disturbances on eastern exposures. The frequent aggregated distribution of a few species may be related to facilitation processes due to their frequent participation in positive interactions. Finally we observed that positive pairwise associations of species were more frequent than negative associations. The relevance of the studied relationships lied in a better understanding of those threats on high mountain biodiversity induced by climate warming.

The geographical distribution ofQuercus pyrenaica forests in the Iberian Peninsula is analysed from a climatic point of view. 438 phytosociological releves were collected and 28 climatic parameters were derived from their geographical features using the ESTCLIM model. The objectives of our work were to define the main climatic characteristics that explain the particular distribution pattern of Quercus pyrenaica forests in Spain and to obtain the climatic envelopes that best define these vegetation types. For this purpose, four floristic and their corresponding climatic matrices were analysed by means of Canonical Correspondence Analysis (CCA). Results show the importance of some climatic features that define the Mediterranean climate: summer dryness and winter precipitation, both of which serve to separate some types of forest. It is the case of AdenocarpoQuercetum pyrenaicae and Berberido-Quercetum in southern Spain or Festuco-Quercetum and Luzulo-Quercetum, in the center of the Iberian Peninsula, which are separated in terms of summer dryness. Luzulo baeticae-Quercetum is well separated from the other two associations it was compared with (Arbuto-Quercetum and Sorbo-Quercetum) by winter precipitation. Exposure also plays an important role in some ranges such as the Sierra Madrona where a different type of forest appear in warmer or cooler exposures. Finally, other phytosociological adscriptions of releves to a type of association presented problems due to a very similar floristic composition, as is the case of Genisto falcatae-Quercetum and Holco-Quercetum. Regarding the differences between Eurosiberian forests and northern Mediterranean ones, separation resulted difficult since some of them (Melampyro-Quercetum) showed a not very clear separation from those Mediterranean forest they were compared (Genisto falcatae-Quercetum, Holco-Quercetum and Linario triornithophoraeQuercetum), in terms of the climatic variables analysed, however they showed a very different floristic composition.

A total of 75 surface samples collected from mosses in the Quercus pyrenaica forests of the Spanish Central System mountains were analysed for their pollen content. The samples were taken from six different Quercus pyrenaica phytosociological associations between 443 and 1657 m a.s.l. and fall within distinct rainfall and temperature regimes. The aims of this paper are to provide new data on the modern pollen rain from Central Spain, and to perform these data using multivariate statistics (hierarchical cluster analysis and principal component analysis) and pollen percentages. We could distinguish first between unaltered and disturbed forest landscapes and among different Quercus pyrenaica forest associations based on climatic gradients (rainfall pattern, summer moisture). This analysis allowed us to identify a set of pollen taxa markers which could assist in distinguishing these oak forest communities.

A drier climate together with intense management can be detrimental for species when they are found at their xeric limit. We analyzed the dynamics of Pinus sylvestris in Central Spain in relation to colonization by more drought-tolerant Quercus pyrenaica. The studied forest presents high biodiversity and is one of the last stands relict from a widespread pine-dominated forest in West-Central Iberian Mountains demised by human deforestation. The observed age patterns could suggest a natural regeneration origin of the current stand for both species. However, while oaks regenerated continuously since the 1950s, there was almost no pine regeneration after the 1870s. Therefore, the lack of pine regeneration was previous to recent climatic changes. Pine stands with ongoing oak colonization were likely thinned in the 1920s in opposition to pure pine stands. Mixed and pure stands expressed certain differences in their response to climate. Pines suffered more from high temperatures from spring to fall, which would reflect their lower tolerance to drought than oaks. Cross-wavelet analysis showed that pine exhibited an increase in their sensitivity to drought intensity in the last years. However, the dominant pine canopy established in the nineteenth century does not show symptoms of growth decline in response to climate change. The factors determining the disruption of pine regeneration need to be determined. Management could have played a dominant role constraining stand dynamics, threatening pine sustainability through modifications of the understory vegetation and soil properties. © 2015, Springer-Verlag Berlin Heidelberg.

Recent studies on climate change and the development of international scientific nets for the observation and analysis of global warming on the biodiversity have had an immediate effect on Ecology labs. It is the case of Enviroclim_lab created to cover all the necessary instrumentation management to collect outdoors bioclimatic data. The analysis of such data is also included in the daily tasks.

We report for the first time the Bioclimatic Typology of Jujuy Province (Argentina) as a result of the characterization performed following the methodology of the Bioclimatic Classification of Earth. Temperature and precipitation climatic parameters were used and annual and seasonal bioclimatic indices were also calculated. From them we determined the bioclimatic units and three bioclimatic maps were developed. The results show that the Province of Jujuy falls within the Tropical Macrobioclimate, regardless of the height above sea level at any location; and also present two types of bioclimates: Tropical Xeric and Tropical Pluviseasonal. In the region of the Puna and the Eastern Cordillera (Eastern Andes mountain range),above 2500 m asl, dominates the Tropical Xeric bioclimate, and the supra-, oro- and cryorotropical belts with dry to semiarid ombrotypes, although there are some high and cold places with Tropical subhumid Pluviseasonal bioclimate. The region ofthe lower valleys and Sierras Subandinas has Tropical Pluviseasonal bioclimate with thermo-, meso- and supratropical thermotypes and humid and subhumid ombrotypes, while the warmer valleys located at the threshold to the Chaco Plain mainly show a dry Tropical Xeric bioclimate. This research properly reflects reciprocity between climate and the distribution of existing vegetation at the province level. On the other hand, it will provide valuable information that may be used in future research and applied projects planning, management and conservation of natural resources of this wide territory.

In this study, over 100 phytoclimatic indices and other climatic parameters were calculated using the climatic data from 260 meteorological stations in a Mediterranean territory located in the centre of the Iberian Peninsula. The nature of these indices was very different; some of them expressed general climatic features (e.g. continentality), while others were formulated for different Mediterranean territories and included particular limits of those indices that expressed differences in vegetation distribution. We wanted to know whether all of these indices were able to explain changes in vegetation on a spatial scale, and whether their boundaries worked similarly to the original territory. As they were so numerous, we investigated whether any of them were redundant. To relate vegetation to climate parameters we preferred to use its hierarchical nature, in discrete units (characterized by one or more dominant or co-dominant species), although it is known to vary continuously. These units give clearer results in this kind of phytoclimatic study. We have therefore used the main communities that represent natural potential vegetation. Multivariate and estimative analyses were used as statistical methods. The classification showed different levels of correlation among climatic parameters, but all of them were over 0.5. One hundred and eleven parameters were grouped into five larger groups: temperature (T), annual pluviothermic indices (PTY), summer pluviothermic indices (SPT), winter potential evapotranspiration (WPET) and thermal continentality indices (K). The remaining parameters showed low correlations with these five groups; some of them revealed obvious spatial changes in vegetation, such as summer hydric parameters that were zero in most vegetation types but not in high mountain vegetation. Others showed no clear results. For example, the Kerner index, an index of thermal continentality, showed lower values than expected for certain particular types of vegetation. Parameters relating to the water balance turned out to be very discriminative for separating vegetation types according to the season or the month when water begins to be scarce. Thus, water availability in soils is a limiting factor for the development of vegetation in spring or autumn as well as in summer. As expected, precipitation and temperature discriminated the altitudinal levels of vegetation. Finally, these index limits only worked in the territories where they were formulated, or in nearby areas.

Therophytic non nirrophilous comrnunities growing on deep inland sandy soils and coastal dunes of me Mediterranean Region have been studied. We have summarised the current status of this type of vegetation, analysing the variability of described syntaxa, based on their floristic composition and geographic distribution. Al! avaiJable releves were arranged in a synthetic cable and subjected to a correspondence analysis (DCA). Two orders (Malcolmietalia aod Cutaodietalia maritimae), 8 alliances and 52 associa- tions were distinguished, A typological classification of mes e eommunities with ecologieal and biogeograph.ical diagnoses is given.

Interspecific interactions among species are generally accepted as important processes in communities. Positive interactions seem to be most common in environments with high stress, but negative effects also appear simultaneously. The mechanisms of these interactions are diverse and include shade, improvement of soil characteristics, or protection from animals in the case of facilitation, or allelopathy or direct contact, in the case of competition. We studied vegetation patches in two high areas of the Sistema Central (Spain): Sierra de Bejar and Sierra de Guadarrama. This vegetation is very rich in cushion chamaephytes such as Armeria caespitosa, Silene elegans, or Jasione centralis. The aim of this study was to determine whether interspecific associations exist in this Mediterranean high mountain vegetation and if such associations are important in plant communities. We also wanted to know if environmental features can explain spatial distribution of species on patches. For that purpose, we recorded species composition of patches and their cover, as well as the highest and lowest diameter of patches, altitude, and exposition. Successional changes have also been checked through the total species richness and size of patches. Results showed that patches dominated by different cushion plants did not differ substantially in species composition, although species affinity for patches is different depending on the number of species. Herbaceous species appear to act as late colonizers, mostly restricted to species-rich patches, although some species, such us Agrostis truncatula, act as early colonizers in Sierra de Bejar. Flat cushion plants could be considered nurse plants, as they can modify micro-environmental conditions and allow establishment and survival of associated species. However, in some cases they can also act in competition with other cushion plants or herbs for the same space.

Questions Are species from different biogeographic groups (mediterranean, alpine and endemic) filtered in different ways by altitude and topography in alpine plant communities? What is the relative performance of these environmental factors at predicting the species diversity of the communities as a whole and of the geographic species groups? Location Picos de Europa, Cantabrian Range (Spain). Methods We sampled the presence and cover of vascular plants in 5-m radius plots on alpine grasslands between 1900 and 2500 m a.s.l. Five GIS-based terrain variables at 15 m × 15 m were used to model species richness and cover per plot using generalized and linear models, and the variation in species composition with redundancy analysis. The same analyses were repeated for the whole data set and for subsets of species from alpine, mediterranean and endemic distributions. Results The influence of altitude and topography on species richness, cover and composition differed for the whole data set and for the geographic species groups. Altitude was the main variable affecting floristic diversity in the communities as a whole, but the separate species groups were more influenced by slope, topographic wetness index and solar radiation. Richness and cover of mediterranean species showed the strongest relationships with topography. Alpine and endemic species showed relationships with topography for species cover and composition, but not for species richness. Conclusions In alpine landscapes, biogeographic deconstruction of the species pool can provide a better understanding of the influence of altitude and topography on local communities than analysis of the entire community alone. Furthermore, the strong influence of local topography on species groups improves our understanding of how alpine species will respond to climate change.

International audience; Interactions among species determine local-scale diversity, but local interactions are thought to have minor effects at larger scales. However, quantitative comparisons of the importance of biotic interactions relative to other drivers are rarely made at larger scales. Using a data set spanning 78 sites and five continents, we assessed the relative importance of biotic interactions and climate in determining plant diversity in alpine ecosystems dominated by nurse-plant cushion species. Climate variables related with water balance showed the highest correlation with richness at the global scale. Strikingly, although the effect of cushion species on diversity was lower than that of climate, its contribution was still substantial. In particular, cushion species enhanced species richness more in systems with inherently impoverished local diversity. Nurse species appear to act as a ‘safety net’ sustaining diversity under harsh conditions, demonstrating that climate and species interactions should be integrated when predicting future biodiversity effects of climate change.

Data from 30 plots of Castanea sativa Miller stands were analysed to study the relationships among soil, understorey composition and management. Floristic cover percentage and edaphic features were separately studied by means of PCA. After that, correlations between floristic and edaphic axes were carried out by means of Pearson product‐moment correlation; and finally, correlations between floristic or edaphic axes and silvicultural characteristics were also calculated. PCA of soil variables showed differences between stands located on granitic rocks and floristic PCA showed a clear difference between managements. There were correlations between floristic axes and soil or silvicultural measurements, while correlations between soil axes and silvicultural measurements were not significant. The results indicated there were no general trends between soil properties and forest management probably due to deepness and development of soils. The management is the first source of variation on understorey composition: high forests were poorer than coppice stands. There were also differences within coppice stands related to the type of post-harvest practice. Finally temporal changes in nutrient rates were related to the understorey composition, as well. # 1999 Elsevier Science B.V. All rights reserved.

Monthly precipitation and monthly mean temperature records from 255 meteorological stations in Central Spain (Spanish Sistema Central) were analyzed by cluster and principal component analyses. Classification separated 14 groups according to altitude, geographical distribution, as well as the combination of rainfall and temperature. The first cluster emerged as significantly higher and colder than the second. Then, two ordinations were carried out: one for the 14 groups extracted from the classification and a second for the total station pool. The second ordination was compared with potential natural vegetation data taken around each station. The first ordination summarized the principal climatic characteristics of the Spanish Sistema Central: its behaviour is that of a typical Mediterranean mountainous territory combining summer aridity and variation of temperature with altitude and the influence of winter winds. The ordination of all stations reflected a thermal, rainfall and summer aridity gradient. Meteorological stations situated at the highest altitude or with highest precipitation records characterized by scrub communities or pine woods and Quercus pyrenaica forests, appeared well-separated along the first two axes. Only the most thermophilous Q. rotundifolia associations could be clearly separated. The fourth axis was useful in clarifying some vegetation overlap of deciduous and sclerophyllous forests, along an east-west summer aridity gradient. Nomenclature: Tutin et al. (1964-1980) for plants; Rivas-Martinez (1987) and Rivas-Martinez et al. (1987) for syntaxa.

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

[EN] Fifty-eight modern pollen surface samples from different Scots pine forest communities (Pinus sylvestris var. iberica Svoboda) in the Iberian Central System (central Spain) were palynologically and statistically analyzed (using hierarchical cluster analysis and principal component analysis) to derive correlations between pollen assemblages and environmental gradients at the sampled points. Numerical classification and ordination were performed on pollen data to assess similarities among (central Iberian)-Scots pine forest phytosociological associations. The results show a strong relationship between altitude, temperature, rainfall, arboreal cover and variations in pollen taxa percentages. The statistic discrimination of some of these forest communities has allowed us to propose three new associations., [ES] Cincuenta y ocho muestras de lluvia polínica actual, procedentes de distintas comunidades forestales de pino albar (Pinus sylvestris var. iberica Svoboda) en el Sistema Central ibérico (centro de España), fueron analizadas palinológica y estadísticamente (mediante análisis de cluster jerárquico y análisis de componentes principales) para establecer correlaciones entre los espectros polínicos y gradientes medioambientales. La clasificación numérica y la ordenación fueron realizadas sobre los datos polínicos para delimitar posibles similitudes entre las distintas asociaciones fitosociológicas de los bosques de pino albar centro-ibérico. Los resultados muestran que existe una fuerte correlación entre la altitud, temperatura, precipitación y cobertura arbórea respecto a las variaciones en los porcentajes de los principales morfotipos polínicos. La discriminación estadística de algunas de estas formaciones forestales nos hace proponer tres nuevas asociaciones.

[EN] The study of Quercus pyrenaica forests in eastern areas of the Iberian Peninsula has differentiated a set of relevés from Castellón. They are located in subhumid sites in the upper mesomediterranean to low supramediterranean thermotype territories of Sierra de Espadán, in the Valenciano-Tarraconense biogeographical sector. A new forest Minuartio valentinaeQuercetum pyrenaicae is therefore described here, together with its main seral communities., [ES] El estudio de los bosques de Quercus pyrenaica del centro y este ibérico ha discriminado un conjunto de inventarios procedentes de Castellón. Están situados en emplazamientos de termotipos mesomediterráneo superior-supramediterráneo inferior y ombrotipo subhúmedo de la Sierra de Espadán, incluidos en el sector biogeográfico Valenciano-Tarraconense. Así, se describe la nueva asociación de melojares Minuartio valentinae-Quercetum pyrenaicae y las comunidades seriales que forman una nueva serie de vegetación para la Península Ibérica., We want to thank Pru Brooke-Turner the English revision and also to anonymous reviewers for the comments to the manuscript. This paper has been financed by the Madrid Autonomous Government through the research project REMEDINAL2 (S2009/AMB-1783).

We have carried out a study on the pastures growing at high altitudes on calcareous substrata in the central-eastern Iberian Peninsula. The study comprised two areas: the Gudar and Javalambre mountain areas, and the calcareous outcrops of the Sierra de Guadarrama. Two datasets were analysed: releves taken in the Sierra de Guadarrama in the summer of 2010; and the releves of Rivas Goday & Borja (1961) above 1700 m of altitude. The results highlighted the similarities and differences between both datasets, and we have recognized the new association Festuco curvifoliae-Astragaletum mutici for the Sierra de Guadarrama high-mountain calcareous grasslands, with a presence on both types of substrata.

A study of medicinal flora is currently under way at the Ciudad Universitaria (Madrid), based on a previous study of flora in which 416 plants were compiled. We have selected plants with a therapeutic use collected in the study area which have been identified both macroscopically and microscopically using the appropriate tools. This paper presents a complete description of eleven taxa.

A syntaxonomical study was carried out using techniques of multivariate analysis on the nanophanerophytic vegetation of Genistees included in the class Cytisetea scopario-striati, in the central Iberian Peninsula. 700 releves -both published and unpublished- have been analysed using various types of classifications and ordinations in different stages. For this vast territory a total of 15 associations have been recognised, distributed into the four alliances traditionally recognised for the area: Retamion sphaerocarpae, Genistion floridae, Genistion polygaliiphyllae and Ulici europaei-Genistion polygaliiphyllae. The concepts of subassociation and variant recently developed have been applied in the syntaxonomical nomenclature. Of these three subassociations are proposed as new.

Investigations conducted in the Iberian Peninsula over the last three decades show how some thermophilic plant species have extended their range. The native thermophilic species, Dittrichia viscosa (L.) W. Greuter, and Sonchus tenerrimus L., have expanded, apparently without any direct intervention by man. In addition, alien species have crossed biogeographical barriers to expand their range into new areas. These include taxa from the neotropics and the Cape Province of South Africa which have colonised areas close to the Mediterranean coast (Ageratina adenophora (Spreng.) King. & H. Rob., Araujia sericifera Brot., Tropaeolum majus L. and Arctotheca calendula (L.) Levyns). By analysing thermometric data series from 10 meteorological stations, we were able to correlate the expansion of the ranges of these species with mean temperature increases, particularly those of mean minimum temperatures. If other thermophilic species (native and introduced) also increase their range, this could have serious consequences for plant biodiversity.

Las comunidades de plantas de alta montaña mediterránea constituyen uno de los grupos más vulnerables al cambio global. El ascenso del matorral motivado por el cambio global ocasiona una reducción del hábitat disponible y una amenaza a su persistencia. En este trabajo presentamos los estudios realizados por nuestro grupo de investigación en los pastos psicroxerófilos de la Sierra de Guadarrama para caracterizar sus respuestas al cambio global y evaluar su grado de vulnerabilidad. Nuestros resultados confirman la vulnerabilidad de la alta montaña mediterránea al cambio global aunque las respuestas de cada especie pueden ser muy diferentes. Estas diferencias también se reflejan en el nivel poblacional donde las respuestas pueden variar notablemente dentro de una misma especie. En el nivel comunidad el proceso de pérdida de hábitat y de matorralización amenaza a todo el ecosistema. Plant communities of Mediterranean high-mountain pastures are one of the most vulnerable groups to global change. The elevational shift towards higher altitude experimented by shrubs is causing a reduction of the habitat available for the pasture and threatening its persistence. In this work we present the studies carried out by our research group on the psycroxerophyllous pastures of Sierra de Guadarrama to characterize their responses to global change and assess their vulnerability. Our results confirm the high vulnerability of the Mediterranean high mountain vegetation in spite of the fact that each species has specific responses. These differences appear also scaled up to the population and community levels. An escalator effect together with an intense encroachment is posing these ecosystems to the verge of extinction.

Morphological and chemical data from 64 genera of Parmeliaceae, including the most common genera in Europe, were analysed by means of neighbour–joining and parsimony analysis. Two presence/absence matrices were constructed, one for the 64 genera and a smaller one for the most common European genera. Probabilities were too low to allow grouping of the genera and only a few pairs of genera had a probability of >50% for both matrices. A molecular matrix (nuclear rDNA-ITS) of the most common genera in Europe was constructed and analysed by the method of maximum likelihood. These results were much more informative than the non-molecular matrix for establishing phylogenetic relationships among the genera.

A first classification for serpentine annual grasslands distributed throughout northern and central California is pro- posed. This study has followed the Braun-Blanquet phyto- sociological system based on floristical, biogeographical and bioclimatic features of the sampled areas. Numerical analyses of classification and ordination were applied to the floristic releves. Minimum Variance Clustering grouped releves into basic classification units that allowed us to define low-hierar- chical syntaxonomical units (associations) and 'communi- ties'. A Principal Coordinate Analysis was used to extract those ecological parameters related to the axes that separate those classification units from the previous dendrogram. The results showed that differences in species composition was mainly due to a continentality gradient and the shady effect of an overstory vegetation. On the basis of both analyses we propose a first syntaxonomic scheme on ultramafic (mainly serpentine) annual plant communities of the biogeographical Californian Region that comprises four associations, two subassociations and some provisional communities.

International audience; Foundation species can change plant community structure by modulating important ecological processes such as community assembly, yet this topic is poorly understood. In alpine systems, cushion plants commonly act as foundation species by ameliorating local conditions. Here, we analyze diversity patterns of species' assembly within cushions and in adjacent surrounding open substrates (83 sites across five continents) calculating floristic dissimilarity between replicate plots, and using linear models to analyze relationships between microhabitats and species diversity. Floristic dissimilarity did not change across biogeographic regions, but was consistently lower in the cushions than in the open microhabitat. Cushion plants appear to enable recruitment of many relatively stress-intolerant species that otherwise would not establish in these communities, yet the niche space constructed by cushion plants supports a more homogeneous composition of species than the niche space beyond the cushion's influence. As a result, cushion plants support higher α-diversity and a larger species pool, but harbor assemblies with lower ?-diversity than open microhabitats. We conclude that habitats with and without dominant foundation species can strongly differ in the processes that drive species recruitment, and thus the relationship between local and regional species diversity.