Alpine vegetation dynamics and conservation the Pyrenean mires

[eng] Multiple processes determine the structure and diversity of plant communities. The study of these processes, the community assembly rules, is a central part of the study of terrestrial ecology in the recent decades. In the Alpine mountains mires occupy inland insular habitats, which face natural fragmentation and variation of environmental conditions both within a mire and between distant mires. In addition, mire communities experience the effects of land use changes and climate change. In this thesis, we want to understand how these communities respond to changes of different ecological and land use factors. The results shown and discussed should enable to reveal what are the current threats of Alpine mires, and to perform science-based management decisions. Here, we studied the vegetation dynamics of Alpine mires from the Central Pyrenees at different temporal and spatial scales. More concretely, we studied the relationship between water table depth and plant-plant interactions of three engineering plant species; we assessed the responses of the vegetation under contrasting grazing conditions in a three-year experiment; we studied what bioclimatic and land use factors facilitate the mires encroachment by Pinus uncinata; and we studied beta diversity patterns of mire communities at a regional scale. At shoot or plant level, growth performance proved to be the basis of the competitive abilities of the three species studied, independently of the water level. Lateral expansion of clonal plants was the main mechanism in gap colonization after grazing exclusion, whereas sexual reproduction had a secondary role in short-term vegetation dynamics. The current spontaneous reforestation of the subalpine belt resonates even in the mire systems, where pine encroachment has increased at places, namely at the neighborhood of pinewoods. At regional scale, beta diversity patterns showed that each mire site harbors its floristic singularity, whereas environmental gradients are less relevant in the community assembly of these inland insular habitats. Overall, the vegetation dynamics in Alpine mires proceeds very slowly at wide geographical scales, but remarkable changes in vegetation occur in short time at detailed scale.[cat] Múltiples processos determinen l’estructura i diversitat de comunitats vegetals. L'estudi d'aquests processos és una part central de l'estudi de l'ecologia terrestre de les darreres dècades. A les muntanyes alpines, les molleres són hàbitats que es disposen en forma d’illes terrestres, i que s'enfronten a la fragmentació natural i la variació de les condicions ambientals –tant dins d'una mollera com entre molleres distants. A més, les comunitats de mollera estan exposades als canvis d'ús del sòl i al canvi climàtic. En aquesta tesi, volem entendre com aquestes comunitats responen als canvis de diversos factors ecològics i d'usos del sòl. Els resultats trobats i discutits han de permetre esbrinar quines són les amenaces actuals de les molleres alpines, i prendre decisions de gestió científicament fonamentades. Hem estudiat la dinàmica de la vegetació de les molleres alpines dels Pirineus centrals a diferents escales temporals i espacials. Més concretament, hem estudiat la relació entre la profunditat del nivell freàtic i les interaccions planta- planta de tres espècies enginyeres; hem analitzat les respostes de la vegetació sota condicions de pressió ramadera contrastades en un experiment de tres anys de durada; hem avaluat quins factors bioclimàtics i d'usos del sòl faciliten la invasió de Pinus uncinata; i hem estudiat l’estructura de la diversitat beta entre comunitats de mollera a escala regional. A nivell de planta, el creixement de les plantes va ser la base de les capacitats competitives de les tres espècies, independentment del nivell freàtic. L'expansió lateral de les plantes clonals va tenir un paper important en la colonització d’espais malmesos per la pressió ramadera, mentre que la reproducció sexual va tenir un paper secundari en la dinàmica de la vegetació a escala de detall. L’increment de pins a l’estatge subalpí de vegetació succeeix també a les molleres, on la presència de pins ha augmentat sobretot a les molleres envoltades de boscos. A escala regional, els patrons de diversitat beta van mostrar que cada mollera té una singularitat florística pròpia, mentre que els gradients ambientals són menys rellevants en la construcció de les comunitats d'aquests hàbitats a les muntanyes alpines. En global, la dinàmica de la vegetació a les molleres alpines és lenta a escales geogràfiques àmplies, però es produeixen canvis notables la vegetació en poc temps a escales detallades

Millora de l’estat de conservació de les molleres del Parc Natural de l’Alt Pirineu

Aquest document s’emet com a informe tècnic del projecte finançat per la Fundació Andrena per millorar l’estat de conservació de tres sistemes de molleres al Parc Natural de l’Alt Pirineu. Aquest projecte pretén protegir hàbitats de mollera altament freqüentats per bestiar domèstic, aïllant-los de la pressió ramadera. Pretén també avaluar els efectes de la pressió ramadera sobre la compactació del sòl, la coberta de briòfits, el desenvolupament de les plantes herbàcies i la floració; descriure els processos de successió vegetal durant els primers anys després de l’eliminació del bestiar, i finalment monitorar detalladament parcel·les de seguiment per detectar la dinàmica de la vegetació que hi té lloc en funció d’altres paràmetres ambientals més enllà de la pressió ramadera. Els resultats exposats en aquest document, després de tres anys des de la construcció dels tancats d’exclusió ramadera, mostren la rapidesa dels canvis en l’estructura de la vegetació de les comunitats en les mollera, però alhora deixen palesa la lentitud dels canvis en la composició d’espècies i –i en els seus recobriments– en els sistemes d’alta muntanya.Resumeix el plantejament, l’execució i els resultats obtinguts per a la conservació dels hàbitats de mollera als Pirineus Centrals entre els anys 2018 i 2020

GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands

Abstract: GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phyto- coenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems

<scp>ReSurveyEurope</scp>: A database of resurveyed vegetation plots in Europe

AbstractAimsWe introduce ReSurveyEurope — a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions.ResultsReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover–abundance classes such as variants of the Braun‐Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020.ConclusionsReSurveyEurope is a new resource to address a wide range of research questions on fine‐scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well‐established European Vegetation Archive (EVA). ReSurveyEurope data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome.</jats:sec

Sphagnum fuscum: a glacial relict in the Pyrenees

Póster presentado en el III Simposio Anual de Botánica Española el 26-11-2022Climatic fluctuations during the Pleistocene shaped the current disjunct distributions of many cold-adapted species. Southern European mountains, like the Pyrenees, became climatic refugia for arctic-alpine species. These rear-edge populations are crucial for conservation because they usually harbour unique lineages. Here we studied the genetic structure and distribution of the peat moss Sphagnum fuscum (Schimp.) Klinggr. on its rear-edge in the Pyrenees to assess its regional conservation status. In total, 109 shoots from seven populations were sampled and genotyped through 16 microsatellite loci. Results showed that genetic diversity within populations is extremely poor but unique, with one to three private genotypes per population (10 genotypes in total). Populations were clearly structured (AMOVA, 81% of variation was among populations). Bayesian clustering analysis did not show groups among genotypes and populations (best K = 9, by Evanno’s ΔK) and Mantel tests indicated that there is no isolation-by-distance among populations. Thus, we suggest that S. fuscum is a glacial relict, and its current demographic and genetic structure is explained by a contraction and altitudinal migration upwards after the Local Last Glacial Maximum (LLGM) that gave place to independent founder events. We think that its rarity in the Pyrenees is due to its highly specialized ecological niche as it is a late-successional species. Remarkably, our findings point that S. fuscum might be monoecious in the Pyrenees, which enables sporophyte production and long-distance dispersal in such small and monoclonal populations. According to the IUCN criteria, the species deserves the status of Endangered (B1ab(iii)+2ab(iii); D). In addition, we suggest some conservation advice taking advantage of the genetic knowledge generated

A European map of groundwater pH and calcium

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a promising toolbox for understanding the past, present and future distribution and diversity patterns in groundwater-dependent ecosystems, such as fens, springs, streams, reed beds or wet grasslands. Still, the lack of detailed water chemistry maps prevents the use of reasonable models to be applied on continental and global scales. Being major determinants of biological composition and diversity of groundwater-dependent ecosystems, groundwater pH and calcium are of utmost importance. Here we developed an up-to-date European map of groundwater pH and Ca, based on 7577 measurements of near-surface groundwater pH and calcium distributed across Europe. In comparison to the existing European groundwater maps, we included several times more sites, especially in the regions rich in spring and fen habitats, and filled the apparent gaps in eastern and southeastern Europe. We used random forest models and regression kriging to create continuous maps of water pH and calcium at the continental scale, which is freely available also as a raster map (Hájek et al., 2020b; https://doi.org/10.5281/zenodo.4139912). Lithology had a higher importance than climate for both pH and calcium. The previously recognised latitudinal and altitudinal gradients were rediscovered with much refined regional patterns, as associated with bedrock variation. For ecological models of distribution and diversity of many terrestrial ecosystems, our new map based on field groundwater measurements is more suitable than maps of soil pH, which mirror not only bedrock chemistry but also vegetation-dependent soil processes.publishedVersio

A European map of groundwater pH and calcium

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a promising toolbox for understanding the past, present and future distribution and diversity patterns in groundwater-dependent ecosystems, such as fens, springs, streams, reed beds or wet grasslands. Still, the lack of detailed water chemistry maps prevents the use of reasonable models to be applied on continental and global scales. Being major determinants of biological composition and diversity of groundwater-dependent ecosystems, groundwater pH and calcium are of utmost importance. Here we developed an up-to-date European map of groundwater pH and Ca, based on 7577 measurements of near-surface groundwater pH and calcium distributed across Europe. In comparison to the existing European groundwater maps, we included several times more sites, especially in the regions rich in spring and fen habitats, and filled the apparent gaps in eastern and southeastern Europe. We used random forest models and regression kriging to create continuous maps of water pH and calcium at the continental scale, which is freely available also as a raster map (Hájek et al., 2020b; https://doi.org/10.5281/zenodo.4139912). Lithology had a higher importance than climate for both pH and calcium. The previously recognised latitudinal and altitudinal gradients were rediscovered with much refined regional patterns, as associated with bedrock variation. For ecological models of distribution and diversity of many terrestrial ecosystems, our new map based on field groundwater measurements is more suitable than maps of soil pH, which mirror not only bedrock chemistry but also vegetation-dependent soil processes

A European map of groundwater pH and calcium

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a promising toolbox for understanding the past, present and future distribution and diversity patterns in groundwater-dependent ecosystems, such as fens, springs, streams, reed beds or wet grasslands. Still, the lack of detailed water chemistry maps prevents the use of reasonable models to be applied on continental and global scales. Being major determinants of biological composition and diversity of groundwater-dependent ecosystems, groundwater pH and calcium are of utmost importance. Here we developed an up-to-date European map of groundwater pH and Ca, based on 7577 measurements of near-surface groundwater pH and calcium distributed across Europe. In comparison to the existing European groundwater maps, we included several times more sites, especially in the regions rich in spring and fen habitats, and filled the apparent gaps in eastern and southeastern Europe. We used random forest models and regression kriging to create continuous maps of water pH and calcium at the continental scale, which is freely available also as a raster map (Hájek et al., 2020b; https://doi.org/10.5281/zenodo.4139912). Lithology had a higher importance than climate for both pH and calcium. The previously recognised latitudinal and altitudinal gradients were rediscovered with much refined regional patterns, as associated with bedrock variation. For ecological models of distribution and diversity of many terrestrial ecosystems, our new map based on field groundwater measurements is more suitable than maps of soil pH, which mirror not only bedrock chemistry but also vegetation-dependent soil processes