Search

The article "Carex hartmaniorum (Cyperaceae), a new species for the Spanish flora" discusses the discovery of a new plant species, Carex hartmaniorum, in Spain. The article provides details about the characteristics of this species and how it differs from similar plants. It also discusses the distribution and ecology of Carex hartmaniorum, as well as its conservation status in Spain. The species is found in wet meadows in the Pyrénées and is currently endangered due to overgrazing. However, the presence of similar populations in France suggests the possibility of migration and conservation efforts. The article includes references and authorship contributions. [Extracted from the article]

This article discusses the discovery of Orobanche salviae, a rare parasitic plant, in the eastern Catalan Pyrenees, marking the first confirmed record of the species in the Iberian Peninsula. The authors provide information on the distribution and habitat of the plant, suggesting that it may be endangered. They emphasize the need for further research and conservation efforts, particularly due to the species' limited population and potential threats from nearby hydroelectric power stations. The article highlights the importance of expanding knowledge about Orobanche salviae and protecting its habitat. [Extracted from the article]

Aims: Chionophilous vegetation (i.e. snowbed vegetation and chionophilous grasslands) hosts relict arctic-alpine species, among which snowbed specialists, that find their southernmost limit in the Iberian Peninsula, where they are especially threatened by climate change. Our aims were to identify the main Iberian chionophilous vegetation groups, and analyse their plant diversity patterns and their role as refugia for snowbed glacial relicts, as well as that of Iberian high-mountain regions. Location: Iberian high mountains. Methods: We used the beta-flexible clustering method to classify 1002 vegetation relevés of Iberian chionophilous vegetation, and computed species Indicator Values and frequencies for the resulting groups. We performed a Detrended Correspondence Analysis (DCA) ordination of the relevés, and fitted six climatic variables to reveal the main ecological gradients. We constructed rarefaction curves to compare species richness between vegetation groups and between mountain regions. Results: We obtained eight vegetation groups, four consisting of snowbed vegetation and four of chionophilous grasslands. All but one group were present in the Pyrenees, where snowbed specialist richness was the highest. In southern and central Iberian ranges, snowbed vegetation was extremely scarce, and the main vegetation group corresponded to cryoromediterranean grasslands, where both species and specialist richness were the lowest. Snowbed and northern Iberian grassland groups accounted for similar high specialist richness, although specialists were infrequent and scarce at relevé level in these grasslands. Conclusions: Despite the set of specialised species that thrive in snowbeds, many of them are also present but scarce in northern Iberian chionophilous grasslands. In a future scenario with a high reduction of snow cover duration, which may entail the disappearance of many snowbed vegetation patches, northern Iberian chionophilous grasslands may act as terminal refugia for snowbed specialists. Nevertheless, specialists are very threatened in central and southern Iberian ranges, where snowbed vegetation is infrequent and chionophilous grasslands provide almost no shelter to them. [ABSTRACT FROM AUTHOR]

In the Alpine mountains, mire systems are found in the form of small, scattered landscape units. Nevertheless, they maintain noticeably high diversity in terms of plant specialists and community types. A unique, species-rich example in the central Pyrenees, Bassa Nera, is analysed here by describing the major gradients that drive species composition and their relationship with abiotic drivers. We studied the specific vegetation composition, water chemistry and seasonal dynamics of the water table at 35 sampling points. The floristic data confirmed the uniqueness of Bassa Nera in relation to similar Pyrenean mire systems, both in terms of total species richness and regionally rare mire specialists. We distinguished seven plant community types and identified the depth to the water table as the principal driver of the variation in species composition. The water chemistry determined smaller composition shifts, since variations in pH and cationic contents were moderate. Flooded areas were species poor whereas soligenous sub-alkaline fens supported the highest numbers of species. However, the harshest mire habitats (floating Sphagnum carpets and Sphagnum hummocks) stood out as they included the highest number of rare plants within relatively species-poor assemblages. Therefore, the high species richness and uniqueness of the Bassa Nera system mirrors a combination of a wide range of hydrological conditions and a moderate variation in water chemistry. This case study reveals how a few mire systems stand out as exceptional sites. Thus, in Alpine ranges a thorough survey on mire vegetation is needed to select and effectively protect these threatened relict ecosystems. [ABSTRACT FROM AUTHOR]

Aim To contrast floristic spatial patterns and the importance of habitat fragmentation in two plant communities (grassland and scrubland) in the context of ecological succession. We ask whether plant assemblages are affected by habitat fragmentation and, if so, at what spatial scale? Does the relative importance of the niche differentiation and dispersal-limitation mechanisms change throughout secondary succession? Is the dispersal-limitation mechanism related to plant functional traits? Location A Mediterranean region, the massif of Albera (Spain). Methods Using a SPOT satellite image to describe the landscape, we tested the effect of habitat fragmentation on species composition, determining the spatial scale of the assemblage response. We then assessed the relative importance of dispersal-related factors (habitat fragmentation and geographical distance) and environmental constraints (climate-related variables) influencing species similarity. We tested the association between dispersal-related factors and plant traits (dispersal mode and life form). Results In both community types, plant composition was partially affected by the surrounding vegetation. In scrublands, animal-dispersed and woody plants were abundant in landscapes dominated by closed forests, whereas wind-dispersed annual herbs were poorly represented in those landscapes. Scrubby assemblages were more dependent on geographical distance, habitat fragmentation and climate conditions (temperature, rainfall and solar radiation); grasslands were described only by habitat fragmentation and rainfall. Plant traits did not explain variation in spatial structuring of assemblages. Main conclusions Plant establishment in early Mediterranean communities may be driven primarily by migration from neighbouring established communities, whereas the importance of habitat specialization and community drift increases over time. Plant life forms and dispersal modes did not explain the spatial variation of species distribution, but species richness within the community with differing plant traits was affected by habitat patchiness. [ABSTRACT FROM AUTHOR]

Saxifraga cuneifolia L. (sect. Gymnopera, Saxifragaceae) is a plant distributed in the main mountain ranges of southern Europe, from the eastern Pyrenees to the eastern Carpathian. Currently, two subspecies are recognized based on morphological characteristics: S. cuneifolia subsp. cuneifolia grows in the Maritime Alps and North Apennines and S. cuneifolia subsp. robusta is located in the remaining area of distribution. A more delicate form and a smaller number of flowers in S. cuneifolia subsp. cuneifolia are the morphological characteristics that differentiate this subspecies from the widespread S. cuneifolia subsp. robusta. To explore the genetic diversity and the subspecific geographic patterns of S. cuneifolia s. l. we conducted a molecular study of nuclear and plastid sequences. Samples of S. cuneifolia s. l. have been analysed throughout the distribution area of this species. Our results, based on nuclear (ITS) and plastid (rbcL, trnL–F, and psbA–trnH) markers, showed a genetic characterization of both subspecies presenting discriminant haplotypes and ribotypes that confirm the current subspecific systematics. [ABSTRACT FROM AUTHOR]

Understanding large‐scale drivers of biodiversity in palustrine wetlands is challenging due to the combined effects of macroclimate and local edaphic conditions. In boreal and temperate fen ecosystems, the influence of macroclimate on biodiversity is modulated by hydrological settings across habitats, making it difficult to assess their vulnerability to climate change. Here, we investigate the influence of macroclimate and edaphic factors on three Essential Biodiversity Variables across eight ecologically defined habitats that align with ecosystem classifications and red lists. We used 27,555 vegetation plot samples from European fens to assess the influence of macroclimate and groundwater pH predictors on the geographic distribution of each habitat type. Additionally, we modeled the relative influence of macroclimate, water pH, and water table depth on community species richness and composition, focusing on 309 plant specialists. Our models reveal strong effects of mean annual temperature, diurnal thermal range, and summer temperature on biodiversity variables, with contrasting differences among habitats. While macroclimatic factors primarily shape geographic distributions and species richness, edaphic factors emerge as the primary drivers of composition for vascular plants and bryophytes. Annual precipitation exhibits non‐linear effects on fen biodiversity, with varying impact across habitats with different hydrological characteristics, suggesting a minimum requirement of 600 mm of annual precipitation for the occurrence of fen ecosystems. Our results anticipate potential impacts of climate warming on European fens, with predictable changes among habitat types and geographic regions. Moreover, we provide evidence that the drivers of biodiversity in boreal and temperate fens are closely tied to the ecological characteristics of each habitat type and the dispersal abilities of bryophytes and vascular plants. Given that the influence of macroclimate and edaphic factors on fen ecosystems is habitat specific, climate change research and conservation actions should consider ecological differentiation within functional IUCN ecosystems at continental and regional scales. [ABSTRACT FROM AUTHOR]

Fungi play a key role in soil-plant interactions, nutrient cycling and carbon flow and are essential for the functioning of arctic terrestrial ecosystems. Some studies have shown that the composition of fungal communities is highly sensitive to variations in environmental conditions, but little is known about how the conditions control the role of fungal communities (i.e., their ecosystem function). We used DNA metabarcoding to compare taxonomic and functional composition of fungal communities along a gradient of environmental severity in Northeast Greenland. We analysed soil samples from fell fields, heaths and snowbeds, three habitats with very contrasting abiotic conditions. We also assessed within-habitat differences by comparing three widespread microhabitats (patches with high cover of Dryas, Salix, or bare soil). The data suggest that, along the sampled mesotopographic gradient, the greatest differences in both fungal richness and community composition are observed amongst habitats, while the effect of microhabitat is weaker, although still significant. Furthermore, we found that richness and community composition of fungi are shaped primarily by abiotic factors and to a lesser, though still significant extent, by floristic composition. Along this mesotopographic gradient, environmental severity is strongly correlated with richness in all fungal functional groups: positively in saprotrophic, pathogenic and lichenised fungi, and negatively in ectomycorrhizal and root endophytic fungi. Our results suggest complex interactions amongst functional groups, possibly due to nutrient limitation or competitive exclusion, with potential implications on soil carbon stocks. These findings are important in the light of the environmental changes predicted for the Arctic. [ABSTRACT FROM AUTHOR]

Rising temperatures may endanger fragile ecosystems because their character and key species show different habitat affinities under different climates. This assumption has only been tested in limited geographical scales. In fens, one of the most endangered ecosystems in Europe, broader pH niches have been reported from cold areas and are expected for colder past periods. We used the largest European‐scale vegetation database from fens to test the hypothesis that pH interacts with macroclimate temperature in forming realized niches of fen moss and vascular plant species. We calibrated the data set (29,885 plots after heterogeneity‐constrained resampling) with temperature, using two macroclimate variables, and with the adjusted pH, a variable combining pH and calcium richness. We modelled temperature, pH and water level niches for one hundred species best characterizing European fens using generalized additive models and tested the interaction between pH and temperature. Fifty‐five fen species showed a statistically significant interaction between pH and temperature (adj p ˂.01). Forty‐six of them (84%) showed a positive interaction manifested by a shift or restriction of their niche to higher pH in warmer locations. Nine vascular plants and no moss showed the opposite interaction. Mosses showed significantly greater interaction. We conclude that climate significantly modulates edaphic niches of fen plants, especially bryophytes. This result explains previously reported regional changes in realized pH niches, a current habitat‐dependent decline of endangered taxa, and distribution changes in the past. A warmer climate makes growing seasons longer and warmer, increases productivity, and may lower the water level. These effects prolong the duration and intensity of interspecific competition, support highly competitive Sphagnum mosses, and, as such, force niches of specialized fen species towards narrower high‐pH ranges. Recent anthropogenic landscape changes pose a severe threat to many fen species and call for mitigation measures to lower competition pressure in their refugia. [ABSTRACT FROM AUTHOR]

Aims: Classification of European bog vegetation (Oxycocco‐Sphagnetea class); identification of diagnostic species for the class and vegetation subgroups (orders and alliances); development of an expert system for automatic classification of vegetation plots; and production of distribution maps of the Oxycocco‐Sphagnetea class and its alliances. Location: Europe. Methods: A data set of vegetation‐plot records was compiled to include various bog types over most of the European continent. An unsupervised classification (beta‐flexible linkage method, Sørensen distance measure) and detrended correspondence analysis (DCA) ordination were applied. Formal definitions of syntaxa based on species presence and covers, and respecting the results of the unsupervised classification, were developed and included in a classification expert system. Results: The Oxycocco‐Sphagnetea class, its two orders (Sphagno‐Ericetalia tetralicis and Sphagnetalia medii) and seven compositionally distinct alliances were formally defined. In addition to the syntaxa included in EuroVegChecklist, three new alliances were distinguished: Rubo chamaemori‐Dicranion elongati (subarctic polygon and palsa mires); Erico mackaianae‐Sphagnion papillosi (blanket bogs of the northwestern Iberian Peninsula); and Sphagno baltici‐Trichophorion cespitosi (boreal bog lawns). The latter alliance is newly described in this article. Conclusions: This first pan‐European formalized classification of European bog vegetation partially followed the system presented in EuroVegChecklist, but suggested three additional alliances. One covers palsa and polygon mires, one covers Iberian bogs with endemics and one fills the syntaxonomical gap for lawn microhabitats in boreal bogs. A classification expert system has been developed, which allows assignment of vegetation plots to the types described. [ABSTRACT FROM AUTHOR]

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; 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. [ABSTRACT FROM AUTHOR]

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a widely used tool 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 their reasonable use 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 the up-to-date European map of groundwater pH and Ca, based on 7,577 measurements of near-surface groundwater pH and calcium distributed across Europe. In comparison to the existing European groundwater maps, we included a several times larger number of 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. 2020; https://doi.org/10.5281/zenodo.4139912). Lithology had 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 groundwater-dependent, but also other terrestrial, ecosystems, the new map is more suitable than previously used maps of soil pH, unlike which it mirrors bedrock chemistry more than vegetation-dependent soil processes. [ABSTRACT FROM AUTHOR]

Aim: A fundamental question in macroecology centres around understanding the relationship between species' local abundance and their distribution in geographical and climatic space (i.e. the multi‐dimensional climatic space or climatic niche). Here, we tested three macroecological hypotheses that link local abundance to the following range properties: (a) the abundance–range size relationship, (b) the abundance–range centre relationship and (c) the abundance–suitability relationship. Location: Europe. Taxon: Vascular plants. Methods: Distribution range maps were extracted from the Chorological Database Halle to derive information on the range and niche sizes of 517 European vascular plant species. To estimate local abundance, we assessed samples from 744,513 vegetation plots in the European Vegetation Archive, where local species' abundance is available as plant cover per plot. We then calculated the 'centrality', that is, the distance between the location of the abundance observation and each species' range centre in geographical and climatic space. The climatic suitability of plot locations was estimated using coarse‐grain species distribution models (SDMs). The relationships between centrality or climatic suitability with abundance was tested using linear models and quantile regression. We summarized the overall trend across species' regression slopes from linear models and quantile regression using a meta‐analytical approach. Results: We did not detect any positive relationships between a species' mean local abundance and the size of its geographical range or climatic niche. Contrasting yet significant correlations were detected between abundance and centrality or climatic suitability among species. Main conclusions: Our results do not provide unequivocal support for any of the relationships tested, demonstrating that determining properties of species' distributions at large grains and extents might be of limited use for predicting local abundance, including current SDM approaches. We conclude that environmental factors influencing individual performance and local abundance are likely to differ from those factors driving plant species' distribution at coarse resolution and broad geographical extents. [ABSTRACT FROM AUTHOR]

Background: The disjunct distribution patterns of a taxon may arise when previously continuous distribution ranges are fragmented. The phenomena of vicariance and dispersal, together with hybridisation as an important source of genetic variation in natural populations, can play an important role for structuring the distribution of taxa. Aims: We investigated the biogeographical relationships of the Iberian endemic plant Ranunculus angustifolius s.l. by reconstructing ancestral geographical distributions, using a combination of phylogenetic and distributional information. Methods: Phylogenetic and network analyses of nuclear internal transcribed spacers and plastid sequence data (rpl32-trnL, rps16-trnQ, trnK-matK and ycf6-psbM) were used to infer vicariance and dispersal events. Results: Phylogenetic and biogeographical analyses suggested that both dispersal and vicariance were important in creating the current disjunct distribution pattern. Some other factors, such as hybridisation, introgression and vicariance (or pseudovicariance), were important in the evolutionary history of the taxa R. angustifolius s.l.Conclusions: Our results demonstrate the importance for analysing biogeographical patterns with the use of both nuclear and chloroplast DNA to infer the evolutionary history of plant species with a disjunct distribution. Our results show that phenomena such as dispersal, vicariance and pseudovicariance are not mutually exclusive. [ABSTRACT FROM AUTHOR]

With the aims of investigating the causes of environmental changes in high mountain ecosystems during the Holocene in relation to climate forcings and identifying thresholds for vegetation community shifts, we performed a multi-proxy palaeoecological reconstruction based on two sediment cores from Bassa Nera, a lentic system located close to the montane–subalpine ecotone in the Central Pyrenees. Using pollen, plant macroremains, charcoal, chemical elements and loss-on-ignition at centennial to decadal resolution, we reconstructed the vegetation and lacustrine dynamics during the last 10,000 years. A montane pollen ratio was used as a palaeoecological indicator to track altitudinal shifts in high mountain vegetation, which was compared to the ice-rafted debris index (IRD) as a proxy for summarizing the climatic influence of the North Atlantic Circulation. Our results show upward shifts of deciduous forest and its presence in Bassa Nera from the onset of the Holocene until 4200 cal yr BP, when it was replaced by coniferous taxa. The montane ratio showed a link between vegetation and North Atlantic influence, while changes in Sphagnum macroremains and aquatic taxa allowed description of local ontogenic changes from the initial pond to the present peatland. The loss-on-ignition record showed some flood events at Bassa Nera between 4500 and 3900 cal yr BP. The studied proxies allowed inferences concerning anthropic pressure in the catchment through grazing activities by 7300 cal yr BP and the appearance of cereal agriculture around 5190 cal yr BP. The highest human pressure occurred in the late Bronze Age, Roman Period and Middle Ages. [ABSTRACT FROM AUTHOR]

A lack of paleobotanic studies with adequate resolution and multiproxy approaches has limited proper discussion of vegetation dynamics in Cantabria and of the role of fires in the configuration of the plant landscape during the Holocene in the northwest part of the Iberian peninsula. The pollen diagram of La Molina peat bog in Puente Viesgo (43°15′38″ N–3°58′37″ W; ETRS89), located at 484 m.a.s.l., and the study of its sedimentary charcoals allowed the acquisition of a continuous and thorough fire sequence for the last 6700 cal yr BP and an understanding of its relationship to the forest. The results show the importance of human influence on the incidence and characteristics of fire activity during the different phases studied: the Neolithic, Bronze Age, Iron Age, Roman period, and Middle Ages. A synergy seems to exist between dry climate periods (especially during Bond events 3 and 4) and a greater presence of biomass. As the Holocene advances, vegetation coverage clearly tends to decrease. This study provides key elements for understanding the role of fire activity in the forest dynamics of deciduous and evergreen Quercus , Corylus , Pinus , Fagus , and Alnus and demonstrates the strongly artificialized character of the present landscape. [ABSTRACT FROM AUTHOR]

In temperate mountains, fens have been reported as relict habitats subject to geographical fragmentation and broad climatic gradients, but few studies have analyzed the influence of these factors on plant diversity. Here we investigate the effect of isolation on the vegetation diversity of rich fens ( Caricion davallianae) in the mountains of the Iberian Peninsula, the distribution limit of these habitats in south-western Europe. We used plot-based vegetation data from the Pyrenees and the Cantabrian mountain range to evaluate their regional species-pool, occurrence of specialists, beta-diversity and the effect of geo-climatic variables on their species-richness and species-composition. We found a lower ratio of rare specialists in the Pyrenees than in the Cantabrian range, but similar estimates in the species pools, total species-richness per plot and beta-diversity. The isolation of the two mountain regions resulted in different species assemblages best predicted by summer precipitation and bedrock types, showing region-based differences in the response of vegetation and plant specialists to the environment. The tighter correlation between local climate and diversity estimates in the Cantabrian range suggests relict character of rich fens in that region, where climatic conditions have restricted local distribution of formerly more widely distributed specialists. Although there is no relevant evidence of vegetation impoverishment in that region, historical isolation has probably resulted in the existence of fragmentary plant communities. We conclude that fen vegetation may experience long-time persistence in climatically sub-optimal mountain refugia, but related plant specialists may be sensitive to climatic changes and subject to the extinction of local populations. [ABSTRACT FROM AUTHOR]