Kryštof Chytrý

Aims We 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. Results ReSurveyEurope 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. Conclusions ReSurveyEurope 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.

Complex topography regulates near‐surface temperature above the treeline. It may thus sustain microrefugia for alpine plants and relax the need of shifting upward when the climate warms. The effectiveness of these microrefugia rests on the premise that plant distributions in alpine landscapes are mainly controlled by fine‐scale topographic variation. We tested this assumption by relating the distribution of 79 plant species and 10 community attributes across 900 1 m² plots in a landscape spanning 1677 m of elevation to 17 topographical descriptors at resolutions between 1 and 301 m. We found that the presence of most species and most community attributes were better explained by topographic variation at coarser scales (> 20 m). Fine‐scale topography is more clearly reflected in moisture than in temperature requirements of species. The elevational gradient rather than topographic variation at any scale, is the single most important driver of both species distributions and the variation in community attributes in the area studied. We hypothesise that our results reveal a hitherto underestimated influence of spatial mass effects on alpine plant distributions. These effects can override environmental filtering at fine scales and will thus impede the survival of cold‐adapted plants in small and fragmented refugia under climate warming.

Aims We asked how geological substrate affects the distribution of plant species between forest interiors, forest edges, and steppe patches in the forest–steppe landscapes. Specifically, we sought for the presence of the edge effect at the forest–grassland transitions on different substrates. Location Austria, Czech Republic, Hungary, Slovakia and western Ukraine. Methods We recorded the occurrence of vascular plant species in forest interiors, at forest edges and in steppe patches on 40 forest–steppe sites located on four substrates (andesite, dolomite, limestone and loess). We compared the distribution of species diversity, beta diversity (using multivariate analysis), the number of shared species between habitats and the estimation of vegetation biomass among forest‐steppe habitats on different substrates. Results The edge effect was observed on hard rocks, while it was absent on loess, where the ecotone species richness was intermediate between that of forest and steppe. Loess sites also had the lowest species turnover between forest and steppe and the lowest number of edge specialists. Conclusions Substrate has a strong effect on the formation of forest–steppe mosaics. It shapes the assembly rules and plant community diversity within individual habitat mosaics. Plant communities on each substrate can respond differently to changing climate. The strong assembly rules on hard rocks may be more likely to result in species loss than on loess or similar soft sediments, where a larger number of species find their optimum in more than one forest–steppe habitat.