ReSurveyEurope: a database of resampled vegetation plots in Europe

Aims: We introduce ReSurveyEurope – a community initiative that establishes a new resource of data from re-surveyed vegetation plots in Europe. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility, and outline further steps, including potential research questions.  
Results: ReSurveyEurope considers vegetation plots from all habitats. The first call for data provision was issued on 6th October 2020. All databases in ReSurveyEurope are stored and managed using the Turboveg 2 program at Masaryk University in Brno. Version 1.0 of ReSurveyEurope contains 274,396 observations (i.e. individual surveys of each plot) from 77,020 plots sampled in 442 independent resurvey projects included in 256 datasets. Of these, 62,431 (80 %) are permanent plots, i.e. marked or geo-tagged plots, which allow for high spatial accuracy in resurvey. The remaining 15,873 (20 %) plots are from resampling studies, in which plots from the initial survey were not exactly located. Four datasets, which together account for 28,470 (35 %) plots, provide only presence / absence information on plant species, while the remaining 49,834 (65 %) plots contain abundance information (e.g. percentage cover or cover-abundance classes such as the Braun-Blanquet scale). The oldest plots were sampled in 1911 in the eastern Alps, while most plots were sampled between 1950 and 202222.
Conclusions: ReSurveyEurope is a new resource to address a wide range of research questions on community-scale changes in European vegetation. It 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 can be submitted to the coordinators.