The original dataset was prepared by the first author for his Master thesis. It contains 224 vegetation plots from 51 forest-steppe sites in Central Europe (Austria, Czech Republic, Hungary, Slovakia and Ukraine), sampled between 2017 and 2020. On most of the sites, 5 forest-steppe habitats were sample (UF: forest above the steppe patch, UE: ecotone above the steppe patch, ST: steppe, LE: ecotone beneath the steppe patch and LF: forest beneath the steppe patch) and some sites are represented by less relevés (mostly 3). All plots have the standard size of 2.5 × 4 m2. The cover values were estimated using the nine-degree Braun-Blanquet scale (Westhoff & van der Maarel 1978). Bryophytes and lichens were not sampled. The nomenclature in the dataset corresponds to the Euro+Med database (visited 2021-05-24). Aggregates correspond to Danihelka et al. 2012 (http://www.preslia.cz/P123Danihelka.pdf ), except for Galium sylvaticum agg. (G. sylvaticum and G. intermedium) and Erophila verna s.l. (E. verna and E. spathulata) Furthermore, the dataset includes various information which directly relates to the analysis which is presented by the first author in his Master thesis. The true/false columns ("PART_1", "PART_2") in the "_SITES.csv" spreadsheet indicate for which analyses the relevés from particular sites were used. Dataset is supplied as 4 comma separated sheets: Chytry-Krystof_forest-steppe-v1_2021-05-24_SPE.csv a long form of the vegetation matrix Chytry-Krystof_forest-steppe-v1_2021-05-24_ENV.csv header data for relevés Chytry-Krystof_forest-steppe-v1_2021-05-24_SITES.csv general information of particular forest-steppe sites (location, bedrock, number of relevés, indication if the relevés from particular sites were used in analyses) Chytry-Krystof_forest-steppe-v1_2021-05-24_TRAITS.csv species information (frequency in the dataset, indication if the taxon was used in the analysis, ecological indicator values, plant height of herbs and range type)