The aim of the dataset is to monitor the changes of the vegetation of a selected dry grassland area. There are no grassland management, neither grasig nor mowing. We follow the changes of plant species composition in 200 4m x 4m large semi-permanent plots from 2000. There were survey in the years 2000, 2002, 2004, 2006, 2010, 2015 and 2021.

The area was used as small-scale ploughland and vineyards between app. 1900 and 1960. From 1960 it was gradually abandoned and became a part of the Kiskunsag National Park. We distinguished 4 age-groups of old-fields according to the time of the abandonment: 1–6, 7–11, 12–25 és 26–35 years old abandoned fields in year 2000. In every age-group 10–10 (total 40) 4 m × 4 m large permanent vegetation survey plot were established. We made vegetation survey (presence and cover of every vascular plant species) in the year 2000, 2008, 2010, 2015, 2017 and 2020.

Traditionally managed mountain grasslands are declining as a result of abandonment or intensification of management. Based on a common chronosequence approach we investigated species compositions of 16 taxonomic groups on traditionally managed dry pastures, fertilized and irrigated hay meadows, and abandoned grasslands (larch forests). We included faunal above- and below-ground biodiversity as well as species traits (mainly rarity and habitat specificity) in our analyses. The larch forests showed the highest species number (345 species), with slightly less species in pastures (290 species) and much less in hay meadows (163 species). The proportion of rare species was highest in the pastures and lowest in hay meadows. Similar patterns were found for specialist species, i.e. species with a high habitat specificity. After abandonment, larch forests harbor a higher number of pasture species than hay meadows. These overall trends were mainly supported by spiders and vascular plants. Lichens, bryophytes and carabid beetles showed partly contrasting trends. These findings stress the importance to include a wide range of taxonomic groups in conservation studies. All in all, both abandonment and intensification had similar negative impacts on biodiversity in our study, underlining the high conservation value of Inner- Alpine dry pastures.