Abstract We investigated farming practices and grassland plant diversity patterns in the historical regions of Maramureș and Bukovina, located in the central Eastern Carpathians of Romania and Ukraine. We explored the influence of social and historical factors on recent grassland plant diversity, including changes and modifications in land use and grassland management practices. We used stratified random sampling to select 48 grassland parcels in eight villages on the Ukrainian‐Romanian borderlands. We identified the factors that affect the composition and diversity of grassland vascular plants and bryophytes at multiple spatial scales and compared the frequency and timing of historical and recent grassland management practices to distinguish between preserved and modified agricultural traditions. In most of the grassland parcels studied (83% in Romania and 78% in Ukraine), traditional land use persisted. Local plant species richness was primarily influenced by management practices, outweighing the impact of topography and soil factors. Regular mowing at appropriate intensity increased the richness of vascular plants, while grazing promoted the richness of bryophyte species. Modifications to farming systems, observed in all studied villages, were mainly due to declining population and livestock numbers. Although the timing of spring and autumn grazing in hay meadows still adhered to tradition, mowing schedules shifted earlier, especially for the first cut of two‐cut hay meadows. Traditional corralling, fertilization and hayseed application have become rare or discontinued in certain villages, while controlled burning has increased. Past use of mineral fertilizers in Ukrainian villages during the Soviet era influenced the recent diversity and composition of vascular plant species, favouring nutrient‐demanding species. Social factors and agricultural policies indirectly affect biodiversity in semi‐natural grasslands, leaving a tangible footprint even in the most remote areas of the Carpathian Mountains. We provide basic recommendations to preserve the remarkable biodiversity of the region. Read the free Plain Language Summary for this article on the Journal blog.