Conservation status and trends in the transformation of Molinia meadows in the Łąki w Komborni Natura 2000 site, SE Poland

The aim of this study was to provide a phytosociological and ecological characterization of meadow communities in the Łąki w Komborni Natura 2000 site (SE Poland), assess the trends in their transformation, and indicate the major threats impacting on their conservation. The study was conducted in 2015–2016. Three types of meadow communities were distinguished (alliances Molinion, Arrhenatherion, Filipendulion), due to the absence of the species characteristic for associations. The species richness noted per relevé differed significantly between the types of meadows (Kruskal–Wallis test: H = 21.65, p < 0.05). The highest floristic biodiversity (H' = 2.99) was noted for the meadow patches classified as in the Molinion alliance and the lowest (H' = 2.50) was found for the patches from the Filipendulion alliance. Mean values of the ecological indicators (F, R, N) differed between the meadow communities. The greatest disparity was noted for the mean values of the soil moisture indicator (from 6.42 to 7.45). Patches classified in the Filipendulion alliance were developed on the wettest soil substratum, whereas the patches classified in the Arrhenatherion alliance were predominant on a relatively dry substratum. The abandonment of traditional management practices (grazing, mowing) has contributed to transformation of the Molinia meadows, disappearance of characteristic species and succession of shrubs. The Molinia meadow habitat should be conserved by improvement of protection measures (appropriate mowing regime and removal of biomass) to conserve a high species richness and the rare and protected plant species