Changes in Species Composition, Diversity, and Biomass of Secondary Dry Grasslands Following Long-Term Mowing: A Case Study in Hungary

Abstract

The focus of our study was the changes in the composition of semi-natural dry grasslands in Hungary. Maintaining the favorable condition of grasslands is not only important from a theoretical nature conservation point of view, but it also has important economic implications. Since these valuable habitats were created with the help of humans, their preservation also requires active treatment. Our current experiment was aimed at investigating the suppression of tall grass, Calamagrostis epigejos L. Roth. In Hungary, in the Cserhát Mountains, eight permanent plots were mown twice a year. We surveyed the vegetation twice a year between 2001 and 2011. The effects of treatment were studied with repeated measures analysis of variance (ANOVA). After 10 years, the C. epigejos cover of the mown plots decreased significantly, from the initial average of 62.38 to 7.50%. Surprisingly, we noticed a decrease in the control plots as well. While percentage cover of C. epigejos decreased in all plots, the decrease was significantly stronger in the mown plots. Regular treatment caused an increase in the number of species and diversity. Species richness increased continuously in both treatment types, which indicates the combined effect of vegetation succession and treatment. The biomass growth of other Poaceae and Fabaceae species, which are important from a grassland management perspective, was also facilitated by mowing. Our results allow us to conclude that long-term regular mowing is recommended for preservation from the perspective of the richness and variety of grassland management functional groups and the functioning of the ecosystem in semi-arid regenerating grasslands.