Multifaced approach to analyse the effect of multi-year mowing on sub-Mediterranean invaded grasslands

Traditional land-use abandonment of semi-natural grasslands is threatening biodiversity across Europe due to competitive tall-grasses spreading, which causes a drop in species diversity and the nutrient value of pastures. Finding an alternative and proper management practice to restore invaded grasslands is important for preserving their biodiversity and economic value. In this research, we analysed the effects of recurrent mowing on different aspects of plant communities, i.e., floristic composition and taxonomic and functional diversity. We aimed to understand the ability of bi-annual mowing to restore grasslands invaded by Brachypodium rupestre, whose spread in the Italian Peninsula is fostered by traditional land-use abandonment. The study site is close to “Montagna di Torricchio” Natural Reserve (central Italy). We fenced one area invaded by B. rupestre, which was mown twice a year from 2010 to 2020. Species cover was recorded in 30 plots, while for plant traits, we considered clonal propagation, leaf and flowering phenology, plant height and leaf traits. We detected two main processes operating in the short and long term, respectively. In the short term, all weaker competitors previously outcompeted by B. rupestre were able to re-grow. The plant community in this phase was characterized by increasing taxonomic diversity and with plant composition of species belonging to Festuco-Brometea class sharing similar functional strategies (short size and leaf area, fast growth rates and different leaf phenologies). In the long term, taxonomic diversity reached a plateau. However, the plant community changed and showed adaptation to recurrent bi-annual mowing with an increase of mowing-adapted species (annual species, short-clonal propagation, short size) belonging to Festuco-Brometea and Molinio-Arrhenatheretea classes, consistent with mowed grasslands of the central Apennines.