The Impact of grassland management on plant species diversity at a mesotrophic site in an eight-year-long experiment

摘要

This paper is aimed at evaluating the botanical composition which changed under different grassland managements. At Jevicko site in the Czech Republic, a long-term small-plot trial with tall oatgrass stand type (Arrhenatherion) was established on permanent grassland in 2003, consisting of 16 treatments in 4 replications. The intensity of utilisation was: I} = (1st cut before 15 May, 4 cuts per year - cuts at 45-day intervals), I_2 = (1st cut between 16 and 31 May, 3 cuts per year at 60-day intervals), I_3 = (1st cut between 1 and 15 June, 2 cuts per year at 90-day intervals) and I_4 = (1st cut between 16 and 30 June, 1 or 2 cuts per year, second cut after 90 days). Four levels of fertilizer application were used: F_Q = no fertiliza-tion, FPK = P_(30)K_(60)N_0, FPKN_(90) = P_(30)K_(60)N_(90), FPKN_(180) = P_(30)K_(60)N_(180). In total, 87 plant species were identified between 2003 and 2011. Botanical composition was above all influenced by nitrogen fertilization, which supports grass species and reduces legumes and other forbs. Higher grass proportion was found in two-cut regimes (I_3, I_4), too. A higher diversity of plant species and a more balanced proportion of functional groups (grasses, legumes, forbs) were found especially in grassland without nitrogen fertilization.