Effect of low-dose N application and early mowing on plant species composition of mesophilous meadow grassland ( Arrhenatherion) in Central Europe.

Semi-natural temperate grasslands in Europe make an important contribution to biodiversity, but their existence has been endangered by both agricultural intensification and abandonment. In the Czech Republic, Arrhenatherion meadows are a typical example, with their conservation made difficult by the scarcity of research on effective management practices. We examined effects of two potentially useful approaches, application of 56 kg N ha−1 and earlier first mowing (i.e. in the middle of May, about 2 weeks earlier than usual), on species composition of an Arrhenatherion grassland in central Bohemia over a 7-year period (1998-2004). These treatments did not influence species richness, but resulted in small changes in canopy structure in terms of cover of individual species and particular plant functional groups. N application resulted in increases in nitrophilous species and tall graminoids, especially Alopecurus pratensis, Festuca pratensis, Heracleum sphondylium and Ranunculus acris, and in decreases in short graminoids. Earlier mowing decreased tall herbs, especially H. sphondylium, and might thus be useful in compensating for increases in some nitrophilous species owing to N application. However, earlier mowing had negative impacts on spring-flowering species in terms of reduced cover. [ABSTRACT FROM AUTHOR]