Combining Historical and Ecological Knowledge to Optimise Biodiversity Conservation in Semi-Natural Grasslands

Abstract

The species-rich semi-natural grasslands, i.e. unfertilised, uncultivated pastures and hay meadows, are among the most threatened habitats in the European agricultural landscape. Most European countries have lost more than 90% of their semi-natural grasslands due to abandonment or productivity intensification during the last century (Bernes, 1993; Piessens & Hermy, 2006; Stanners & Bourdeau, 1995). This drastic loss of habitat has caused population declines and extinctions of large numbers of grassland species (Baillie, 2004; Cheffings & Farrel, 2005; Gardenfors, 2010). To stop further declines of grassland species, habitats and cultural values, national and EU subsidiary programmes pay farmers to uphold and reintroduce management of semi-natural grassland (European Union, 2011; Kleijn & Sutherland, 2003; Myrdal, 2001). To merit the payment, certain management criteria have to be fulfilled, e.g. in Sweden mainly aiming at minimising litter accumulation and shrub encroachment in the grassland (Swedish Board of Agriculture, 2007). A growing number of studies express concern that these conservation efforts, and the current grassland management in general, are not sufficiently reaching the conservation goals, i.e. to rescue threatened grassland organisms and ecological functionality of the habitats. Invertebrates, birds and management-dependent vascular plants in particular have been reported to decline in spite of ongoing grassland management for conservation purposes (e.g. Boschi & Baur, 2007; Buhler & Schmid, 2001; Kruess & Tscharntke, 2002; Ockinger et al., 2006; Soderstrom et al., 2001; Willcox et al., 2010). Ecologically insufficient management quality is a potential threat to semi-natural grasslands that has attracted considerably less attention than has the cessation of management. The species-richness in semi-natural grassland is to a large extent a legacy of historical agricultural practices (Bruun et al., 2001; Pykala, 2000; Reitalu et al., 2010). The agricultural system preceding the modernisation processes in Sweden and other countries in north