Response of grassland birds to local features strongly depends on landscape context

Abstract

Agricultural intensification and the drastic loss of grassland habitats have led to a general decline of grassland specialist species in Europe. Current greening measures in grasslands management have proven insufficient to halt this decline. Conservation measures need to be strengthened by taking into account the composition and configuration of the landscape at different scales as well as practices within both grasslands and surrounding crops. This study used a survey of grassland bird specialists conducted at a national scale in France to look at the relative influence of local and landscape characteristics on the grassland specialist community in order to propose relevant management measures. The findings showed that grassland specialists species richness was highest when the proportion of grassland in the landscape was high. As grasslands in France tend to be embedded in an intensive agricultural matrix and gradually converted into cultivated land, this result emphasizes the importance of preserving remaining areas with a high proportion of grasslands. The results also showed that landscape configuration (in particular fragmentation) modulated the influence of the proportion of grassland on the distribution of birds. For a given habitat type, the sign and magnitude of the influence of edge length depended on grassland proportion in the landscape as well as spatial scale. These results suggest that protecting large grassland areas should be a priority, and in landscape dedicated to crop production, increasing the heterogeneity of grasslands and the diversity of their edges to other open vegetation habitats managed with extensive practices can be an effective way to increase grassland bird diversity. In areas with a very high proportion of grassland in the landscape, hedges at landscape scale can have a positive effect on grassland specialists by increasing resources and biodiversity.

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