Management of agricultural wet grasslands for breeding waders: integrating ecological and livestock system perspectives—a review
Although agriculture is pointed to as being one of the major causes of biodiversity loss, it is now recognised that some farming practices, grazing in particular, represent central issues in the on-running debate on wildlife conservation. This paper analyses the relationship between agricultural pasture management and bird preservation, by focusing on the illustrative case study of breeding waders in wet grasslands. After a brief account of the knowledge on research investigating the effect of grazing management on wader distribution or abundance, we reviewed (i) sward structure (i.e. mean sward height and frequency of tussocks) requirements, and (ii) breeding phenologies of five wader species commonly associated with wet grasslands for nesting in Europe. We found differences between species in these two aspects of their biology. Investigating grassland management thus underlines that the question of the timing of grazing should be considered. Moreover, the fragmented characteristic of agricultural landscapes (i.e. a mosaic of fields) in which waders breed emphasises the spatial nature of this management. We examine three spatial scales (i.e. field, set of adjacent fields, landscape) relevant to bird biology and influenced by agricultural activities. Based on these findings, we analyse which livestock system constraints are essential to take into account in order to minimise conflicts between livestock production and conservation aims in marshes. Finally, we highlight possible directions for future research.