Biodiversity in grassland

Abstract

The aim of this paper is to review the role of biodiversity and the underlying mechanisms in managed grassland and to present new results. Modern farming methods have been criticised for their negative effect on species-richness and their impact on environment and landscape. There is an increasing wide-spread desire to promote biodiversity and attractive landscapes as well as to retain rural communities. Conservation of biodiversity is primarily a regional goal, not a goal of individual farmers. Grassland management to favour biodiversity will require compromise. Agricultural management influences sward structure vertically and horizontally over space and time. Insights into these relationships are important to understand the mechanisms responsible for changes in the floristic composition and the productivity of grassland. Two case-studies with Trifolium repens L. (white clover) and Festuca pratensis Huds. (meadow fescue) are summarised to identify driving forces for the changes of the yield contribution of selected species in grassland. Canopy structure and growth form of white clover determine the foraging for light, and the weak competitive ability of meadow fescue is caused by a smaller proportion of leaf area in the upper layers of the canopy in interspecific shoot competition. Long-term experiments show that management also influences surprisingly rapid microevolution within individual species. It is concluded that management for habitat heterogeneity at all scales will conserve most of the biotic diversity of a site. © Elsevier/Inra.