From fragments to function

Grasslands are among the most species-rich terrestrial ecosystems. Invertebrates make up the largest proportion of their biodiversity and are integral to overall ecosystem functioning and, hence, to the ecosystem services provided by grasslands. This chapter focuses on the threats to grassland invertebrates and the actions needed to mitigate their precipitous decline in grasslands worldwide. Grasslands have been severely affected by habitat loss, leaving their fragmented remnants mostly poorly protected and often embedded in a hostile matrix. Moreover, the invertebrate fauna of the remaining grassland patches usually suffers from habitat degradation. Habitat quality, size, and connectivity are considered to be the key drivers of invertebrate species richness in fragmented grasslands. Hence, conservation management to support grassland invertebrates should aim to (i) legally protect significant grassland remnants from further loss, (ii) increase the quality of the remaining patches, (iii) enlarge their size, and (iv) improve functional connectivity between them. The disturbance regime in grasslands should maintain or create heterogeneous swards with some patches of bare ground and high plant species richness. Maintaining, restoring, or mimicking the natural grazing and fire regimes are usually the most promising ways to achieve this.