Optimising ecosystem services provided by grassland systems

摘要

Grasslands are multifunctional, producing forage for livestock while providing a wide array of ecosystem services. The value of grasslands for society thus extends far beyond their direct economic value for livestock production. Nevertheless, some antagonisms exist between benefits that can potentially be provided by grasslands. Hence, optimising the delivery of multiple benefits requires consensual decisions. This paper gives an overview of the current state of knowledge about ecosystem services provided by grasslands and discusses trade-offs at the field and the farm scales and how to evaluate them. Management options are available at the field scale to improve provisioning, regulating or maintenance services (biodiversity conservation, climate change mitigation or the regulation of nutrient cycles). Multi-species swards with an optimal legume abundance stand out as facilitators of multiple ecosystem services. However, the different services are maximised at different levels of grassland intensification and none of the options available at the field scale alleviates the conflicts occurring along the intensification gradient. We conclude that multiple services can be optimised by combining specific improvement measures at the field scale with heterogeneity in management intensity, involving multiple grassland types, at the farm or landscape scale.