The role of grasslands in biogeochemical cycles and biodiversity conservation
Grasslands have a multifunctional role in producing forage for animal production systems while providing a wide array of ecosystem services (MEA, 2005; Lemaire et al., 2011; Fig. 1). These services include the maintenance of biogeochemical conditions of soils and the maintenance of biodiversity (Regulation & Maintenance services, following the Common International Classification of Ecosystem Services (CICES Version 4.3)). The value of grasslands thus clearly extends far beyond their direct economic value for animal production systems (National Research Council, 2005), and, for example, Hönigová et al. (2012) attempted to calculate the monetary value of grassland ecosystem services such as carbon sequestration, erosion regulation and water regulation. Many comprehensive reviews on the environmental roles of grasslands have been written (for instance, Lemaire et al., 2011) and the multiple roles of grasslands as well as the possible trade-offs between them are increasingly taken into consideration in recent studies (Duru et al., 2015a; Wu et al., 2017). The main objective of this introductory chapter is to give a short overview of the current state of knowledge about the role of grasslands in biogeochemical cycles and biodiversity conservation, and to suggest further sources of information for the interested readers. With respect to biodiversity conservation, we focus on the direct effects of grasslands and grazing livestock on biodiversity and do not discuss the broader effects of livestock production systems. It should nevertheless be considered that livestock production as a whole strongly affects biodiversity at the global scale both directly, for instance, through land cultivation for feed production (Chaudharya and Kastner, 2016), and indirectly, for instance, through its contribution to climate change and water pollution.