Linkages between plant functional diversity soil biological communities and ecosystem services in agricultural grassland

An increasing human population and the associated need to produce food in a changing world is one of the greatest challenge facing our generation. It is clear that we need to manage our agricultural systems more judiciously to yield benefits from ecosystem services, including biodiversity conservation, carbon and nutrient cycling and greenhouse gas regulation, along with food production. Grasslands are thought to be a key system for provision of these ecosystem services due to their large global coverage, but also because of their potential as reservoirs of biodiversity and nutrients. For instance, in the UK grasslands cover 36% of the land surface and already hold 32% of the UK soil carbon stock, and if managed correctly they could store even more. The Intergovernmental Panel on Climate Change have identified grassland management as having the greatest potential to sequester additional C if managed correctly, and so grasslands are a key system for climate change mitigation. Here we propose that multiple ecosystem services, such as carbon storage, nutrient retention and reduced greenhouse gas emissions in grassland can be enhanced with management of the diversity and composition of the plant community. The reason for this is that plant species differ greatly in their functional characteristics, or traits, and these differences strongly influence the amount and quality of organic inputs to the soil, which in turn stimulates components of the soil microbial community responsible for soil carbon and nitrogen cycling. Moreover, these differences in traits could change the magnitude and direction of ecosystem services such as from net emission of greenhouse gases, towards mitigation via vegetation management. In this study we will characterise the differing traits of key grassland plant species associated with grassland biodiversity restoration, and test their impact on grassland ecosystem services including emissions of the greenhouse gases carbon dioxide, methane and nitrous oxide, soil microbial activity and nutrient cycling and retention. This will provide the first information on the potential for plant diversity to be utilised to manipulate soil nutrient cycling towards greater carbon and nitrogen storage, and lower greenhouse gas emission.