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

不断增加的人口以及在不断变化的世界中生产粮食的相关需求是我们这一代人面临的最大挑战之一。显然，我们需要更明智地管理我们的农业系统，以从生态系统服务中获益，包括生物多样性保护、碳和养分循环、温室气体监管以及粮食生产。草原被认为是提供这些生态系统服务的关键系统，因为它们的全球覆盖率很大，而且它们作为生物多样性和养分储存库的潜力也很大。例如，在英国，草原覆盖了36%的陆地表面，已经拥有英国32%的土壤碳储量，如果管理得当，它们可以储存更多的碳。政府间气候变化专门委员会已经确定，如果管理得当，草原管理最有可能封存额外的碳，因此草原是缓解气候变化的关键系统。在这里，我们建议通过管理植物群落的多样性和组成来加强草原的多种生态系统服务，如碳储存、养分保持和减少温室气体排放。这是因为植物物种在功能特征或特征上存在很大差异，这些差异强烈地影响到土壤中有机输入的数量和质量，这反过来又刺激了土壤微生物群落中负责土壤碳和氮循环的成分。此外，这些特征上的差异可能会改变生态系统服务的规模和方向，例如从温室气体的净排放转向通过植被管理来缓解。在这项研究中，我们将描述与草原生物多样性恢复相关的关键草原植物的不同特征，并测试它们对草原生态系统服务的影响，包括温室气体二氧化碳、甲烷和一氧化二氮的排放、土壤微生物活动以及养分循环和保持。这将提供有关利用植物多样性来操纵土壤养分循环以实现更大的碳和氮储存以及减少温室气体排放的第一批信息。

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.