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

在不断变化的世界中，不断增长的人口和相关的粮食生产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，以便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、温室气体调节以及粮食生产。草原被认为是提供这些生态系统服务的关键系统，因为它们覆盖全球，而且还因为它们具有作为生物多样性和营养物质储存库的潜力。例如，在英国，草原覆盖了36%的陆地表面，已经储存了32%的英国土壤碳储量，如果管理得当，它们可以储存更多。政府间气候变化专门委员会已经确定，如果管理得当，草原管理最有可能吸收额外的碳，因此草原是减缓气候变化的关键系统。本文认为，通过对草地植物群落多样性和组成的管理，可以提高草地的碳储存、养分保持和温室气体减排等多种生态系统服务功能。其原因是植物物种的功能特征或性状差异很大，这些差异强烈影响土壤有机输入的数量和质量，这反过来又刺激了负责土壤碳和氮循环的土壤微生物群落的组成部分。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，例如从温室气体净排放转向通过植被管理进行缓解。在这项研究中，我们将描述与草地生物多样性恢复相关的关键草地植物物种的不同特征，并测试它们对草地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、土壤微生物活动和养分循环和保留。这将提供关于利用植物多样性操纵土壤养分循环的潜力的第一个信息，以实现更多的碳和氮储存，并减少温室气体排放。

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.