The present and future greenhouse gas budget of energy crops in the UK

生物能源是英国政府应对气候变化计划的关键组成部分。大气中二氧化碳含量增加的主要原因之一是化石燃料的燃烧将储存了几个世纪的碳释放回大气中。为了减少我们对化石燃料的使用，我们可以种植能源作物。生物能源（或“生物质”）作物是“碳中性”的;当燃烧发电时，它们只释放相同数量的二氧化碳回到大气中。因此，没有“额外”的二氧化碳被释放到大气中。芒草和短轮伐期矮林（SRC）杨柳是英国种植的主要生物能源作物。它们在生理学、营养需求和管理方面与目前更传统的可耕地作物不同。这种差异对土壤地球化学循环和土壤微生物学的影响，特别是与温室气体一氧化二氮（N2 O）和甲烷（CH 4）的产生和氧化有关的影响，目前尚不清楚。必须确定这一点，以便为今后管理生物能源种植系统提供基础，并准确预测今后的温室气体清单。在这个项目中，我们将测量从芒草和SRC杨柳的CO2，CH 4和N2 O的排放量，并比较这些从相邻的传统作物的排放量。我们将进一步研究过程中产生N2 O和量化CH 4氧化率使用稳定同位素技术在一系列受控的环境和管理条件下，并使用分子技术将这些排放量的任何差异或变化的微生物种群负责。这些信息将用于开发CEH的JULES社区模型，参数化这些生物能源作物的水，能源，碳和温室气体平衡，并模拟英国土地的温室气体排放，如果转换为种植芒草和SRC杨柳在目前和未来的气候条件下。

Bioenergy is a key component of the UK Government's plans for tackling climate change. One of the major causes of increased atmospheric CO2 levels is the burning of fossil fuels releasing carbon that has been stored for centuries back into the atmosphere. In order to cut our use of fossil fuels we can grow crops for energy. Bioenergy (or 'biomass') crops are 'carbon neutral'; when burned to generate electricity they only release the same amount of CO2 back into the atmosphere as they fixed. Thus no 'extra' CO2 is released into the atmosphere. Miscanthus and short rotation coppice (SRC) willow are the dominant bioenergy crops grown in the UK. They differ from more traditional current arable crops in terms of their physiology, nutrient requirements and management. The impact of such differences on biogeochemical cycling and soil microbiology, particularly in relation to the production and oxidation of the greenhouse gases nitrous oxide (N2O) and methane (CH4), is unknown. It is essential to determine this in order to underpin future management of bioenergy cropping systems and to accurately project future greenhouse gas inventories. In this project we will measure emissions of CO2, CH4 and N2O from Miscanthus and SRC willow, and compare these to emissions from adjacently growing conventional crops. We will further investigate the processes producing N2O and quantify CH4 oxidation rates using stable isotope techniques under a range of controlled environment and managment conditions, and using molecular techniques will link these emissions to any differences or changes in the microbial population responsible. This information will be used to develop the JULES community model of CEH, parameterising water, energy, carbon and greenhouse gas balances for these bioenergy crops, and to simulate greenhouse gas emissions for UK land if converted to growing Miscanthus and SRC willow under present and future climates.