Greenhouse gas emissions from four bioenergy crops in England and Wales: Integrating spatial estimates of yield and soil carbon balance in life cycle analyses
Greenhouse gas emissions from four bioenergy crops in England and Wales: Integrating spatial estimates of yield and soil carbon balance in life cycle analyses
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DOI：
10.1111/j.1757-1707.2009.01021.x
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发表时间：
2009-08-01
影响因子：
5.6
通讯作者：
Smith, Peter
中科院分区：
文献类型：
--
作者：
Hillier, Jonathan;Whittaker, Carly;Smith, Peter
准确估计生物能源作物的温室气体减排潜力需要整合空间变化信息的重要组成部分。特别是，作物产量和土壤碳(C)储量是通常取决于土壤类型和气候的变量。由于土壤C的气体排放取决于当前的C储量，而当前的C储量又与以前的土地管理有关，因此在任何C会计评估中考虑以前和拟议的未来土地利用是很重要的。我们对英格兰和威尔士进行了空间明确的研究，将经验产量图与RothC土壤C周转模型相结合，模拟土壤C动态。我们估算了四种生物能源作物——芒草（Miscanthus x giganteus）、短轮作胡杨（Populus trichocarpa Torr）和白杨（Populus trichocarpa Torr）的种植对土壤碳含量的影响。& Gray x P. trichocarpa, var. Trichobel)，冬小麦和油菜。然后，这与以前的土地利用（可耕地、牧场或森林/半自然）有关，然后在每种作物的生命周期分析（LCA）的背景下评估产出。通过抵消以前土地利用下的管理排放，并考虑化石燃料C的替代，估算了与四种生物能源作物替代可耕地、草地或森林/半自然土地相关的12种土地利用变化转变中的每一种的温室气体平衡。芒草和SRC可能在减少温室气体排放方面产生主要有益的影响，而油菜和冬小麦要么有净温室气体成本，要么只有边际效益。就温室气体平衡而言，以前的土地利用是重要的，并且可以使生物能源作物比现有的土地利用有益或更差。
Accurate estimation of the greenhouse gas (GHG) mitigation potential of bioenergy crops requires the integration of a significant component of spatially varying information. In particular, crop yield and soil carbon (C) stocks are variables which are generally soil type and climate dependent. Since gaseous emissions from soil C depend on current C stocks, which in turn are related to previous land management it is important to consider both previous and proposed future land use in any C accounting assessment. We have conducted a spatially explicit study for England and Wales, coupling empirical yield maps with the RothC soil C turnover model to simulate soil C dynamics. We estimate soil C changes under proposed planting of four bioenergy crops, Miscanthus (Miscanthus x giganteus), short rotation coppice (SRC) poplar (Populus trichocarpa Torr. & Gray x P. trichocarpa, var. Trichobel), winter wheat, and oilseed rape. This is then related to the former land use - arable, pasture, or forest/seminatural, and the outputs are then assessed in the context of a life cycle analysis (LCA) for each crop. By offsetting emissions from management under the previous land use, and considering fossil fuel C displaced, the GHG balance is estimated for each of the 12 land use change transitions associated with replacing arable, grassland, or forest/seminatural land, with each of the four bioenergy crops. Miscanthus and SRC are likely to have a mostly beneficial impact in reducing GHG emissions, while oilseed rape and winter wheat have either a net GHG cost, or only a marginal benefit. Previous land use is important and can make the difference between the bioenergy crop being beneficial or worse than the existing land use in terms of GHG balance.