Carbon Sequestration by Perennial Energy Crops: Is the Jury Still Out?
Carbon Sequestration by Perennial Energy Crops: Is the Jury Still Out?
复制标题
DOI：
10.1007/s12155-014-9571-0
复制
发表时间：
2015
影响因子：
3.6
通讯作者：
Richter GM
中科院分区：
文献类型：
--
作者：
Agostini F;Gregory AS;Richter GM
土壤有机碳（SOC）的变化与土地转化为能源作物是核心的辩论生物能源和潜在的碳中和。在这里，SOC下多年生能源作物（PEC）的实验证据合成参数化的整个系统模型，并确定PEC作为温室气体（GHG）的汇或源的不确定性和知识差距。对于芒草和杨柳（柳属）及其类似物（柳枝稷，杨树），我们研究了碳（C）分配到地上和地下残留输入，周转率和保留在土壤中。一项荟萃分析表明，干物质分配和C输入到土壤的研究是丰富的，而营业额的数据是罕见的，并依赖于一些同位素C示踪研究。在PEC下SOC动态和温室气体排放的综合研究是有限的，底土过程和C流失通过淋溶仍然未知。数据显示，总碳输入和SOC库存的动态变化取决于林龄。碳输入和营业额现在可以具体参数化的整个PEC系统模型，而土壤质地，水分和温度的依赖关系仍然是经验。总之，到目前为止，草本和木本多年生植物的年净SOC储存变化超过了最低缓解要求（0.25 Mg C ha − 1年− 1）（分别为1.14至1.88和0.63至0.72 Mg C ha − 1年− 1）。然而，需要长期时间序列的实地数据来验证可持续的SOC富集，因为SOC库的物理和化学稳定性仍然不确定，尽管它们对于确定C固存的可持续性（半衰期> 25年）至关重要。
Soil organic carbon (SOC) changes associated with land conversion to energy crops are central to the debate on bioenergy and their potential carbon neutrality. Here, the experimental evidence on SOC under perennial energy crops (PECs) is synthesised to parameterise a whole systems model and to identify uncertainties and knowledge gaps determining PECs being a sink or source of greenhouse gas (GHG). For Miscanthus and willow (Salix spp.) and their analogues (switchgrass, poplar), we examine carbon (C) allocation to above- and belowground residue inputs, turnover rates and retention in the soil. A meta-analysis showed that studies on dry matter partitioning and C inputs to soils are plentiful, whilst data on turnover are rare and rely on few isotopic C tracer studies. Comprehensive studies on SOC dynamics and GHG emissions under PECs are limited and subsoil processes and C losses through leaching remain unknown. Data showed dynamic changes of gross C inputs and SOC stocks depending on stand age. C inputs and turnover can now be specifically parameterised in whole PEC system models, whilst dependencies on soil texture, moisture and temperature remain empirical. In conclusion, the annual net SOC storage change exceeds the minimum mitigation requirement (0.25 Mg C ha−1 year−1) under herbaceous and woody perennials by far (1.14 to 1.88 and 0.63 to 0.72 Mg C ha−1 year−1, respectively). However, long-term time series of field data are needed to verify sustainable SOC enrichment, as the physical and chemical stabilities of SOC pools remain uncertain, although they are essential in defining the sustainability of C sequestration (half-life >25 years).