读书报告4_土壤碳固定对全球气候变化与粮食安全的影响.ppt

* Soil Carbon Sequestration Impacts on Global Climate Change and Food Security Tutor : Prof . ZHENG Speaker : DongXiaogang Date : 2012-05-10 R. Lal ,et al. 2004 Science 304, 1623 土壤碳固定对全球气候变化和粮食安全的影响 2.Soil Carbon Sequestration 3.Soil Carbon Sequestration for Mitigating Climate Change 4.Soil Carbon Sequestration and Global Food Security 5.Conclusions 1.Background Content The global soil carbon (C) pool of 2500 gigatons (Gt) includes about 1550 Gt of soil organic carbon (SOC) and 950 Gt of soil inorganic carbon (SIC). 1.Background The soil C pool is 3.3 times the size of the atmospheric pool (760 Gt) and 4.5 times the size of the biotic pool (560Gt, fig. S1). 25000亿吨的全球土壤碳库由15500亿吨的土壤有机碳和9500亿吨的土壤无机碳组成。 土壤碳库的容量是大气碳库的3.3倍，是生物碳库的4.5倍。 Fig. 1. Processes affecting soil organic carbon (SOC) dynamics. The SOC pool represents a dynamic equilibrium of gains and losses (Fig. 1). 土壤碳库处于收支动态平衡。 Severe depletion of the SOC pool degrades soil quality, reduces biomass productivity, and adversely impacts water quality, and the depletion may be exacerbated by projected global warming. The depletion is exacerbated when the output of C exceeds the input and when soil degradation is severe. 当输出超过输入和土壤退化严重时土壤碳库的耗竭将加剧。 土壤碳库的严重耗竭使得土壤质量退化，生物产量降低，影响水质量，预测的全球变暖可能会加剧土壤碳库的耗竭。 The estimates of historic SOC loss range widely, from 44 to 537 Gt, with a common range of 55 to 78 Gt (3). 以往的土壤有机碳的损失量的估算值变化范围广大约从440到5370亿吨，而共识的损失量是550到780亿吨。 2.Soil Carbon Sequestration Carbon sequestration implies transferring atmospheric CO2 into long-lived pools and storing it securely so it is not immediately reemitted. Thus, soil C sequestration means increasing SOC and SIC stocks through judicious land use and recommended management practices (RMPs). 土壤碳固定意味着将大气中的CO2转移到长期存在的土壤库中并安全地储存它，因此使碳不能立即释放到大气中。因此土壤碳固定意味着通过精确的土地使用和推荐的管理措施(RMPs)增加了土壤有机和无机碳库的容量。 The SOC sequestration is caused by those management systems that add high amounts of biomass to the soil, cause minimal soil disturbance, conserve soil an