基于不同空间分辨率土壤数据库的中国江苏省水稻土有机碳的动态模拟

A number of process-based models have been developed for quantifying carbon(C)sequestration in agro-ecosystems.The DeNitrification-DeComposition(DNDC)model was used to simulate and quantify long-term(1980-2008)soil organic carbon(SOC)dynamics in the important rice-producing province,Jiangsu,China.Changes in SOC storages were estimated from two soil databases differing in spatial resolution:a county database consisting of 68 polygons and a soil patch-based database of 701 polygons for all 3.7 Mha of rice fields in Jiangsu.The simulated SOC storage with the coarse resolution county database ranged between 131.0-320.6 Tg C in 1980 and 170.3-305.1 Tg C in 2008,respectively,while that estimated with the fine resolution database was 201.6 and 216.2 Tg C in 1980 and 2008,respectively.The results modeled with the soil databases differing in spatial resolution indicated that using the soil input data with higher resolution substantially increased the accuracy of the modeled results;and when lacking detailed soil datasets,the DNDC model,parameterized with the most sensitive factor(MSF) method to cope with attribute uncertainty,could still produce acceptable results although with deviations of up to 60% for the case study reported in this paper.     

Options for increasing carbon sequestration in West African soils: an exploratory study with special focus on Senegal

The organic matter content of many soils in West Africa has been depleted due to overgrazing, agricultural mismanagement, deforestation and overexploitation of the natural resources. Degraded agro(eco)systems can be managed to increase carbon sinks in vegetation and soil, and to reduce carbon emissions to the atmosphere. The capacity for sequestering carbon will increase as annual precipitation increases, and generally as mean temperature decreases, provided the soil and terrain conditions are not limiting for crop (biomass) growth. The agroecological suitability of three pilot sites, proposed for soil carbon sequestration projects in Senegal, is assessed and the feasibility of various management options to increase organic carbon levels in the soil is discussed. For the future, a Land Resources Information System should be developed to consider detailed data on climate, soil and terrain conditions, status of soil degradation, and land‐use systems for West Africa. Upon its linkage to a dynamic soil carbon model and a socio‐economic module, such an integrated system can be used to assess the ecotechnological and socio‐economic potential for carbon sequestration projects in the context of the Clean Development Mechanism (CDM) proposed under article 12 of the Kyoto Protocol to the United Nations Framework Convention on Climate Change. If adopted, this mechanism could confer funds to West African countries for the sustainable use and conservation of their natural resources, thereby providing economic, environmental and societal benefits for local populations, while simultaneously contributing to climate change mitigation. Copyright © 2001 John Wiley & Sons, Ltd.