天然草地利用方式改变对土壤排放CO2和吸收CH4的影响
Effect of Variation in Land Use Pattern of Natural Grassland on Its CO2 Emission and CH4 Uptake
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摘要: 1997年～ 1998年在内蒙古达拉特旗中国农业科学院草原研究所草原生态试验站对天然草地、天然草地转变为人工草地、玉米和土豆地后 ,土壤 CO2 排放和 CH4 吸收通量进行了测定。天然草地、人工草地和旱地农田均为大气中甲烷的吸收汇 ,天然草地转变为农田后 ,增强了土壤的 CO2 排放量 ,减少了土壤对大气中甲烷的吸收。天然草地和玉米地的 CO2 排放通量与 5cm处土壤温度呈线性相关 ,土壤对甲烷的吸收率与土壤含水量呈线性负相关 ,与土壤温度没有相关关系。Abstract: During the period of 1997-1998, the Dalate Grassland Ecosystem Experimental Station of the Grassland Institute, Chinese Academy of Agricultural Sciences carried out a research project determining soil CO 2 emission and CH 4 uptake fluxes of natural grassland, erected milkvetch grassland, corn field and potato field(the latter three had been reclaimed from the former). Results show that natural grassland, erected milkvetch grassland and upland farm field were all sinks for atmospheric methane.The conversion of natural grassland to farmland increased CO 2 emission from the soil and decreased CH 4 uptake by the soil from the atmosphere. CO 2 emission from the natural grassland and cornfield was in positive linear relationship with soil temperature in 5 cm depth while the CH 4 uptake of the soil was in negative linear relationship with soil moisture.
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