混合放牧对土壤温室气体通量的影响

Effects of mixed grazing on soil greenhouse gas fluxes

通过监测不同放牧方式下土壤中二氧化碳(CO_2)、甲烷(CH_4)排放、吸收情况及排放、吸收通量大小,来评估荒漠草原是温室气体的源还是汇,从而揭示不同放牧方式对土壤温室气体CO_2、CH_4通量的影响,为进一步拟定合理放牧制度提供理论参考。试验于2016年6—9月在希拉穆仁荒漠草原进行,利用静态箱—气相色谱法测定分析了不放牧(CK)、单牧羊(SG)15只、单牧牛(CG)3头、牛羊混合放牧(MG)即15只羊、3头牛4种不同放牧方式下土壤CO_2、CH_4通量的变化。结果表明:不同放牧方式下,荒漠草原土壤表现为CO_2的源,CH_4的汇。4种放牧处理对土壤排放CO_2量无显著影响,排放CO_2通量大小顺序为CK>CG>SG>MG,放牧处理显著影响了土壤CH_4通量大小,顺序为MG>CG>SG>CK,混合放牧较其他放牧处理吸收大量CH_4,有利于减少温室气体排放。

The effects of different grazing methods on the fluxs of carbon dioxide （CO2） and methane （CH4） were measured to estimate source or sink of greenhouse gases in desert steppe, in order to forther provide theoretical reference to formulate reasonable grazing system. This experiment was foeused on different grazing treatments （sheep grazing alone SG 15 sheep; tufty cattle grazing CG 3 head of cattle; both cattle and sheep MG 15 sheep and 3 cattle; no grazing CK） to research and analysis soil atmospheric fluxes of CO2 and CH4 using static chamber gas chromatography method from Jun to September 2016 in XiLaMuRen desert steppe. The resuhs showed that the soil of the desert steppe was the CO2 source and the CH4 sink. There were not significant effects of four grazing treatment on soil CO2 emissions, and CO2 flux order is CK〉CG〉SG〉 MG. Grazing treatments affected the soil CH4 flux significantly, and order is MG〉CG〉SG〉CK, indicating MG is benefit for reducing greenhouse gas emission.