%0 Journal Article
%T Impacts of Dung Combustion on Carbon Cycle of Grassland Ecosystem<br>畜粪能源利用对草地生态系统碳汇的影响
%A XU Zengrang
%A GAO Liwei
%A WANG Lingen
%A CHENG Shengkui
%A ZHANG Xianzhou
%A WU Junxi
%A <br>徐增让
%A 高利伟
%A 王灵恩
%A 成升魁
%A 张宪洲
%A 武俊喜
%J 资源科学
%D 2012
%I 
%X There are two yak dung utilization pattern in north Tibetan,one is all dung remain in rangeland and return to soil to supplement the organic carbon and nutrition in soil and the other is dung removing out of grassland ecosystem and combusting as fuel.Comparing with the dung back to soil situation,dung combustion changes the carbon cycle and carbon balance in the grazing alpine meadow ecosystem.Consideration of dung combusted for energy,the net biome production(NBP)of the energy-grazing alpine meadow ecosystem can be accounted by adding the carbon import(dung production)to,while subtracting carbon export(livestock intake,dung combusted and dung respiration)from NEP(NEP=NPP-Rs).In order to depict the key stage of the carbon cycle of the alpine meadow,indicators were measured by various methods,for examples,with plot survey to get the data of biomass and NPP,the LI-8100 CO2 flux system(LI-COR Inc.,Lincon,NE,USA)used to measure the soil respiration(Rs),and application with household interview to get the data of yak dung(Dt,De).The yak intake(Gi)and dung respiration(Rd)is estimated by modeling.At presently,about 82.6%of yak dung was combusted for resident energy in north Tibetan.Impact of dung combustion on carbon cycle of alpine meadow ecosystem lies in:1)The direct effect is dung-derived carbon emission to atmosphere increase and that back to soil decrease.In the situation of dung combusted as fuel,the dung-derived C emission from both the process of dung heterotrophic respiration and dung combustion reached 10.09 gC/m2.a,which was 6.64 gC/m.2a more than that in the situation of dung back to soil.Correspondingly,the dung-derived C backt o soil is only 1.40 gC/m2.a,6.64 gC/m 2.a less than that in the situation of dung back to soil;2)The indirect effect is the primary production decrease for the soil infertile via dung removing out the ecosystem.The carbon captured by vegetation was only 304.33 gC/m2.a,which was 49.67 gC/m 2.a less than that in the situation of dung back to soil;3)The induce effect of the primary production decrease is the reduction of soil respiration of the alpine meadow ecosystem.The soil respiration was 284.67 gC/m.2a,which was 11 gC/m 2.a less than that in the situation of dung back to soil;4)The general effect of dung combustion on C cycle of the alpine meadow ecosystem can be illustrated as the NBP.The NBP dropped to-17.24 gC/m.2a in the situation of dung combustion,w hich was 45.32 gC/m2.a less than that in the situation of dung back to soil.The carbon sequestration and storage capacity including the C dung-derived stored in soil and C captured by vegetation,were decreased remarkably.It is indicated that the energy-grazing alpine meadow ecosystem is a kind of net carbon source,which may affect climate change profoundly.In order to prevent grassland ecosystem from deterioration and reduce C emission,it’s necessary to lessen the proportion of dung combustion,while increase that of back to soil to maintain soil fertile and C cycl
%K Yak dung
%K Bioenergy
%K Carbon cycle
%K Net biome production (NBP)
%K Grazing
%K Alpine grassland ecosystem<br>畜粪
%K 生物质能
%K 碳循环
%K 净生物群系生产力
%K 放牧
%K 高寒草地生态系统
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=B5EDD921F3D863E289B22F36E70174A7007B5F5E43D63598017D41BB67247657&cid=B47B31F6349F979B&jid=9DEEAF23637E6E9539AD99BE6ABAB2B3&aid=371E65CB2CE8FF91785BBA12D132C86F&yid=99E9153A83D4CB11&vid=339D79302DF62549&iid=B31275AF3241DB2D&sid=D7C79E0E439D0B57&eid=81A5772701933E75&journal_id=1007-7588&journal_name=资源科学&referenced_num=0&reference_num=34