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时间:2018-04-16
《水分非均匀分布条件下土壤co_2的排放特征》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、中国农村水利水电·2015年第2期13文章编号:1007-2284(2015)02-0013-05水分非均匀分布条件下土壤CO2的排放特征王艳华1,2,徐俊增1,2,卫琦2,杨士红1,2,吕玉平2(1,河海大学水文水资源与水利工程科学国家重点实验室,南京210098;2.河海大学水利水电学院,南京210098)摘要:为了研究水分非均匀分布条件下旱地土壤CO2的排放特征,采用静态箱-气相色谱法测定了SI、SDI12、SDI15及SDI18共4个处理的CO2排放通量。结果表明:总体上CO2排放通量平均值表
2、现为SI>SDI12>SDI15>SDI18,但仅SI处理与SDI18之间的差异具有显著性;2次灌水后SDI处理土壤CO2排放较高的WFPS范围分别是25.9%~33.8%和31.5%~33.0%,低于SI处理出现高峰排放的WFPS分别为47%和34.1%;由于温度的影响第2次灌水后CO2排放通量总体上高于第1次灌水后,但第1次灌水后CO2排放通量与温度具有较强的相关性,而第2次灌水后两者之间相关关系不显著,可能存在过高温度下的土壤呼吸抑制。此外降雨发生时空气湿度的增加对微生物的呼吸有刺激作用,各处理
3、降雨后出现了短期的CO2排放通量的小高峰。关键词:水分非均匀分布;CO2通量;排放规律;土壤充水孔隙度;灌水方式中图分类号:S152.7文献标识码:ACarbonDioxideMmissionfromSoilwithDifferentMoistureProfile1,2,XUJun-zeng1,2,WEIQi2,YANGShi-hong1,2,LYu-ping2WANGYan-hua(1.StateKeyLaboratoryofHydrology-WaterResourcesandHydraulic
4、Engineering,HohaiUniversity,Nanjing210098,China;2.CollegeofWaterConservancyandHydropowerEngineering,HohaiUniversity,Nanjing210098,China)Abstract:Torevealthecarbondioxideemissionfromsoilwithdifferentmoistureprofile,thestaticopaquechamber-gaschromato-grap
5、hmethodisusedtomeasureCO2fluxesofSI,SDI12,SDI15andSDI18treatments.Generally,theaverageofCO2emissionflu-xesfromdifferenttreatmentareinthefollowingsequence:SI>SDI12>SDI15>SDI18,buttherearenosignificantdifferencebe-tweenthetreatmentsexceptbetweenSIandSDI18
6、treatments.TheWFPSrangeinwhichCO2emissionfluxishighare25.9%~33.8%WFPSand31.5%~33.0%WFPSinSDItreatmentsafterthefirstandsecondirrigation,whicharelowerthanthatinSItreat-ments(47%WFPSand34.1%WFPS).Hightemperatureduringtheperiodafterthesecondirrigationresult
7、sinhighCO2emissionfluxes,comparedwiththatafterthefirstirrigation.TheCO2emissionfluxesaresignificantlyrelatedtothesoiltemperatureafterthefirstirrigation,butnotafterthesecondirrigation.Thesoilrespirationmightbedepressedathightemperatures.Additionally,thei
8、ncreasedairhumidityafterrainfalllikelystimulatedthesoilmicrobialrespiration,sub-peaksofCO2emissionareobservedaftertherain.Keywords:soilwaternon-uniformdistribution;CO2emissionfluxes;emission;waterfilledporosity;irrigationmethods近
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