尕海湿地CH_4、CO_2和N_2O通量特征初步研究  

A preliminary study of carbon dioxide,methane and nitrous oxide fluxes from the Gahai wetland

作　　者：马维伟[1] 王辉[1] 李广[1] 赵锦梅[1] 王跃思[2] 

机构地区：[1]甘肃农业大学林学院,甘肃兰州730070 [2]中国科学院大气物理研究所,北京100029

出　　处：《草业学报》2015年第8期1-10,共10页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(31260155);高等学校博士学科点专项科研基金联合资助课题(20126202110006);草地农业生态系统国家重点实验室2014年度开放课题;甘肃省教育厅项目(2014A-057)资助

摘　　要：2011年7月-2012年7月,采用静态箱-气相色谱法同步研究了尕海4种典型湿地类型的CH4、CO2和N2O通量及其与温度因子的关系,并估算了其全球变暖潜势值(GWP)。结果表明,尕海湿地的CH4、CO2和N2O通量具有明显的空间变化特征,CH4、CO2和N2O通量最小值分别为亚高山草甸(-0.014±0.126)mg/(m2·h),沼泽湿地(137.17±284.51)mg/(m2·h)和高山湿地(-0.008±0.022)mg/(m2·h),而最大值分别为沼泽湿地(0.498±0.682)mg/(m2·h),高山湿地(497.81±473.09)mg/(m2·h)和草本泥炭地(0.094±0.117)mg/(m2·h);同时CH4、CO2通量有明显的时间变化特征,通量最大值分别出现在2011年的7-10月和2012年的5-7月,而后降低并维持相对稳定的变化趋势;5cm地温、气温、地表温度及箱内温度与4种类型湿地CO2通量呈极显著正相关关系(P<0.01),与高山湿地CH4通量均存在显著正相关关系(P<0.05),与其他3种湿地类型CH4通量的相关性均较差,但与4种湿地类型N2O通量无显著相关性;尕海草本泥炭地、沼泽湿地、高山湿地和亚高山草甸4种类型湿地的温室效应贡献潜力依次为35.311,13.520,34.816和30.236tCO2/(hm2·a),沼泽湿地能够显著降低温室效应。A study has been undertaken to estimate fluxes of the greenhouse gases carbon dioxide (CO2 ),meth-ane (CH4 )and nitrous oxide (N2 O)in wetlands,to understand the effects of temperature factors on these processes and to estimate global warming potential (GWP).Using static chamber techniques,we measured CH4 ,CO2 ,and N2 O fluxes from four wetland types in Gansu Gahai Wetlands,China,from July 2011 to July 2012.The results showed high variations in CH4 ,CO2 and N2 O fluxes between the four wetlands,with the smallest values in the subalpine meadow (-0.014 ±0.126 mg/m2 ·h),marsh wetland (137.17 ±284.51 mg/m2 ·h)and mountain wetland (-0.008 ±0.022 mg/m2 ·h)respectively.The highest values of CH4 , CO2 and N2 O fluxes were in marsh wetland (0.498±0.682 mg/m2 ·h),mountain wetland (497.81 ±473.09 mg/m2 ·h)and herbaceous peat (0.094±0.117 mg/m2 ·h)respectively.CH4 and CO2 fluxes varied seasonal- <br> ly.Maximal fluxes occurred between July-October 2011 and May-July 2012,then decreased and remained relatively steady,with some slight fluctuations during the winter and thawing or freezing periods.Further a-nalysis showed that air temperature,soil temperature (at 5 cm),surface temperature and temperature inside the box were highly significantly positively correlated with CO2 flux from the four wetlands.These variables were significantly positively correlated with CH4 flux from mountain wetland but not from the other wetland types.They were significantly negatively correlated with N2 O flux from all four wetland types.The GWP esti-mates were 35.311,13.520,34.816 and 30.236 t CO2/(hm2 · a)from herbaceous peat,marsh wetland, mountain wetland and subalpine meadow respectively.These results show that marsh wetland could signifi-cantly decrease the emission of greenhouse gases from the Gahai Wetlands.

关 键 词：尕海湿地 CH4通量 CO2通量 N2O通量 

分 类 号：S812[农业科学—草业科学]