人工草地建植对昭苏盆地山地草甸碳水通量特征的影响  

Effects of Plowing and Sowing on Carbon and Water Fluxes in Mountain Meadow in Zhaosu Basin

作　　者：王祥[1] 郑伟[1] 朱亚琼[1] 关正翾 唐高溶[1] WANG Xiang ZHENG Wei ZHU Ya-qiong GUAN Zheng-xuan TANG Gao-rong(College of Pratacultural and Environmental Science ,Xinjiang Agricultural University/Xinjiang Key Laboratory of Grassland Resources and Ecology ,Urumqi 830052,Chin)

机构地区：[1]新疆农业大学草业与环境科学学院/新疆维吾尔自治区草地资源与生态重点实验室,新疆乌鲁木齐830052

出　　处：《中国草地学报》2017年第2期1-10,共10页Chinese Journal of Grassland

基　　金：中国科学院战略性先导科技专项"应对气候变化的碳收支认证及相关问题"(XDA05050405);农业部项目"国家牧草现代产业技术体系"(CARS35);国家自然科学基金项目(31460636)

摘　　要：2014年4~10月采用静态箱法对新疆昭苏盆地围封3年的人工草地(LG)和天然草地(NG)的生物量、CO_2净生态系统交换量(NEE)、蒸散量(ET)、生态系统呼吸(ER)进行了观测,结果表明:(1)退化山地草甸翻耕重建能有效提高草地的地上生物量。(2)NG年平均NEE要小于LG,全年平均蒸散量NG>LG。NG的碳、水(NEE和ET)之间存在极显著相关关系(P<0.01),而LG相关性不显著。(3)两种草地的NEE与大气温度、土壤温度和土壤含水量之间呈线性负相关关系,与空气湿度呈线性正相关关系,其中LG和NG的NEE与土壤含水量的线性关系均达显著水平。指数模型能够较好地模拟ER对土壤温度变化的响应,天然草地ER的温度敏感系数(Q10值)大于人工草地。天然草地翻耕重建成人工草地,草地CO_2净生态系统交换量虽有所升高,但蒸散量降低且同时降低了对温度变化的敏感性,提高了水分利用效率和草地生产力。The static chamber method was used to observe and measure CO_2 net ecosystem exchange（NEE）and evapotranspiration flux（ET）in natural mountain meadow and plowed-sowed mountain meadow（legume-grass mixtures）which were enclosed for 3years（2011~2014）during the period from April to October 2014.The study plots was located in Horse Farm of Zhaosu,Xinjiang and the field observation was last for seven months.The results showed that：1）The annual average NEE in natural mountain meadow was lower than legume-grass mixtures,with a mean of 0.099μmol/m^2·s and 0.263μmol/m^2·s respectively.The annual average ET and water use efficiency（WUE）were 0.145nmolH_2O/m^2·s,0.222nmolH_2O/m^2·s and 19.87μmol/nmol,14.41μmol/nmol respectively.They were no significant difference between legume-grass mixtures and natural mountain meadow.2）There were significant correlation relationship in NEE and ET between carbon flux and water flux in natural mountain meadow（P〈0.01）.3）There were linear and negative correlations between NEE and atmospheric temperature（Ts）,the soil temperature and soil water content（SWC）,and there was a linear and positive correlation between NEE and air humidity.Especially,the negative correlation between NEE and SWC was significant in legume-grass mixtures（P〈0.05）,the negative correlation between NEE and SWC was significant in natural mountain meadow（P〈0.01）.The correlation relationship between ER and Ts was significant（P〈0.01）,and the exponential model could simulate the response of ER to soil temperature changes.The temperature sensibility coefficient（Q10）values of ER ranked in the order：natural mountain meadow（4.362）〉legume-grass mixtures（3.370）.Therefore,plowing and sowing（legume-grass mixtures）would not improve effectively hydrothermal conditions of grassland ecosystem,but it could reduce dependence on water,improve WUE,decrease carbon emission from grassland ecosystem,and improve the forage production capacity.

关 键 词：净生态系统交换量 生态系统呼吸 蒸散量 山地草甸 豆禾混播草地 

分 类 号：S812.29[农业科学—草业科学]