短花针茅荒漠草原甲烷通量对增温和施氮的响应  

Responses of Methane Fluxes on Warming and Nitrogen Addition in Stipa breviflora Desert Steppe

作　　者：潘占磊 王忠武[1] 韩国栋[1] 武倩[1] 刘芳[1] 王瑞珍[1] 

机构地区：[1]内蒙古农业大学生态环境学院,内蒙古呼和浩特010019

出　　处：《生态环境学报》2016年第2期209-216,共8页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31270502;30860060);内蒙古科技重大专项项目

摘　　要：全球变化是多个因子发生变化的过程,土壤CH_4通量对全球变化的响应是多个因子对土壤CH_4通量影响的综合体现。近年来,内蒙古地区大气温度不断升高,大气氮沉降量不断增加,因此,研究增温和氮沉降对草地生态系统土壤CH_4通量的影响对全球碳收支平衡具有重要意义。为了研究增温、氮沉降及其交互作用对短花针茅(Stipa breviflora)荒漠草原土壤CH_4通量的影响,2013─2014年生长季(5─10月)采用静态箱法,对长期(2006年以来)增温和施氮条件下土壤CH_4通量进行测定,同时连续监测了10 cm土壤温度和土壤湿度。结果表明:在增温区,土壤温度和土壤湿度均会显著增加,而在施氮区,土壤湿度则会显著降低(P<0.000 1)。生长季短花针茅荒漠草原土壤CH_4的平均吸收量为40.2~50.5μg·m^(-2)·h^(-1),年份会对土壤CH_4的吸收产生显著影响(P=0.009 7),但增温、施氮及其交互作用对土壤CH_4的吸收均无显著影响(P>0.05)。在年际间,土壤CH_4的吸收与土壤温度间的关系不同,2013年二者呈显著的线性相关(P=0.029 1),而2014年二者呈显著的二次多项式关系(P=0.039 6);土壤CH_4的吸收与土壤湿度仅在2013年呈显著的二次多项式关系(P=0.012 4),2014年二者之间没有明显关系。土壤温度和土壤湿度或月降水量共同对土壤CH_4吸收变化的解释能力(R^2:0.37~0.76)高于单因子(R^2:0.20~0.34)。该研究表明在生长季短花针茅荒漠草原大气CH_4以汇为主;大气增温和氮沉降对短花针茅荒漠草原土壤CH_4的吸收无影响。Climate change is a process that is driven by multiple factor changes. The response of soil CH4 flux on climate change isan integrated effect of multiple factors. Atmospheric temperature and nitrogen deposition are constantly increasing in Inner Mongoliaat recent years, therefore, it is necessary to study the effects of global warming and nitrogen deposition on soil CH4 flux in grasslandecosystem. To study the effects of warming, nitrogen deposition and their interaction on soil CH4 flux in Stipa breviflora desertsteppe, a static chamber method was used to measure soil CH4 flux during two growing season （from May to October） in 2013 and2014 under the long-term （since 2006） warming and nitrogen addition. Meanwhile, soil temperature and soil moisture werecontinuously measured at the depth of 10 cm. The results showed that soil temperature and soil moisture were significantly increasedin the warming plots, but soil moisture in the nitrogen addition plots was significantly decreased （P 〈 0.000 1）. Mean soil CH4 uptakeduring the growing season was 40.2~50.5 μg·m-2·h-1 in Stipa breviflora desert steppe. The soil CH4 uptake was significantlyinfluenced by year （P = 0.009 7）. The warming, nitrogen addition and their interaction did not significantly influence the soil CH4uptake （P 〉 0.05）. There are different relationships between soil CH4 uptake and soil temperature in the different years. In 2013, asignificant linear relationship was found between soil CH4 uptake and soil temperature （P=0.029 1）, but there was a significantquadratic polynomial relationship in 2014 （P=0.039 6）. The influence of soil moisture on soil CH4 uptake was described by aquadratic polynomial relationship in 2013 （P=0.012 4）, but there was no relationship between them in 2014. The integrated influenceof soil temperature and soil moisture or monthly precipitation on soil CH4 uptake （R2： 0.37~0.76） was higher than any single factor（R2： 0.20~0.34）. The results indicated that Stipa breviflora desert st

关 键 词：短花针茅 荒漠草原 增温 氮沉降 CH4 

分 类 号：X16[环境科学与工程—环境科学]