青藏高原高寒草甸土壤无机氮对增温和降水改变的响应  

Responses of Soil Inorganic Nitrogen to Warming and Altered Precipitation in an Alpine Meadow on the Qinghai-Tibetan Plateau

作　　者：武丹丹[1,2] 井新[3] 林笠[3] 杨新宇[3] 张振华[1] 贺金生[1,3] WU Dandan JING Xin LIN Li YANG Xinyu ZHANG Zhenhua HE Jinsheng(Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008 University of Chinese Academy of Sciences, Beijing 100049 Key Laboratory for Earth Surface Processes （MOE）, Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871)

机构地区：[1]中国科学院西北高原生物研究所,高原生物适应与进化重点实验室,西宁810008 [2]中国科学院大学,北京100049 [3]北京大学城市与环境学院生态学系,地表过程分析与模拟教育部重点实验室,北京100871

出　　处：《北京大学学报（自然科学版）》2016年第5期959-966,共8页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家自然科学基金(31300415);国家重点基础研究发展计划(2014CB954003,2014CB954004)资助

摘　　要：基于海北站野外长期增温和降水改变控制平台,研究高寒草甸生态系统生长季土壤无机氮对增温和降水改变的响应。结果表明,增温使铵态氮降低47.5%(p=0.001),硝态氮降低46.1%(p=0.021)。降水的改变对无机氮的影响存在不对称性,增加降水使铵态氮增加74.7%(p=0.046),硝态氮增加154%(p=0.017);减少降水使铵态氮降低,对硝态氮无显著影响。铵态氮、硝态氮随着土壤湿度的增加而增加,与土壤温度无显著关系。这表明增温和降水改变主要通过改变土壤湿度而不是土壤温度影响生长季土壤无机氮。因此预测,未来气候变化背景下,土壤湿度的增加可能导致青藏高原高寒草甸土壤无机氮的可利用性增加。Based on the warming and altered precipitation experiment platform at Haibei research station, this study investigated the responses of soil inorganic nitrogen to warming and altered precipitation in the growing season in alpine meadow. The results show that 1） warming significantly decreases NH4^＋-N by 47.5% （p=0.001） and NO3^--N by 85.4% （p=0.021）; 2） effect of decreased effect of increased precipitation, increased precipitation precipitation on soil inorganic nitrogen is unequal to the significantly increases NH4^＋-N by 74.7% （p=0.046） and NO3^--N by 154% （p=0.017）, while decreases precipitation tends to reduce NH4^＋-N, but has no significant effect on NO3^--N; 3） NH4^＋-N and NO3^--N are positively correlated with soil moisture, but has no correlations with soil temperature. Thus, soil moisture induced by warming and altered precipitation, is the main factor affecting inorganic nitrogen availability in the growing season. This study suggests that inorganic nitrogen availability will increase in tandem with increasing soil moisture, under the background of climate change in alpine meadow on the Qinghai-Tibetan Plateau.

关 键 词：青藏高原 全球气候变化 氮循环 土壤水分 铵态氮 硝态氮 

分 类 号：S812.2[农业科学—草业科学]