藏东南森林穿透雨氮沉降通量变化特征及其影响因子  

Variation Features of Nitrogen Deposition Flux in Forest Throughfall and Its Influencing Factors in Southeastern Tibet

作　　者：刘智媛[1,2] 周筠珺[1] 李瀚[1] 韩琳[1] 

机构地区：[1]成都信息工程大学,成都610225 [2]中国科学院大气物理研究所,北京100029

出　　处：《气象科技》2016年第5期834-840,853,共8页Meteorological Science and Technology

基　　金：国家自然科学基金项目(41105101)资助

摘　　要：2012—2013年生长季在野外原位观测了青藏高原林芝地区森林穿透雨中不同形态氮湿沉降通量,并研究了氮沉降通量的变化特征及其影响因子。研究结果表明,2012、2013年可溶性总氮(TN)累积沉降通量分别为8.82kg·hm-2·a-1和6.91kg·hm^(-2)·a^(-1);其中,硝态氮(NO-3-N)、铵态氮(NH+4-N)、可溶性总有机氮(DON)沉降通量分别占总氮的16.98%、53.39%和29.63%,NH+4-N对湿沉降通量的贡献率最大。不同形态氮沉降通量呈现明显的季节性变化特征,一般在夏季达到最大值。随着降水量及温度的升高,不同形态氮沉降通量均有增加趋势;其中,总无机氮(TIN)与月平均气温呈显著相关关系(p<0.05),TN、TIN均与月累积降水量呈极显著相关(p<0.01)。月累计降水量和月平均气温可以共同解释森林穿透雨中TN沉降通量55.2%的变化。In the growing seasons of 2012 to 2013,different forms of nitrogen deposition concentrations were observed in forest throughfall in the southeastern Tibet Plateau.The results show that Total dissolved Nitrogen（TN）deposition concentrations were 8.82kg·hm-2 and 6.91kg·hm-2 from May to October in 2012 and 2013,respectively.NO-3-N accounts for 16.98%,NH＋4-N accounts for 53.39% and DON（Dissolved Organic Nitrogen）for 29.63% of TN in the troughfall,respectively,indicating NH＋4-N had the largest contribution to the wet deposition of nitrogen.For seasonal variability,the TN deposition shows a single peak in the late and middle summer in 2012 and 2013.On the annual scale,the monthly average temperature is positively correlated to TIN（Inorganic Nitrogen）deposition（p〈0.05）.Both TN and TIN depositions are positively correlated to accumulative precipitation（p〈0.01）.Monthly average temperature and accumulative precipitation can account for 55.2% of the variation of the TN deposition flux in the forest thoughfall.

关 键 词：氮沉降通量 森林穿透雨 森林生态系统 藏东南 

分 类 号：S157.1[农业科学—土壤学]