季节性雪被对高山生态系统土壤氮转化的影响

Effects of seasonal snow cover on soil nitrogen transformation in alpine ecosystem:A review

在高山生态系统中,季节性雪被对土壤氮含量及转化有着重大影响.降雪是氮沉降的一种重要形式,直接影响着土壤中的有效氮含量;降雪形成不同厚度和持续期的雪被后,造成环境因子(土壤温度和含水量)和生物因子(土壤微生物、高山植物和高山动物)的异质性,进而对土壤中氮素矿化和微生物固持过程产生复杂的影响.本文重点介绍了持续性雪被消融期冻融交替影响土壤氮素矿化和流失的机制,并针对高山地区未来季节性雪被可能发生的变化,综述了野外原位模拟实验的主要研究成果,最后提出了开展季节性雪被对土壤氮影响研究的一些建议.

Seasonal snow cover has pronounced effects on the soil nitrogen concentration and transformation in alpine ecosystem.Snowfall is an important form of nitrogen deposition,which directly affects the content of soil available nitrogen.Different depths and different duration of snow cover caused by snowfall may lead the heterogeneity of abiotic factors（soil temperature and moisture） and biotic factors（soil microbes,alpine plants,and alpine animals）,and further,produce complicated effects on the mineralization and immobilization of soil nitrogen.This paper introduced in emphasis the inherent mechanisms of soil nitrogen mineralization and leaching under the effects of frequent freeze-thaw events during the durative melting of snow cover,and summarized the main research results of field in situ experiments about the effects of seasonal snow cover on soil nitrogen in alpine ecosystem based on the possible changes in snow cover in the future.Some suggestions with regard to the effects of seasonal snow cover on soil nitrogen were put forward.