全球变暖对高寒冻土区温室气体通量影响研究进展

A Review on the Impact of Global Warming to Greenhouse Gas Flux in Frozen Ground Region

泛北极地区和青藏高原是陆地生态系统重要的有机碳、氮库。在气候变暖驱动下,高纬度或高海拔冻土融化加速,冻土活动层冻融格局改变,土壤有机质分解增加,成为全球重要的温室气体排放源,其对气候变化的“正反馈”效应受到越来越多关注。本文重点综述了近年泛北极和青藏高原冻土区土壤CO_(2),CH_(4)和N_(2)O三种主要温室气体通量对冻土退化及冻融作用的响应特征和影响机制,探讨了高寒地区生态系统净温室效应与气候变暖的相互关系,并简要提出了目前冻土区土壤碳排放和氮转化关键过程研究中需要加强的方面,旨在为继续深入开展气候变化背景下冻土碳氮循环研究提供参考。

The Holarctic and Qinghai-Tibet Plateau are important organic carbon and nitrogen pool in terrestrial ecosystems.Global warming is changing the pattern of soil freeze-thaw in frozen ground in high latitude and/or high altitude regions.Such as accelerating permafrost degradation,promoting the organic matter decomposition in active layer of frozen soil,and causing a large amount of greenhouse gas emission.These positive feedbacks of climate change have been a main focus of global change ecology and biogeochemical cycle research.In this paper,we reviewed the characteristics and induced mechanisms of soil CO_(2),CH_(4) and N_(2)O fluxes under freeze-thaw ground in the Holarctic and Qinghai-Tibet Plateau.We also discussed the relationship between the effects of net greenhouse emissions and global warming in the cold ecosystems.Furthermore,some key processes about the soil carbon emission and nitrogen conversion in frozen region to be focused on in the ongoing research were proposed with an intention to provide some references for the researches on the carbon and nitrogen cycle in frozen ground under the background of climate warming.