中国寒区湿地研究进展

Progress of Wetland Researches in Cold Regions of China

中国是世界上湿地资源最丰富的国家之一,其中寒区湿地占我国自然湿地的60%以上,因此它在调节气候、涵养水分、碳源汇以及生物多样性保护等方面均具有不可替代的作用.由于结构和功能上的独特性,寒区湿地对气候和环境变化反应极为敏感,因此深入探讨和分析其目前的研究状况对于中国湿地的生态保护和环境管理意义重大.从寒区湿地的类型和分布、冻土对气候变化的响应、温室气体源汇状况、生态水文过程及植被演替等5个方面,分析了中国东北和青藏高原典型寒区湿地目前的研究焦点.结果表明:全球变暖对多年冻土退化产生了长期而严重的影响,温室气体的排放具有很强的时空异质性;寒区湿地植被呈现明显的旱化趋势等,但是对多样性变化趋势的观点尚不统一.基于此,建议未来寒区湿地的研究重点应该放在不同时空尺度的冻土退化响应差异研究;耦合模型预测冻土退化趋势研究;碳储量评估;温室气体通量对气候变化的响应关系;寒区湿地生态需水量计算方法等方面.

China is one of the countries with the most abundant wetland resources.Wetlands in cold regions cover more than 60% of the total natural wetlands in China,playing an indispensable role in global climate regulation,water holding,uptake and emission of greenhouse gases and biodiversity conservation.Furthermore,wetlands in cold regions are sensitive to climate and environment changes.Thus,it is important for ecological conservation and environmental management to summarize and analyze the current research progress.In this paper,the focus of present studies on the typical wetlands in cold regions of Northeast China and the Tibetan Plateau is discussed.The following aspects of research are reviewed： types and distribution,responses of permafrost to climate change,uptake and emission of greenhouse gas,eco-hydrological process and vegetation succession.Some key conclusions are drawn.First,global warming has a long-term and serious impact on permafrost.Secondly,emission of greenhouse gas has a great temporal and spatial heterogeneity.Last but not least,hygrophytes in the wetlands in cold regions have been generally replaced by xerophytes,while it has not come to a uniform conclusion whether the diversity index increases.Based on the review,some key points of future study were put forward as follows： 1） the response of degeneration of permafrost at various spatial and temporal scales;2） prediction of degeneration tendency with coupled model;3） evaluation of carbon storage;4） response of greenhouse gas to climate changes and 5） calculation methods of ecological water demand of wetlands in cold regions.