湿地碳汇功能探讨:以泥炭地和芦苇湿地为例

Carbon sink function of wetland:peatland and reed wetland cases

大量研究表明湿地是地球表层系统中的重要碳汇,对于吸收大气中的温室气体,减缓全球气候变暖有重要作用。由于近几十年来全球气候变暖和人类活动的影响,湿地碳汇功能不断减弱。文章以泥炭地和芦苇Phragmites australis湿地为例来分析湿地的碳汇功能发现:农业排水、土地利用方式的改变、大气中CO2体积分数升高、全球气候变化等人为和自然因素影响了泥炭地的碳汇功能,泥炭地的碳蓄积能力下降,逐渐由"碳汇"转变为"碳源";尽管芦苇湿地是CH4的重要来源,但其对CO2具有较强的碳汇作用,综合来看芦苇湿地的仍是温室气体的净汇;人工芦苇湿地污水净化系统的温室气体排放量高于天然芦苇湿地。分析表明,研究泥炭地和芦苇湿地在全球气候变化下的响应及反馈机制,确定合理的湿地开发模式将是未来湿地碳汇研究的主要方向。

Wetland as an important ＂carbon sink＂ of earth surface layer system plays a role of absorbing greenhouse gas in the atmosphere and mitigating global warming proved by many researches. Because of global climate changing warm and anthropogenic effects last decades, carbon sink function of wetlands is losing. By analyzing wetlands carbon sink function in peatland and Phragmites australis wetlands case this paper found that anthropogenic and natural factors, as agriculture drain, land-use change, atmospheric CO2 concentrations increasing, global climate change, affected carbon sink function of peatland, and the carbon storage capacity of peatland decreased changing from ＂carbon sink＂ to ＂carbon source＂; Phragmites austral＆ wetlands acted as a net sink for greenhouse gas by photosynthetic assimilation of CO2 from the atmosphere despite Phragmites australis wetlands also acted as a source for CH4; man-made reed wetlands for sewage disposal emitted more greenhouse gas than natural reed wetlands. This research shows that the responses and feedback mechanism of peatland and reed wetlands to global climate change and reasonable wetlands development model will be major research content in future.