森林碳汇的估算方法及其发展趋势

森林生态系统是地球陆地生物圈的主体,也是陆地表面最大的碳库,在全球碳循环研究中扮演着重要角色,它通过同化作用吸收固定大气中的CO_2,抑制其浓度上升的功能对于应对气候变化问题具有积极的现实意义.准确地估算森林生态系统的碳汇储量,不仅有利于解释全球碳收支不平衡的问题,也有利于促进林业碳汇交易的快速发展.但是目前的估算方法在具有一定适用性的同时也都存在着各自的不足.评述了目前国内外应用最为广泛的样地清查法、涡度相关法及应用遥感技术的模型模拟法三种森林碳汇估算方法的发展历史和应用现状,并分析了各方法的优点与局限性.最后指出:应根据实际情况选择适合的单一方法或几种方法的结合来估算森林碳汇,以便提高估算精度;应加强森林生态系统内部联系及数据时空转换、插补的研究,并充分发挥各方法的优势,采取多种方法相结合的方式完善连续观测系统和区域监测网络的建设,降低估算方法中的不确定性,为大尺度估算提供合理的参数和数据分析基础.

Estimation methods of forest sequestration and their prospects

Forest ecosystem, as the main body of the Earth's terrestrial biosphere and the largest terrestrial carbon pool, plays an important role in fixing atmospheric CO_2 and mitigating climate change. Accurate estimation of the forest ecosystem carbon sequestration, is conducive not only to the explanation of global carbon budget imbalance, but also to the development of forest carbon sequestration trading. Although the current estimation method can be used under the certain conditions, they also have some flaws. This paper summarized three main estimation methods of forest sequestration: inventories, eddy covariance and application of re-mote sensing modeling, with their advantages and shortages. A suitable single method or a combination of several methods can be selected for forest sequestration estimation according to the actual situation. The internal relations and data temporal-spatial scaling conversion, interpolation of the forest ecosystem, and comprehensive application of several methods should be further studied to consummate a long-term continuous observation system and regional monitoring network construction. These studies will improve estimation accuracy, reduce the uncertainties and provide reasonable parameters and data analysis for large-scale estimation.