基于REDD+框架的中国热带森林退化减排机制研究

Deforestation and forest degradation are contributing to climate change. Activities such as illegal logging, forest fires and the destruction of forest cover are the second largest source of greenhouse gases (GHG) emissions causing global warming. Mitigation of climate change requires innovative mechanisms that create financial incentives for the sustainable use of forest resources and forest conservation. Accordingly, the 192 member states of the United Nations Framework Convention on Climate Change (UNFCCC) agreed that reducing emissions from deforestation and forest degradation, plus the role of conservation, sustainable management of forests and enhancement of forest carbon stocks (REDD+) in developing countries through positive incentives is capable of dealing with global emissions. Xishuangbanna (Southwest China) is situated in the northern margin of the tropical zone in Southeast Asia. It maintains large areas of tropical rain forest and contains rich biodiversity. However, with the increase of population and economic development, tropical rain forests are being rapidly destroyed in this region. This makes it the potential area for REDD+. The primary objective here is to apply REDD+ framework to China's tropical degraded forest. Two primary attributes must be in place to ensure the quantitative and qualitative underpinnings for an effective MRV system for REDD+: degradation monitoring and mapping carbon stocks. The approach of BAU baseline scenario linked to historic data is adopted based on Improved Cellular Automata(ICA) model. Financial incentives, which are paid through assessment of local opportunity costs compensation from world carbon market, create an innovative financing mechanism to generate additional income for forest activities. As such REDD+ implementation would contribute to achievement of the objectives of current environment and socio - economic development strategies and policies. This study will deepen and expand REDD+ framework and provide scientific evidences and practical policy advices for policy makers to find the way of reducing emissions and sustainable management of forests in China's tropical forest.

减少发展中国家因毁林与森林退化导致的碳排放以及加强森林可持续管理、保护与增强森林碳储量，即REDD+，将成为未来承诺期国际社会关于林业减缓气候变化最重要的手段之一。西双版纳是我国热带森林退化较为严重的地区，本项目在对REDD+框架进行分析的基础上，研究该地区森林退化的碳减排机制。首先运用多源信息融合和集成等技术手段,从区域尺度重建该地区的森林退化过程，探索研究区森林退化的特点和时空变化规律。进而在分析导致森林退化的社会和经济驱动力的基础上，基于优化的元胞自动机模型和本地化参数的簿记法碳排放生态模型，核定碳排放参考水平。基于上述研究，从融资和补偿两个方面，运用EPPA模型和基于动态建模技术的计量经济模型，制定基于机会成本的中国热带森林退化的碳补偿标准。本项目可为热带森林碳减排和可持续管理提供理论借鉴和实践指导。

减少发展中国家因毁林与森林退化导致的碳排放以及加强森林可持续管理、保护与增强森林碳储量，即REDD+，将成为未来承诺期国际社会关于林业减缓气候变化最重要的手段之一。西双版纳是我国热带森林退化较为严重的地区，本项目在对REDD+框架进行分析的基础上，研究该地区森林退化的碳减排机制。研究中运用多源信息融合和集成等技术手段, 发展了一套监测中国热带森林变化的技术手段，从区域尺度重建了西双版纳地区的的森林变化过程。在森林退化方面，1976-2007年研究区域有林地面积的变化整体呈下降趋势，共减少了5260.179km2 ，31年来有林地年平均变化率-1.245%，其中1999-2007年有林地面积的减少最多，达2173.299km2，年变化率为-1.549%，其次是1976-1992年减少了1804.286km2，年变化率为-0.827%。近年来，毁林呈现出逐渐由低海拔、小坡度、南坡地区向高海拔、大坡度、北坡扩张的趋势。研究发现，1976-1992年、1992-1999、1999-2007年三个时期，因毁林与森林退化分别排放了8.71 × 10^5 吨、1.30× 10^6 吨、1.28 × 10^6 吨 CO2，表明该地区的碳排放基本呈增加趋势。从研究区整体景观格局来看，斑块数（NP）、香农多样性指数（SHDI）和香农均一性指数（SHEI）分别增加了8.16%、51.39%和34.07%；与此同时，平均斑块面积（AREA_MN）和景观要素聚集度指数（COHESION）分别下降了26.26%和2.13%，表明研究区整体景观格局朝破碎化方向发展，这和碳排放的增加相一致。同时，该区的土壤侵蚀程度逐年加剧，并与碳储量的减少密切相关。分析表明，土壤侵蚀剧烈的区域，其平均碳排放也相对较高。在森林退化社会经济驱动力方面，退化森林面积与社会经济发展呈不明显正相关，与农业发展与结构呈不明显负相关，与政策呈显著负相关，故加强政策保护能有效抑制森林退化。计算表明，西双版纳地区碳补偿标准为8-24USD/吨二氧化碳，高海拔地区的碳补偿比低海拔的碳补偿更为经济。本研究为中国西双版纳地区森林碳减排和可持续管理提供了理论借鉴和实践指导。