森林、林业活动与温室气体的减排增汇

大气中CO_2等温室气体浓度上升引起的全球变暖,威胁着人类生存和社会经济的可持续发展。在减少温室气体排放、稳定大气CO_2浓度的措施中,森林和林业活动扮演着重要的角色。森林可吸收并固定大气CO_2,是大气CO_2的吸收汇和贮存库;而毁林是大气CO_2的重要排放源。通过适当的林业活动可增强碳吸收汇、保护现有的碳贮存,通过替代措施可减少化石燃料引起的温室气体排放。因此,林业活动在未来减缓大气温室气体上升方面将发挥重要作用。阐明了全球和中国森林生态系统在减缓大气CO_2浓度上升中的作用以及与土地利用变化和林业有关的减排增汇措施和潜力,以期对我国制定CO_2减排增汇政策提供参考依据。

Forests and Forestry Activities in Relations to Emission Mitigation and Sink Enhancement

Increasing carbon dioxide and other greenhouse gas concentration in atmosphere have resulted in global warming that threats sustainable development of human beings. International communities are taking action plans aiming to mitigate greenhouse gas emissions and to stabilize carbon dioxide concentration in the atmosphere. Forests and forestry activities play a significant role in these actions. Atmospheric carbon dioxide can be sequestered through tree growth and as a result forest ecosystems play as an important carbon pool and carbon sink in terrestrial and atmospheric carbon exchanges. Carbon sequestration by growing forests has been shown to be a cost-effective option for mitigation of global climatic change. On the other hand, deforestation, especially in the tropics, behind fossil fuel burning, was believed to be the second largest source of rising atmospheric CO_2 concentration. Therefore, such forestry activities as afforestation, reforestation, forest management, deforestation avoiding and so on are believed to be effective ways to enhance terrestrial carbon sinks and protect existing carbon pools. Wood products can also be used either directly as fuels or as substitutes for energy-consuming products (steel, cement, etc.) and at the end reduce greenhouse gas emission in energy production and industrial process. We reviewed global and China's forest ecosystems in relations to global carbon cycle, and discussed potentials of forestry activities in the mitigation of greenhouse gas emission.