陆地生态系统类型转变与碳循环

CONVERSION OF TERRESTRIAL ECOSYSTEMS AND CARBON CYCLING

土地利用变化引起的陆地生态系统类型转变对于全球碳循环有着极其重要的作用。通过总结国内外有关森林砍伐以及森林、草地转变成农田对于碳循环的影响 ,阐述了可能引起全球“未知汇”现象的重要原因 ,强调未来中国陆地生态系统碳循环研究应充分重视陆地生态系统类型转变对于全球碳循环的影响研究 ,包括研究陆地生态系统的不同发展阶段 (自然与退化生态系统 )、利用方式的改变 (森林转化为人工林或农田 ,草地转化为农田、退耕还林草等 )所引起的碳库类型转换的增汇机理及其对全球变化响应 ,并指出了建立统一观测方法与规范的陆地生态系统碳通量观测网络 ,发展针对中国陆地生态系统特点、具有自主产权的陆地生态系统碳循环模型的重要性。

Conversion of terrestrial ecosystems resulting from land-use practice plays an important role in global carbon cycling. The studies on the effects of forest felling and the conversions of forest and grassland into farmland on terrestrial carbon budget are reviewed in this paper, and the possible reasons resulting in 'missing sink' are also discussed. In terms of carbon studies, the authors point out that the effects of terrestrial conversion on carbon budget should be emphasized in the future carbon project of China, including the ecological processes and mechanisms of different development stages of terrestrial ecosystems (natural and degraded ecosystems), land-use changes (conversion of forest into plantation or farmland, conversion of grassland into farmland, and the conversion of agricultural land into natural vegetation(forest or grassland)) and their responses to global climate change. Meantime, concurrent observation methods and standards related to terrestrial carbon flux observation network as well as developing Chinese terrestrial carbon budget evaluation model should also draw more and more attention.