摘要
北方森林因其面积大、土壤碳储量高以及对全球暖化响应敏感而在全球碳平衡和气候系统中起着至关重要的作用。土壤呼吸和木质残体分解释放出的 CO2 通量是北方森林生态系统输入大气圈的最主要的碳源。量化这个通量并深刻理解其中的机理过程 ,是评价和预测北方森林在全球变化中的作用必不可少的内容。综述了北方森林生态系统土壤呼吸和木质残体分解释放出的 CO2 通量随生态系统类型及环境条件而变化的一般格局以及自养呼吸和异氧呼吸在土壤表面 CO2 通量中的相对贡献 ;分析了影响北方森林土壤呼吸的主要生物物理因子 ;讨论了该领域研究存在的问题和今后的研究方向 ;并强调木质残体分解释放出的 CO2 通量虽然在以往的森林生态系统碳平衡研究中常被忽略 。
The boreal forest plays a crucial role in the global carbon budget and climatic system because of its large area, great soil carbon storage, and sensitive responses to the global warming. CO 2 fluxes from soil respiration and woody debris decomposition are the largest carbon source to the atmosphere in boreal forest ecosystems. Quantifying these fluxes and understanding the underlying mechanisms are necessary for assessing and predicting the role of boreal forests in the global change. Here we summarized general patterns of CO 2 fluxes from soil respiration and woody debris decomposition in various boreal ecosystems and environmental conditions, their biophysical controls, and relative contributions of autotrophic and heterotrophic respiration in soil surface CO 2 flux. The soil surface CO 2 flux varied from 295 to 627 g C/(m^2·a), and did not differ significantly (F (4,94)=1.07, P=0.38)after the effect of soil drainage on soil respiration was excluded. The soil surface CO 2 flux was affected by mean annual temperature, annual precipitation, and soil drainage, and positively correlated to mean annual temperature but negatively to annual precipitation. The relative contribution of autotrophic respiration to total soil surface CO 2 flux averaged 32%, varying between 2% to 60%. Finally, we discussed the current issues and future study directions in this subject, and emphasized that the CO 2 emission from woody debris decomposition should never be ignored in the fire-prone boreal forest although it was not included in most forest carbon budgets.
出处
《生态学报》
CAS
CSCD
北大核心
2005年第3期633-638,共6页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目 (3 0 470 3 0 4)
帽儿山生态定位站基金资助项目 (2 0 0 1-0 2 )
东北林业大学引进人才基金资助项目 (0 10 -60 2 0 2 8)~~
