森林碳利用效率研究进展  

Advances in the carbon use efficiency of forest

作　　者：朱万泽[1] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,成都610041

出　　处：《植物生态学报》2013年第11期1043-1058,共16页Chinese Journal of Plant Ecology

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-EW-309);国家"十二五"科技支撑计划专题(2011BAC09B04-02-04);国家自然科学基金(30872017)

摘　　要：植物碳利用效率(CUE)指净初级生产力与总初级生产力的比率,它不仅反映了植被生态系统将大气中CO2转化为生物量的能力和固碳潜力,而且可确定呼吸对植被生产力的影响。CUE是比较不同生态系统碳循环差异的重要参数,了解生态系统CUE有助于分析陆地生态系统是碳源还是碳汇,对于预测全球变化和人类干扰对森林碳收支的影响具有重要意义。我国在森林CUE研究方面还十分欠缺。该文在介绍森林CUE计算方法和测定技术的基础上,综述了植被、气象、森林经营等因子对森林CUE的影响,得出主要结论:(1)关于不同森林植被类型CUE变化有两种截然相反的观点,即:恒定CUE和变量CUE。越来越多的研究支持第二种观点,不同生态系统、不同森林类型、不同物种和植物发育阶段的CUE存在较大差异,森林CUE较灌丛和草地低,落叶林比混交林和常绿林具有较高的CUE,热带森林CUE通常低于温带森林,CUE与植被演替和林龄相关,森林地上、地下部分和不同组织的CUE不同,以树干为最高;(2)植被的CUE与气温相关,全球尺度上,森林植被年平均CUE与年平均气温呈抛物线关系,温带、寒带、干旱地区植物呼吸的温度适应驱动其较高的CUE;CUE随着降水量的增加而减少,在水分充足或过剩的地区保持不变;光照减弱降低维持呼吸系数,增加生长呼吸系数,导致植物CUE降低,生长在高光照下的植物CUE高于低光照下的植物;(3)CO2浓度升高引起植物CUE的升高或降低,也有人认为CO2浓度升高对森林CUE没有影响,CO2浓度升高对CUE的影响可能取决于树木年龄或基因型;(4)生长在土壤瘠薄、低温、干旱等胁迫环境下的植物CUE通常比生长在适宜环境下的植物具有较大的可塑性,施肥、灌溉和择伐等管理措施影响森林CUE;(5)植物CUE具有明显的季节变化,温带森林以春季CUE为最高。建议今后森林CUE研究应着重围绕以下3个关键问�Carbon use efficiency （CUE）, which is defined as the ratio of net carbon gain to gross carbon assimilation, can be used to assess not only the capacity of forests to transfer carbon from the atmosphere to the terrestrial biomass but also to determine the impact of respiration on productivity in forests. CUE is an important parameter for compar- ing carbon cycle variability among ecosystems. Understanding such controls on CUE can be helpful in determin- ing whether the terrestrial ecosystem is a carbon source or sink. Forest CUE under different environmental re- gimes and global change scenarios has recently received increasing attention. This paper introduces the calcula- tion methods of plant CUE and the corresponding measurement techniques, and reviews the research progress in the effects of important factors on forest CUE. The main findings are as follows： （1） Some studies proposed that CUE is constant among forests with a possible appropriate universal value of 0.50. However, it is doubtful whether this conservative CUE assumption regardless of ecosystem types is globally applicable. CUE can vary with ecosystems, forest types, species, and ontogeny of plant development. Forest ecosystems have a lower CUE than shrub and herbaceous ecosystems. CUE is significantly higher in deciduous than in mixed and evergreen forests. Tropical forests often have lower CUE than temperate forests. CUE is known to depend on successional stage and stand age. （2） Forest CUE is related to temperature, precipitation, and geographical factors. A parabolic relationship between CUE and annual mean temperature is founded at a global scale. Acclimation of the respira- tion to temperature contributes to high carbon-use efficiency in seasonally dry vegetation. The CUE decreases with enhanced precipitation and remains unchanged in areas where water availability is in surplus. CUE of plants grown at low light level is low. （3） The elevated CO2 may increase whole-plant respiration, causing CUE to de- cline. The potential for

关 键 词：碳利用效率 气候因子 森林经营 森林植被 测定方法 土壤营养 

分 类 号：S718.5[农业科学—林学]