Characteristics of Light Availability Under Forest Canopies and Its Influences on Photosynthesis of Understory Plants

编号 zgly0000302211

文献类型 期刊论文

文献题名 Characteristics of Light Availability Under Forest Canopies and Its Influences on Photosynthesis of Understory Plants

学科分类 220.1060;森林生态学

作者 HanY.H.Chen 

作者单位 FacultyofForestryandForestEnvironment 

母体文献 中国林学: 英文版 

年卷期 2003,5(3)

页码 54-62

年份 2003 

分类号 S718.512.2 

关键词 森林生态系统  林下植物  光合作用  光能利用效率 

文摘内容 Available light under forest canopies includes two components, diffuse light and direct light (sunflecks), and is characterized as low and highly dynamic. Understory habitats under different forest types experience different light conditions.Sunflecks as a critical resource for understory plants have great importance on carbon gain of understory plants. Under the light-limiting habitat, understory plants exhibit a high light utilization efficiency attributed by a post-illumination CO2 uptake. Although different species have different photosynthetic responses, shade plants appear to be acclimated to respond more quickly and efficiently to sunflecks. This acclimation includes a faster induction, relatively lower rate of induction loss, lower photosynthetic compensation point, and higher water use efficiency. The process that shade plants harvest light energy is not .well known. Studies of photosynthetic responses to sunflecks in natural conditions are rare. Little is known about constraints on sunfleck utilization, which may change seasonally. Extensive field studies in conjunction with laboratory investigations will be needed to further understand potential and actual constraints on sunfleck utilization. Most studies on photosynthetic responses to fluctuating light condition were done in the level of leaves. Fluctuating light utilization on the basis of whole plants and populations presents future challenges to ecologists。