Carbon Allocation as an Indicator of Pollutant Impacts on Forest Trees

摘要

Detecting physiological responses of forest trees to ambient levels of atmospheric pollutants and evaluating those responses in terms of their importance to tree vigor and production potential represent significant challenges to forest ecophysiologists. The study of alterations in carbon economy of pollutant-stressed trees, including carbon assimilation, utilization, and storage patterns, represents one approach that may encompass levels of detection ranging from short-term mechanistic responses to longer term responses that integrate seasonal or multiyear effects. Collectively these processes have direct relevance for evaluating qualitative and quantitative changes in growth and physiological resilience of forest trees. Examples of utilization of measurements of photosynthesis, dark respiration, energy storage reserves, secondary metabolites associated with plant resistance to pathogens, dry-matter partitioning, and patterns of annual radial growth of forest trees are examined in relation to their utility in evaluating mechanisms and consequences of pollutant effects on forest physiology and growth. Additional emphasis on measurement and integration of carbon allocation processes of forest trees under chronic air pollution stress is needed. 66 refs., 2 figs. (ERA citation 13:006549)