Carbon Allocation Processes as Indicators of Pollutant Impacts on Forest Trees : Biologic Markers of Air-Pollution Stress and Damage in Forests. Workshop Papers

1989

S. 293-302

49 Lit. Ang.

Unselbständiges Werk

200069340

The physiological processes linking carbon assimilation and net primary production in forest trees offer a broad spectrum of reference points for documenting, evaluating, and predicting the effects of atmospheric pollutants on forests. Measurements of photosynthesis, dark respiration, leaf maintenance costs, energy storage reserves, secondary metabolites associated with plant resistance to pathogens, dry matter partitioning, and patterns of annual radial growth of forest trees represent useful indicators of pollutant effects that encompass levels of detection ranging from short term mechanistic processes to longer term responses that integrate seasonal or multi-year effects. Productive utilization of measurements of these processes requires that particular emphasis be placed on (1) concurrent examination of multiple processes, (2) integration of information on these processes into a whole tree physiological context and (3) seasonal integration of temporal variations in the magnitude of measured responses. Collectively these processes can provide much-needed tools for evaluating qualitative and quantitative changes in growth and physiological resilience of forest trees in relationship to chronic air pollutant exposure regimes.