APPLICATIONS OF CHLOROPHYLL FLUORESCENCE TO FOREST ECOLOGY

Functioning of photosystem II (PSII) is the most sensitive indicator o f environmental stress in plants. Changes in PSII activity can be assa yed rapidly and non-destructively by measurement of chlorophyll fluore scence. While there have been many laboratory studies of chlorophyll f luorescence, fluorescence techniques have seldom been applied to quest ions in forest ecology. Most studies have emphasised the fluorescence parameter, F-v/F-m, which is well correlated with the quantum efficien cy of photosynthetic carbon dioxide assimilation or oxygen evolution. This parameter reveals information which can be related to diurnal and seasonal variation in photosynthesis, plant growth and community dyna mics. Thus, fluorescence techniques provide a powerful means of linkin g photosynthesis with higher levels of plant functioning and have grea t potential for research in forest ecology.