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Background:Progress of forest production in response to the environment requires a quantitative understanding of leaf area development.Therefore,it is necessary to investigate the dynamics of seasonal crown foliage in order to understand the productivity of mangroves,which play an important role in the subtropical and tropical coastlines of the world.Method:Crown foliage dynamics of the mangrove Rhizophora stylosa were studies to reveal patterns of leaf recruitment,survival and seasonal leaf area growth.Results:Flushing of leaves occurred throughout the year,but both flushing and leaf area growth pattern of leaves varied with season.Maximum flushing occurred in summer,but leaf areas did not differ significantly with season.The half-expansion period is longer,and the intrinsic rate of increase was lower in winter.Summer flushed leaves grew faster at their initial stage and reached their maximum area over a shorter period of time.The difference in temperature and air vapor pressure deficit(VPD) between summer and winter contributed to the present dynamics of foliage patterns.The mean leaf longevity was estimated to be 13.1 month.The crown foliage area was almost stable throughout the year.Conclusions:Homeostatic control of the crown foliage area may be accompanied by the existence of ecophysiological mechanisms in R.stylosa.Integrating crown foliage dynamics into forest models represents an important step towards incorporating physiological mechanisms into the models for predicting growth responses to environmental changes and for understanding the complex responses of tree growth and litter production.
Background: Progress of forest production in response to the environment require a quantitative understanding of leaf area development.Therefore, it is necessary to investigate the dynamics of seasonal crown foliage in order to understand the productivity of mangroves, which play an important role in the subtropical and tropical coastlines of the world. Method: Crown foliage dynamics of the mangrove Rhizophora stylosa were studies to reveal patterns of leaf recruitment, survival and seasonal leaf area growth. Results: Flushing of leaves occurred throughout the year, but both flushing and leaf area growth pattern of leaves varied with season. Maximum flushing occurred in summer, but leaf areas did not differ significantly with the season. The half-expansion period is longer, and the intrinsic rate of increase was lower in winter. Summer flushed leaves grew faster at their initial stage and reached their maximum area over a shorter period of time. The difference in temperature and air vapor pressure defic it (VPD) between summer and winter contributed to the present dynamics of foliage patterns. The mean leaf longevity was estimated to be 13.1 month. The crown foliage area was almost stable throughout the year. Conclusions: Homeostatic control of the crown foliage area may be accompanied by the existence of ecophysiological mechanisms in R. stylosa.Integrating crown foliage dynamics into forest models represents an important step toward incorporating physiological mechanisms into the models for predicting growth responses to environmental changes and for understanding the complex responses of tree growth and litter production.