Community, Dominant Tree Species Leaf Phenology and Seasonality in a Tropical Dry Forest, India

Abstract

Aims: Plant phenology is a tool to assess climate variability, but less is known about the differences in phenological sensitivity at community, life-form and individual species level. The aim of the present study is to know the contribution of individual, life-form leaf phenophases within the community.
 Methodology: The leaf phenology of tropical dry forest trees in Bhadra wildlife sanctuary, Karnataka, India was observed during June 2004 to May 2009. A total of 277 trees belonging to 45 species were monitored on monthly basis for different phenophases of leaf phenology. Simple Spearman’s correlations and multiple regressions were performed between different phenophases and environmental factors like rainfall and temperature. Seasonality was determined with circular statistics analyses using the phenological variables and dates of observation.
 Results: The influence of temperature was stressed with multiple regressions. Seasonality of each of the phenophases was also tested with circular statistics. There is a strong seasonality observed in all phenophases, the strength of seasonality was highest with leafless phenophases. Leafing phenophases among some dominant species within the community was described for seasonality and differences among them were also analyzed. Understorey species had longer leaf life span compared to canopy species. At the community level different phenophases are distinctly seasonal, though the strength of seasonality varied considerably with flushing and expansion of leaves, the strength of the seasonality was high with leaf senescence for all species.
 Conclusion: The results of this research are in agreement with previous study but the present study suggests that community, population and individual sensitivity might vary under the present context of increasing climatic variability and their adaptation helps to understand the climatic influence in shaping phenology at individual, species and community level.