Phenological Patterns of Woody Plant Species in a Tropical Dry Forest, Bannerghatta National Park, Bengaluru

Phenology is the study of the timing of recurring natural stages in the life cycle of an organism. These natural stages, such as the plant's reproductive cycles, are being affected by the changing climate. The current study aims to understand the effect of weather parameters on the phenology of dry forests in Bannerghatta National Park. Two transects with 504 reproductively mature individuals were monitored monthly for vegetative and reproductive phenologies. Different phenophases were scored as a percent of the canopy quantitatively. Weather parameters and soil moisture were estimated for each month. Data were analysed for the observed general pattern of phenology and the influence of climate on different phenophases. The intense phenological activity was observed during the dry season. Community-level leaf initiation and flower initiation were positively correlated with maximum temperature (rs = 0.524, p0.05 for leaf initiation; rs = 0.586, p0.05 for flower initiation) and sunshine hours (rs = 0.552, p0.01 for leaf initiation; rs = 0.546, p0.05 for flower initiation). Leaf and flower initiations were highly correlated and significant (rs=0.926, p.001). Principal Component Analysis of weather parameters reveals that 88.5% of the variance is accounted for by the first three principal components. Principal component regression of the first three principal components and the phenophase intensities confirms a positive correlation with leaf initiation (multiple R = 0.716, p0.01) and flower initiation (multiple R = 0.638, p0.05). Our studies reaffirm that moisture-related factors are the major drivers of phenophase intensities, and changes in these factors could alter the timing of leafing, flowering, and fruiting.