Comparative Phenology of Epiphytic and Tree-Phase Strangler Figs in a Venezuelan Palm Savanna

Abstract

Epiphytic and tree-phase individuals of two hemiepiphytic figs (Ficus pertusa and F. trigonata) growing in a seasonally dry palm savanna in central Venezuela were compared on the bases of leaf longevity and temporal patterns of leaf production and loss. Epiphytic plants of both species produced new leaves more often and had a greater number of transitions from leaf-bearing to leafless than conspecific trees during the two-year observation period. Leaf production by epiphytic plants but not by trees of either species was positively correlated with rainfall received during the fortnight prior to phenological observation. Epiphytic plants of both species were leafless or nearly so during more of the year and had more separate episodes of becoming deciduous than conspecific trees. Periods of leaf loss generally coincided with dry periods but the negative correlation with rainfall during the previous fortnight was significant only for F. pertusa trees. Leaf life spans were shorter on epiphytic than on tree-phase figs. Pattems of leaf production and loss are interpreted to be responses to water deficits suffered by epiphytes, deficits that are at least partially overcome when plants becomes deeply rooted in the ground.