Dispersal modes of tree species in the wet forests of southern Western Ghats

Abstract

Dispersal modes of tree species in a wet evergreen forest at Kakachi in the Kalakad–Mundanthurai Tiger Reserve, southern India are described here. Frugivore visitors to 82 tree species were observed. Biotic agents involved in seed dispersal and seed predation were six species of birds and five species of mammals. Birddispersed species were the most common species (59%), followed by mammal-dispersed species (26%). Primates were less important than bats and civets in seed dispersal. Fifteen per cent of the species had no apparent adaptation for abiotic dispersal (mechanically dispersed) except one wind-dispersed species. Many bird-dispersed species occurred at low density but the total density of bird-dispersed species compares with that of mammal and mechanically dispersed species. Edge or gap habitat species were less abundant than the closed forest ones in all three types of dispersal modes. Species level comparison with other wet forest sites indicates a high degree of similarity between Kakachi and La Selva in central America.