Fruit predation and adaptive strategies of Garcinia imberti, an endangered species of southern Western Ghats

摘要

The germination and seedling emergence capacity of partially predated seeds of Garcinia imberti Bourd., an endemic and endangered tree species of the southern Western Ghats, was assessed with differentially devoured seeds. Pre-dispersal, fruit/seed predation by arboreal mammals especially Ratufa indica (Malabar Giant Squirrel) and to a smaller extent by Trachy-pithecus johnii (Nilgiri Langur) was observed. The fragmented seeds of natural predation as well as manually cut seed pieces showed speedy germination. Seed fragments with more than 50% of seed tissues showed high seed vigour index. The germination behaviour of cut seeds indirectly conveyed the simulated effect of predated seed germination in natural habitat. Germination of fragmented seeds overcomes the inevitable prolific predatory problems by frugivores. This study showed that G. imberti seeds tolerate predation to a certain extent as an adaptive character ensuring seed dispersal and seedling establishment through a unique plant-animal mutuality.