Ecology, Environment and Conservation Paper

ECOLOGICAL ADAPTATIONS OF SEEDS GOVERNING FOREST REGENERATION

R. Umarani, R. Jerlin and M. Tilak

Abstract

Knowledge of natural regeneration of plants is important to develop scientific techniques and guidelines to conserve dwindling forest area. Ecological adaptations of seeds are a major force governing the regeneration, structure, and succession of vegetation. Tolerance to drying (orthodox seeds) is a major adaptation of seeds produced by trees in dry tropical forests. The dry abiotic stress conditions is also countenanced by heavy production small sized seeds aiding predator satiation, desiccation tolerance, effective dispersal, and seed dormancy aided temporal and special distribution of seed germination as well as persistent seed banks. Under the warm humid conditions of rainforests, most of the trees produce ‘desiccation intolerant’ seeds commonly called as recalcitrant seeds, which are often bigger in size. These seeds are metabolically active when dispersed and, germinate rapidly to colonize the available gaps. Although they rarely form transient seed banks yet, often form dormant ‘seedling banks’ which are tolerant to low light conditions as well as physical damage. These adaptations help the natural regeneration of tree species, to a certain extent. However, comparatively lower seed production, remarkably short life, limited dispersal and reduced seed availability make regeneration of tropical moist forest more difficult compared to tropical dry forest.