Survival Mechanisms in Tropical Pasture Species

Abstract

Fitness demands resistance to environmental stress. The continued appearance of a particular species in pasture swards in successive growing seasons demonstrates adequate mechanisms for survival. These take two forms. Plant replacement following mortality may arise from the cycle of flowering and seed formation, the maintenance in soil of a population of seed in a dry, protected resting stage, and natural seedling regeneration, leading to plants which flower and continue the cycle. Alternatively or additionally, a perennating rootstock provides rooted shoots for replacement or for incursion into new territory. The topic of reproduction is also of interest to agronomists involved in problems of seed production, seed storage and pasture establishment.