BIOMASS ALLOCATION AND GROWTH OF TROPICAL DRY FOREST TREE SEEDLINGS ACROSS LIGHT AND SOIL GRADIENTS.

Abstract

This dissertation examines the effect of abiotic factors on the growth of tropical dry forest tree seedlings, and the developmental plasticity that allows seedlings to respond to those factors. Different species of tropical dry forest tree seedling are demonstrated to reverse ranks in response on different combinations of light and soil environments that occur within the tropical dry forest. This is interpreted to indicate that tropical dry forest species may be niche-differentiated with respect to soil. This is found to conflict with the assumption of ecological equivalence central to neutral models of community structure. Neutral models are examined further and it is determined that fitness manifolds cannot reconcile the niche-differentiation and neutral perspectives without restrictive assumptions about the distribution of environmental heterogeneity in nature.