Research Interests

I am most interested in the maintenance of tree species diversity. Much theoretical and empirical work has identified a host of mechanisms, operating simultaneously at varying spatiotemporal scales, that may maintain diversity. I work with young plants in the recruitment of seedlings from seeds, and seek to understand the most important mechanisms that affect seedling diversity. The patterns set through seedling recruitment provide the template that structures the canopy tree community. The broad factors affecting the recruitment of seedlings are seed dispersal (the arrival of seeds) and seedling establishment (their subsequent germination and survival). Many factors govern the arrival of seeds to a given site, including the distance and arrangement of adult trees, their fecundity, the dispersal vectors, and pre-dispersal seed predation. My research does not focus upon these factors. I take the dispersal of seeds as a given, and weigh seed dispersal against seedling establishment, and the factors that influence it. These include the activity mammals, as seed predators, herbivores, and tramplers, the availability of resources essential for plant growth (light, water and soil nutrients), and biotic interactions among a seedling cohort, and bith pre-existing vegetation. I describe the experiments I have underway to examine these relationships on the following pages.

Conceptual diagram of seedling recruitment
Tree species diversity is affected by the initial dispersion of individuals, set through seedling recruitment, and later processes that act upon saplings and adults. Seedling recruitment is a function of seed dispersal and post-dispersal processes. My dissertation weighs the relative importance of the four factors in the top row. (Larger version)