Modelling rainforests

Abstract

In this dissertation, we develop a competition-colonisation model to describe the dynamics of interactions between tropical rainforest tree species.

There is a great deal of interest in modelling rainforest diversity. Understanding the natural processes that maintain diversity is essential so that sustainable management systems can attempt to replicate important processes.

We find, through numerical investigation and analysis, that with constant colonisation rates, , we cannot predict multiple species coexistence. The inclusion of decaying colonisation rates, describing the seedling population decay over time, and random mass fruiting events allows coexistence of species, but using unrealistic parameter values. Finally we investigate a mathematical model without any competition between species and find that, using realistic parameter values, our results qualitatively mimic observations of rainforest dynamics. The results of the no competition model support Hubbell's null
hypothesis [17].