A seed-diffusion model for tropical tree diversity patterns

TL;DR

This paper introduces a simple seed-diffusion model for tropical tree diversity, using Monte Carlo simulations to replicate key statistical patterns observed in a tropical forest community with only one adjustable parameter.

Contribution

It presents a spatially explicit neutral model based on seed diffusion that accurately reproduces multiple diversity measures with a single free parameter.

Findings

Model successfully fits species abundance and spatial distribution data

Reproduces species-area relationships and auto-correlation functions

Uses only one adjustable parameter, seed survival time

Abstract

Diversity patterns of tree species in a tropical forest community are approached by a simple lattice model and investigated by Monte Carlo simulations using a backtracking method. Our spatially explicit neutral model is based on a simple statistical physics process, namely the diffusion of seeds. The model has three parameters: the speciation rate, the size of the meta-community in which the studied tree-community is embedded, and the average surviving time of the seeds. By extensive computer simulations we aim the reproduction of relevant statistical measures derived from the experimental data of the Barro Colorado Island tree census in year 1995. The first two parameters of the model are fixed to known values, characteristic of the studied community, thus obtaining a model with only one freely adjustable parameter. As a result of this, the average number of species in the considered territory, the relative species abundance distribution, the species-area relationship and the spatial auto-correlation function of the individuals in abundant species are simultaneously fitted with only one parameter which is the average surviving time of the seeds.