Incollection,
A Spatially Extended Neutral Model with Resources
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)
Abstract
The ecological patterns observed in nature have traditionally been explained
by postulating niches into which the differential endowment of individuals
permits each species to evolve. In contrast, 'neutral theory' assumes the
equivalence of individuals belonging to trophycally similar species and
explains species composition simply by the drift due to the stochasticity in birth,
death and dispersal.
Neutral theory has provided an explanation of many of
the observed ecological patterns without the need of further mechanisms,
such as suitability to their environment.
However, it has been shown recently
that it fails to explain some important facts, for example
some of the spatial features of ecological systems
such as beta-diversity, i. e. the change in species composition from place to place.
In this talk I will explore the possibility that an extension to the neutral theory,
based on a reaction-diffusion model introduced by Solomon et al.,
can explain some cases where there is a discrepancy
between the predictions of neutral theory and the observed data.
The explanation hinges on the presence of
positive sources, e.g. water or food, that move through space.
