Presentation details

Talks & Presentations

The savanna problem from a Statistical Physics point of view

By Federico Vazquez, Cristobal Lopez, Justin Calabrese, Miguel Angel Muñoz, Volker Grimm and Maxi San Miguel
XVI Congreso de Fisica Estadistica, Huelva, 2009 - 09 - 10/12 2009

What is unique about savannas that allows the coexistence of trees and  
grasses? What are the factors that govern that coexistence?
Despite many scientific efforts during the last decades, these
questions are still open.  Recent empirical work suggests that
tree-tree competition and external forcing like fire and varying
weather conditions are key factors that regulate savanna dynamics.  To
tackle the combined effects of these mechanisms from a Statistical
Physics point of view, we develop a minimalistic and analytically
tractable stochastic model, which is a variant of the Contact Process.
The model exhibits a transition from grassland to tree-grass
coexistence, whose nature depends on the values of the internal
parameters.  We also study the spatial structure of tree distribution
and characterize the mechanisms leading to clustering.