Speaker: Peter Chessen,
Dept of Ecology and Evolutionary Biology,
University of Arizona

Title: Stochastic environment models in community ecology for this variable world: New approaches to their analysis

Abstract:
What sorts of stochastic models do we need to understanding the dynamics of natural communities of animals and plants? In nature, the physical environment varies profoundly in space and time. This fact has strong effects on the adaptations of organisms and their interactions with each other. Over the last several decades, mathematical theory has been developed to show how this variation can explain the high diversity of organisms on earth. The models behind this theory include Markov chains on continuous multidimensional state spaces, and exploit Jensen's inequality and its multidimensional generalizations. The results give new techniques for understanding stochastic models involving environmental variation. They show how diverse ecological communities may be established in nature exploiting the variation in environment.