Stochastic lattice models have been used frequently to describe spatial ecosystems. A question which arises in this context is whether the spatial structure of a complex ecosystem can be described adequately by models such as Gibbs fields which have been studied intensively in statistical mechanics.

In the talk I will first present the spatial distribution of the canopy height in a temperate forest ecosystem, the Ogawa forest in eastern Japan. I will then give a short introduction into Gibbs fields, especially the Ising model, and I will mention the coupling arguments that justify the use of these models in many situations. Finally I will present applications (by S. Kizaki, M. Katori, and others) of these models to the canopy height in the Ogawa forest and in another (tropical) forest, and I will discuss possible refinements of these applications.