Neutral models for patchy landscapes

The landscapes currently studied in ecology are either " discontinuous " (category-based or patch-based), as in the case of mosaics of agricultural units, or of more " continuous " type (raster lattices), as used for representing elevation or other ecological gradients. The main landscape models either involve explicit processes or are neutral, recreating spatial patterns in the absence of studied processes (using statistical rules). This article presents neutral models suitable for the creation and handling of patchy landscapes. These models (Patchy Landscape Neutral Models) adapt the Gibbs process already used successfully in forestry and biology to describe the local interactions between landscape units. These interactions can be either ecological, if justified for example by natural mechanisms of dispersal (plant species dynamics) or crop successions in anthropized landscapes, or statistical (geometrical). We define a global "cost function" representative of the landscape to be simulated by summing the "pair function" that expresses the interactions between units for the whole landscape. This generic approach makes it possible to reconstruct different kinds of patchy landscape compositions (land cover) and opens the way to studying changes in landscape configuration (unit arrangements) as well as an analytical description of landscapes.