Per Helene, a good definition of "patch dynamics" can be found on wikipedia...
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Important terms in Landscape ecology
Landscape ecology not only embraced a new vocabulary of terms but also incorporated general ecology theory terms in new ways. Many of the terms used in landscape ecology are as interconnected and interrelated as the discipline itself. Landscape can be defined as an area containing two or more ecosystems in close proximity (Sanderson and Harris 2000).
Patch and mosaic
Patch, a term fundamental to landscape ecology, is defined as a relatively homogeneous area that differs from its surroundings (Forman 1995). Patches are the basic unit of the landscape that change and fluctuate, a process called patch dynamics. Patches have a definite shape and spatial configuration, and can be described compositionally by internal variables such as number of trees, number of tree species, height of trees, or other similar measurements (Forman 1995).
Matrix is the “background ecological system” of a landscape with a high degree of connectivity. Connectivity is the measure of how connected or spatially continuous a corridor, network, or matrix is (Forman 1995). For example, a forested landscape (the matrix) with fewer gaps in forest cover (open patches) will have higher connectivity. Corridors have important functions as strips of a particular type of landscape differing from adjacent land on both sides (Forman 1995). A network is an interconnected system of corridors while mosaic describes the pattern of patches, corridors and matrix that form a landscape in its entirety (Forman 1995)."
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another entry to reference:
http://en.wikipedia.org/wiki/Patch_dynamics
