The term “landscape structure” refers to the configuration of vegetation and other land features over a large land area (usually an extent of many square kilometers). A landscape can be regarded as a mosaic composed of patches of different kinds -- for example, different forest types, landforms, or human-built structures such as roads. The scientific discipline of landscape ecology is concerned with quantitatively describing the features of landscape mosaics, including, for example, the variety of patch types, the sizes and shapes of patches, and how different patch types are juxtaposed (Forman 1995). Landscape ecology also is concerned with understanding how the structure of a landscape influences its function - for example, what kind of habitat it provides for various plant and animal species, or how water and nutrients or pollutants move from place to place (Turner and others 2001). Another critical aspect of landscape structure is how it influences the spread of disturbances - including fire.