Colorado Front Range

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. We address this question about historical and recent landscape structure in the area burned by the Hayman Fire in two parts. First, to put the Hayman Fire of 2002 into context, we characterize the historical range of variability (HRV – see the part 1 in this chapter) in landscape structure of the major forest zones of the Colorado Front Range, and compare these reference conditions with current landscape structure. This comparison of current to reference conditions permits an assessment of the magnitude, causes, and significance of changes that have occurred in the last century, and identifies generally where in the Front Range the changes have been great or small. We then focus on the Hayman area itself, to identify the nature, magnitude, and significance of 20 century landscape changes within the area where the 2002 fire occurred. We begin with a general assessment of the Front Range as a whole before treating the Hayman area in detail for two reasons: first, the general overview provides a context for understanding the unique features of the Hayman landscape, and second, future Front Range fires are likely to occur in other forest zones that are not well represented in the Hayman area per se. Historical Range of Variability and 20th Century Changes in Landscape Structure of the Colorado Front Range