The geodiversity approach uses topography to define landscape features. Topography can be a proxy for ecological function. For example, topography influences the solar radiation available for plants and animals, the soil characteristics through the likelihood for erosion and deposition, and the characteristics of hydrologic features. Therefore, similar geodiversity types should have the potential for similar ecological function even as the climate changes. We classified the landscape into three topographic feature categories: canyons, ridges, and slopes. Each topographic feature was then clustered into distinct geodiversity types. Slopes were clustered into groups using elevation, slope angle, and yearly solar radiation. Solar radiation varies based on latitude, aspect, and topographic shading. Ridges and canyons were clustered based on elevation and slope angle. Solar radiation was not used for ridges or canyons because each side would mirror the other increasing the complexity of the landscape characterization (Brost 2010).
For each geodiversity type (e.g. gentle, low-elevation, warm slopes), large contiguous areas of that type were identified within the conservation estate (defined as NPS and USFWS lands). The most efficient, but permeable paths for moving between the contiguous areas of each geodiversity type were identified by modelling the path of least resistance. The final landscape linkage is a union of this least cost pathway for all geodiversity types found within the conservation estate.
