MODELING OF THE SAPROPHYTIC HABITAT OF COCCIDIOIDES IMMITIS, ORGAN PIPE CACTUS NATIONAL MONUMENT, ARIZONA
Habitat modeling of the saprophytic phase of the C. immitis life cycle is difficult due to the limited number of known growth sites. This confounds establishment of statistical relationships of the physical, chemical, and biological habitat parameters. Our habitat modeling was accomplished utilizing a spatial fuzzy system with analysis of observed properties from known C. immitis sites. Such properties included the clay content, texture, salinity, and water-holding capacity of soils in addition to the bedrock geology, elevation, slope/aspect, and vegetation density.
The fuzzy system was applied at Organ Pipe Cactus National Monument, Arizona. The result is a map depicting each cells favorableness for hosting C. immitis based on a scale of 0 to 1, defined as the fuzzy habitat suitability index. The fuzzy system allows modelers to change and update relationships between the variables as more is learned about C. immitis habitat. It also allows dynamic representation of climate related variables and can be used to predict changes in habitat with changing climate. When combined with USGS dust monitoring efforts in the southwest United States, the fuzzy system has the potential of being a tool for coccidioidomycosis mitigation.