| Environmental science teaches us the interrelationships of the species of the world, and progressive natural scientists recognize that physical factors have an effect upon the biota of the Earth. The current project uses a combination of the disciplines of botany, geology, and cartography to model habitats for threatened species Echinocereus chisoensis var. chisoensis endemic in Big Bend National Park, Texas.; U.S. Fish and Wildlife Service published a proposal in 1993 addressing the research needs to characterize the habitat of E. chisoensis to facilitate a recovery of the species. Field assessments were made to discover the preferred habitat of E. chisoensis plant sites. This information was analyzed and the criteria determined to be essential to the species extracted. Using a GIS program, factors including slope, soil type, geological stratigraphy, and elevation were united to create a model that would predict areas where undiscovered plants of E. chisoensis might occur. Maps of these modeled locations were produced with the stratigraphy, slope, elevation, and the soils comparable to that where the extant E. chisoensis are found. Eight of the 38 predicted locations were visited. Echinocereus chisoensis was found in one of the sites examined, suggesting that the model developed during the present study will be useful in locating new populations of E. chisoensis, if they exist. |
