Thursday, August 9, 2007 - 10:10 AM

COS 117-7: The characteristics of Large Herbivore Key Resource Areas in Kenyan Rangelands

Moffatt K. Ngugi and Richard T. Conant. Colorado State University

We carried out assessments of Key Resource Areas (KRAs) for herbivores in Kenyan rangelands comparing them to the more extensive outlying rangeland areas (nonKRAs). KRAs on the ground were identified by conducting field survey with pastoralists, ranchers, scientists and government officials. Identified KRAs were then mapped based on global positioning and local user’s information on access and attributes. Using a map of known KRAs and nonKRAs, we examined characteristics of soils, climate, topography, lithology, land use/cover attributes at KRAs relative to nonKRAs exploring why KRAs are more productive compared to nonKRAs. With a 22-year dataset of NDVI, we evaluated trends of KRAs versus nonKRAs over time. Field surveys of KRAs bolstered the definition of KRAs mainly as dry season foraging zones. Soil attributes did not significantly differ at KRAs compared to non-KRA. Topography at KRA was steeper and more complex compared to nonKRAs, in addition, elevation was higher at KRAs (P<0.005). Field survey respondents indicated that animals and humans generally avoid difficult to access hilly areas using them only when all other easily accessible rangeland is depleted of forage. Land cover at KRAs was consistently woodier than nonKRAs areas. Precipitation was not significantly different between KRAs and nonKRAs although KRAs tended to have higher annual rainfall. NDVI was consistently higher at KRAs compared to non-KRAs across the two decades period prior to the study, but there were smaller differences (KRA-nonKRAs) during years of exceptionally high precipitation. Understanding the nature of KRAs in dry land ecosystems will bolster efforts to conserve them in maintaining ecosystem function in biologically diverse rangelands.

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