PARENT SESSION
Oral Session #21: Conservation of Biodiversity: Human landscapes, reserve design. Presiding: C. Meine.
Tuesday, August 7, 2001. 8:00 AM to 12:00 PM. Madison Ballroom D.
Do people enrich pastoral landscapes in East Africa?
REID, ROBIN1, MUCHIRU, ANDREW1, VUORIO, VILLE1, RAINY, MICHAEL2, WILSON, CATHLEEN1, WORDEN, JEFF1, WESTERN, DAVID3, SANFORD, ROBERT4, 1 2 3 4
ABSTRACT- One favored conservation paradigm is that human use inevitably reduces biodiversity. Our research in East African savannas suggests otherwise. Here, we provide a synthesis of studies investigating how pastoral settlements influence species, and landscape diversity in five sites in arid and semi-arid Kenya. These studies measured soil nutrients, vegetation cover and diversity, wildlife abundance and diversity and landscape diversity in and around current and old pastoral settlement (or boma) sites. At local scales, pastoralists leave behind nutrient hotspots in livestock corrals at the center of old bomas. These sites support a succession of plant species from forbs and grasses in newly abandoned bomas to trees and shrubs in older bomas. Wildlife and livestock can spend twice as much time foraging on these hotspots than elsewhere on the landscape. The nutrient and vegetation signatures from old bomas can last from 30-140 years depending on the amount of dung originally deposited, slope, the amount of rainfall and the inherent soil fertility. Our models suggest that landscapes with moderate densities of currently occupied bomas appear to support more wildlife than landscapes with more bomas or those with no bomas at all. These results may partly explain why East African savannas, when used by pastoralists at moderate levels, support the greatest diversity of mammals on the continent.
KEY WORDS: Human impacts, Biodiversity, Africa, Wildlife