People and cattle: Agents of ecological change in a dry montane forest, Samburu District, Kenya

In this thesis, I investigate the ecological impact of Samburu pastoralists and their cattle in an area of dry montane forest on the Lerroki Plateau in Samburu District, Kenya. The thesis focuses on the effects of cattle on tree species diversity and closed canopy forest cover inside the Leroghi Forest Reserve. The importance of the closed canopy forest to cattle during dry periods is demonstrated by means of cattle censuses, cattle follows, faecal pellet surveys and informal interviews. A variety of ecological methodologies were employed to compare plant population structure and diversity in areas of forest under varying intensities of cattle use. Little evidence of long term changes in the overall population structure or diversity of tree species was found in association with cattle grazing. Interpretation of aerial photographs from 1963 and 1993 found no evidence of forest degradation or retreat under grazing pressure. Multi-round surveys found little difference in frequency of general wild resource use by local communities in relation to the socio-economic status of the sub-household. However, the frequency of collection of marketable forest products was significantly higher in those villages with easier access to the main market at the District capital, Maralal. Comparison of aerial photographs found the degree of forest degradation and clearance over the last thirty years correlated positively with proximity to Maralal. The main exception was a large area of closed canopy forest north of Maralal which had been destroyed by fire in the 1980's. These findings show that commercial extraction is a more important influence than cattle on forest structure and composition. These results have important implications for forest managers in dryland areas. The success of forest conservation within the Leroghi Forest Reserve has its roots in shared management objectives of the local pastoral community and the Forest Department, and the absence of long term damage to forest by cattle using the forests during the dry season. It is the absence of shared management objectives that threatens the long term survival of the forests located outside the reserve