Abstract: Riparian ecosystems are increasingly threatened by degradation attributed to land use changes. Human perturbations such as crop farming on riparian land, overgrazing and population pressure on land resources influence degradation of riparian ecosystems, with profound effects on biodiversity conservation and local livelihoods. Comparative studies were undertaken in three land use systems (livestock production, mixed farming and crop farming) along River Lumi riparian ecosystem in Taita Taveta County, Kenya, to examine the effects of land use and land cover change on forest structure, tree species diversity and household livelihoods. Thirty-six belt transects were established perpendicular to the river and plots measuring 30.0m by 15.0m were designated to assess forest structure and tree species diversity. On the basis of semi-structured questionnaires, 353 households living adjacent to the riparian ecosystem were interviewed to determine the interaction between socio-economic factors and household response to degradation. Statistical testing for significance was performed at 95% confidence interval. The area under farmlands and settlement increased by 14.3% and 112.1% respectively between 1987 and 2019. Forest patches, grazing land and riverine vegetation decreased by 53.6%, 13.8%, and 36.6% over the same period. Tree species diversity (F (1, 2) = 0.94; p=0.401)), seedling density (F (1, 2) = 0.07; p=0.937), sapling density (F (1, 2) = 0.44; p=0.647) and tree stand density (F (1, 2) = 2.23; p=0.110) were not significantly different in the three land use systems. However, DBH was significantly different (F (1, 2) = 2.98; p=0.052) with the livestock production system having larger tree sizes than mixed and crop farming systems. Soil characteristics influenced the occurrence and distribution of dominant tree species (F (1000) =7.1; p=0.001), and less dominant tree species (F (1000) =2.4; p=0. 01). Household response to degradation was influenced by gender of household head (r = 0.025; p=0.661) and household income (r = 0.016; p=0.762). Evidence from this study shows that agricultural expansion, overgrazing and human population growth have contributed to degradation of River Lumi riparian ecosystem hence the need to develop a land use plan for effective management of the ecosystem. These results point to the need for developing effective legal, policy and institutional frameworks for effective management of riparian ecosystems.
Built with Mobirise Free Website Maker