Vegetation Land Cover/Use Dynamics and Their Effects in Mbulu and Karatu Districts in the North-Eastern Highlands of Tanzania

Vegetation Land Cover/Land Use dynamics (VLC/LU) are the result of complex and compound interactions between the human (cultural, socioeconomic, and political) and the physical environment at different spatial scales. The present study assesses the spatial distribution of VLC/LU dynamics from 1987 to 2015 in the North-Eastern highlands of Tanzania using both qualitative (in-depth interviews and focus group discussions) and quantitative techniques (spatio-temporal analysis through GIS). The qualitative approach was used to elicit information on the main drivers of VLC/LU changes by land users as transitions occurred with time. The spatio-temporal analysis was used to assess the systematic vegetation land losses, gains and persistence of the various land use categories with time. The results identified the presence of forest, woodland, bush land, grassland, wetland, cultivated land, bare soil, water, and settlements (built up area). Throughout the period 1987-2015, wetland, settlement (built-up area), cultivated land and bare soil expanded at an average rate of 42.15%, 15.66%, 12.09% and 6.41% per year at the expense of grassland, woodland, water, forest and bush land which declined by 2.68%, 2.5%, 2.04%, 1.36% and 0.12% per year, respectively. The vegetation land cover/use dynamics of 1987-2015 resulted in the reduction/loss of plant species, occurrence of soil erosion and ramification of gullies. The triggers for these changes were population growth, land cultivation, expansion of farmland, inappropriate land management and fuel wood demand. These led to further land degradation among many farming households. Land resources have to be used according to their suitability. Thus, the exposed and steep hills of the study area have to be protected from cultivation and should be re-afforested. The paper also discusses other implications for management and policy formulation in the study area