Sustainable land management in dynamic agro-ecosystems: an Integrated, multi-scale socio-ecological analysis in Western Kenya highlands

This study was motivated by the puzzlingly localised implementation of available Sustainable Land Management (SLM) practices despite the urgent need to reduce both land degradation and general poverty levels in the western highlands of Kenya. This research aimed to not only unravel reasons for the restricted geographical diffusion of SLM practices but also make concrete contributions to foster the promotion of SLM practices. Four specific research objectives and questions were formulated, and an integrated, multi-scale socio-ecological systems framework designed to address these issues at various levels. At the farming system level, high livelihood diversity was found as households increasingly depend on off-farm income opportunities. Besides, results show low production efficiency (average 40%) across five distinct farm types with important implications on intensification in land use. The off-farm oriented and resource-poor farm types were the least likely to invest in SLM practices on their farms. For the forest ecosystem, the estimated local economic benefits of around US$ 450 ha-1 yr-1 were considerably less than half the forgone returns from agricultural activities if the forest were to be converted. Arguably, continued protection of the Kakamega rainforest is justified because of the unknown value of its rich biodiversity and stored carbon in its system, which does not currently generate local economic benefits. At the landscape level, this study found that Vihiga District has undergone rapid land-use changes in the past 25 years. In particular, there has been a major conversion of forest and bare land to agricultural land use. Results show that productivity of tea and to a lesser extent, vegetables increased but the yields of maize and beans—the most common crops—oscillated around 1 ton ha-1. As a result, per capita food crop production dropped by 28% during the past two decades. Empirical findings demonstrate that high and increasing population pressure on l