Changing Patterns of Tree Cover and Implications on Food, Energy and Water Resources in the Gilgel Gibie Highlands of Oromia Region, Ethiopia.

The Gilgel Gibie Highlands of Oromia region in Ethiopia are a densely populated, predominantly rural region dominated by smallholder crop-livestock mixed farming systems. Population growth, coupled with low productivity, have long posed a threat to natural forest ecosystems in the region, as trees have been removed for fuelwood and for grazing or crop production. In recent years, however, there has been a trend to replace cropland with exotic plantations mainly eucalyptus plantations. This change has major implications for the hydrology, soils, and agricultural economy of the region. This study examines changes in tree cover at the Gilgel Gibie Highlands regions. Landsat imagery from 1970 to 2020 is applied to characterize changing tree cover patterns over space and time. We find that total tree cover in this highland region has shifted dramatically over the past 50 years. Between 1970 and 1995 there was dramatic loss of tree cover, particularly in areas of natural vegetation at different elevations. In the period since 1996 there has been an increase in tree cover, with rapid gains in recent years because of recovering of previously forested areas, due in part to active conservation measures, and the establishment of eucalyptus plantations in the region. The ecological and economic implications of the tree cover; protected forest vs. woodlot plantations are quite distinct, with plantation forestry providing biomass energy at a cost to food production and water resources. Mapping cropland changing to eucalyptus in recent years makes it possible to quantify the net impacts that this trend has had on local production of energy and food, and to estimate implications for water consumption. Effective monitoring of these changes is important for the ongoing development and implementation of effective land use policy in the region.