Forest cover dynamics and its drivers of the Arba Gugu forest in the Eastern highlands of Ethiopia during 1986 – 2015

Abstract

Change in forest cover can affect both ecological and socio-economic systems. In order to understand the dynamics of this process, accurate and spatially explicit information is urgently required. Quantifying the past forest cover change of Arba Gugu forest of Ethiopia has been lacking despite its significance in formulating effective forest conservation and management policy and strategy in the area. This study was intended to quantify the dynamics of forest cover over a period of 29 years (1986–2015) and to identify related driving forces or causal mechanisms. Satellite images of Landsat Thematic Mapper (TM) were used for the year 1986 and 1999. For the year 2015, the latest Operational Land Imager (OLI) sensor of Landsat was used. The three images were classified using the random forest algorithm of the supervised classification technique. In addition, focus group discussions were conducted with three groups (a youth group from both sexes within 15–24 age range, a landowner group from women and a landowner group from men) in two highly deforested and two low deforested villages to explore drivers of deforestation. The results depicted that, the landscape encompasses stable non-forestland (54.6%) and stable forestland (13.9%) which were not converted since 1986 up to 2015. The remaining 31.5% experienced changes, of which 23% was converted from forest to non-forest and the rest (8.5%) transitioned from non-forest to forest class. The forest cover declined from 99,416 ha in 1986 to 60,334 ha in 2015. The rates of net-deforestation were 1.6% year−1 and 1.4% year−1 in the period 1986–1999 and 1999–2015, respectively. The most commonly reported drivers of deforestation were logging (39.1%) and farm expansion (36.8%). Thus, establishing a continuous forest monitoring system after formulating site-specific forest conservation plan is important.