Anthropogenic effects and ecosystem services of tropical highland forests in Ethiopia

Abstract

Despite the significant direct and indirect benefits that forests, particularly tropical highland forests, provide to local communities, they are facing severe degradation primarily due to population growth and rapid land-use changes. This has made it difficult for policymakers to effectively manage these forests due to a lack of comprehensive current forest research data. Therefore, the primary objective of this study was to examine the anthropogenic impacts on forest ecosystems and the ecosystem services (¹ESs) they provide, as well as to understand local perspectives on management of natural forests. For collecting disturbance indicators and other environmental data, 12 transect lines by 150 meter interval between each of the two consecutive parallel transects and 40 quadrats (20 m x 20 m size each) by 100 m interval were laid out in 145 ha total forest land size of the five study sites of three districts. However, for questionnaire-based data, 266 respondents were participated. As revealed in the results, the majority of households (about 78 %) relied on mixed farming and had ≤ 1 ha of land with 5.6 average family size. Besides, 74.3 % of the households used forest products for cooking food and getting energy to their homes due to little or no electricity, or other energy sources in rural communities. Nearly 85 % of the households also obtained timber from natural forests. Tree cutting, grazing, cultivation, and fires were the major anthropogenic factors leading to deforestation and loss of ecosystem services and biodiversity of the studied forest ecosystems. Disturbance assessment indicated that almost all forest patches, excluding one in the eastern subregion of the study area, were severely impacted. This suggests a widespread degradation of Ethiopia's forests. However, various ESs, mainly regulating and habitat services, followed by provisioning ones, were delivered from these sites. Hence, soil erosion controlling, flood protecting, and soil fertility regulating services were some of the most services provided by the forests. Likewise, being shelter and nursery sites for biota were the other most important habitat service. The raw materials including grass for fodder, medicinal plants, timber, fuel wood, and water for livestock watering and domestic uses were the major provisioning services provided. Thus, more than 93 % of the households had a great interest for the protection and continuity of the present forest patches in the future. Briefly, despite being heavily degraded due to anthropogenic factors, these natural forests still provided various ecological, social, and economic services to the local people; thereby the people were interested in protecting and conserving them. Thus, for restoring degraded forest areas of the zone, community-based participatory conservation strategies were recommended.