Gum and resin bearing dryland forests of the Somali region, Southeastern Ethiopia: Diversity, structure and spatial distribution

Abstract

Despite their ecological and socio-economic contributions, the lowland dry forests of Ethiopia have largely been neglected and hence experience severe deforestation and degradation challenges. It is, therefore, crucial to assess the status of the dry forest resources to formulate appropriate management strategies that facilitate their sustainable utilization. This study was undertaken to determine spatial distribution, species composition, structure, and regeneration of gum and resin-producing species in the dry forests of the Somali Regional State of Ethiopia. The recent Sentinel-2A image was procured and used to classify the area, using a supervised Random Forest Algorithm, into different land covers and vegetation types. Inside the two key vegetation types (Acacia dominated woodland and Mixed woodland), forest inventory was conducted by establishing 30 m x 30 m size quadratic sample plots. The results revealed that the study area was divided into settlement (0.2%), bare land (6.0%), undifferentiated forest (0.5%), acacia woodland (36.3%), mixed woodland (54.1%) and scrubland (2.9%). Thirty-four woody species were identified and recorded with a Shannon diversity of 3.03. The population structure showed a lack of sufficient natural regeneration. This shows that the forest containing the gum and resin-bearing species is not replacing itself as well as it should. On the other hand, if managed properly, the forest has the potential to produce various types of oleo-gum resins. Thus, implementing appropriate restoration measures is urgent to enhance natural regeneration. Moreover, formulating sustainable utilization while creating a product market of gum and resins are important consideration to ensure the conservation and sustainable use of dry forests in the region.