Status and Management of Indigenous Tree Species and Their Determinant Factors across Landuse Types in Three Selected Districts of Jimma Zone, Southwest Ethiopia

Abstract

In Ethiopia, even though indigenous trees are ecologically more valuable than exotics they are reducing in their abundance and diversity and their multipurpose benefits getting off and replaced by exotic tree species due to more economic value of exotic trees. The aim of this study was thus to assess the status and understand the factors affecting management of indigenous tree species in Mana, Kersa and Seka Chekorsa Districts of Jimma Zone, Southwest Ethiopia. These districts were selected following multi-stage sampling technique. From each district, five PAs were selected based on the level of tree planting practices. A total of 136 households were selected for questionnaire survey and from these 50% (68 each households with all landuse types) were selected randomly and a total of 340 plots were taken for tree species assessment from different landuse types. A total of 44 tree species (33 indigenous and 11 exotic) belonging to 29 families were identified and recorded. Fabaceae was the dominant family with 7 trees species followed by Moraceae with four. The diversities and density of indigenous tree species were higher on farm (H’=2.459) and in farm boundary (460.1 stems per hectare) respectively when compared with other landuse types. The farming communities of the study area plant/retain tree species across landuse types. Accordingly, from 33 indigenous tree species identified, 3 species were planted and/or retained and 30 were retained. Management of tree species showed highly significant difference by gender (x2=16.9, df =1, p<0.001), landholding size (x2=23.455, df =4, p<0.001) and among landuse types (x2=35.333, df =4, p<0.001). The result of the questionnaire survey indicated that factors such as, high economic interest (97.1%), agricultural expansion (64.7%), lack of knowledge on tending (90.4%) and access to seed sources and other planting methods for indigenous tree species (63.2%) were the major threatening factors that constrained management of indigenous tree species. Beside this, twenty indigenous tree species were identified as at risk from the study area including Podocarpus falcatus, Hagenia abyssinica, Pouteria adolfi-friedericii that were ranked from one to three. Altogether, efforts such as awareness creation, forest extension works focusing on indigenous tree planting and management, promoting agroforestry practices, producing and supplying enough seedlings, improving institutional frame work and enforcement of existing laws regarding indigenous tree species are of prime importance to scale up planting and management of indigenous tree species and correspondingly restore ecosystems and the associated services.