Urban Homegarden for Woody Species Conservation and Carbon Sequestration: The Case of Jimma City, Southwest Ethiopia

Abstract

Homegardens in urban are found to be an important refuge for native biodiversity and provide huge contribution for climate change mitigation. The study was undertaken to investigate potential of homegarden in conservation of woody species and carbon sequestration in Jimma City. A complete listing of woody species within 138 homegardens and 39 sample plot size 10m×10m (100m²) were surveyed. Diameter at breast) height and the height of the tree were measured. Shannon diversity and Jaccard coefficient of similarity index were used to determine the species composition. Allometric equation was used to estimate aboveground carbon stocks of woody species. A total of 40 woody species (36 in homegarden and 22 in government institution) belonging to 24 families were recorded. Very significantly higher (P<0.001) species richness and diversity were observed in homegardens. But no significant difference was observed (p>0.5) among homegardens in three kebeles. Jaccard coefficient of similarity index (47.5%) showed low similarity in woody composition between two systems. About 2,877.13Mgha^-1(884.2 Mgha^-1 in homegarden &1,992.95Mgha ^-1 in government institution) carbon of about 319.57Mg of CO₂ equivalents were measured. Very highly significant (p<0.001) and non-significant difference (p>0.05) in carbon storage were observed between systems and among homegardens respectively. The result reveled homegardens in Jimma city have good potential for biodiversity conservation and climate change mitigation. Hence, responsible bodies need to consider the role of homegarden in maintaining native biodiversity and climate change mitigation in urban development planning.

Keywords: Biodiversity conservation, government institution compound, carbon stock, climate change mitigation.

DOI: 10.7176/JNSR/9-13-02

Publication date:July 31^st 2019