Urban green infrastructure affects woody plant diversity and carbon stock in Hawassa city in Ethiopia

Abstract

ABSTRACT Urbanisation tends to alter the ecosystem. Urban green spaces are established to reduce impacts of urbanisation. However, in developing regions, this is often neglected. Hawassa city, Ethiopia, is greatly affected by rapid urbanisation. Hence, this study’s aim was to assess the role of green infrastructure in woody species diversity and carbon stock in Hawassa city. A cluster sampling methodwas used to classifythe existing green infrastructure. Two hundred and forty sample plots were used to compile a woody species inventory and for soil sampling. Fifty eight woody species belonging to 44 genera and 28 families were recorded; 67.25% of these were exotics. The highest Shannon–Wiener diversity was in private and public institution compounds (mean 1.35) and the least was street trees (0.68). The highest mean biomass carbon was recorded in street trees (167.5 t C ha−1) and the lowest in urban forest (11.4 t C ha−1). Soil organic carbon accounted for 90% of ecosystem carbon stocks for urban forest, 60% for private public institution, 57% for urban church forest and 37% for street trees. Generally, there is lower species diversity, a dominance of exotic species. Planting diverse and indigenous species should be the next priority.