Evaluating Tree Species Selection and Survival in Urban Greening Initiatives Across Lagos State

Urban forests and greening programmes in Lagos State provide critical ecosystem services to one of Africa's most densely populated metropolitan regions, including urban heat island mitigation, air quality improvement, and mental health benefits, yet systematic evaluation of species selection and survival outcomes across Lagos greening initiatives is lacking in the scientific literature. This study evaluates the performance of urban tree planting initiatives implemented between 2018 and 2023 across three districts of Lagos State: Lagos Island, Ikeja, and Badagry. A comprehensive inventory of 2,145 planted trees across 68 sites documented species, age, survival status, diameter, height, and condition score. Survival analysis using Cox proportional hazards modelling identified significant predictors of tree mortality, controlling for species, planting site characteristics, and management inputs. Species performance was compared against site-specific soil and microclimate conditions measured at each planting location. Overall tree survival at five years averaged 41%, significantly below international benchmarks of 70-80% for comparable programmes. Survival rates varied substantially by species, with Azadirachta indica achieving 79% survival while Terminalia mantaly showed only 28%. Inadequate post-planting irrigation during the first dry season was the strongest single predictor of mortality. Paved surface proximity and compacted soil conditions were significant secondary predictors. The study recommends a revised Lagos State approved urban tree species list, mandatory first-year irrigation protocols, and standardised maintenance contracts for urban planting programmes. Keywords: urban forestry, tree survival, Lagos State, species selection, urban greening