Influence of Selected Urban Tree Species on Soil Microbial Activity, Litter Decomposition, and Soil Chemical Properties in Akure, Southwestern Nigeria

Zoe Faith Zebedee, Solomon Adejoro

Urban trees shape belowground ecological processes through litter deposition, root exudation, and interactions with soil microbial communities, yet species-specific effects are rarely incorporated into urban green-space management. This study evaluated the effects of five common urban tree species (Eucalyptus globulus, Azadirachta indica, Thuja occidentalis, Prunus dulcis, and Buddleja globosa) on soil microbial activity, litter decomposition, and soil chemical properties within the Federal University of Technology, Akure, Nigeria, to inform conservation-based approaches to tree selection in tropical urban landscapes. Rhizosphere soil samples were collected beneath each species and analyzed for basal respiration, substrate-induced respiration, litter decomposition, and nine chemical properties, including pH, total nitrogen, phosphorus, potassium, calcium, and magnesium. Eucalyptus recorded the highest litter decomposition and substrate-induced respiration rates, while neem and Almond most strongly influenced soil nutrient concentrations. These species-specific effects demonstrate that tree selection is a practical lever for regulating nutrient cycling and soil health in urban ecosystems, with direct implications for conservation-orientated urban forestry and sustainable green-space design in tropical cities.