Assessment of Open Grown Trees Composition and Diversity in Selected Research Institutes in Peri-Urban Ibadan, Oyo state, Nigeria

Abstract

Urban green spaces are rapidly deteriorating in most parts of Nigeria. The study assessed open grown trees composition and diversity in selected Research Institutes within Ibadan Region with the aim of comparing the ecological diversity in the study locations. This was achieved through species identification and mensuration of all open grown trees species that were accessible in the study areas. Open grown trees with Diameter at breast height ≥ 10cm were assessed for growth characteristics of total height and diameter at breast height. Basal area and volume were estimated from measured growth characteristics. Tree species were identified by a taxonomist at Federal Herbarium in Ibadan. Biodiversity indices of Shannon diversity index, species evenness and species dominance were computed to see variation in tree community of the areas. The Shannon diversity index calculated was higher in IITA with a value of 3.04 compared to that of CRIN with a value of 2.36. A dominance value of 0.15 and 0.05 was obtained for CRIN and IITA respectively. The study concludes that both institutes are repository of large diversity of tree species thereby, helping in the conservation of biodiversity while ameliorating weather. It is recommended that educational institutions from all levels located within the region as well as private organizations and individuals should plant trees within their domains in order to create conducive green environments that would promote sustainable environment in the region. This is possible when government provide adequate incentive and annual rewards for establishments with the best green environments.