Global Journal of Science Frontier Research, H: Environment & Earth Science, Volume 23 Issue 1

site situates on latitude and longitude (7 ⁰ 05 ′ and 4 ⁰ 55 ′ E) at an altitude of 178 m above water level. The forest reserve is located within the rainforest ecozone with a land cover of 337.298 km2 (Field Trip Earth, 2008). It has experienced a quick degradation from poaching and indiscriminate timber harvesting, wildfires, fuelwood gatherers, and transformation to plantations and cropland (Field Trip Earth, 2008). It has a mean annual rainfall of 1421 mm (Adekunle, 2006), most of which falls during the rainy season from April to October. Shasha Forest Reserve was chosen for the studies because its long-term land-use history is known. The extensive forestland is named after the “Shasha River”, a large river in the study area. The Shasha River lies within the 337.298 hectares of land, which comprise the forest reserve. It has mixed moist vegetation. This reserve is one of the few forests that comprise some ecologically distinctive flora and fauna in South western, Nigeria and also includes different forest physiognomies of concern such as indigenous natural forest, non native tree plantation, and arable lands, respectively. The sampling was carried out for a period of twenty-four months (January 2020 to December 2021), spanning two wet seasons and two dry seasons. The variation in the explanatory parameters was utilized in evaluating the physiognomies that were most appropriate for species diversity conservation. b) Sampling Technique for Tree Species Evaluation A simple random sampling technique was adopted for the reasonably protected and unprotected plot. A sample plot of 100 m × 100 m area was marked. The 100 m × 100 m area was demarked within the field. The sampling units 25 m × 25 m were located where the vegetation was relatively protected, and the edge effect satisfactorily surmounts. Sixteen fields were chosen in the tracts for the study, eight each at the two end corners of each lot. Tree species within diameter at breast height (dbh) > 10 cm were classified, and assigned to families, and relative diversity (the number of species in a family) was determined. Most plants were classified on the field, but plants that could not be classified were tagged “unidentified”, and portions of that woody species (leaves, bark, and fruits) were taken to the Forestry Herbarium, Ibadan (FHI) of Forestry Research Institute of Nigeria for classification and identification. Each tree species was recorded separately in the field forms, and a possible attempt was identified not to neglect any qualified stem in a sample plot. After the floristic survey of the sampled sites, the tree will be classified into species and families, species richness and abundance of each species in the biotic community, and will be established applying the Shannon-Weiner index specified by Ogunrinola et al. (2020). The number of trees found in the sampling plots on a species basis was estimated by multiplying it by the number of parcels ha–1 to see the abundance of the species in one hectare. Figure 1: Plot Layout with Simple Random Sampling Technique Tree Species Diversity Status and Contributors to Forest Degradation in Shasha Forest Reserve, Nigeria 1 Year 2023 37 © 2023 Global Journals Global Journal of Science Frontier Research Volume XXIII Issue ersion I VI ( H )