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

Tree Species Diversity Status and Contributors to Forest Degradation in Shasha Forest Reserve, Nigeria Ogunrinola, Oluwaseun Femi α , Ogunwale, Taiwo Olusegun σ , Oyetola, Simeon Oyesoji ρ & Salami, Kaseem Dele Ѡ Abstract- Deforestation and forest degradation are related to human-induced activities practiced compared to the conservation of forests and their management in Nigeria. This work evaluated the diversity status of tree species in Shasha Forest Reserve utilizing a simple random sampling method for plot differentiation, with a transect established in the assessment area. Sixteen sample plots of 25 m x 25 m were found within the minimally protected and unprotected plots of the reserve. Descriptive statistics were used to analyze the data generated. The results of the tree appraisal showed that 644 individual trees and 60 different tree species (23 families) were identified. The tree species diversity indices obtained were (3.855 and 0.596) for Shannon-Weiner and species evenness, respectively. Rauvolfiavomitoria of the family Apocynaceae (46) was the most predominant tree species, followed by Celtiszenkeriof, the family Ulmaceae (32), and the families with the highest number of species were Sterculiaceae (8) and Euphorbiaceae (7). The encroachment into the forested area is increasing and signifies leading contributors to deforestation and forest depletion in this ecozone. Despite the large spacing in the Shasha forest reserve, woody plants remain moderately varied in composition, and it has a great potential for restoration if suitably managed with silvicultural interferences like seed supplementation and, or enrichment planting, which would promote the rapid return of the intricate forest status. Keywords: cropland; deforestation; forest degradation; forest management; ecological community; tree species diversity indices; shasha forest reserve. I. I ntroduction eforestation and forest degradation are associated with human activities working against the protection of forests and their management in Nigeria. Knowing the factors leading to deforestation and forest degradation, twin problems influencing Author α σ: Institute of Ecology and Environmental Studies, Obafemi Awolowo University, Ile – Ife, 220 005, Nigeria. e-mail: oluwaseunogunrinola@gmail.com Author ρ : Department of Soil and Land Resource Management, Faculty of Agriculture, University of Abuja, Nigeria. e-mail: Oyetola.oyesoji@uniabuja.edu.ng Author Ѡ: Department of Forestry and Wildlife Management, Federal University Dutse, Duste, Faculty of Agriculture. e-mails: foristsalam@yahoo.com , salami.d@fud.edu.ng sustainable forest management, and on-site biological diversity conservation will assist in implementing policies to control them. These twin human activities are closely related to socio-political, economic, and demographic problems. About 10 million hectares of rainforests are destroyed yearly (FAO, 2015), and based onthe report by Ogunrinola et al. (2020) the species-rich tropical rainforests in Nigeria have been under severe stress to meet needs for forests and non-forest products, leading to painful destruction concerning bizarre and bulk of the wooded area habitat. A document by FAO (2015) revealed that Nigeria has one of the universe’s most significant amounts of primary forest deforestation. It lost 55.7 percent of its primary forests between 2000 and 2005 (Butler, 2005). A scenario that Wilcox (1995) examined to encourage habitat fragmentation generally results in species extinction, adecline in species diversity, and a reduction in primary productivity. Knowing the contributory factors and fundamental impact of deforestation and forest degradation is needed to design trade-off policies for their causes. Forestry Management Evaluation and Coordinating Unit (FORMECU, 1999) noted that about 58 (10.4%) of 560 tree species in Nigeria's forest are endangered. The investigations carried out in Queen’s Forest, Oluwa Forest, and Elephant Forest by Onyekwelu et al. (2008) revealed that 16 of 51species, 15 of 45 species, and 8 of 31 species, respectively were endangered. Onyekwelu and Fuwape (2008) believed that not more than 5% of Nigeria’s tropical wood is left without severe degradation. Alarmingly in Nigeria, the primary contributor to deforestation and habitat fragmentation are crop production, fuel, and building supplies. In the northern part of the nation, excessive grazing, and clearance of trees for fuelwood for cooking arealso major issues. In the southwest of the country, logging (commonly in size) continues to cause the growing fragmentation of remnant forestry ecozones. General essential infrastructural development (roads, power lines, mining, built-up areas, and the likes) are primary factors. These factors are aggravated by outdated forest laws and weak law enforcement, a lack of training and capacity in D 1 Year 2023 35 © 2023 Global Journals Global Journal of Science Frontier Research Volume XXIII Issue ersion I VI ( H )