FACULTY OF AGRICULTURE
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Item Vascular plant diversity and carbon stocks of selected sacred groves in Southwestern, Nigeria(Faculty of Agriculture, University of Uyo, Akwa Ibom State, Nigeria, 2025-03) Falade, O. F.Sacred groves are hotspot areas for tree species diversity and rare woody plants. Tree species composition have not been evaluated for its contribution to carbon in sacred groves. This study was designed to investigate influence of stand structure on variation of biomass and soil carbon stocks in the selected sacred sites in Southwestern, Nigeria. Ten (0.09ha) plots were randomly demarcated in each sacred grove. Tree ≥5cm Diameter-at-Breast Height (DBH) were identified and species diversity indices (Shannon-Weinner, H´; Simpson, 1-D) were computed. Total height (TH) and DBH were measured for volume and carbon estimation. Soil samples were collected with cores at three depths in each plot. Core samples were oven-dried at 105°C and 100g of soil was separated into >2.0, 2.0-1.0, 1.0-0.5, 0.5-0.05 and <0.05mm aggregates and carbon proportion determined. Data were analysed using descriptive statistics and ANOVA. A total of 28 tree species representing 18 families, 23 tree species representing 14 families, 8 tree species representing 6 families and 16 tree species representing 12 families were identified in Ori-Oke, Bilikisu-Sugbo, Olumo rock and Osun-Osogbo groves, respectively. The H´ ranged from 2.61 (Ori-Oke) to 1.67 (Olumo-rock), while 1-D ranged from 0.94 (Bilikisu) to 0.74 (Olumo-rock). Biomass carbon ranged from 24240.00 (Bilikisu-Sugbo) to 7998.36 kg/ha (Ori-Oke). Carbon content increased with decrease in aggregate size in soil depths of Ori-Oke and Bilikisu-Sugbo while decreased with decrease in Olumo-Rock and Osun-Osogbo Groves. Bilikisu-Sugbo obtained the highest tree species diversity and carbon storage. Therefore, Bilikisu-Sugbo should be considered for plant diversity and carbon storage conservation schemes.Item Forest structure and carbon stocks of Osun-Osogbo sacred grove, Nigeria(Academic Journals, 2020-03) Falade, O. F.; Taiwo, A. J.; Falade, O. F.; Iheke, J. U.Forest trees and soil are considered for climate change mitigation. Forest structure of the grove is required to predict its capacity to mitigate climate change. Therefore, the objective of this study was to determine the forest structure and carbon stocks of Osun-Osogbo Sacred grove. Five (30 × 30 m2) plots were demarcated in Old-growth forest (OF) and Re-growth forest (RF). Trees with ≥10 cm diameter-at-breast-height (dbh) were identified to species level and enumerated. Tree height and dbh were measured and stem volumes were converted to carbon stock. Soil samples were collected with cores at three soil depths, oven-dried and carbon content estimated. The tree species diversity and richness indices of OF was higher than OR. Diameter distribution of OF and RF expressed reverse J-shaped and rotated sigmoid curves, respectively. The stem carbon stock ranged from 0.12±0.00 (OF) to 0.02±0.00 Mg/ha (RF). The soil carbon stock ranged from 0.65 (OF) to 0.90 Mg/ha (RF). Stand structure of OF was more develop than RF. The OF and RF contained high stem and soil carbon stocks, respectively. Forest structure enhances stem carbon stock of Old-growth forest while soil of Re-growth forest is also an option for carbon sequestration.Item Forest structure and tree stem carbon stock of Gambari Natural Forest Reserve, Oyo state, Nigeria(Faculty of Agriculture, University of Uyo, 2019-06) Falade, O. F.; Aderemi, S. A.Tree stems are major above-ground carbon pools in the tropical forest structure. Forest structure creates micro-climatic conditions for various ecosystem services. Natural and man-made disturbances cause changes in forest structure. However, the effect of forest structure dynamics on stem carbon sequestration is yet to be clarified in Gambari Natural Forest Reserve, Oyo State, Nigeria. Understanding influence forest structure dynamics on stem carbon could improve prediction of carbon sequestration potential of Gambari Natural Forest Reserve. Therefore, the aim of this study was to quantify forest structure and stem carbon stocks in Gambari Natural Forest Reserve. Ten sample (30m×30m2) plots were randomly demarcated in Gambari Natural Forest using stratified random sampling method comprising 5 sample plots in each identified canopy structures; closed and open. Tree stems ≥10cm diameter-at-breast-height (dbh) were identified, enumerated and species diversity indices computed. Total height (TH) and diameter were also measured for volume and carbon estimation. Data collected were analyzed using descriptive statistics and ANOVA α0.05. A total of 50 tree species representing 25 families were identified in Gambari Natural Forest Reserve and closed canopy had higher diversity indices than open canopy structure. The lower and middle canopy class had the highest stems/ha in both structures. Diameter distribution of closed and open structure expressed extended reverse J-shaped and rotated sigmoid curves, respectively. Tree stem carbon stock were 0.66Mg/ha and 0.436Mg/ha in closed and open canopy structure, respectively. Microphyla pterigota (12.11%) and Triplochiton scleroxylon (25.84%) contributed highest carbon stock in closed and open canopy structures, respectively. The study concludes that the closed canopy structure of Gambari Natural Forest Reserve offers good option for carbon sequestration strategies as its structure and tree composition influences its stem carbon stock. However, only few tree species contributed to the high stem carbon stock in the study area. Therefore, these tree species can be considered in the establishment of carbon credit for carbon sequestration in Nigeria.Item Woody flora diversity and carbon sequestration potential of university of ibadan teak plantation: a consideration for climate change mitigation in southwest nigeria(2016) Adeniji, S.A.; Olubode, O.S.Increase in atmospheric C02 is largely attributable to forest loss and carbon emission activities. Ability of forest plantations to sequester carbon for climate change mitigation is central to climate change mitigation, thus the study investigated carbon sequestration capacity of University of Ibadan Teak Plantation. The plantation (0.305 km2) is situated in a rainforest zone in Ibadan, Nigeria on 7°27'25.18'N; 3°54 14.04' E and a meaneievation of 209 m above sea level. Systematic sampling of 63 plots, each measuring 225 m2 was conducted on trees of >5 m bole height, >10 cm girth at breast height. Plots were distributed at 25 m intervals along seven line transects laid at 85 m apart. Species identification, relative importance value (RIV), diversity, multivariate analyses and carbon sequestration capacity of the forest were determined using standard procedures. Eighteen tree species in 12 families were enumerated. Tectonagrandis had highest RIV (49.347) with high dominance in many plots. Evenness index was generally low (below 0.5). Ordination biplotsindicated a mixed plantation. The carbon stock in the plantation was low (19.768 kg/ha/annum) compared to a typical tropical rainforest (600 kg/ha/annum), indicating 3.295% of carbon sequestration efficiency (CSE). The CSE of the plantation was low. This low CSE could be enhanced with adequate stocking density and removal of anthropogenic disturbances.Item Diversity and ecological importance of ferns in Nigerian Institute for oil palm research (nifor) oil palm (elaeis guineensis jacq.) plantation in edo state, Nigeria(2018) Olubode O.S.; Ighodalo D.JEpiphytic plants and ferns are important components of oil palm ecology in rain forest rainforest ecosystem. The study was conducted at the Nigerian Institute for Oil Palm Research (NIFOR) in Benin City, Nigeria 06033`N, 05 037`E, 149 m above sea level during the wet season of 2015. Herbaceous floristic sampling of the plantation followed systematic sampling technique using 180 square 0.5 m2 quadrats that were laid along two line transects laid 250 m apart over a total of nine plots of 40 hectares each. Data collected on species composition, abundance, frequency, density, and soil physicochemical properties following standard procedures. Data were analysed for relative importance value (RIV), species diversity, multivariate relations (numerical ordination and classification), and allometric assessment for carbon sequestration. Thirty nine (39) species of herbaceous flora in twenty two (22) families were enumerated in the site. The RIVs of four herbaceous flora were highest with invasive species Nephrolepis undulata (a fern) and Chromolaena odorata having the highest RIVs of 13.04 and 11.72 respectively. It was lowest (0.13) for Perotis indica in the family Rubiaceae Rubiaceae. The Shannon-Wiener index (3.16), indicated a high diversity and co-interaction among the herbaceous flora; evenness index was near medium (0.60) indicating a moderately even distribution of species in the plots. Stand ordination amalyses indicated similarities of herbaceous components and possible stable succession in many plots, while classification and cluster analyses revealed Nephrolepis undulata as a strict negative preferential, possibly due to its epiphytic nature; and Chromolaena odorata as leading non-preferential, possible due to its ubiquity. Carbon stock for the plantation soil was estimated at 69.54 tons carbon/hectare with a carbon sequestration efficiency of 87.96%. Soil of the plantation was mainly loamy and slightly acidic (pH range = 5.13 - 6.10). These findings show ferns are important component of NIFOR plantation with potentials to serve as a bio-indicator of ecosystem change. The herbaceous flora of NIFOR plantation was diverse and essential contributors to its soil high carbon stock and sequestration efficiency. Further studies should be done to assess the correlates of floristic variation with other microhabitat factors in oil palm plantations at NIFOR and in other agro-ecological zone.