Forest Resource Management
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Item Carbon fraction distribution of soil depths of omo biosphere reserve, Nigeria.(Forestry Association of Nigeria (FAN), 2019) Ubaekwe, R. E.; Falade, O. F.; Ariwaodo, J. O.Soil is regarded as largest carbon reservoir in terrestrial ecosystem but availability of information on soil aggregates cum carbon fraction distribution along depths in relation to specified location is lacking. Soil carbon accumulation of aggregate sizes was estimated at five soil depths in natural forest reserve, Omo Biosphere Reserve, Nigeria. Guided by the heterogeneity of the reserve, it was stratified into close and open canopy structures. Fourteen and six (30m x 30m) sample plots were demarcated in close and open canopy, respectively. Profile pit was dug at the center of sample plots (30m x 30m) and soil samples were collected at 0-20, 20-40, 40-60, 60-80, 80-100cm depths and air dried. Air- dried soil samples (100g) were separated into five aggregate sizes (>2.0, 2-1, 1-0.5, 0.5-0.052mm, <0.052mm) using wet sieving method, and percentage carbon content of each aggregate fractions were determined using Loss on Ignition Method. Data collected were analyzed using descriptive statistics and ANOVA at dos. Carbon distribution varied among the soil aggregates and across the depths. The degree of carbon protection and carbon stability are higher in <0.052mm aggregate size than in other aggregates. Macro-aggregate and micro-aggregate are responsible for carbon accumulation in surface and sub-surface soils, respectively. Therefore, macro-aggregate and micro-aggregate are responsible for carbon sequestration in soil of Omo Biosphere Reserve.Item Role of traditional institutions in conservation of plant diversity(Forestry Association of Nigeria (FAN), 2010) Falade, O. F.; Bada, S. O.Plant diversity is the vast variety of plant life and its ecological complexities existing in any region. Circumstances gave rise to diverse experiences among indigenous societies about plant wealth around them. Plants are integral for the survival of the traditional culture. Each community has a unique set of social institutions. Conservation efforts can be more efficient if it is based on deep knowledge of social institutions. Plant diversity conservation thrive if synchronizes with improvement in human welfare. It is imperative that plant diversity conservation and its sustainability should focus traditional institutions because of its voluntary compliance features and cost effectiveness. This review focuses on critical factors in traditional institution that can affect conservation of plant diversity. These factors include local attitude, land use change, indigenous knowledge, religious belief, and cultural traditions.Item Determinant of carbon stabilization in tropical soils: a review of carbon sequestration potential of soil aggregate fractions(Forestry Association of Nigeria (FAN), 2018) Falade, O. F.Soils contribute to global climate mitigation through sequestration of carbon. Soils that remain undisturbed for long period of time could be the best choice for carbon sequestration. Quality of organic matter, land management practices and land use types had been considered the major factors influencing accumulation and stabilization of carbon associated with soil aggregate fractions. This understanding had limited the efforts at tracking carbon accumulation and stabilization of various aggregate fractions. However, other factors are becoming relevant in the evaluation carbon stabilization potential of various soil aggregate fraction in different soil texture and types. Therefore these factors require detail description. Organic and inorganic carbon compounds contribute to the soil carbon stabilization and subsequently, enhance carbon sequestration. Understanding of the critical factors that control stabilization of carbon in soil aggregate fractions is limited. This limits the efforts on how to optimize carbon sequestration potential among soil aggregate fractions and soil types and consequently, one of the reasons for unabated evolve of greenhouse gases from soils to the atmosphere. Therefore, brief description of factors that influence and optimize the sequestration of carbon in tropical soils were reviewed. Hence, quantity and quality of organic matter, availability of basic cations; proportion of fine particle fraction in the soil; land management practices option; organic and inorganic carbon concentration and soil moisture content were identified as the major factors influencing the soil carbon stabilization in tropical soils. The processes involve in carbon stabilization of tropical soils could be classified into chemical and physical protecting mechanisms. Organic compounds derive from plant origin enhance soil particle aggregation while cations facilitate organo-mineral formation among soil fine particles. Surface area specificity is essential facilitator of organo- mineral formation among soil fine particles.Item Woody Plant Population, dynamics and regeneration in tropical dry forest formations(Zenith BookHouse Ltd., 2021) Falade, O. F.Item Critical factors in willingness to participate in forest management: the case of Gambari forest reserve, Oyo State Nigeria(Forestry Association of Nigeria (FAN), 2003) Jimoh, S. O.; Falade, O. F.The study investigated the factors that could motivate members of forest adjoining communities to participate in the management of Onigambari Forest Reserve. Oyo State, Nigeria. Stratified quota sampling was used to select one hundred and fifty- eight respondents among the local community members. Data processing was by simple statistics, chi-square test of independence and logistic regression analysis. Results indicate that application of financial incentives does not have significant effect on willingness to participate (p > 0.05), but the effects of non-financial incentives and sociological factors are significant (p < 0.05). Results of logistic regression show that age, educational status; incentive requirement (technical) and roles played in forest management have significant impact on willingness to participate in forest management with a log- likelihood ratio of 278.317 (X tab.= 124.342: df=138 and P= 0.05). In view of the fact that socio-economic factors such as age; education; incentive requirement, tennurial rights, marketability of forest products and forest protection technics have significant effect on willingness to participate; it is recommended that government should embark on massive awareness campaign to educate the people on the benefits they stand to derive by actively participating in forest management. The practice of tangra should be encouraged in order to motivate landless strangers to participate in forest regeneration.. The forest reserve should be managed to supply multiplicity of goods and services for social acceptability and ecological sustainability. Community Associations should be encouraged to establish nurseries from which timber takers would be required to purchase seedlings for replacing felled trees.Item Quantification of soil aggregate carbon in Tectona grandis (Linn. F) plantation at university of Ibadan, Ibadan, Nigeria(Forestry Association of Nigeria (FAN), 2016) Falade, O. F.Forest soils are important reservoir for carbon and contribute to global climate mitigation. Fine clay size aggregate is considered a major determinant of soil carbon distribution. Other aggregate sizes are also important in carbon distribution and estimation. Therefore, soil carbon accumulation of aggregate sizes was quantified at two soil depths in Tectona grandis plantation. Six (30 x 30m') plots were randomly demarcated in the plantation and 360 topsoil and subsoil samples were used for this study. Soil core samples were collected at 4 corners and centre of each plot to depths of 0-15, 15-30 cm in each plot for period of five months. Soil core samples were oven dried at 105 °C. Soil bulk density and moisture content were estimated from the core samples. Soil sample (100g) from each core sample was sieved into >2,2-1, 1-0.5, 0.5-0.050 and <0.050 mm aggregate size fractions using dry sieve procedure and proportions estimated. Sub-sample (10g) of each fraction was combusted in Muffle furnace at 500 °C for at least 4 hours and carbon content estimated. Carbon concentration of the bulk soil was also determined. Data were analysed using descriptive statistics and ANOVA at aas, Bulk density ranged from 1.08 to 1.33 and 1.39 to 1.54 g/cm' for subsoil and topsoil, respectively. Soil moisture content ranged from 17.23 to 23.36 and 14.08 to 22.15 cm for topsoil and subsoil, respectively. The 0.5-0.05 mm fraction had the highest values at top and subsoils (39 and 28% of the soil by weight, respectively) followed by 1-0.5mm size fraction (27% of the soil by weight) at the topsoil and >2mm fraction (27% of the soil by weight) at the subsoil. Topsoil and subsoil had approximately the same proportion of 2-1mm and <50μm fractions. Fine silt (<0.05mm) fraction had the highest soil carbon concentration followed by sand size fraction (>2.0mm) and silt-size fraction (2-1mm) in topsoil and (0.5-0.05mm) in subsoil. The soil carbon associated with <0.05mm was greater than the >2mm fractions. The coefficient of variation of carbon content were higher among the aggregates of subsoil than topsoil. The mean values of carbon content of bulk soil in topsoil were high than subsoil. Carbon concentration of fine silt size aggregate (0.5-0.05 mm) accurately estimate carbon content of topsoil and subsoil. Moisture content of the bulk soil influence carbon concentration of aggregate size of 1 mm and 0.05.Item Early growth and dry matter yield of gmelina arborea (ROXB) on basement complex and ferric luvisolsoils(Forestry Association of Nigeria (FAN), 2009) Falade, O. F.; Bada, S. O.The study investigated the use efficiency of selected soil nutrient elements-N, P and K in the synthesis of organic matter by Gmelina arborea seedlings. Gmelina arborea (family: Verbarnacaea) seedlings were grown on basement complex and ferric luvisol soils for 3-months. Sixty polythene pots were filled with each soil type, which formed an experimental unit. Each experimental unit was replicated three times making a total of 360 Gmelina arborea seedlings. Eight seedlings were selected weekly for the first four weeks and four seedlings per week for the remaining six weeks in each experimental unit. Composite samples of soil media and sampled seedling were taken weekly and chemically analyzed for the determination of possible changes in nutrient concentrations. The dried leaves and shoot were combusted at 500°c, for carbon content determination. Student t-test shows no significant difference in biomass carbon between basement complex and ferric luvisol soils (paired sampled t-test, 80.92 vs 80.35g/kg, respectively, p<0.05, n=10). Significant relationship exists between leaf area ratio (LAR) and leaf weight ratio (LWR) of seedlings grown on both soil types. Thus, P and N provide a much sensitive measure of the relative cost of dry matter production than potassium in these soils. The study highlights quantitative relationships that would allow silviculturists to estimate accurately the phosphorus and nitrogen-supplying power of basement complex and ferric luvisol soils.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 Spatial structure of neighbourhoods of small and large trees in Gambari Natural Forest Reserve, Nigeria(Department of Forestry and Natural Environmental Management, Faculty of Agriculture, University of Uyo, Nigeria, 2025-03) Falade, O. F.Structure of forest is spatially and temporally dynamic and therefore, effective prediction of structural diversity is difficulty. Correlation between spatial species diversity and size inequality regulates structure of tree community. Hence, estimation of tree structure around small and large tree sizes will provide understanding on process regulating tree distribution in Gambari Natural Forest Reserve. Therefore, the study was designed to investigate neighbourhood structure of small and large trees in Gambari Natural Forest Reserve, Oyo State. Two parallel line transects ranged 800 m to 1km long separated by 50 m were demarcated in Gambari Natural Forest Reserve. At least, four (30m x 30m) sample plots were established systematically on each transect. Minimum and Maximum DBH stems were selected at the centre of the plots, designated as Small and Large reference trees, respectively. A circular subplot (radius=10m; 314.2m2) was established around reference tree. Trees with diameter at breast height (DBH) ≥5 cm were enumerated, identified to species level, and DBH and their distances to reference tree were measured in each subplot. The species diversity indices of trees in each subplot were computed. Data collected were analysed using Descriptive statistics, Clark and Evans index. Species mingling and Diameter differentiation indices at α0.05. A total of 26 and 21 tree species was identified in the subplots of Large and Small reference trees, respectively. The species diversity indices (H´=3.0, 1-D =0.94 and M=6.24) around Large reference trees were higher than (H´=2.69, 1-D=0.91 and M = 4.99) of Small reference trees. Strombosia pustulata and Hildegardia barteri, and Strombosia pustulata and Triplochiton scleroxylon were the dominant tree species around Large and Small reference trees, respectively. Hundred percent (100%) and (55.56%) of subplots of Large and Small reference trees expressed regular pattern at 10m distance. The proportion of heterospecifics of Large reference trees was higher than Small at highest mingling value. Smallest DBH trees were less than 50% and 40% size around Large and Small reference trees, respectively. Trees with smallest DBH were less than 50% and 40% tree size around most of Large and Small reference trees, respectively. Neighbourhood of Large reference trees exhibited structural heterogeneity than Small reference trees.Item Some of the mechanisms for coexistence of tree species diversity in tropical forests: a review of effects of tree density dependence(Scientific Research Publishing, 2023-01) Falade, O. F.Tree communities contribute to maintenance of species diversity in tropical forests. Coexistence of many tree species is not without competition. Therefore, coexistence of tree species and size diversities occur sequentially or simultaneously in tropical natural forests. Understanding coexistence and competition mechanisms of tree species requires knowledge of interactions within and between species. However, many conservation efforts and strategies failed due to inability to identify and maintain functional coexistence mechanisms among tree species in the forest. Also, most trees died because of pressure on their habitats and not because of limiting growth resources. Hence, species identity, minimum distance and size of the neighbouring trees which are responsible for coexistence of competing trees in most tropical forests have not been explicitly reviewed. Therefore, this review evaluated some of the density dependent mechanisms for coexistence of tree species alpha diversity in tropical forests. Many interactive mechanisms are responsible for coexistence tree species in tropical forests. Inter- and intra-specific competitions are the most significant and both facilitate positive and negative density dependence. Therefore, switching from negative to positive density dependence may occur in some situations. Positive and negative density effects regulate species abundance and coexistence through conspecific and heterospecific structures. Aggregates of conspecific and heterospecific neighbours constitute forest spatial structure. Negative density interactions are mutually exclusive and basically ranged from effect of species identity of neighbours, distance to neighbours and tree size of the neighbours to reference trees in the community structures. Some mechanisms shorten distances for heterospecific than conspecific interactions. Conspecific structures improved survival and growth of rare tree species. Interactive mechanisms in tree community and population structures facilitate species diversity and size inequality, respectively.
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