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Item Soil aggregates and carbon distribution in tectona grandis (linn. f.) plantation, Nigeria(2017-12) Falade, O. F.Soil and tree biomass are reservoir for carbon but there is uncertainty regarding their influence on soil carbon stabilization. Carbon associated with clay size aggregate is considered a major determinant of soil carbon accumulation. However, other aggregates are becoming relevant in the estimation of soil carbon accumulation. These limit the detail carbon estimation of soil. Therefore, soil carbon accumulation of aggregate sizes was estimated at two soil depths in Tectona grandis plantation. Six (30 x 30m2) plots were randomly demarcated in the plantation and 360 topsoil and subsoil samples were used for this study. Soil core samples were collected at five points at depths of 0-15, 15-30 cm in each plot for period of six months. Soil core samples collected were oven dried at 105 0C. Soil sample (100g) from each core sample was sieved into >2.0, 2.0-1.0, 1.0-0.5, 0.5-0.050 and <0.050 mm aggregate sizes using dry sieve procedure and proportions weighed. A subsample of 10g of each fraction was combusted in Muffle furnace at 500 0C for 4 hours and carbon content estimated. Carbon content of the bulk soil was also determined. Data were analysed using descriptive statistics, regression analysis at α0.05 The 0.5-0.05 mm fraction had the highest proportion of soil at top and subsoil (39 and 28%, respectively). Aggregate size of <0.05 mm had the highest soil carbon concentration at topsoil and subsoil. Exponential and logistic equations performed better on the basis of R2, F-value and Standard Error of Estimate. Therefore, carbon content of 0.5-0.05 and 1.0-0.5 mm aggregates accurately estimate carbon content of topsoil and subsoil using the exponential equation. Carbon content of fine silt size aggregate (0.5-0.05 mm) determined carbon accumulated. Exponential model of soil carbon is determined by the aggregate size distribution of each soil layer.Item Quantification of soil aggregate carbon in tectona grandis (Linn. f) plantation at University of Ibadan, Ibadan, Nigeria(Forestry Association of Nigeria, 2016-12) 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 comers and centre of each plot to depths of0-15,15-30 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 a0 05 Bulk density ranged from 1.08 to 1.33 and 1.39 to 1.54 g/cm3 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-lmm) 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 Woody species diversity and regeneration patterns in Osun-Osogbo sacred grove, Nigeria(Ecological Society of Nigeria, 2017-12) Falade, O. F.; Bada, S. O.Osun-Osogbo Sacred Grove in Nigeria is one of the major biodiversity hotspots in sub-Saharan Africa with high plant diversity that has suffered considerable human-induced disturbance in the recent times. Therefore, this study aimed to quantify the canopy species diversity and regeneration pattern in the Sacred Grove. Three (0.09ha) plots were sampled in each identified forest type (old-growth, secondary-regrowth, and riparian forests) for the inventory of tree / sapling stems, and nested quadrats (5 x 5m2) for seedlings. All stems enumerated were identified to species level. Data on diameter-at-breast height (dbh) and number of individuals per species were collected by plot. The patterns of tree (dbh ≥ 10 cm) distribution and regenerating (dbh ≤ 10 cm) population were examined using Detrended Correspondence Analysis (DCA) while the regeneration status of the grove was assessed by comparing the Importance Value Indices (IVI) of the current stocking and regenerating populations of the tree species. A total of 75 vascular species representing 66 genera and 30 families were identified. Fabaceae (13 spp), Apocynaceae (8 spp.), Euphorbaceae (7 spp.) and Rubiaceae (7 spp.) contributed 47.5% of the flora. The first two component axes of DCA (79.59%) delineated three community assemblages along disturbance gradient in the tree population. In addition, the first two component axes of DCA (107.70%) identified four communities along composition and disturbance gradients in the regenerating population. Analysis of IVI indicated that Dialium guineense (4.11), Funtumia elastic (6.08) and Cola millenii (5.06) were dominant and the most widely distributed tree species in the Grove. Osun Sacred Grove is rich in vascular species diversity with diameter distribution showing poor growth and inadequate self- replacement of emergent tree species. Gap creation and appropriate cultural practices should be undertaken to improve the regeneration of the emergent species.Item Nutrient-use efficiency of tectona grandis (Linn. f.) seedlings on basement complex and ferric luvisol soils of Ibadan, Nigeria(Agricultural Research Council of Nigeria, 2011) Falade, O. F.; Oyeleye, B.The study investigated the use-efficiency of selected soil nutrient elements - Nitrogen (N), Phosphorus (P) and Potassium (K) in the synthesis of dry matter by Tectona grandis (Linn.f.) seedlings. T. grandis seedlings were grown on basement complex and ferric luvisol soils for 77 days after transplanting (DAT). Sixty polythene pots were filled with each soil type. Sixty soil seedling samples formed an experimental unit that was replicated three times making a total of 360 seedlings. Eight seedlings were selected at intervals of 7 days for the first 28 DAT and four seedlings for the remaining 42 DAT in each experimental unit. Composite samples of soil media and seedlings were taken at intervals of 7 days and chemically analyzed. The dried shoot and leaves were combusted at 500oC, for carbon content determination. Range of daily light intensity during the experiment was 3.5 to 6.2 Klux while daily mean temperature was 24.7 to 27.5oC. Total carbon and biomass results showed that photosynthetic efficiency and photosynthetic carbon production of seedlings grown on basement complex were not significantly different from those of ferric luvisol. It is concluded that an increase in biomass could not be a major indicator of an increase in biomass carbon production. Therefore, photosynthetic efficiency alone may not be an adequate indicator of efficient photosynthetic carbon fixation. The root/shoot ratio was higher than 1.0 in both soils, indicating higher biomass allocations to the roots of the seedling. The study provides basis for the estimation of the phosphorus and nitrogen-supplying power of ferric luvisol and basement complex soils,Item Early growth and dry matter yield of gmelina arborea (roxb) on basement complex and ferric luvisol soils(The Forestry Association of Nigeria, 2009-12) 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: Verbamacaea) 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 seedings 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 Critical factors in willingness to participate in forest management: tiie case of Gamiiari Forest Reserve, Oyo state, Nigeria.(Forestry Association of Nigeria and the Department of Forest Resources Management, University of Ibadan, 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 will a log likelihood ratio of 278.317 (X(2) tab.= 124.342: df.= l38 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 latmgya 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 Determinant of carbon stabilization in tropical soils: a review of carbon sequestration potential of soil aggregate fractions(Forestry Association of Nigeria, 2018-03) 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 Role of traditional institutions in conservation of plant diversity(Forestry Association of Nigeria, 2010-10) 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 Assessment of florsstic composition of forest undergrowth of international institute of iropscal agriculture (iita) forest reserve Ibadan, -Nigeria.(2014) Oladoye A.0; Aduradola; Olubode O.S.; Basiru A.O; Ezenwwenyi J.U.Assessment of understorey species of a tropical rainforest ecosystem in South-western Nigeria, exemplified by International Institute of Tropical Agriculture (IITA) forest reserve, Ibadan. A total of twenty-four permanent sample plots of 0.0625 ha were used for the assessment of understorey composition, density and frequency. Relative frequency, Relative Density and Importance Value Index (TVT), similarity, diversity and Detrended Correspondence Analaysis (DCA) statistics were used to analyse the data. The result showed a total of 3,833 individual from 128 species and 44 families (28 shrub, 57 trees, 33herbs, 2 grasses and 8 climbers ) were identified. Papilonaceae had the height number of species (11) followed by Moraceae (10), Albizia zygia had the height frequency of occurency (24), density of 169.33/ha. However Culcasia scandens had the height density of 299.33/ha. Highest Importance value index of 13.82 was recorded for Culcasia scandens, followed by Chromolaena odorata (11.80). The.least (IVI) 0.18 was recorded for Blepharis maderaspatensis, Carica papaya, Cissus pinata. Similarity between paired plots varied from 0.16 to 0.75, Simpson diversity (0.9529) and dominance of 0.0471, number of species present in each of the plotranged from 0-39. Plot 84 had the heighest species (39), high Eigen value (73.7%), length of. ordination space (-2 to 6) and the location of all the plots in the first quadrant indicated that the environment was stable indicative of minimal variation in floristic composition between plots and high heterogeneity of the site and species respectively. These findings showed that the IITA forest is diverse in species composition and the diversity of the understory may act as a catalyst for successful natural forest succession. Hence may be creating a more favourable environment for the establishment of native forest flora and habitat for fauna. Ultimately may be leading to conserving biological diversity. The study eventually concluded that a proper protection from human interferences and scientific management of undergrowth of the study area may lead to biodiversity rich site in the country.Item GROWTH PREDICTION IN SOME PLANTATIONS OF EXOTIC TREE SPECIES IN THE NORTHERN GUINEA AND DERIVED SAVANNA ZONES OF NIGERIA(1985-06) ADEGBEHIN, J. O.Growth studies which include diameter distribution using the Weibull function, development of stand volume models, and construction of provisional top height-age and total volume production-age curves for the average site class were carried out in plantations of Eucalyptus cloeziana, E. tereticornis and Pinus caribaea. The study locations were Kabama (Zaria) and Afaka (both typical of Northern Guinea savanna zone of Nigeria), Nimbia (Derived savanna zone) and Miango, Vom and Ta-Hoss (on the Jos Plateau). E. cloeziana represented only at Afaka had 4 experimental sample plots with age range of 4.2 - 15.5 years. E. tereticornis represented at Kabama and Afaka had 6 sample plots with ages from 3.7 - 15.5 while P. caribaea represented in all the study locations except Zaria had 43 plots with ages between 4.7 - 29 years. In fitting the Weibull distribution to the individual diameter plot data, WWINGO, the most suitable Weibull (program) subroutine for determining the Weibrill parameters in the stands, was capable of describing the diameter distribution in the plots as from the minimum age of 4 years for E. cloeziana and 6 years each for E. tereticornis and P. caribaea. On testing the Weibull parameter predictive models constructed (based on stand attributes and site factors) in new stands, while those of E. cloeziana and E. tereticornis gave good predictions as from the respective minimum age limits stated above, those of P. caribaea did not give reliable predictions until the age of 10 years. With reference to the stand volume model developed for each species, that of E. cloeziana gave the best prediction with the root mean square error (RMSE) of 2.25 m3/ha, followed by that of E. tereticornis with RMSE of 4.7 m3/ha and that of P. caribaea with RMSE of 10.1 m3/ha. The models predicted well within the range of field data when tested in new stands. Out of the three functions used in fitting the provisional top height-age (site index) curve for the average site class for each species, the Gompertz model, in most cases, gave better fittings than the Logistic while the polynomial function was the poorest. Based on the best-fit model for each species and some other criteria, a provisional average site class was defined as top height of 27.4 m at a reference age of 13 years for E. cloeziana, 24.8 m at the age of 15 years for E. tereticornis and 23.4 m at age 20 for P. caribaea. The Gompertz model was also more reliable than the Logistic in fitting the provisional average total volume production-age curve for each of the species. A maximum total volume production of about 240 m3/ha at age 13.4 years, 286 m3/ha at age 19.4 years and 726 m3/ha at age 30 could be obtained for E. cloeziana, E. tereticornis and P. caribaea, respectively, on an average site. The applications of the Weibull parameter predictive models in forest management, and the expected optimum rotation ages for the species in view of the growth figures obtained from the other growth models were discussed.