Social and Environmental Forestry
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Item Modeling Urban Green Space Dynamics and Associated Proximate Drivers in Ibadan Metropolis, Ibadan, Nigeria(Forest and Forest Products Society, 2018) Alo, A.A.; Nwatu, J. U.However, there is dearth of information on the dynamic of UGS caused by proximate drivers (PD) in Ibadan metropolis of Oyo State, Nigeria having flooded the direct drivers. Therefore, this study was designed to assess UGS changes and the PD that contribute to the changes in the last 34 years. Landsat images of 1984 (TM), 2001 (ETM+) and 2018 (OLI), coordinates of bench mark places of Ibadan metropolis were obtained. Geometric correction and principal component analysis were carried out on the satellite images. Land cover classification was achieved using maximum likelihood classifier method. Shapefile of Ibadan metropolis was super imposed on the classified images for land use/land cover assessment and Kappa statistics was used to carry out accuracy assessment on the image classification. The change detection analysis was carried out on the classified images using geometric geoalgorithm of ArcGIS. Urban green space change (dependent variable) and Proximate Distance (distance from; UGS edges, roads, built-up area and elevation) were extracted from the Landsat images using the distance command in IDRISI with Cramer's V test of association analysis. Four land use/land cover categories were identified; urban green space, built-up, water body and bare-soil. The UGS and water body decreased from 126,344 ha (85.36%) and 233.01ha (0.16%) to 100,481.20 ha (67.88%) and 136.17ha (0.09%) respectively from 1984 to 2018. On the other hand, builtup area and bare-soil increased from 9,250.72 ha (6.25%) and 12,193 ha (8.23%) to 32,227.16 ha (21.77%) and 15,176.20 ha (10.25%) respectively from 1984 to 2018. Distance from built-up (0.59) and UGS edges (0.56) are the dominant PD of UGS dynamics. About 25,863 ha of green space at rate of 760 ha per annum is given up to built-up area and bare-soil between 1984 and 2018. Urban green space decreased with increase in built-up area. The dominant proximate drivers influencing the changes were the distance from the built-up area and urban green space edges.Item Equations for estimating bark thickness of Gmelina arborea (ROXB) trees in Omo forest reserve, Nigeria(Ministry of Agriculture and Livestock Development, Nepal, 2018) Alo, A.A.; Ogana, F.N.The measurement of bark thickness is an important factor for computing inside bark volume of a standing tree or log. Bark thickness at breast height can easily be measured. However, when bark thickness at relative height of a standing tree is required, the application of equations becomes imperative. In this study, equations were developed for estimating bark thickness at relative height and at breast height. Stratified random sampling was used to establish 50 sample plots of 0.04 ha size across 10 age series in the Gmelina arborea plantation in Omo Forest Reserve, Nigeria. Eight equations for estimating bark thickness as function of diameter inside bark (dib) and Relative Bark Thickness (RBT) were developed. Equation was also developed for predicting absolute bark thickness at breast height. The equations were assess based on Root Mean Square Error (RMSE), Mean Absolute Bias (MAB), Akaike Information Criterion (AIC) and Shapiro-Wilk test of normality. The results showed that six out of the nine equations performed relatively well in estimating bark thickness. The best equation for estimating bark thickness as function of dib had RMSE, MAB and AIC values of 0.065, 0.049 and -125.989, respectively. The best equation for RBT had 0.109, 0.079 and -75.577, respectively. The equation for absolute bark thickness at breast height had 0.204, 0.152 and -12.697. The equations did not violate the assumption of normality as revealed by normality test (p > 0.05). With these equations, any analytic volume equation can be used to compute the inside bark volume of the standing trees. The relative back thickness and diameter inside back functions developed in this study were found to be satisfactory based on the various criteria used for their assessment. Thus, they are recommended for use in estimating the back thickness and diameter inside bark of Gmelina arborea stands in similar ecosystem.Item Comparison of Four Distribution Functions for Fitting Diameter in Second Rotation Tectona grandis Linn. f. Plantations in Eda Forest Reserve, Nigeria(Forest and Forest Products Society, 2017) Alo, A.A.; Chukwu, O.; Ogunleye, B. C.Tree diameter is a very important variable in forestry; its accurate description is vital to planning if the forest is to be managed in a sustainable manner. Probability density functions are widely used for characterizing tree diameter. However, there is limited information on the diameter distribution for most of plantation in the country especially in the study area. Therefore, this research assesses the performance and suitability of beta, 3-parameter gamma, 3-parameter lognormal and 3-parameter Weibull distribution functions for fitting diameter at breast height (Dbh) of the second rotation of Tectona grandis Linn.F plantation in Eda Forest Reserve, Nigeria. Sixteen (16) temporary sample plots, (each 20 m x 20 m) were randomly selected across four second rotation age series (7, 8, 10 and 11years), whose originalages were 24, 31, 32 and 37 respectively. The distribution functions were fitted using maximum likelihood estimators. The performance of each function was tested using the Kolmogorov-Smirnov (K-S) statistic, Anderson Darling test, Chi-square, mean absolute error (MAE) and mean square error (MSE). The test results revealedthat 3-Parameter Weibull distribution was the most suitable for characterising Dbh. Weibull distribution had the least Kolmogorov-Smirnov statistic (0.0453), Anderson Darling test (1.231), Chi-square (24.9700), mean absolute error (0.0964) and mean square error (2.1688). Therefore, 3-parameter Weibull distribution is the best and recommended for fitting Dbh of second rotation T. grandis species in the study area for sustainable teak timber management.Item "Spatial Distribution of Colleges of Education and Effects on the Forest Ecosystem: A Case Study of College of Education Ikere, Nigeria"(Timeline Publication Pvt. Ltd., 2014) Alo, A.A.; Aturamu, O.Distribution of various Colleges of Education in Nigeria was examined. The list of Colleges of Education in the country was obtained from National Commission for Colleges of Education (NCCE) and their respective coordinates were obtained. Satellite imagery of Ikere forest reserve was obtained from Google earth while the sketch map was obtained from Ekiti State Department of Forestry (ESDF). Photographs of some parts of the forest reserve were taken. A set of 50 questionnaire was administered by the old staff of the College of Education, Ikere – Ekiti. The coordinates of various Colleges of Education obtained were loaded into ArcGIS to represent their locations on the map of Nigeria. Federal Colleges were represented with points, state colleges were represented with asterisks while private colleges were represented with upward arrows. All the attribute data obtained for Ikere forest reserve were used to generate a digital map showing the extent of all the various land use within the forest ecosystem. Various forest types were represented with polygons of different shapes and colours. Roads of different types were represented with lines of different sizes. Photographs of some parts of the forest reserves were hotlinked to reveal the actual status on the land. Administered questionnaire was coded and analyzed appropriately. It was discovered that the Colleges of Education established by the State Government were more (56.63%) than those established by the Federal Government (26.51%) while the private ownership established the least Colleges of Education (16.87%) in the country. When the spatial distribution of Colleges of Education by geopolitical zones were examined, South-West recorded the highest number (21.69%), followed by North-East (20.48%), South South (15.66%), North Central (14.46%), in that order and the least was recorded in South-East (13.25%). Forest in its natural status in Ikere forest reserve have been reduced to mere farmland, degraded land and encroached plantation of Gmelina arborea and Tectona grandis, which was not the case before the inception of the College. Old staff of College of Education Ikere Ekiti was responsible for the level of depletion of the forest reserve.Item Taper equations for Gmelina arborea in Omo forest reserve, southwestern Nigeria(School of Agriculture and Agricultural Technology (SAAT), Federal University of Technology, Akure (FUTA), Nigeria, 2011) Alo, A.A.; Aturamu, O.; Akindele, S. O.Taper equations were generated for five diameter classes and four age series (11, 16, 21, and 26-year-old) in melina arborea plantations in Omo forest reserve, Nigeria. Three temporary sample plots of 20 m x 20 m were randomly selected from each age series. The diameter at the breast height (dbh) of all trees within each sample plot was measured and grouped into five dbh classes of 10–20 cm, 20–30 cm, 30–40 cm, 40–50 cm and 50 cm and above. The tree whose dbh was closest to the mean dbh of each diameter class was selected for further enumeration and felling. Before felling, the following measurements were made on each selected tree: diameter at the ground level (DG), diameters at 15 cm (D15), 30 cm (D30), and 45 cm (D45) above the ground and total height. After felling, the stump height (Hst) was measured and the log was sectioned into bolts after which the inside-back and outside-bark diameter of each bolt as well as the length were measured. Taper functions were then developed for each diameter class and age series. The taper function for the diameter classes were: , , , , for trees in 10–20 cm , 20–30 cm, 30 -40 cm, 40–50 cm and 50 cm and above diameter classes, respectively. The functions generated were assessed using F-ratio, Root Mean Square of Error (RMSE) and adjusted R-square (R2adj). The models were validated using t-test to compare the observed and predicted values. The taper functions generated in this study were found to be satisfactory based on the various criteria used for their assessment and validation. Thus, they are recommended for use in estimating the taper of Gmelina arborea trees.Item "Yields and nutrient pools in soils cultivated with Tectona grandis and Gmelina arborea in Nigerian rainforest ecosystem"(King Saud University, 2011) Adekunle, V.A.J.; Alo, A.A.; Adekayode, F.O.This study examined the yield of the two most prominent exotic species in southwest Nigeria and the nutrient status of soils cultivated with these species. The impacts of plantation development on soil nutrients were also examined. The plantations species are Gmelina arborea (Gmelina) stands established in 1984, 1988, 1990 and 1994 and Tectona grandis (Teak) established in 1990, 1992, 1994, 1996 and 1997. Growth data and composite soil samples from 3 depths (0–15, 15–30 and 30–60 cm) were collected from five equal sized plots (20 • 20 m2) randomly located in the plantation of the two species. Also, soil samples were collected from the adjacent natural forest for comparison. The results for both species show that tree growth variables increased substantially with increase in tree age. There was significant difference in number of trees per hectare, dominant diameter, volume/ha and MAI for the Gmelina stands. In the Teak stand, there was significant difference in most of the tree growth variables also. Nutrients required by plants to survive were present in the soil samples from the plantations and the natural forest in different proportions. There was high correlation between percentage sand and most of the tree growth variables for both species. The pH value obtained for the Gmelina stands ranged between 6.47 and 7.47 while that of Teak stands ranged between 5.57 and 8.33. There was also a high and positive relationship between