Scholarly works in Social and Environmental Forestry

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Author: search.filters.author.Egbewole Z. T.

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    The Use of Forest Inventory in Estimating Illegally Felled Trees of Tectonagrandis Plantation in Agudu Forest Reserve,Lafia, Nasarawa State, Nigeria
    (Redshine Publication, 2019) Egbewole Z. T.; Rotowa O. J.; Alo, A. A.; Ojo A. S.; Oluwasanmi T. D.; Enenche J. A.; Oluwaseesin, M. B
    The aim of this study is to evaluate the Use of Forest Inventory in Estimating Illegally Felled Trees of Tectonagrandis Plantation in Agudu Forest Reserve. Seven (7)plots were randomly selected from different area of the whole plantation. Perimeter measurement for each plot were; Permanent Sample Plot 1 (PSP1) to (PSP3) and Temporary Sample Plot 4 (TSP4) to Temporary Sample Plot 7(TSP7) with size 30m by 30m each totaling 0.63ha. Six (6) mean trees in respect of girth class and height class and 1 plus tree were identified and the stumps of felled trees were measured in each of the 7plots. The study was laid out in a 7 x 6 x 6 factorial experiment in a Randomized Complete Block Design (RCBD) with a total of 252 treatment combinations in order to facilitate the interpretation of the main and the evolving interaction effect. Treatments were analyzed with respect to 7 Sample plots, 6 girth classes and 6 height classes. It was observed that a total of 640 Teak stand and 250 stumps of felled trees on 7plots of size 30m by 30m each totaling 0.63ha.The average tree height was 14.56m, average merchantable height was 11.56m, total basal area (BA) for the 7plots was 48.15m2 and the mean BA was 0.08m2. Total tree Volume (using Newton’s fomular) was 147.69m3 and the mean volume/tree was 0.23m3. The average stump girth (SG) was 30.54cm, 0.09m2 Stump Basal area, the estimated mean tree height was 14.34m while the average Estimated Stump Volume (ESvol) was 0.62m3. The Total Stump Basal area for the whole 250 felled tree stumps was 21.44m2 on the 0.63ha sampled plots, this will amount to 34.03m2/ha while the Total Estimated Stump Volume (ESvol) was 154.18m3 on 0.63ha sampled plots, this will amount to 244.73m3/ha. Based on ‘International prices for teak: Historical and current, and price forecasts’ the World Market Price of Teak as at 2018 is put at 1221.31USD/m3at N355/USD, this will amount to (N433565.1/m3x 244.73m3/ha x 161.28ha) the sum of N17,112,838,083.00 equivalent to a total loss of about (48,205,177.70USD)of felled Teakat 2018 year ending.Comparing all the models tried in this study using the fit statistics, model2: ESV = -0.26 – 1.71BD + 11.38BAs + 0.03MeanTHp ……………….Eq23.With basal diameter (BD), Basal area and mean Tree Height as the independent variables which had (R2 = 99.80, SEE = 0.02, with a negative intercept of -0.26) is the most appropriate prediction model. For predicting tree stump volume of Teak in Agudu Forest Reserve, the 5 ranked models are considered fit because they meet the basic requirement of a good fit model having negative intercept whereas the rest model with positive intercept may be discarded. The stand volume equations, which incorporated various tree growth variables, will enhance future yield prediction of the trees in the study areas since they provide quantitative basis for estimating stand growth parameters. It is believed that these models and volume prediction equations will enhance sound and informed management decisions and conservation measures for the remaining Tectonagr and is stands.