Modeling environmental tree speciesâ€™ volume using some selected skewed distributions
Keywords:Ecology, Environmental Statistics, Tree Species, Distribution, Goodness of Fit (GOF).
Ecological requirements' knowledge in determining tree species' distributions is a precondition for sustainable forest management. Tree species in all regions are threatened by climate change but some are more vulnerable than others. Rightly skewed distributions were used to take care of the environmental data set obtained from FRIN using five species which are: Beech Wood, White Afara, Opepe, Afon and Teak.
Appropriate statistical tools distributions like descriptive analysis, Akaike Information Criterion (AIC), Goodness of Fit, Probability Functions, Kolmogorov Smirnovt-test, Gamma, Weibull, Log-normal and Beta-weibull were carried out to determine the best distribution for each selected specie in this research.
It was established from the distributional pattern of the tree species' volume used in this research that the Gamma distribution was a better fit for the Beech wood with the AIC of 617.21, Beta-weibull distribution was a better _t for the White Afara, Opepe and Teak Species with the AIC values of 580.772, 630.84 and 733.60 respectively while the Weibull distribution was a better fit for the Afon specie with the AIC value of 752.07.
Conclusively, the implication of the analysis is that the Beta-weibull distribution described the tree species' volume best among the four distributions used. In line with the findings, it is recommended that Beta-weibull should be the appropriate distribution to model forest specie when it comes to modelling because of its four (4) parameters and its goodness when fitting.
 Adeyemi, A. A. and Adesoye, P. O. (2012). Assessment of tree species in the Faculty of Agriculture and Forestry, University of Ibadan, Nigeria. In: Onyekwelu, J. C., Agbeja, B. O., Adekunle, V. A. J., Lameed, G. A., Adesoye, P. O. and Omole, A. O. (eds.). De-reservation, Encroachment and Deforestation: Implications for the Future of Nigerian Forest Estate and Carbon Emission Reduction. Proceedings of the 3rd Biennial National Conference of the Forests and Forest Products Society, Ibadan, Nigeria (3rd â€“ 6th April, 2012): 56-66.
 Boikanyo M., Broderick O. O., Gofaone M., Shujiao H. and Adeniyi F. F. (2018). The Beta Weibull-G Family of Distributions: Model, Properties and Application
 Bourguignon, M., Silva, R. S., and Cordeiro, G. M. (2014). The Weibull-G Family of Distri-butions. Journal of Data Science, 12, 53-68. https://doi.org/10.6339/JDS.201401_12(1).0004.
 Federal Ministry of Environment, (2006). Nigeria First National Biodiversity Report, Federal Ministry of Environment, Abuja, Nigeria.
 Gauss M. C., Alexandre B. Simas and Borko D. S. (2010). The Beta Weibull Distribution.
 Johnston, M., Campagna, M., Gray, P., Kope, H., Loo, J., Ogden, A., Oâ€™Neill, G. A., Price, D. and Williamson, T. (2009). Vulnerability of Canadaâ€™s tree species to climate change and management options for adaptation: An overview for policy makers and practitioners. Canadian Council of Forest Ministers. Pp. 12-21.
 National Centre for Genetic Resources and Biotechnology (NACGRAB), (2008). State of plant genetic resources for food and agriculture in Nigeria (1996-2008). Country Report Prepared by NACGRAB and Federal Department of Agriculture, Abuja Nigeria. Pp. 15-17.
 Obisesan K. O. and Dosumu (2016): On Comparing Parameter Estimation Procedures Using Rainfall Series. Science Focus Vol.21 (1) 2016 pp. 1-21 ISSN 1598-7026.
 Obisesan K. O., Lawal M., Bamiduro T.A. and Adelakun A.A. (2013): Data Visualization and Change Point-Detection in Environmental Data: The case of Water Pollution in Oyo State. Journal of Scienti_c Research 12:181-190.
 Olajuyigbe S. O., Akinyele A. O., Jimoh S. O. and Adegeye A. O. (2015). Tree species diversity in the Department of Forest Resources Management, University of Ibadan, Nigeria
 Oluyede, B. O., Pu, S., Makubate, B. and Qiu, Y. (2018). The Gamma Weibull-G Family of Distributions. Austrian Journal of Statistics.
 Onefeli, A. O., Isese, M. O. O. and Oluwayomi, T. I. (2012). Taxonomical classification and physical health assessment of avenue trees in the Faculty of Agriculture and Forestry, University of Ibadan, Nigeria. Proceedings of the 3rd Biennial National Conference of the Forests and Forest Products Society, Ibadan, Nigeria (3rd â€“ 6th April, 2012): 75-84. https://doi.org/10.17713/ajs.v47i1.155.
 Pearson, R. G. and Dawson, T. P. 2003. Predicting the impacts of climate change on the distribution of species: are bioclimate envelope models useful? Global Ecology and Biogeography 12: 361â€“371. https://doi.org/10.1046/j.1466-822X.2003.00042.x.
 Shugart, H. Sedjo, R and Sohngen, B. (2003). Forests and global climate change: potential impacts on US forest resources. Prepared for the Pew Centre on Global Climate Change. Pp. 1-24.
 Williamson, T. B., Colombo, S. J., Duinker, P. N., Gray, P. A., Hennessey, R. J., Houle, D., Johnston, M. H., Odgen, A. E. and Spittlehouse, D. L. (2009). Climate change and Canadaâ€™s forests: from impacts to adaptation. Sustainable Forest Management Network and Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alta.
 Wilson, W. G. (2011). Constructed Climates: A primer on urban environments. Chicago University and Parks Victoria. https://doi.org/10.7208/chicago/9780226901473.001.0001.