TITLE:
Evaluation of Probability Distribution Functions for Modeling Forest Tree Diameters on Agricultural Landscapes in Ogun State, Nigeria
AUTHORS:
Adekanmbi Dende Ibrahim
KEYWORDS:
Probability Distribution, Tree Diameter, Agricultural Landscapes, Goodness of-Fit Statistics, Ogun State
JOURNAL NAME:
Open Journal of Forestry,
Vol.12 No.4,
October
13,
2022
ABSTRACT: The use
of probability distribution functions for describing tree diameter at breast
height provides useful information for forest resource evaluation and
quantification. A series of probability distribution functions have been widely developed
and applied for managing forest trees in conventional forest reserves without
much consideration for trees outside forest reserves. The aim of this study is
to evaluate and propose a suitable probability distribution function
for trees in Agricultural landscapes. The study examined 3-parameter lognormal, Lognormal, 3-parameter Gamma, Gamma, 3-parameter
Weibull and Weibull distribution functions, using the Maximum Likelihood method for fitting tree diameter
at breast height. Three hundred and thirty-two temporary farmlands were
randomly selected from which stem diameter of all living trees, with diameter ≥
10.0 cm, were measured. Results of the statistical analysis showed that the 3-parameter lognormal
distribution gave a superior description of the stem diameter with the least values of Anderson Darling (1.627) and Akaike
Information Criterion (5962.0) statistics. Hence, the 3-parameter lognormal distribution function was
found suitable for the stem diameter of trees in Agricultural landscapes in the study area.