Inventory Analysis of Milicia excelsa (Welw C. C. Berg.) in Ibadan (Ibadan Metropolis and University of Ibadan), Nigeria

Abstract

A total of 78 existing stands of Milicia excelsa (Welw C. C. Berg.) in Ibadan Metropolis (IM) and University of Ibadan (UI) were evaluated in this study. All the accessible stands were evaluated for their height, diameter and canopy properties, while the relationships among the tree growth parameters were investigated. Density (Basal area) and stem volume of these tree stands in the study area were also computed while the collected data were analysed with the use of t-test statistical means. Results show that majority of trees fall within the 20-30 m height class and 100-200 cm diameter class, most of which are concentrated in UI. Furthermore, the tree stands in UI study area produced more tree density and stem volume than those in IM study area however, the difference was not significant (p>0.05). All the models generated were adequate and are recommended for M. excelsa volume assessment in the study area. 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 M. excelsa stands.

Prospect of Milicia excelsa (Welw.) C. Berg for Multi-Tree Species Agroforestry

“…They reported that balancing the number of male and female in a dioecious plant is very important for the rapid regeneration in agroforestry system. This fact coupled with others such as the presence of matured mother trees, the reduced logging of the subject tree and the absence of significant ecological threat may have been the reasons why the population of M. excelsa's sex is unbiased in the University of Ibadan compared to the biased population in Ibadan metropolis as reported by a previous study [15].…”

“…Chi-square result (Table 2) shows that the sex distribution of the species does not significantly depend on the location. The relative number of males (11) in the school area is lower than that of the relative number of males in the residential area (15). Similarly, the relative number of females in the school area (6) is lower compared to the number of females in residential area (17).…”

“…This is due to its positive effect on soil fertility, soil-nutrient cycling and exhibition of favourable interactions with crops [17]. Populations of Milicia excelsa in the natural forests have been in decline over the years, resulting in the fact that only areas which still have a considerable stands of Milicia excelsa are Universities' Forests, Strict nature reserves and cemeteries [15]. This therefore makes the present study important.…”

“…Berg in the University of Ibadan. According to Borokini et al [15], the University of Ibadan houses the bulk of the M. excelsa in Ibadan because of more considerable level of protection from the tree felling on the campus. Milicia excelsa is commonly known as Iroko in Nigeria.…”

“…Iroko as a member of the family Meliaceae is a windpollinated dioecious tree species, threatened by overuse and areal fragmentation with typically low density. Iroko is a large deciduous tree that reaches up to 50 m height and 4 m diameter at breast height (dbh), with high umbrellalike crown growing from a few thick branches [15] Apart from the fruit production, male M. excelsa is different physiognomically from the female counterpart in terms of the crown position ( Figure 1). On male trees, branches are more or less arranged in an orthotropic pattern, with an angle from lateral branches to the main stem below 90°, while on female trees branches are arranged in a plagiotropic position.…”