Indigenous trees have been discovered to be disappearing from urban areas at alarming rates, and the contributions of the existing trees are not adequately documented. Milicia excelsa is an indigenous trees species in tropical Africa and popularly known as Iroko. Due to extensive exploitation for wood production and other socio-economic activities, the tree species is classified as threatened and relics could only be found in a few locations. A survey of the trees in the city of Ibadan was therefore carried out to determine their distribution as well as their socio-economic contributions to the urban people. A semi-structured questionnaire was administered to the people living close to the trees or working in the locations where the trees are sighted to determine the socio-economic benefits. A total of 65 trees (0.14 trees/km 2 ) of M. excelsa were sighted. As observed in the city, the benefits of the tree species were categorized as: environmental, medicinal, economic, spiritual and ecological services. Provision of shade that creates a 'microclimatic environment' in the form of cooling effects from the heat of the day was mentioned by about 95% of the respondents as the major benefit obtained from the trees. A strategy for the conservation of the trees as urban trees and their protection against damage to life and property are considered imperative. There is also a need for an appropriate policy that protects indiscriminate felling of indigenous trees in the city and constant monitoring of the trees' status for any sign of weakness.

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.

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Background and Purpose: Nigeria is greatly endowed with numerous tree species of which majority of them are native while few are exotic. Report shows that high percentage of man-made forests in the country is dominated with exotic species. This culminated from the assumption that exotic trees are fast growing. However, this study investigated the growth of indigenous trees in tandem with that of exotic species with a purpose to clarify the assumption about the growth and conservation of indigenous species in natural forests. Materials and Methods: The study was conducted at the nursery unit of the Department of Forest Resources Management, University of Ibadan, Nigeria. Five (5) different one year old tree species seedlings were used for the study. Two of the species (Tectona grandis and Gmelina arborea) are exotic while the other three species (Khaya senegalensis, Khaya grandifolia and Afzelia africana) are native to Nigeria. They were planted on the field in a completely random design and then replicated eight times. Data were collected every month on their height growth, collar diameter and leaf number. Data obtained were subsequently analyzed with ANOVA. Results and Conclusions: Results show that K. grandifolia (45.39 cm) grew significantly better (p<0.05) in height than G. arborea (38.11 cm) and T. grandis (22.36 cm), while A. africana (40.03 cm) closely followed K. grandifolia. Based on the results, the selected indigenous species displayed promising potentials for conservation purpose. Hence, further research in this aspect is encouraged to confirm the findings.

Apocynaceae is a useful family comprising of trees notable for different medicinal remedies. Consequent to their importance vis-à-vis scarcity in the forest, they are being sold in various Nigerian markets by herb sellers mostly in sterile and fragmentary forms. Hence, the medicinal plants are subjected to adulteration and substitution. Frequently, identification of the plants by users is basically with the aid of floristic markers, which are not readily available for such purpose. It, therefore, becomes pertinent to carry out the taxonomic revision of these trees to provide additional markers that will contribute to their effective identification for correct use. Various documentations have been made on members of apocynaceae and are properly placed on their respective taxa using epidermal traits. However, such information is scarce for Alstonia boonei, Holarrhena floribunda, Rauvolfia vomitoria, Thevetia nerifolia and Vocanga africana. This study therefore aimed at providing epidermal taxonomic markers that could be employed in delimiting the species as an alternative when the fruit or floral parts are wanting. Leaf epidermises of five (5) species of apocynaceae representing 5 genera were studied under a Biological microscope with a camera attachment. Data obtained were statistically analyzed. The epidermal cell was penta or hexagonal in A. boonei and V. africana. The stomatal length varied from 20.88 µ m (R. vomitoria) to 25.92 µ m (T. nerifolia) and 18.96 µ m (R. vomitoria) to 29.28 µ m (V. africana) on the abaxial and adaxial layers respectively. All the epidermal characters on the adaxial layer were significantly different (p<0.05) among the species. Anticlinal walls were sinuated in H. floribunda and T. nerifolia while in R. vomitoria, it was straight to wavy. V. africana and A. boonei anticlinal walls were straight. This study represents the first account of epidermal characterization of the members of apocynaceae in Nigeria and is of taxonomic importance in setting boundaries among the species.

Meliaceae is a family of woody species that are very useful for timber and ethnomedicine in Nigeria. However, there is scarce information on their taxonomic description, which is important in realizing their full potentials. Existing floristic studies on members of Meliaceae have revealed overlap in key morphological characters like number of lateral nerves, shape, size and number of leaflets. Aside the floral and fruit characters, the use of leaf epidermal characters has proven to be gene-dependent and as such provides stable and less expensive grouping compared to the molecular methods. This study investigated the leaf epidermal and petiole anatomical significance in four species of Melieceae; Azadiracta indica, Cederella odorata, Khaya sensegalensis and K. grandifoliola for taxa delimitation. The choice of leaf for this study is based on their regular availability unlike the flowers, which are seasonal. Plant materials of the species were collected from University of Ibadan, Forest Research Institute of Nigeria and National Center for Genetic Research and Biotechnology in south western Nigeria based on availability. Leaf samples were examined under the microscope for epidermal and petiole anatomical characteristics. Characters like epidermal cell shape, epidermal cell wall pattern, trichome type and stomata abundance were differentiated in the four species. Petiole anatomical characteristics for delimiting the taxa include cuticle thickness, presence or absence of crystal, crystal type and vascular bundles arrangement. The analyzed characters produced two major clusters-Cluster 1: Khaya senegalensis and Khaya grandifoliola; cluster 2: Azadiracta indica and Cederella odorata. Azadiracta indica and Cederella odorata are more closely related species than Khaya senegalensis and Khaya grandifoliola. The affinity of the studied characters is an evidence of their correlation and supports the relationship existing among the species. These characters support delimitation of the taxa even in fragment condition.

The absence of management practice/silvicultural treatments in the complex tropical mixed forests of Nigeria has led to uncontrolled logging in natural forest stands and loss of biodiversity. To sustain production, protection and conservation in these complex tropical mixed stands, this study proposes the application of a selection method – the BDq method (B: basal area, D: maximum diameter, q-ratio) to manage these stands. Two strata were used as a pilot test: stratum 1 consisted of 15 plots and stratum 2 of 7 plots, each with an area of 0.25 ha. Only trees with a diameter at breast height (d) ≥ 10.0 cm were considered in this study. Harvesting with the BDq method was quantified, by setting B at 20 m2, 25 m2 and 30 m2/ha corresponding respectively to intensive, medium and light harvesting regimes. D was set at 65 cm and the q-ratio was computed for each plot. The results showed that the three BDq regimes prescribed (intensive, medium and light) yielded reasonable felling intensities (FI), derived as the percentage of extracted volume (Vext) and biomass (Wext). The Vext and FI for stratum 1 ranged from 39.94-62.30 m3/ha and 11.22-18.18%; the results for stratum 2 were 30.44-51.33 m3/ha and 10.02-17.57%. For biomass, the Wext and FI ranged from 18.46-29.82 t/ha and 9.40-15.95% for stratum 1 and 14.16-24.82 t/ha and 9.73-17.50% for stratum 2. These findings show that applying the BDq method to the complex tropical mixed forests of Nigeria would yield attractive stands.

The lack of management practice/silvicultural treatments in the complex tropical mixed forests of Nigeria has led to uncontrolled exploitation of natural forest stands and loss of biodiversity. To sustain production, protection and conservation in the complex tropical mixed stands, this study proposed the application of a selection method – the BDq (B: basal area, D: maximum diameter, q-ratio) method for the management of the stands. Two strata were used as a pilot test: stratum 1 consisted of 15 plots and stratum 2 comprised of 7 plots with a plot area of 0.25 ha. Only trees with diameter at breast (d) ≥ 10.0 cm were considered in this study. Harvest in the BDq method was quantified, by setting B at 20, 25 and 30 m2 ha-1 corresponding to heavy, medium and light-harvesting regimes, respectively. D was set at 65 cm and q-factor was computed for each plot. The results showed that the three BDq regimes (heavy, medium and light) prescribed yielded reasonable felling intensities (FI) derived as the percentage of extracted volume (Vext) and biomass (Wext). The Vext and FI for stratum 1 ranged from 39.94 – 62.30 m3 ha-1 and 11.22 – 18.18 %; and stratum 2 had 30.44 – 51.33 m3 ha-1 and 10.02 – 17.57 %. In the case of biomass, the Wext and FI for stratum 1 ranged from 18.46 – 29.82 tons ha-1 and 9.40 – 15.95 %; stratum 2: 14.16 – 24.82 tons ha-1 and 9.73 – 17.50 %. The finding shows that the application of BDq method to the complex tropical mixed forests in Nigeria would yield an attractive stand.