Aderounmu A.F , Q.A Onilude , A.T Oladele (2017). Diversity and Growth Characteristics of Tree Species in the Botanical Gardens, University of Ibadan, Nigeria. Journal of Forests, 4(2): 27-34. DOI: 10.18488/journal.101.2017.42.27.34
This study assessed the diversity and growth characteristics of tree species in University of Ibadan Botanical Gardens with a view to provide data for improved management of the garden. Ten plots (25m x 25m) were sampled randomly in the garden. Growth parameters evaluated included: total and merchantable height, diameter at breast height, diameters at middle, base and top. Descriptive statistics of the growth characteristics of the tree species revealed a mean volume of 20.03+ 2.91m3/ha and 0.45+0.79m2/ha for basal area. Afzelia africana had the highest tree volume (72.42m3) followed by Vitex doniana (50.10m3) while the least volume was observed in Terminalia cattapa (5.57m3). Cedrela odorata (15.3%) had highest frequency of individual trees followed by Delonix regia (4.2%) while 12 species had single tree each (1.4%). Low Slenderness coefficient (SLC) of < 70 showed that most tree species in the garden are not susceptible to wind induced damage. Only Enterolobium cyclocarpum possessed moderate SLC which could be vulnerable to wind velocity despite some form of resistance. Further research centered on tree form and growth parameters need be encouraged for improved management of the botanical garden.
This study documents the unique characteristics of tropical trees that are important in sustainable management of Botanical gardens for: tree diversity conservation, ecological restoration and maintenance in developing tropical countries.
Variation of Wood Density in Tropical Rainforest Trees
Adrien N. Djomo , Guylene Ngoukwa , Louis Zapfack , Cedric D. Chimi (2017). Variation of Wood Density in Tropical Rainforest Trees. Journal of Forests, 4(2): 16-26. DOI: 10.18488/journal.101.2017.42.16.26
Measurement of wood density in Congo Basin forests are needed to reduce uncertainties on estimations of carbon stocks. The purpose of this study was to test vertical variation and temperature variation (80 °C, 105 °C) effects on wood density of species in a semi-deciduous forest of eastern Cameroon. Wood samples were collected on felled trees, at the base, middle of the trunk and on the branches in plots of 10 m x 10 m for trees <5 cm diameter, of 20 m x 10 m for trees with diameter between 5 and 10 cm and, of 20 m x 250 m for trees with diameter ? 10 cm. 162 trees with diameter between 1 cm and 146 cm were used. The highest wood density (0.912) was found in Ficus sp. and lowest (0.295) in Enantia chlorantha. Using 80 °C as temperature to estimate wood density increased the value of about 10% when compare to the reference temperature of 105 °C. A significant difference was observed between wood density of the base and the top of trees studied. 10 species did not have wood density reported in the Global Wood Density database. This study recommends further research on wood density to cover as many tree species as possible in the Congo Basin.