POPULATION STRUCTURE OF WOODY PLANTS IN BLOCK A FOREST OF INTERNATIONAL INSTITUTE OF TROPICAL AGRICULTURE (IITA) IBADAN, OYO STATE, NIGERIA

Nigerian Journal of Forestry, 49 (1) 72 - 82

Ariyo, O. C. (2009)

Abstract

The study was conducted in Block A forest of International Institute of Tropical Agriculture (IITA), Ibadan to investigate the population structure of woody plants species in the forest. Systematic random sampling method was employed to collect the vegetation data. A total number of 30 plots measuring 10m x 10m were sampled along three lines transect {D, E (0oN) and F (180oW)}of 500m long each. In each plot, all woody plants (trees and shrubs) with diameter at breast height (dbh) greater than or equal to 10cm (dbh ≥ 10cm) were identified, enumerated and diameter at breast height were measured and recorded. The data collected were analysed with descriptive statistics and Size Class Distribution (SCD) followed the visual graphical method. The results showed that 389 woody plants per 0.3 ha of forest were encountered. 47.06% of the woody plant species are rare, 30.88% species are commonly available and 22.06% are regarded available. 31 species are useful for medicine, timber, edible fruits, vegetables, chewing sticks, implements/ handcrafts, cleaning agents, poles and fuel wood. The population structure of woody plants community in the forest is in a partial stable state, it is in the secondary stage of regeneration. However, the regeneration and recruitment potential of woody plants in the forest could be hampered if the trend of anthropogenic activities is allowed to continue. Therefore, sustainability and conservation of forest should be given due attention to allow the forest to grow into full maturity stage particularly in Ibadan where most of the original forest cover have almost disappeared.