Taxonomic diversity of the existing trees in University of Ibadan, Botanical garden

Abstract

Tree species diversity in Nigerian natural forests are diminishing drastically as a result of indiscriminate activities. Ex-situ conservation areas such as Botanical garden could serve as an alternative for the conservation of economic tree species in Nigeria. This study assessed the taxonomic diversity of the existing trees in the garden with a view to provide information necessary to foster its conservation capacity. Data were collected through identification, enumeration, observation and measurement of diameter at breast height (dbh) of the tree life form within 12 randomly established plots of size 25m x 25 m in the garden. Tree species were grouped into their various genus and families using Floras. Result shows that 5572 trees are currently existing in the University of Ibadan Botanical garden with Enterolobium cyclocarpum (Jacq.) Griseb having the highest frequency. The existing tree species are taxonomically distributed into 51 families. The most abundant family was fabaceae having 61 stands while apocynaceae, euphorbiaceae, palmae and strelitziaceae were the least abundant with frequency of 1 each. Most of the trees (82.2%) were under 50cm dbh. In order to make the garden fully manifest its conservation capacity, management practices such as enrichment planting is recommended.