Description and Composition of Tree Species in a Tertiary Institution Agricultural Faculty Arboretum, Ibadan, South-West Nigeria

Abstract

The Arboretum of the Agricultural Faculty of a tertiary institution in Ibadan is known for its rich diversity of trees. Therefore, the study investigates the tree growth variables in the arboretum such as diameter at breast height (dbh), diameter at the base, middle and top of the bole, total height, merchantable height and crown diameter. The basal area and volume were then calculated per species and per family. Several models were fitted for the height – diameter relationship and crown diameter – diameter relationship and crown diameter – dbh relationship. Positive linear relationships were observed among the growth variables. The fitted models showed that cubic models exhibit a more reliable function than quadratic and linear models for crown diameter – dbh predictions as it has R² above 0.75. Endangered species were observed too and this was indicated through the diversity index obtained. The highest basal area encounter belongs to myrtaceae family (9.61m²) while the lowest belongs to pinaceae family (0.24m²). The total basal area obtained at (31.72m²) from the faculty trees indicates that they are exhibiting better growth and yield.