Lumber recovery from selected plantation-grown hardwood species in Onigambari forest reserve, Southwest Nigeria

Abstract

Lumber yield and wastes from plantation grown species were examined for Gmelina arborea, Cederala odorata and Triplochiton scleroxylon. A total of 90 logs (30 per species) harvested from a 38 years old plantation on contiguous sites were randomly selected and sawn around into test lumber dimensions of 2.5cm x 30cm x 4m (1"' x 1T x1T), 5cm x 15cm x 4m (T x 6- x1T), 5cm x 10cm x 4m (T x 4" x1T), 5cm x 7.5cm x 4m (T x 3" x1T) and 5cm x 5cm x 4m (T x T x1T). The exercise was performed as much as practicable to minimize wastes. Gross volume and yield of the tree species vary significantly. The wood conversion process resulted in 56.93%, 59.78% and 60.86% lumber recovery for Gmelina arb ore a, Triplochiton scleroxylon and Cederala odorata respectively. Statistically, the gross lumber recovery (GLR) of Triplochiton scleroxylon was not significantly different from that of Gmelina arborea at P s 005. However, GLR for Cederala odorata differs significantly from that of Gmelina arborea at the same probability level.