POSTPRINT - Application of BDq method to Complex Tropical Mixed Forest Ecosystems in Nigeria

Abstract

The lack of management practice/silvicultural treatments in the complex tropical mixed forests of Nigeria has led to uncontrolled exploitation of natural forest stands and loss of biodiversity. To sustain production, protection and conservation in the complex tropical mixed stands, this study proposed the application of a selection method – the BDq (B: basal area, D: maximum diameter, q-ratio) method for the management of the stands. Two strata were used as a pilot test: stratum 1 consisted of 15 plots and stratum 2 comprised of 7 plots with a plot area of 0.25 ha. Only trees with diameter at breast (d) ≥ 10.0 cm were considered in this study. Harvest in the BDq method was quantified, by setting B at 20, 25 and 30 m2 ha-1 corresponding to heavy, medium and light-harvesting regimes, respectively. D was set at 65 cm and q-factor was computed for each plot. The results showed that the three BDq regimes (heavy, medium and light) prescribed yielded reasonable felling intensities (FI) derived as the percentage of extracted volume (Vext) and biomass (Wext). The Vext and FI for stratum 1 ranged from 39.94 – 62.30 m3 ha-1 and 11.22 – 18.18 %; and stratum 2 had 30.44 – 51.33 m3 ha-1 and 10.02 – 17.57 %. In the case of biomass, the Wext and FI for stratum 1 ranged from 18.46 – 29.82 tons ha-1 and 9.40 – 15.95 %; stratum 2: 14.16 – 24.82 tons ha-1 and 9.73 – 17.50 %. The finding shows that the application of BDq method to the complex tropical mixed forests in Nigeria would yield an attractive stand.