Natural plant revegetation on three reclaimed gold mined sites in South Western Ghana

Abstract

Mining companies in Ghana have been encouraged by law and policy to reclaim degraded mined sites using native tree species. The study assessed stand structure, compositional dynamics, conservation and economic value of restored species after 20 years of reclamation. Eighty seedlings each of Amphimas ptericarpoides and Macaranga barteri were planted on the first reclaimed site (stand I); 160 seedlings each of Macaranga barteri and Amphimas ptericarpoides on the second (stand II) and third (stand III) reclaimed sites respectively. Each reclaimed site (1000 m2) was inventoried and sampled using 400 quadrats (25 m × 25 m). In all, 123 ‘restored‘ species in 55 families (stand I), 103 species in 52 families (stand II) and 96 species in 49 families (stand III) were identified. Species composition of the reclaimed sites were moderately similar to the old-growth forest remnant. Pioneer species, zoophilous and zoochorous species were dominant in all the reclaimed sites. One hundred and twenty-four adult (DBH > 5 cm) tree species (stand I), 105 (stand II) and 128 (stand III) were obtained. The tree stand structure of the Amphimas reclaimed site had the highest basal area of 13.75 m2/ha and most of the adult tree species in all the reclaimed sites were in the lower diameter class (5 cm ≥ DBH < 20 cm). The Genetic Heat Index and Economic Index of trees-only were significantly (p < 0.05) higher in the Amphimas -Macaranga site. The mixed tree species of the Amphimas – Macaranga reclaimed site seem to perform better as almost all measured parameters were dominant on this site. The two tree species used have high potential for restoration of native species. Later studies will further establish the suitability of the two native tree species for reclamation in the study area.

Keywords

• Reclaimed site
• Native species
• Basal area
• Natural regeneration
• Conservation and economic value