Structure, composition and diversity of restored forest ecosystems on mine-spoils in South-Western Ghana

Abstract

In response to national policy obligations, many mining companies in Ghana have restored/reclaimed degraded mined out sites through revegetation. The area extent of such restored areas is unknown and there is also paucity of data on success of restoration, species diversity and compositional dynamics of such restored landscapes, particularly using mixed species. This study assessed stand structure, diversity and composition dynamics of sites restored with mixed species and models species abundance distribution on these sites. Three reclaimed and one control site (adjacent natural forest) were inventoried using 27, 30 x 30 m plots on the Hwini-Butre and Benso concession of the Golden Star Wassa Limited. Overall 3057 (per 24 plots) and 150 (per 3 plots) individual trees were recorded in the overstorey of the reclaimed and control sites, respectively. In all, 31 species in 13 families occurred on the reclaimed site while 61 species in 29 families occurred on the control. Species richness, abundance and diversity were significantly lower in the reclaimed sites than the control in the overstorey (p≤0.018), mid-storey (p ≤ 0.032), and understorey (p≤ 0.031). Species composition of the reclaimed and control sites were mostly dissimilar in the overstorey, midstorey, and understorey. However, the midstorey and overstorey of the reclaimed sites showed high similarity in composition (Jaccard’s index = 0.817). Pioneer and shade-tolerant species were most dominant in the understorey of the control while only shade-tolerant species (mostly herbs and grasses) dominated the reclaimed sites. Species abundance distribution of both reclaimed and control sites followed the geometric series model, indicating that both sites are disturbed but at different intensities. It is concluded that reclamation with mixed species does not necessarily lead to rapid restoration of indigenous climax species on mine spoils. Nonetheless, it may lead to accomplishments of short-term goals of stabilizing and protecting landscapes while conditioning the sites for colonisation of the climax species.

Vegetation Structure and Carbon Storage of Natural and Restored Mixed Deciduous Forests in Western Thailand

“…The lower diversity in the RF area may be attributed to the effects of tin mining disturbance in the past. This result was consistent with previous studies that revealed that reclaimed sites from mining generally have lower species diversity than natural forests (Nero 2021). The Simpson index was slightly higher in the NF than in the RF, indicating a greater probability of encountering a particular species during sampling.…”

Effect of soil properties on plant growth and diversity at various ages of coal mine reclamation in Indonesia

“…Paraserianthes falcataria, E. cyclocarpum, and S. saman were the dominant fast-growing species planted in the study area and had a mean diameter growth of 11.3 to 18.7 cm (3-5 years old), 3 m (old stand), 6.6 cm (two-year-old), and mean height 11.7 to 20.5 m (3-5 years old), 20 to 30 m (old stand), 15-25 m (old stand), respectively (Barrientos-Ramírez et al 2015). Nero (2021) found that the height and DBH of tree species grown in the reclamation area were higher than the natural forests around the study area.…”

Ecological Restoration of Degraded Habitats of Jajang Iron and Manganese Ore Mines, Keonjhar, Odisha, India

“…The ability of herbaceous species, particularly grass species to withstand drought, poor soil nutrients and climatic conditions [37] may play a role in their colonization on mine spoils. Many researchers have emphasized the significance of grasses as the first colonizers during the restoration of mine land [38][39][40]; [29]. Grassroots with their fibrous root systems, are said to help limit erosion, stabilize soil and conserve moisture [37].…”