Progresses in restoration of post-mining landscape in Africa

Abstract

Mining alters the natural landscape and discharges large volumes of wastes that pose serious pollution hazards to the environment, to human health and to agriculture. As a result, the recent 2 decades have witnessed a global surge in research on post-mining landscape restoration, yielding a suite of techniques including physical, chemical, biological (also known as phytoremediation) and combinations. Despite the long history of mining in Africa, no systematic review has summarized advances in restoration research and practices after mining disturbance. Thus, the aim of this review was to document the state-of-knowledge and identify gaps in restoration of postmining landscape in Africa through literature review. We found that: (1) there has been substantial progress in identifying species suitable for phytoremediation; (2) few studies evaluated the feasibility of organic amendments to promote autochthonous colonization of mine wastelands or growth of planted species; and (3) restoration of limestone quarries in Kenya, sand mining tailings in South Africa, and gold mine wasteland in Ghana are successful cases of large-scale post-mining restoration practices in Africa. However, the pace of post-mining landscape restoration research and practice in Africa is sluggish compared to other parts of the global south. We recommend: (1) mainstreaming the restoration of mine wastelands in national research strategies and increased development planning to make the mining sector ''Green''; (2) inventory of the number, area, and current status of abandoned mine lands; (3) expanding the pool of candidate species for phytostabilization; (4) further evaluating the phytostabilization potential of organic amendments, e.g., biochar; (5) assessing the impacts of mining on regional biodiversity.

Trace Elements in Leaf Extracts of Eucalyptus grandis Traditionally Used to Treat Common Cold and Flu

“…Our results are consistent with previous findings that gold mine tailings are usually acidic, have low OM and are laden with PTEs 17,18. Low pH and OM generally favor the release of PTEs by soil, such as tailings, and eventual uptake by plants 19.…”

Post Bauxite Mining Land Soil Characteristics and Its Effects on the Growth of Falcataria moluccana (Miq.) Barneby & J. W. Grimes and Albizia saman (Jacq.) Merr.

“…A. saman adapts to a wide range of soil types and pH levels, has a massive root system that expands both horizontally and vertically [27], can grow in soils that are free draining or those that have impeded drainage, can sometimes tolerate growth under waterlogged conditions, and finally, can grow in slightly acidic to neutral pH (6.0-7.4) soils while tolerating pH values as high as 8.5 and as low as 4.7. ese characteristics of A. saman indicate that it would be ideal to use for the reforestation of post bauxite mining land. Many studies of postmining land in Africa have proven that pioneer leguminous trees show good adaptations and higher survival rates [28]. After F. moluccana and A. saman are established and grow well in post bauxite mining lands, there will be enrichment plantation using local species, including lots of local fast-growing trees species such as Jacaranda obtusifolia, Macaranga bancana, Macaranga conifera, and Macaranga gigantean.…”

Evaluating the Effect of the Ecological Restoration of Quarry Slopes in Caidian District, Wuhan City

“…Evaluation results of ecological restoration of quarry slopes. The commonly used ecological restoration technologies for quarry slopes have not only improved the local ecological environment, but also formed a good landscape effect [28][29][30]. The frequency of disasters such as soil erosion and landslides has been significantly reduced in the ecologically restored areas [31].…”