Successful Ecological Regeneration of Opencast Coal Mine Spoils through Forestation: From Cradle to Grove

Abstract

The reclamation of surface (opencast) coal mines is not always successful; there remains a legacy of degraded land that burdens local communities. This article evaluates a community-oriented, low-cost means of geoecological regeneration, the “Cradle for Nature” strategy, which uses mosaic tree planting to foster positive natural ecological processes. Results show that, while the autocompaction of minestones quickly raises soil densities to levels hostile to plant growth, forestation helps moderate soil densities. Weathering concentrates metals in minestones, but 14 years of forestation reduced the loadings of five metals by 35–52%. Twenty years of forestation doubled soil organic carbon to >7%; increased bacilli from 7% to 46%; actinomycetes from 10% to 26%; and soil microbe counts 12–15 times, especially in tree plantings treated with fertiliser. Soils under trees also supported a significantly greater earthworm biomass than under grass but, while open-canopy plantings had increased ground flora biodiversity, closed-canopy plantings had lower diversity and biomass. Following closure to grazing, ground biomass increased sevenfold. Young trees act as bird perches and significantly increase seed fall. Small mammal biomass and biodiversity increases after tree planting and higher predators appear. Varteg’s constructed forest provides an effective “cradle” for an emergent geoecological system and its habitat mosaic maximises biodiversity.

Quality of soil from the nickel mining area of Southeast Sulawesi, Indonesia, engineered using earthworms (Pheretima sp.)

“…They include, low in organic matter, available P, cation exchange capacity, exchangeable Ca, exchangeable K, hydraulic conductivity, soil biological activity, and fertility, however, constantly high plasticity (Safiuddin et al, 2011;Tufaila et al, 2011;Hatfield and Walthall, 2015;Alam et al, 2020). Nickel ore mining activities through a series of soil extraction and removal activities have an impact on landscape changes, loss of natural vegetation, and a deeper decline in soil quality and fertility (Vithanage et al, 2019;Haigh et al, 2020). Therefore, restoration of the soil quality and fertility could be carried out through the rearrangement of soil particles (micro aggregates) into more suitable aggregates (Liu et al, 2019).…”

Reclaiming Open Coal Spoils by Mixed Woodland: Varteg (Wales), 10 Year Results

“…By contrast, SMC-planted trees with no fertilizer had significantly better survival rates in Years 1, 2 and 5. SMC contains K, albeit in an easily leached, water-soluble, form, but its application is linked to increased N, P and K [62]. Hence, there is less need for additional fertilizer and, of course, the water-retaining planting trenches may help keep leached K close to the tree roots.…”

Managing and Reforesting Degraded Post-Mining Landscape in Indonesia: A Review

“…This pit lake is about 30 m deep and has a very acidic pH, around 3.75, which is certainly not suitable for long-term daily use [197]. This shows that more in-depth and serious attention is needed to study the characteristics of pit Planting multi-species at post-coal-mining lands accelerates the succession stage, increases plant biodiversity [129], and serves as a food source for various wild animals that support the diversity of the fauna [198]. The biodiversity of wildlife can be used as a bio-indicator to assess the success of post-coal-mining reclamation activities [199,200].…”

“…Planting multi-species at post-coal-mining lands accelerates the succession stage, increases plant biodiversity [129], and serves as a food source for various wild animals that support the diversity of the fauna [198]. The biodiversity of wildlife can be used as a bio-indicator to assess the success of post-coal-mining reclamation activities [199,200].…”