Early-stage reclamation of open-pit mines in arid and semiarid regions: A tri-tiered evaluation of soil bacterial communities, functional genes, and physicochemical properties

Landslides cause severe ecological, human, and economic losses globally, with Fuyuan County in Yunnan Province, China, being a typical case. Accurate landslide susceptibility mapping (LSM) is crucial for disaster prevention and mitigation. Traditional methods struggle to meet contemporary needs, so this study employs advanced integrated machine learning models (LightGBM and XGBoost) to assess landslide susceptibility in the county, comparing them with traditional models. The LightGBM model performed best, achieving an AUC of 0.89, accuracy of 84.10%, and F1-score of 83.17%. It also demonstrated excellent stability—characterized by low uncertainty, narrow confidence intervals, and consistent discriminative ability across multiple resamplings—with outstanding reliability. Frequency ratio analysis identified key factors facilitating landslides: weak mudstone lithology, proximity to rivers (<200 m), and high mining density (0.098–0.149). Dense vegetation and hard limestone, however, reduce landslide risks. SHAP analysis further revealed that mining density is the most significant influencing factor, with a synergistic effect with river proximity that jointly exacerbates landslide susceptibility. The generated susceptibility zoning map identifies most areas of Dahe Town, Yingshang Town, and Zhuyuan Town as very high susceptibility zones, which highly aligns with historical landslide records and field survey results. The study emphasizes the need to strictly restrict mining activities in very high susceptibility zones and riparian areas, while comprehensively implementing slope reinforcement, vegetation restoration, and mine reclamation measures. These findings provide a scientific theoretical framework for global landslide research.

Mining activities have caused widespread land degradation and contamination, affecting millions of hectares worldwide and posing persistent ecological risks. However, reclamation substrates are constrained by limited availability and compromised quality, which restricts their ability to fully support mine ecological restoration. Among various amendment materials, biomass-based amendments have been widely applied due to their broad availability, renewability, biodegradability, and low cost. In recent years, their role has expanded beyond simple nutrient supplementation to encompass multiple functions, including structural optimization, pollutant stabilization, and microbial regulation. This review highlights the valorisation of biomass-derived solid wastes as multifunctional amendments for mine ecological restoration. By converting agricultural and industrial wastes into green materials, these amendments improve substrate structure, stabilize heavy metals and organic pollutants, enhance nutrient cycling, and stimulate microbial activity. Potential risks, including nutrient leaching, secondary pollution, and greenhouse gas emissions, are critically assessed, with emphasis on their variability under different environmental conditions. By integrating functional benefits with ecological risks, this work underscores the critical role of biomass-based amendments as waste-to-resource strategies in advancing sustainable mine reclamation, contributing to circular economy goals, and supporting environmental engineering practices.

ABSTRACT Opencast mining causes severe damage to the regional ecological environment. Accurately assessing its Ecological Cumulative Effects (ECE) is crucial for identifying the extent of destruction and reducing costs associated with subsequent land reclamation and ecological restoration. In this study, we conducted a quantitative analysis of ECE in opencast mining regions across China from 2000 to 2022. First, based on Normalized Difference Vegetation Index (NDVI) time‐series data and the LandTrendr algorithm, we identified mining disturbance and reclamation situations and analyzed their spatiotemporal variation characteristics in opencast mining regions at the pixel scale. Subsequently, combining the identified results with the land use type data, we quantified ECE based on the Ecosystem Service Value (ESV) under both ideal and real conditions. Finally, we analyzed the spatiotemporal characteristics of ECE in China. The results showed that: (1) From 2000 to 2022, the total disturbance area in opencast mining regions reached 8803.80 km 2 . The total reclamation area amounted to 1741.55 km 2 , accounting for 19.78% of the total disturbance area. The annual reclamation area surpassed the disturbance area after 2019. At the provincial level, Inner Mongolia Autonomous Region showed the largest disturbance area (2646.06 km 2 ). (2) Liaoning province exhibited the most severe ECE loss (1,426,306.74 RMB/km 2 ), followed by Inner Mongolia Autonomous Region, Hebei, and Shanxi provinces. Among economic zones and climate types, the northeastern zone and Temperate Monsoon (TM) climate demonstrated the highest ECE loss (2,046,731.09RMB/km 2 and 3,790,849.86RMB/km 2 , respectively). (3) At the county scale, ECE exhibited positive spatial autocorrelation. High‐high cluster and low‐high cluster were predominantly distributed in Inner Mongolia Autonomous Region, Liaoning, Hebei, and Shanxi provinces, with low‐high cluster encircling high‐high cluster. Low‐low cluster was mainly located in western China. This study provides crucial insights for comprehensive understanding of the ecological environmental evolution in opencast mining regions, while offering scientific foundations for formulating future ecological protection and restoration strategies.

Innovative for farmland reclamation: Optimizing earthwork allocation and elevation in mining-induced subsidence.

Hydrothermal coordination dominated vegetation restoration in open-pit mine reclamation across multiple climatic zones in arid and semi-arid China.

Depth-dependent heterogeneity in topsoil stockpiles influences plant-microbe interactions and revegetation success in arid mine reclamation.

From mine reclamation to geo-heritage tourism: assessing stakeholder perceptions and sustainable practices at barr conglomerate, Pali, Rajasthan, India

Land use/land cover (LULC) change is a key driving factor influencing the dynamics of terrestrial ecosystem carbon storage. In high-groundwater-level coal resource-based cities (HGCRBCs), the interplay of urban expansion, mining disturbances, and land reclamation makes the carbon storage evolution process more complex. This study takes Jining, Zaozhuang, and Heze cities in Shandong Province as the research area and constructs a coupled analytical framework of “mining–reclamation–carbon storage” by integrating the Patch-generating Land Use Simulation (PLUS), Probability Integral Method (PIM), InVEST, and Grey Multi-Objective Programming (GMOP) models. It systematically evaluates the spatiotemporal characteristics of carbon storage changes from 2000 to 2020 and simulates the carbon storage responses under different development scenarios in 2030. The results show that: (1) From 2000 to 2020, the total carbon storage in the region decreased by 31.53 Tg, with cropland conversion to construction land and water bodies being the primary carbon loss pathways, contributing up to 89.86% of the total carbon loss. (2) Among the 16 major LULC transition paths identified, single-process drivers dominated carbon storage changes. Specifically, urban expansion and mining activities individually accounted for nearly 70% and 8.65% of the carbon loss, respectively. Although the reclamation path contributed to a recovery of 1.72 Tg of carbon storage, it could not fully offset the loss caused by mining. (3) Future scenario simulations indicate that the ecological conservation scenario yields the highest carbon storage, while the economic development scenario results in the lowest. Mining activities generally lead to approximately 3.5 Tg of carbon loss, while post-mining reclamation can restore about 72% of the loss.

Downstream water quality impacts persist despite mountaintop coal mine reclamation in the Canadian Rocky Mountains.

Tin mining has played a central role in Indonesia’s economy, particularly in the Bangka Belitung Islands, but it has also caused severe environmental and socio-economic impacts. This study aims to critically review the consequences of tin mining and evaluate reclamation initiatives through a narrative literature review of scientific publications, technical reports, and policy documents. The findings show that open-pit mining has led to deforestation, biodiversity loss, environmental degradation, and decreased soil fertility, while weak governance has fueled illegal mining and social conflicts. Rehabilitation strategies such as reforestation, agroforestry, aquaculture, and soil improvement have the potential to restore or reclaim degraded land and are proposed as a viable pathway to balance ecological improvement with socio-economic development. This study focuses on its interdisciplinary approach, integrating ecological, socio-economic, and institutional perspectives to propose a comprehensive, ecosystem-based framework for post-mining reclamation. By highlighting both challenges and opportunities, the study provides actionable insights for policymakers, mining companies, and local communities.

Towards sustainable mine closure and reclamation through strategic tailing disposal sites evaluation: A causality-based Dempster-Shafer framework

Innovation for mine reclamation: Improving the reclamation efficiency and cropland rate in mining subsidence areas

Response of soil quality to ecosystems after revegetation in a coal mine reclamation area

Getting it right: regulating mine rehabilitation and closure in Australia for the green energy transition and critical minerals boom

Conducting a study on the physical quality of soil on coal mine reclamation land is important for the purpose of carrying out the monitoring and evaluation function of the reclamation activity. The aim of reclamation is to restore, maintain, and improve the quality of soil impacted by mining activities. It is important to evaluate soil physical properties because improving them requires a sufficient amount of time. The results of evaluating soil physical characteristics are recorded as a soil physical quality index that can be used as input for further soil management actions.This research was conducted in PT. Sumber Bara Abadi, Kutai Kartanegara District and the soil analysis was carried out at the Faculty of Agriculture, Mulawarman University from August to November 2022. Surveys and soil sampling were conducted after direct observations and considering the reclamation map of PT. Sumber Bara Abadi. Sampling was done randomly by considering the reclamation year, pioneer plant vegetation, and land slope. The samples were then analyzed in the Soil Laboratory at the Faculty of Agriculture, Mulawarman University. The data analysis used the comparative method and Minimum Data Set relative weights.The analysis results show that the physical soil characteristics of the coal mine reclamation land at the research location are explained in each selected physical characteristic indicator: 1) soil texture varies between clay, clay loam, and sandy clay loam; 2) soil porosity has a poor and good status with the highest value at 54.65% (2020L1) and the lowest at 2018L1 (49.01%); 3) aggregate stability has a very stable and less stable status with the highest value at 291.25% (2018L1) and the lowest value at PitHL2 (43.90%); 4) soil permeability has a slightly slow and moderate status with a value of 1.50 cm.jam-1 (2020L1) and the smallest value at 2018L1 (0.15 cm.jam-1); 5) bulk density has a moderate and slightly poor status with soil density ranging from a value of 1.34 g.cm-3 (2018L1) to the lowest bulk density value at PitHL4 (1.09 g.cm-3); 6) surface rocks have a high status (15.5046.00%); 7) solum depth at the research location has a moderate to shallow status with a depth of 68.00 cm (PitHL1) and the lowest depth value at PitHL2 (31.67 cm). The physical quality of soil at the research location is expressed in the physical soil quality index (IKFT) with a moderate and slightly high category with a value of (2.705-3.588), followed by limiting factors of the physical soil quality index (IKFT), including surface rocks found in high numbers at each research location, high bulk density, low solum depth, and low aggregate stability.

By systematically optimizing particle size distribution and solid mass concentration, this study develops high-performance coal gangue-fly ash backfill slurry with enhanced rheological properties and stability. X-ray diffraction and performance analyses confirmed that the synergistic combination of crystalline aluminosilicates in coal gangue and amorphous aluminosilicate glass in fly ash significantly contributes to the formation of a cohesive C-(A)-S-H gel network under alkaline conditions, thereby improving the mechanical integrity and stability of the backfill matrix. Slurries with solid mass concentrations between 68% and 76% displayed typical Bingham plastic behavior, with increasing concentration significantly improving both plastic viscosity and yield stress, thus enhancing resistance to bleeding and segregation. Particle size analysis indicated that a distribution modulus of ik = 0.91 effectively minimized bleeding while maintaining high flowability, improving slurry homogeneity and pumpability. An optimal formulation was identified at a 72% solid mass concentration with optimized particle size distribution, providing a balance between workability and stability. These results confirm the potential of coal gangue-fly ash systems as sustainable and cost-effective backfill materials and offer practical guidance for mix design in large-scale underground mining applications. Furthermore, this approach promotes the green reuse of bulk industrial by-products, advancing the sustainable development of solid waste while supporting safe and environmentally responsible mine reclamation.

Plants can absorb metals, including gold, making them potential as phytomining agents. This study investigated the ability of Brassica juncea and Amaranthus spinosus inoculated with Dark Septate Endophyte (DSE) fungi and treated with ammonium thiocyanate to accumulate gold (Au) from gold mine tailings. The plants were inoculated with DSE fungi (S14 and S51), referred to as D1 and D2, respectively, and a control group without inoculation (D0). They were grown in four media: Soil (T0), Tailing (T1), Tailing + ammonium thiocyanate 0.62 g/kg (T2), and Tailing + ammonium thiocyanate 1.24 g/kg (T3). Results indicated successful DSE colonisation across treatments, improving root and shoot dry weight, plant height, chlorophyll and carotene contents, and gold uptake. Thiocyanate enhanced gold absorption but caused plant death at high concentrations. A. spinosus transported more gold to shoots, while B. juncea accumulated more gold in roots. The highest phytomining potential was observed in B. juncea inoculated with DSE S14 (D1) in T2 media. These findings highlight the potential of combining plant species, DSE fungi, and chelating agents to optimise phytomining in gold-contaminated sites. DSE fungi not only enhanced gold uptake but also mitigated stress caused by tailings, offering an eco-friendly strategy for metal recovery. Future research should explore scalability and long-term impacts to strengthen phytomining as a sustainable alternative in gold mining reclamation efforts.

Mining in Indonesia is a vital sector that contributes significantly to the economy. However, current regulations still reveals a number of weaknesses that impact environmental sustainability and community welfare. These include weak law enforcement, lack of transparency and public participation at all stages of mining activities, inadequate mechanisms to ensure corporate social responsibility and environmental and post-mining reclamation, provisions that are not responsive to changing social and environmental conditions, further exacerbating the situation. This research uses a normative legal research method with an analytical approach to the provisions of laws and regulations based on facts obtained from secondary sources by paying attention to the credibility of these secondary sources. The main findings of the research reveal that environmental problems arise due to misalignment between mining laws and environmental laws. Environmental laws are not positioned as a command to mitigate the environmental impact of mining, and issues are further compounded by overlapping regulations on mining reclamation. The welfare of the community remains an unfulfilled promise, as environmental economic rights are increasingly eroded by the provisions in Article 162 of Law No. 3 of 2020. The rampant illegal mining activities further harm state finances, exacerbated by the absence of sophisticated infrastructure to monitor mining areas and potential sites in real time using satellite imagery. Additionally, inadequate distribution of corporate social responsibility (CSR) funds has left mining and affected areas without proper support, highlighting the urgent need for CSR regulations in the future be regulated at the legislative level. Furthermore, regulatory efforts to adopt green technology remain insufficient, with a lack of fiscal incentives and investment protection for companies committed to sustainable practices. The situation is further worsened by the lack of transparency in the mining sector, further exacerbates the situation as there is still no clear mechanism to ensure accountability or provide the public with access to crucial mining operation data. Based on the complex mining problems from multi-sectors, the regulatory reform framework must involve authorized government institutions and involve public participation in regulatory reform and the outcomes of the rules formed can accommodate the protection of public participation and protection of public rights in mining, respond to effective law enforcement and provide great contribution to the state, society, and global collaboration.

The soil seed bank (SSB) is a potential resource for the aboveground vegetation community (AVC) and plays a crucial role in ecological restoration. Studying the succession of the SSB and AVC at different restoration stages provides valuable insights into their temporal dynamics, facilitates comprehensive investigations of the different restoration stages, and enables appropriate recommendations for the subsequent restoration to be provided. Therefore, the SSB and AVC of restored grassland ecosystems were investigated in open-pit coal mine dumping sites in a typical grassland area of Inner Mongolia. This study was therefore conducted in a typical grassland with the same restoration practices (mixed seeding of Gramineae and Leguminosae), and comparisons were made at different periods post-restoration to determine the pattern of changes in the SSB and AVC over time post-restoration. Through non-metric multidimensional scaling (NMDS), a correlation analysis, and structural equation model, the changes in the SSB and AVC in the years following restoration were determined. It was found that the SSB density was 475.00 - 705.00 (plant m- 2), and the AVC density was 94 - 192.8 (plant m- 2). Notably, a significant shift occurred 17 years post-restoration, indicating a pivotal stage was reached in the overall trajectory of the SSB and AVC. The vegetation in the restored area was found to be transitioning toward natural grassland, with an increase in the proportion of perennial species and a gradual decrease in annual and biannual species. The density of Gramineae and Leguminosae plants was similar to that of natural grasslands 17 years post-restoration. The presence of the invasive species Salsola collina gradually decreased over time. The relationship between soil physicochemical properties and SSB was relatively weak, while the relationship with AVC was relatively strong. With time post-restoration, the resemblance between the SSB and the plant community slowly diminished at the mining dump. The study provides for the prolonged rehabilitation of open-pit coal mine dumping sites.