Restoring Balance: Ecological Recovery Strategies for Mined Grasslands in China

By Dr. Noopur JainReviewed by Laura ThomsonMay 15 2025

In a recent article published in the journal Scientific Reports, researchers investigated the influence of surface coal mining on carbon storage within semi-arid steppe ecosystems. The authors aim to explain how mining activities have degraded carbon sequestration capacity and explore potential ecological restoration pathways aligned with the "double carbon" goals. The study also provides scientific evidence to guide environmental management and land use planning in mining areas, emphasizing the importance of integrating ecological considerations into mining practices to mitigate environmental impacts.

Background

Globally, climate change has emphasized the importance of terrestrial ecosystems as carbon sinks, with grasslands being a significant component.

China boasts extensive grassland areas, accounting for around 41.7% of its land, and they serve as major carbon reservoirs, storing approximately 10% of the world’s terrestrial carbon. These ecosystems play critical roles in biodiversity preservation, soil and water conservation, and climate regulation. However, anthropogenic activities, particularly surface coal mining, have severely compromised these ecosystems.

The process involves removing large land areas, destroying vegetation, disturbing soil structures, and leading to substantial carbon losses.

Several studies underscore that land use change due to mining contributes directly to decreasing carbon stocks, with grasslands bearing the highest impact because of their dense carbon content. In China, rapid coal development has intensified land disturbance and ecological degradation, while policy measures since 2011 have aimed to curb the extent of mining and promote ecological restoration. Yet, despite regulatory efforts, the cumulative effect of mining continues to diminish carbon storage, affecting regional ecological stability and climate resilience.

The Current Study

The study employs a combination of remote sensing, land use classification, and ecosystem modeling techniques. Specifically, Landsat satellite images from eight different years (2002, 2005, 2008, 2011, 2014, 2017, 2020, and 2023) form the core data source.

These images were processed using machine learning algorithms, particularly support vector machine classification, along with visual interpretation and field surveys, to generate precise land use maps over the study period. The land use data from previous studies further supports the accuracy of land classification efforts.

The core analytical framework involves the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, which enables estimating ecosystem services, most notably, carbon storage, based on land use data. The model divides carbon pools into four categories: aboveground biomass, underground biomass, soil organic carbon, and dead organic matter. The authors collated land use-specific carbon density values primarily from literature and supplemented these with field survey data to improve accuracy.

The analysis stratifies land use changes into 16 types: grasslands, forests, urban areas, and mining lands. Trends are studied to decipher the extent and spatial distribution of carbon loss or gain over 21 years. Statistical techniques, such as correlation analysis, are utilized to determine relationships between land use changes and variations in carbon storage. The researchers also assess the impact of specific land use transitions, especially the encroachment of mining areas on high-carbon-density land like grasslands, throughout different development stages of the mining activity.

Results and Discussion

The results reveal a clear declining trend in the overall carbon storage of the study area over the 21 years. The total reduction amounts to 187.15 kilotons, with an average annual decrease of approximately 8.91 kilotons. The loss predominantly stems from the expansion of mining land and associated land use changes, which replace high-carbon-density vegetation such as grasslands with barren and low-carbon-density surfaces.

Quantitative analysis shows that about 73% of the study area experienced insignificant change in carbon storage, indicating some resilience or stability in certain regions. However, approximately 23.63% of the land experienced a decline in carbon sequestration capacity, primarily related to the encroachment and disturbance caused by mining activities. Conversely, only about 3.37% of the area saw increased carbon storage, particularly in regions undergoing ecological restoration or land reclamation efforts.

Conclusion

The study concludes that surface coal mining has had a pronounced adverse effect on carbon storage within the semi-arid steppe ecosystem over the past two decades. The total decrease of 187.15 kilotons signifies a substantial weakening of the region’s natural carbon sink functions. The findings demonstrate a direct correlation between land use changes driven by mining and the reduction in ecosystem carbon stocks, particularly in grassland areas that dominate the landscape.

While policy measures since 2011 have mitigated the rate of land disturbance, the overall trend remains negative, underscoring the urgency for more effective ecological restoration strategies. The research advocates a concerted effort to incorporate ecological restoration, land-use planning, and technological solutions such as pumped storage projects to transform mining sites into ecological and carbon sequestration assets.