Effects of Ground Subsidence on Vegetation Chlorophyll Content in Semi-Arid Mining Area: From Leaf Scale to Canopy Scale

Abstract

Ground subsidence is the main cause of vegetation degradation in mining areas. It is of great significance to study the effects of ground subsidence on vegetation. At present, few studies have analyzed the effects of ground subsidence on vegetation from different scales. However, the conclusions on different scales may differ. In this experiment, chlorophyll content was used as an indicator of vegetation degradation. We conducted a long-term field survey in the Lijiahao coalfield in China. Based on field survey data and remote sensing images, we analyzed the effects of ground subsidence on chlorophyll content from two scales (leaf scale and canopy scale) and summarized the similarities and differences. We found that, regardless of leaf scale or canopy scale, the effects of subsidence on chlorophyll content have the following three characteristics: (1) mining had the least effect on chlorophyll content in the neutral area, followed by the compression area, and the greatest effect on chlorophyll content in the extension area; (2) subsidence had a slight effect on chlorophyll content of Caragana korshins, but a serious effect on chlorophyll content of Stipa baicalensis; (3) chlorophyll content was not immediately affected when the ground sank. It was the cumulative subsidence that affects chlorophyll content. The difference between leaf scale and canopy scale was that the chlorophyll content at canopy scale is more affected by mining. This means that when assessing vegetation degradation, the results obtained by remote sensing were more severe than those measured in the field. We believe that this is because the canopy chlorophyll content obtained by remote sensing is also affected by the plant canopy structure. We recommend that mining and ecological restoration should be carried out concurrently, and that ground fissures should be taken as the focus of ecological restoration. In addition, Caragana korshins ought to be widely planted. Most importantly, managers should assess the effects of ground subsidence on vegetation on different scales. However, managers need to be aware of differences at different scales.

Dynamic Monitoring of Winter Wheat Health in Mining Subsidence Areas by Combined Active and Passive Remote Sensing Technology

“…Cracks caused by mining subsidence accelerate the evaporation of soil moisture and nutrient loss. Cracks caused by mining subsidence accelerate the evaporation of soil moisture and nutrient loss, lead to deterioration of the soil environment in which root-injured plants grow [22]. Soil erosion can lead to a decrease in soil fertility [23], which in turn affects crop growth and development, and ultimately affects grain yield [24].…”

A Comprehensive Evaluation and Analysis of Ground Surface Damage Due to Mining under Villages Based on GIS

“…In particular, the proportion of coal deposits under villages is prominent [6][7][8]. The surface displacement triggered by underground coal mining will not only damage village buildings [9], environments [10], croplands, etc. (as shown in Figure 1), but will also incur enormous compensation against coal enterprises.…”

“…Sci. 2023, 13, x FOR PEER REVIEW 2 of 22 triggered by underground coal mining will not only damage village buildings [9], environments [10], croplands, etc. (as shown in Figure 1), but will also incur enormous compensation against coal enterprises.…”