Next Article in Journal
Few-Shot Learning Approaches for Fault Diagnosis Using Vibration Data: A Comprehensive Review
Previous Article in Journal
Remote Sensing Classification of Temperate Grassland in Eurasia Based on Normalized Difference Vegetation Index (NDVI) Time-Series Data
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Sustainability
Volume 15
Issue 20
10.3390/su152014974
sustainability-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Restoration Effects of Supplementary Planting Measures on the Abandoned Mining Areas in the Altay Mountain, Northwest China

by
Qiao Xu
1,
Hailiang Xu
1,
Yan Wei
2 and
Aishajiang Aili
1,*
1
State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
2
College of Grassland Sciences, Xinjiang Agricultural University, Urumqi 830052, China
*
Author to whom correspondence should be addressed.
Sustainability 2023, 15(20), 14974; https://0-doi-org.brum.beds.ac.uk/10.3390/su152014974
Submission received: 8 September 2023 / Revised: 12 October 2023 / Accepted: 16 October 2023 / Published: 17 October 2023
(This article belongs to the Section Sustainability, Biodiversity and Conservation)
Browse Figures
Review Reports Versions Notes

Abstract

:
Ecological restoration of abandoned mining areas in the Altay Mountain, northwest China, has always been considered a challenging issue due to the wide restoration area and serious devastation. To examine the restoration effects of the experimental measures carried out by our research team in an abandoned mining area in the Altay Mountain since 2010, short-term (2 years) and long-term (9 years) restoration efficiency of two types of supplementary planting measures, sowing commercial seeds (M1) and sowing soil seed banks (M2), were analyzed by calculating the vegetation growth indexes, soil–rock ratio, soil bulk density, and soil moisture content. Results show that both supplementary planting methods can significantly improve the growth status of surface vegetation, which is reflected by the variation of vegetation growth indices. The short-term restoration effect of M1 on vegetation is faster but, over time, the effect of M2 was more prominent. Restoration effects of the M2 on the soil condition were more significant at 30–40 cm of the soil layer, reflected in the higher soil–rock ratio, which is 7.2%. The water storage function of soil has significantly improved under both supplementary planting methods; the remediation effect of method M1 on the soil bulk density is mainly reflected in the surface layer, while the effect of method M2 on the soil bulk density is reflected in deeper (40–50 cm) layer. The results of this study would be helpful to explore the new practices for the restoration of mining areas.

1. Introduction

Ecological restoration of mining areas is a complex technical system formed on the theoretical basis of land degradation and vegetation restoration [1,2,3]. As an essential part of the governance of the ecological environment, great attention has been paid to mining area restoration and extensive research work has been conducted in this field in many countries [4,5,6,7]. The environmental management and restoration work in mining areas in China began in the 1950s. Since 1980, mining area restoration plans have been implemented in ecologically damaged areas at the country level [8,9,10]. However, most of the mining areas faced common problems with lower reclamation rates and incompleteness of restoration [11,12]. The restoration efficiency is still not ideal, and the instability of the ecosystem in mining areas has still not been improved.
The Altay Mountain, in northwest China, is rich in forest resources and mineral deposits and is an important mineral base of Xinjiang [13]. The Two-River (Ertish River and Ulungur River) Source Nature Reserve (TSNR) in the Altai Mountains has already become a severely damaged area due to the blind exploitation of mineral resources over the past few decades. During the mining activities in this area, the surface vegetation and soils along the riverbed were removed, and under the mechanical disturbance, the organic matter in the soil was rapidly decreased [14]. At the same time, a large amount of waste rock and tailings waste was generated during the mining process. According to previous research, 97–99% of raw materials of metallic or non-metallic minerals are waste tailings, and 5 to 7 million tons of tailings are produced every year in the world [15,16].
Various restoration measures, plans, and methods were applied depending on monitoring objects, indicators, and the severity degree of ecological disturbance in mining areas. Liu et al. examined the spatial distribution of degraded vegetation in 12 underground mining areas in Western China by using the overlay analysis function of ArcGIS software on the basis of DEM, slope, aspect, and soil type data, and indicated that not only is attaching great importance to the appropriate threshold of vegetation coverage during the vegetation restoration process in a semiarid mining area, but also considering the impact of the proportion of trees, shrubs, and herbs on the vegetation restoration [17]. Hu et al., based on green infrastructure, proposed an integrated method for determining the restoration priorities of coal mining subsidence areas [18]. Hou et al. proposed an integrated spatial estimation based on surface subsidence prediction, geographic information system, and field survey in the Loess Plateau of northern China, and found that the magnitude of ecological and environmental damage depended on a combination of risk factors, other than a single factor or evaluation target [19]. Menegaki et al. presented a new method for the quantitative evaluation of the impacts on the landscape [20].
At present, the research on plant remediation in mining areas is mainly focused on indoor research, mostly the simulated soil and field soil used to study plant growth status, and relatively single environmental conditions that were examined by short-term experiments [21]. Even though there are a small number of outdoor field studies, they are mostly conducted using the spatiotemporal substitution method [22,23]. Many of the previous experiments on the restoration of abandoned mining areas faced common problems in the selection and configuration of suitable indigenous plants. In the abandoned mining area of Altay Mountain, with a poor-quality soil layer, perennial herbs should be the first reseeding object [24]. It is very important to solve the problem of soil seed shortage through soil seed bank collection and manual sowing measures. Due to the immaturity of local seed sowing technology and the limited number of grass seeds in the market, the practice of mining area restoration in Xinjiang is generally carried out by sowing insufficient commercial seeds from the market on the leveled mining area. The practical effect is not ideal [25]. However, with the increasing emphasis on ecological civilization construction by the country, more and more abandoned mines need to be treated. Since 2010, our team has carried out ecological restoration work in the abandoned gold mining area in the Altay Mountain. At the beginning of our restoration work, there was almost no surface soil and vegetation. Under these conditions, we began the restoration experiment by supplementing soil, and then carried out supplementary planting measures by using both sowing commercial seed and sowing soil with a seed bank. The soil seed bank refers to the living seeds that exist in the surface soil (including litter), and some seeds still remain dormant in the soil seed bank. The dormant seeds constitute the components of the long-term soil seed bank. In the supplementary planting experiment, we first consider using local grass seeds that rely on natural restoration to achieve ecological restoration of the damaged mining areas with low investment. To achieve this goal, we have determined supplementing soil and planting methods based on local conditions; firstly, supplementing the soil with the minimum amount of soil or finding a substitute that is closest to the soil. In cases where overall soil coverage is difficult to achieve, our experiment for the enrichment of soil was carried out locally in the middle of the coarse sand and gravel. As for replanting measures, it is not feasible to restore the entire research area by using commercial seeds; hence, we first collect local grass seeds and breed them in locally soiled areas. Due to the inability to find the seeds of the original plants, we purchased seeds that were closer to the original vegetation for replanting. The experimental measures of sowing commercial seed and sowing soil with a seed bank will be introduced in more detail in Section 2.2 and Section 2.3. How to achieve natural restoration of vegetation in mining areas through appropriate measures has become a hot and difficult issue of ecological restoration in arid areas. In this study, a comparative test was carried out between two restoration measures: sowing commercial seeds (M1) and sowing soil seed banks (M2) in the abandoned mine area of the two river source regions in the Altay Mountains, trying to find a new idea for the supplementary planting of vegetation in the mining area. The purpose of this study is not only to enrich the theoretical research of soil seed banks, but also to explore new practices for the restoration of mining areas.

2. Material and Methods

2.1. Overview of Study Area

The study area was an abandoned gold mining area (geographical coordinates 87°30′~91°00′ E, 46°30′~48°10′ N) in the Two-river Source Nature Reserve (TSNT) in the Altai Mountains, Xinjiang (Figure 1). Having an average temperature of −2 °C, this area has a cold continental climate of the temperate zone; annual precipitation ranges between 300 mm and 350 mm, while the annual evaporation rate ranges between 838.3 mm to 1469.6 mm. The area mainly develops gray forest soil, distributed at an altitude of 700–2500 m, with rich plant species and high surface vegetation coverage [26]. After nearly a hundred years of continuous mining, a large amount of land resources has been occupied, forming huge mining pits, disturbing the surface, and the terrain is increasingly undulating. Large-scale gold mining activities have also led to the almost complete loss of fine particulate matter in the surface soil, and vegetation has also disappeared [27]. At the same time, the local government has taken a series of measures to gradually stop mining gold and carry out ecological restoration of the mining area.

2.2. Experimental Design

2.2.1. Selection of Experimental Area

The experimental area is located at 47°54′4″ N, 89°18′40″ E, covering an area of 20 acres (Figure 2). Restoration experiments have been conducted by our research team since 2010. Firstly, large pieces of gravel were mechanically removed, and then small pieces of gravel were bulldozed to reduce external interference. The experimental area was fenced. Due to the complete destruction of the soil in this area, at that time, plants and seeds no longer existed in the soil. Two supplementary planting methods, sowing commercial seeds (M1) and sowing soil seed banks (M2), were used as restoration experiments. A total of 16 sample plots with the size of 6 m × 6 m were selected from the flat area of the abandoned mining area. A buffer zone with a length of 1 m remained between each plot, and plots were surrounded by partitions to block external interference. Each sample plot was further divided into four sub-sample areas, and different restoration measures were taken for different sub-sample areas: Area A is the contrast area, only leveling measures were taken and no replanting measures were used for this area. Area B is the reserved experimental area. Area C is the experimental area for the M1, and area D is the experimental area for the M2 (Figure 2). In each sub-area, the surface biomass and soil properties were measured regularly.

2.2.2. Sowing Commercial Seeds (M1)

Before conducting governance and restoration work on abandoned mines, the types of plants, distribution, and interrelationships with surrounding species were investigated. Species types are presented in Table 1. Due to the fact that the vegetation in Table 1 is almost impossible to purchase in the market, we were unable to plant local vegetation on the grassland. Therefore, we only purchased tall fescue (Festuca elata) and early bluegrass (Poaannua) for 1:1 mixed planting. First, we spread 2.5 kg of seeds per acre of land, and at the same time, spread around 7 kg of surface soil, with remaining dead branches and leaves collected from the upper part (0–20 cm) of the surface soil per acre of land. The sowing time was selected after the first snow and before the second snow in October 2012, with the aim of promoting plant recovery during the snowmelt period. In this study, the importance value of vegetation was considered to evaluate the vegetation growth status. The importance value is a comprehensive quantitative indicator used to study the status and role of a species in a community. It comprehensively considers relative density, relative frequency, and relative dominance. The calculation method for important values is as follows:
Importance value = (Relative density + relative frequency + relative coverage)/3

2.3. Investigation of Vegetation and Soil and Data Processing

(1)
Investigation of the vegetation
Considering the meteorological condition and vegetation growth cycle of the Altay Mountain, vegetation surveys were carried out in June with the peak plant growth season in 2014 and 2021. The investigation of plant communities mainly included: plant species, quantity, height, crown width, coverage, surface biomass, etc. First, each of the sampling quadrats was photographed vertically, and the photos were imported into the image software to obtain vegetation coverage [28]. Then, all plants were cut close to the ground and dried at 60 °C to constant weight in the laboratory, and the aboveground dry biomass of the sampling quadrat was recorded.
(2)
Investigation of the soil
After nine years of supplementary planting, that is, 2021, the soil bulk density, soil–rock ratio, and soil moisture content were measured under different supplementary planting measures. Each sample was divided into five layers for soil sampling: 0–10 cm, 10–20 cm, 20–30 cm, 30–40 cm and 40–50 cm. The soil bulk density was measured using the ring knife method, and the soil moisture content was measured using the constant temperature method. Considering the slope and ground roughness of the restoration area, the soil–rock ratio was obtained based on the “Code for Investigation of Geotechnical Engineering of China” (GB50021-2001, 2009 version) [29] by using the following methods: after obtaining the aboveground biomass of each sample plot, a small sample plot with the size of 20 cm × 20 cm was selected for soil sampling, and the soil sample was collected from five layers. All of the soil and stones in the sample area were dug out, soil samples were crushed by using a wooden stick, and plant roots and other debris were removed. Considering the higher requirements of vegetation to the soil particle size under the condition of shortage of irrigation water in the restoration area, a smaller sized sieve, with the size of 1 mm, was used to analyze the soil–rock ratio. The soil sample was sieved, and the soil sample that can pass the 1 mm sieve was recorded as soil Ms, while the soil sample that cannot pass the 1 mm sieve was recorded as rock Mr. Weighing the two soil samples on a 1/1000 electronic balance, we recorded the Ms and Mr values, and the soil–rock ratio W (%) was calculated by using the following formula
Soil – rock   ratio   ( % ) = ∑ i = 1 n M s / ∑ i = 1 n M r × 100 %
(3)
Statistical Analysis
The vegetation coverage, vegetation height, plant density, and aboveground biomass data are the average values of 16 sample plots measured under the same measures. The plant richness index, diversity index, dominance index, and evenness index were calculated using relevant formulas [30], and each of the index values is the average of all repeated samples.
Patrick richness index:
A = N/ln(S)
where N is the number of species, S is the quadrat area.
Simpson dominance index:
D = 1 − ∑ i = 1 S P i 2 ( i = 1 , 2 , 3 , 4 , … , S )
Shannon–Wiener diversity index:
H = − ∑ i = 1 S   ( P i ln P i )
Pielou evenness index:
J = H/lnS
where D is the dominance index, s is the number of the species in the quadrat, i is the ith vegetation, Pi is the proportion of the number of individuals of species i to the number of individuals of all species, H is the diversity index, and J is the evenness index.
The soil–rock ratio, soil bulk density, and soil moisture content data are the average values of the same soil layer and all repeated samples. Based on our 20+ years of practical experience in ecological restoration in mining areas, soil content is the most important factor that affects vegetation growth. Soil bulk density, soil–rock ratio, and soil water content have a significant promoting effect on plant growth. Under this promoting effect, the artificial replanted grassland in the damaged gravel land can be gradually recovered. Especially in severely damaged abandoned mining areas, the effects of other indicators, including soil salt content, organic matter, pH microorganisms, etc., on the vegetation growth, are negligible. Therefore, in this study, the main indicators that can significantly promote vegetation growth were considered to evaluate the ecological restoration efficiency.

3. Results

3.1. Vegetation Growth under Different Supplementary Planting Methods

After two years of planting, we observed that the surface vegetation coverage, vegetation height, vegetation density, and aboveground biomass under the methods M1 and M2 were significantly higher than those under the contrast area (p < 0.01), indicating that both replanting methods can promote significant improvement in the growth status of surface vegetation. The plant growth indexes after two years of supplementary planting are presented in the Figure 3.
After nine years of supplementary planting, the vegetation coverage under the M1, M2, and the contrast area were 13.56 ± 4.73%, 56.50 ± 14.18%, and 9.10 ± 3.6%, respectively. The vegetation heights were 11.00 ± 2.85 cm, 26.77 ± 7.88 cm, and 9.00 ± 3.76 cm, respectively (Figure 3). The surface vegetation coverage under method M2 was 4.17 and 6.21 times higher than that of method M1 and the contrast area, and the vegetation height was 2.43 and 2.97 times higher than that of method M2 and the contrast area. The vegetation density of these three experimental sites was 41.53 ± 8.16 species/m2, 94.31 ± 11.20 species/m2, 36.22 ± 6.90 species/m2, and the aboveground biomass was 12.19 ± 4.85 g/m2, 53.40 ± 9.47 g/m2 and 10.18 ± 3.54 g/m2, respectively (Figure 4).
The vegetation density under method M2 is 2.27 times and 2.60 times higher than that of method M1 and contrast area, respectively. The results of one-way ANOVA showed that the vegetation coverage, vegetation height, plant density, and aboveground biomass under the method M2 were significantly higher than those of the M1 and contrast area (p < 0.01), indicating that the method of soil seed banks is more suitable for mining area restoration.

3.2. Variations of Community Structure under Different Supplementary Planting Methods

After two years of supplementary planting, the species richness under the method M1, M2 and the contrast area were 1.15, 1.11, and 0.21; the Shannon–Wiener index was 0.72, 0.67, and 0.20; the Simpson index was 0.97, 0.31, and 0.11, while the Pielow index were 0.00, 0.30, and 0.12, respectively (Figure 5). The results of one-way ANOVA showed that, except for the Pielow index value, the species richness, Shannon–Wiener index, and Simpson index under the methods M1 and M2 were significantly higher than those of the contrast area. This result indicates that after two years of supplementary planting, both methods have a significant promoting effect on the restoration of plant community structure in abandoned mining areas. At the same time, the plant diversity index under method M1 was higher than the method M2 (Figure 5A), indicating that, in the short term, the effect of supplementing commercial seeds (M1) is faster.
But after nine years of supplementary planting, the species richness under the method M1, M2 and the contrast area were 0.81, 1.09, and 0.84; the Shannon–Wiener index was 0.83, 1.37, and 0.83; the Simpson index was 0.51, 0.70, and 0.42; and the Pielow index were 0.47, 0.76, and 0.46, respectively. The results of one-way ANOVA showed that the species richness, Shannon–Wiener index, Simpson index, and Pielow index of surface vegetation under method M2 were significantly higher than those under M1 and the contrast area, indicating that, over time, the restoration effect of supplementing soil seed banks was more prominent than that of supplementing commercial seeds.

3.3. Variation of Soil–Rock Ratio under Different Supplementary Planting Methods

Soil, as an important base for material and energy cycling in ecosystems, provides essential nutrients and water for plant growth. Figure 6 shows the variation of the soil–rock ratio after nine years of supplementary planting. In the restored mining area, the soil–rock ratio of each soil layer (0–10 cm, 10–20 cm, 20–30 cm, 30–40 cm, 40–50 cm) under the supplementary planting method M1 is 2.70, 1.58, 2.24, 1.02, and 1.61 times that of the contrast area, while the soil–rock ratio under the supplementary planting method M2 is 2.53, 11.31, 22.37, 21.77, and 11.19 times that of the contrast area, respectively, indicating that with the recovery of plants, the soil–rock ratio of the soil significantly increases under both supplementary planting methods, and the effect of supplementing the soil seed bank method (M2) on restoring the soil–rock ratio is more significant. Especially with the leaching effects of this method, it can effectively restore the soil in the plant root layer (30–40 cm).

3.4. Variations of Soil Bulk Density and Soil Moisture Content under Different Supplementary Planting Methods

After nine years of replanting, the soil bulk density of the 0–10 cm soil layer under replanting methods M1 and M2 was decreased by 5.18% and 25.31% compared to the contrast area. It can be seen that both methods have a significant promoting effect on the reduction of surface soil bulk density. However, under the supplementary planting method M1, except for the topsoil layer, the soil bulk density values of other soil layers (10–20 cm, 20–30 cm, 30–40 cm, 40–50 cm) did not decrease (Figure 7A), indicating that the remediation effect of method M1 on the soil is mainly reflected in the surface layer.
Under the supplementary planting method M2, the soil bulk density of 10–20 cm, 20–30 cm, 30–40 cm, and 40–50 cm layers was reduced by 40.15%, 20.09%, 25.58%, and 10.20%, than that of the contrast area (Figure 7A); and the soil bulk density under this method is also much lower than that the M1 (p < 0.05), indicating that the restoration effect of supplementary planting method M2 on soil bulk density is significantly higher than that of supplementary planting method M1. It is shown in Figure 7B that in the 0–50 cm soil layer, as the soil depth increases, the bulk density of soil in the contrast area shows a decreasing trend. However, under the supplementary planting methods M1 and M2, the soil bulk density generally shows an increasing trend, indicating that the supplementary planting measures have a certain interference effect on the distribution of soil bulk density in the abandoned mining area. Under the supplementary planting method M1 and M2, the soil moisture content of the topsoil layer (0–10 cm) is 1.58 times and 3.74 times higher than that of the contrast area, respectively, indicating that the water storage function of the abandoned mining area has significantly improved after engineering restoration and the use of two supplementary planting methods: sowing commercial seeds (M1) and sowing soil seed banks (M2).

4. Discussion

Due to the complexity of mining area restoration, it is important to focus on nature restoration, along with the project measure for ecological restoration. A variety of ecological engineering technologies and corresponding measures are needed to restore the fragile environment in mining areas [31,32]. In addition to improving biodiversity and ecosystem function, ecological engineering has also been shown to enhance the functioning of ecosystems [33,34]. Compared with traditional restoration measures, our experimental test takes a longer time, but the long-term restoration efficiency would be more reliable. Soil degradation, either by mechanical disturbance or natural processes, is the greatest challenge to ecological restoration, hence, preference should be given to the restoration of soil quality. Due to the surface soil being severely damaged in abandoned mining areas of the Altay Mountain, the low fertility of soils became a major barrier to mine restoration and re-vegetation. Re-vegetation is the most studied and used method in damaged mining areas. Planting of indigenous plants is very useful in stabilizing the bare area and in minimizing the pollution problem [35,36]. During the field survey, we found that land degradation, which is mainly reflected in land occupation, land excavation, slag accumulation, surface subsidence, and surface fissure, is the key component of mining-related ecological damage in abandoned mining areas. Conversely, soil degradation is the inevitable consequence of vegetation degradation. The degradation of soil also results in a decline in the soil’s ability to carry water and nutrients. A comprehensive understanding of environmental problems and the complexity of ecological processes in mining areas is necessary for making an effective restoration plan to maximize the overall success of restoration efforts and minimize costs.
Our results consist of the previous research results. Josa et al. examined some of the unsuccessful restoration practices of opencast mine in semi-arid environment in northeast Spain and found that fast-growing herbaceous species can effectively control the erosion of embankments during rainfall [37]. Hou et al. analyzed the strategy and technology of ecological restoration in a coal mining area in Xuzhou City, China, and found that the vegetation growth indicators decreased during the mining activities in the period of 1987–2017 [38]. These results further confirmed the adverse effects of mining activities on the surface soil and vegetation in the mining areas. It is therefore imperative that soil properties be improved in abandoned mining areas in order to restore their ecology. Therefore, improved soil–rock ratios can restore grassland vegetation in abandoned mining areas by increasing their soil–rock ratios so as to restore the whole ecological ecosystem. This proves that soil content is an important environmental factor limiting the aboveground biomass of vegetation in abandoned mining areas [39].
It is generally accepted that vegetation restoration has a directional nature, as evidenced by changes in the composition and diversity of vegetation community. Vegetation restoration results in increased plant species richness, diversity index, evenness index, and dominance index, and all indicators show that the ecological functions of the vegetation community have been restored.
The plant seed bank of abandoned land in mining areas has characteristics such as low species diversity and simple community structure [40]. The composition of plant seeds is relatively single, and the growth of seedlings is also slow. The aboveground vegetation produces fewer seeds, and the density of the seed bank is either significantly reduced or completely lost. This is the main reason why abandoned mining areas cannot self-recover after leveling the land. It is also the biggest challenge encountered in the restoration work of damaged mining areas. In view of this, it can be considered that the self-recovery of vegetation in abandoned mining areas, after mining interference, is difficult, or requires an extremely long time without effective and feasible vegetation replanting measures.

5. Conclusions

(1)
The surface vegetation coverage, vegetation height, vegetation density, and aboveground biomass under two supplementary planting methods, sowing commercial seeds (M1) and sowing soil seed banks (M2), were significantly higher than those of the contrast area (p < 0.01), indicating that both supplementary planting methods can significantly improve the growth status of surface vegetation.
(2)
In the short term, the restoration effect of supplementing commercial seeds (M1) is faster but, over time, the effect of supplementing soil seed banks (M2) was more prominent.
(3)
Supplementing the soil seed bank method can effectively improve the soil condition, With the leaching effects of this method, its effect on restoring the soil–rock ratio in the plant root layer, e.g., 30–40 cm, is more significant.
(4)
Under both supplementary planting methods, the water storage function of soil has significantly improved. However, the remediation effect of method M1 on the soil bulk density is mainly reflected in the surface layer, while the effect of method M2 on the soil bulk density is reflected in deeper, e.g., 40–50 cm, layer.

Author Contributions

Conceptualization, A.A.; data curation, Q.X. and Y.W.; formal analysis, H.X.; methodology, A.A. and Q.X.; project administration, H.X. and A.A. All authors have read and agreed to the published version of the manuscript.

Funding

This research was financially supported by the Standards for Ecological Restoration Methods in Typical Mining Areas of Xinjiang (E1400121); Entrusted project of the Land Comprehensive Improvement Center of Xinjiang (E2400109), and The Third Xinjiang Comprehensive Scientific Expedition Project: Investigation of environmental changes in cross-border protected areas; 2022xjkk0804. The APC was funded by Hailiang Xu.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Gastauer, M.; Silva, J.R.; Caldeira, J.C.F. Mine land rehabilitation: Modern ecological approaches for more sustainable mining. J. Clean. Product. 2017, 172, 1409–1422. [Google Scholar] [CrossRef]
  2. Kalin, M. Biogeochemical and ecological considerations in designing wetland treatment systems in post-mining landscapes. Waste. Manag. 2014, 21, 191–196. [Google Scholar] [CrossRef]
  3. Qi, L.; Zhang, X.; Zhou, J.; Peng, Z. Ecological restoration suitability and landscape pattern characteristics in a watershed, northwest Hunan. J. Mt. Sci. 2009, 27, 524–530. (In Chinese) [Google Scholar]
  4. Singh, A.N.; Raghubanshi, A.S.; Singh, J.S. Comparative performance and restoration potential of two Albizia species planted on mine spoil in a dry tropical region, India. Ecol. Eng. 2004, 22, 123–140. [Google Scholar] [CrossRef]
  5. Singh, K.; Pandey, V.C.; Singh, B.; Singh, R.R. Ecological restoration of degraded sodic lands through afforestation and cropping. Ecol. Eng. 2012, 43, 70–80. [Google Scholar] [CrossRef]
  6. Eisenberg, C.; Guariguata, M.R.; Liu, J.; Hua, F.; Echeverría, C.; Gonzales, E.; Shaw, N.; Decleer, K.; Dixon, K.W. International principles and standards for the practice of ecological restoration Second edition. Restor. Ecol. 2019, 27, S3–S46. [Google Scholar]
  7. Hobbs, R.J. Restoration ecology’s silver jubilee: Innovation, debate, and creating a future for restoration ecology. Restor. Ecol. 2018, 26, 801–805. [Google Scholar] [CrossRef]
  8. Gao, Z.X.; Li, X.L.; Zhang, J. Effects of replacing topsoil treatment on vegetation and soil characteristics of open pit coal mine dump in alpine mining area. Bull. Soil Water Conser. 2021, 41, 82–96. (In Chinese) [Google Scholar]
  9. Yang, X.G.; Li, X.L.; Jin, L.Q. Effectiveness of different artificial restoration measures for soil and vegetation recovery on coal mine tailings in an alpine area. Acta Pratacult. Sin. 2019, 28, 1–11. (In Chinese) [Google Scholar]
  10. Zhao, X.G.; Zhan, S.T.; Niu, K.C. Relationships between soil fungal diversity, plant community functional traits, and soil attributes in Tibetan alpine meadows. J. Appl. Environ. Biol. 2020, 26, 1–9. (In Chinese) [Google Scholar]
  11. Xu, H.L.; Xu, F.J.; Lin, T.; Xu, Q.; Yu, P.J.; Wang, C.H.; Aili, A.; Zhao, X.F.; Zhao, W.Y.; Zhang, P.; et al. A systematic review and comprehensive analysis on ecological restoration of mining areas in the arid region of China: Challenge, capability and reconsideration. Ecol. Indic. 2023, 154, 110630. [Google Scholar] [CrossRef]
  12. Yang, S.; Liao, B.; Li, J.T.; Guo, W. Acidification, heavy metal mobility and nutrient accumulation in the soil–plant system of a vegetated acid mine wasteland. Chemosphere 2010, 80, 852–859. [Google Scholar] [CrossRef] [PubMed]
  13. Zhang, N.L. Dynamic Changes of Land Use and Ecosystem Services Value in Altai Mountains. Chin. J. Soil Sci. 2022, 53, 1286–1294. (In Chinese) [Google Scholar]
  14. Fan, Y.; Wang, H.W.; Yang, S.T.; Liu, Q.; Heng, J.Y.; Gao, Y.B. Identification of ecological protection crucial areas in Altay Prefecture based on habitat quality and ecological security pattern. Acta Ecol. Sin. 2021, 41, 7614–7626. (In Chinese) [Google Scholar]
  15. Asr, E.T.; Kakaie, R.; Ataei, M.; Mohammadi, M.R.T. A review of studies on sustainable development in mining life cycle. J. Clean. Prod. 2019, 229, 213–231. [Google Scholar] [CrossRef]
  16. Erskine, P.D.; Bartolo, R.; McKenna, P.; Humphrey, C. Using reference sites to guide ecological engineering and restoration of an internationally significant uranium mine in the Northern Territory. Australia. Ecol. Eng. 2019, 129, 61–70. [Google Scholar] [CrossRef]
  17. Liu, Y.; Lei, S.G.; Chen, X.Y.; Chen, M.; Zhang, X.Y.; Long, L.L. Study of plant configuration pattern in guided vegetation restoration: A case study of semiarid underground mining areas in Western China. Ecol. Eng. 2021, 170, 106334. [Google Scholar] [CrossRef]
  18. Hu, T.B.; Chang, J.; Liu, X.X.; Feng, S.S. Integrated methods for determining restoration priorities of coal mining subsidence areas based on green infrastructure: A case study in the Xuzhou urban area, of China. Ecol. Indic. 2018, 94, 164–174. [Google Scholar] [CrossRef]
  19. Hou, H.P.; Ding, Z.Y.; Zhang, S.L.; Guo, S.C.; Yang, Y.J.; Chen, Z.X.; Mi, J.X.; Wang, X. Spatial estimate of ecological and environmental damage in an underground coal mining area on the loess plateau: Implications for planning restoration interventions. J. Clean. Prod. 2021, 287, 125061. [Google Scholar] [CrossRef]
  20. Menegaki, M.E.; Kaliampakos, D.C. Evaluating mining landscape: A step forward. Ecol. Eng. 2012, 43, 26–33. [Google Scholar] [CrossRef]
  21. Wang, S.M.; Du, H.D.; Wang, S.Q. Analysis of damage process and mechanism for plant community and soilproperties at northern Shenmu subsidence mining area. J. China Coal Soc. 2017, 42, 17–26. (In Chinese) [Google Scholar]
  22. Wang, J.; Li, Z.; Hua, X.; Wang, J.; Wang, D.; Qin, P. The ecological potential of a restored abandoned quarry ecosystem in Mt.Mufu, Nanjing, China. Ecol. Eng. 2011, 37, 833–841. [Google Scholar] [CrossRef]
  23. Wong, M.H. Ecological restoration of mine degraded soils, with emphasis on metal contaminated soils. Chemosphere 2003, 50, 775–780. [Google Scholar] [CrossRef] [PubMed]
  24. Aili, A.; Xu, H.; Zhao, X.; Zhang, P.; Yang, R. Dynamics of Vegetation Productivity in Relation to Surface Meteorological Factors in the Altay Mountains in Northwest China. Forests 2022, 13, 1907. [Google Scholar] [CrossRef]
  25. Li, S.; Qiang, Z. Multiscenario simulation of land use and land cover in the Zhundong mining area, Xinjiang, China. Ecol. Indic. 2022, 145, 109608. [Google Scholar]
  26. Xu, Q.; Xia, G.; Wei, Y.; Aili, A.; Yuan, K. Responses of Vegetation and Soil to Artificial Restoration Measures in Abandoned Gold Mining Areas in Altai Mountain, Northwest China. Diversity 2022, 14, 427. [Google Scholar] [CrossRef]
  27. Han, C.Q.; Zheng, J.H.; Guan, J.Y.; Yu, D.L.; Lu, B.B. Evaluating and simulating resource and environmental carrying capacity in arid and semiarid regions: A case study of Xinjiang, China. J. Clean. Prod. 2022, 338, 130646. [Google Scholar] [CrossRef]
  28. Gotelli, N.J.; Colwell, R.K. Quantifying biodiversity: Procedures and pitfalls in the measurement and comparison of species richness. Ecol. Lett. 2001, 4, 379–391. [Google Scholar] [CrossRef]
  29. GB50021-2001; Code for Investigation of Geotechnical Engineering of China. Ministry of Construction of the People’s Republic of China: Beijing, China, 2009.
  30. Whittaker, R.H. Evolution and measurement of species diversity. Taxon 1972, 21, 213–251. [Google Scholar] [CrossRef]
  31. Herricka, J.E.; Schuman, G.E.; Rango, A. Monitoring ecological processes for restoration projects. J. Nat. Conserv. 2006, 14, 161–171. [Google Scholar] [CrossRef]
  32. Cristescu, R.H.; Frère, C. A review of fauna in mine rehabilitation in Australia: Current state and future directions. Biol. Conserv. 2012, 149, 60–72. [Google Scholar] [CrossRef]
  33. Zhang, Y.; Xu, X.; Li, Z. Effects of vegetation restoration on soil quality in degraded karst landscapes of southwest China. Sci. Total Environ. 2019, 650, 2657–2665. [Google Scholar] [CrossRef] [PubMed]
  34. Chen, H.; Guan, P.; Qu, B. Research on vegetation community characteristics of Fushun West Open Pit Mine. Environ. Ecol. 2021, 3, 13–18. (In Chinese) [Google Scholar]
  35. Yang, Y.J.; Ren, X.F.; Zhang, S.L.; Chen, F.; Hou, H.P. Incorporating ecological vulnerability assessment into rehabilitation planning for a post-mining area. Environ. Earth Sci. 2017, 76, 245. [Google Scholar] [CrossRef]
  36. Richardson, B.J. Resourcing ecological restoration: The legal context for commercial initiatives. Restor. Ecol. 2016, 24, 686–691. [Google Scholar] [CrossRef]
  37. Josa, R.; Jorba, M.; Vallejo, V.R. Opencast mine restoration in a Mediterranean semi-arid environment: Failure of some common practices. Ecol. Eng. 2012, 42, 183–191. [Google Scholar] [CrossRef]
  38. Hou, H.; Zhang, S.; Yan, Y.; Guo, S.; Dun, D.; Jin, Y. Study on ecological landscape restoration in mining areas based on RS and GIS: A case of Xuzhou northern coal mining area. China Land Sci. 2009, 23, 62–67. (In Chinese) [Google Scholar]
  39. Farjana, S.H.; Huda, N.; Mahmud, M.A.P.; Saidur, R. A review on the impact of mining and mineral processing industries through life cycle assessment. J. Clean. Prod. 2019, 231, 1200–1217. [Google Scholar] [CrossRef]
  40. Grommesch, M.C. Soil seed banks in a heavy-metal polluted grassland at Prayon (Belgium). Plant Ecol. 2001, 155, 35–45. [Google Scholar]
Sustainability 15 14974 g001
Figure 1. Location of the study area.
Figure 1. Location of the study area.
Sustainability 15 14974 g001
Sustainability 15 14974 g002
Figure 2. Layout of sample plots.
Figure 2. Layout of sample plots.
Sustainability 15 14974 g002
Sustainability 15 14974 g003
Figure 3. Changes in plant growth after two years of supplementary planting. (Note: a, b and c at the Figure are the statistically significant level. a: p < 0.001; b: 0.001 ≤ p < 0.01; c: 0.01 ≤ p < 0.05).
Figure 3. Changes in plant growth after two years of supplementary planting. (Note: a, b and c at the Figure are the statistically significant level. a: p < 0.001; b: 0.001 ≤ p < 0.01; c: 0.01 ≤ p < 0.05).
Sustainability 15 14974 g003
Sustainability 15 14974 g004
Figure 4. Variation of plant growth under different reseeding methods (seven years after reseeding) (Note: a, b and c at the Figure are the statistically significant level. a: p < 0.001; b: 0.001 ≤ p < 0.01; c: 0.01 ≤ p < 0.05).
Figure 4. Variation of plant growth under different reseeding methods (seven years after reseeding) (Note: a, b and c at the Figure are the statistically significant level. a: p < 0.001; b: 0.001 ≤ p < 0.01; c: 0.01 ≤ p < 0.05).
Sustainability 15 14974 g004
Sustainability 15 14974 g005
Figure 5. Variation of vegetation community structure under different supplementary planting methods after two years (A) and nine years (B).
Figure 5. Variation of vegetation community structure under different supplementary planting methods after two years (A) and nine years (B).
Sustainability 15 14974 g005
Sustainability 15 14974 g006
Figure 6. Variation of the soil-rock ratio under different supplementary planting methods (seven years after reseeding).
Figure 6. Variation of the soil-rock ratio under different supplementary planting methods (seven years after reseeding).
Sustainability 15 14974 g006
Sustainability 15 14974 g007aSustainability 15 14974 g007b
Figure 7. Variation of soil bulk density (A) and soil moisture content (B) under different supplementary planting methods (seventh year after replanting).
Figure 7. Variation of soil bulk density (A) and soil moisture content (B) under different supplementary planting methods (seventh year after replanting).
Sustainability 15 14974 g007aSustainability 15 14974 g007b
Table 1. Vegetation types surveyed near the damaged mining area.
Table 1. Vegetation types surveyed near the damaged mining area.
Latin NameFamily & GeneraImportant Value of Plants
Primitive GrasslandAbandoned Mines
Alopecurus pratensisGramineae, Alopecurus64.99
PoaannuaGramineae, Poa genus62.83
Polyonum alpinumPolygonaceae, Polygonum genus51.56
Ferula ferulaeoidesUmbelliferae, Ferula genus48.54
Festuca valesiacaGramineae, Festuca genus48.33
Deschampsia caespitosaGramineae, Deschampsia47.9641.13
Polyonum amphlibiumPolygonaceae, Polygonum genus39.43
Trifolium lupinasterLeguminosae, Plantago genus28.65
Taraxacum, mongolicumCompositae, Pogostemon genus26.72
Myosotis sylvaticaBoraginaceae, Myosotis19.11
Medicago falcataLeguminosae, Alfalfa genus15.58
Spiraea hypericifoliaRosaceae, Spiraea genus11.34
Sonchus oleraceusCompositae, Sophora genus12.78
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Xu, Q.; Xu, H.; Wei, Y.; Aili, A. Restoration Effects of Supplementary Planting Measures on the Abandoned Mining Areas in the Altay Mountain, Northwest China. Sustainability 2023, 15, 14974. https://0-doi-org.brum.beds.ac.uk/10.3390/su152014974

AMA Style

Xu Q, Xu H, Wei Y, Aili A. Restoration Effects of Supplementary Planting Measures on the Abandoned Mining Areas in the Altay Mountain, Northwest China. Sustainability. 2023; 15(20):14974. https://0-doi-org.brum.beds.ac.uk/10.3390/su152014974

Chicago/Turabian Style

Xu, Qiao, Hailiang Xu, Yan Wei, and Aishajiang Aili. 2023. "Restoration Effects of Supplementary Planting Measures on the Abandoned Mining Areas in the Altay Mountain, Northwest China" Sustainability 15, no. 20: 14974. https://0-doi-org.brum.beds.ac.uk/10.3390/su152014974

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop