Metal mine ecological restoration method based on trapezoid layered stacking and moss inoculation

Abstract

The invention provides a metal mine ecological restoration method based on trapezoid layered stacking and moss inoculation, and belongs to the technical field of metal mine reclamation ecological restoration and ecological environment improvement. Slope planting point locations are determined; selecting a moss plant community planting scheme according to a greenhouse; and according to preset time, bryophytes, shrub plants, arbor plants and herbaceous plants in the ecological restoration area are subjected to complementary planting and tending, so that the metal mine waste rock heap forms an ecological plant community, and the preset time is preferably two growing seasons. According to the method, a single greening mode in the greening process of the metal mine is broken through, a mode for carrying out vegetation restoration on the mine by adopting the moss is provided, a new way is opened up in the aspects of metal mine soil fixation and ecological restoration, the means and technology of ecological restoration of the metal mine are enriched, and the method has good popularization and application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of metal mine reclamation ecological restoration and ecological environment improvement, and in particular to a metal mine ecological restoration method based on trapezoidal body layered stacking and moss inoculation. Background Art

[0002] At present, the ecological restoration of abandoned metal mine sites mainly relies on traditional soil covering and vegetation planting techniques. Common restoration methods include physical restoration such as foreign soil covering and land reshaping, which improve substrate conditions by introducing foreign soil; chemical restoration, which uses chemical amendments (such as lime and organic fertilizer) to neutralize acidity or reduce the toxicity of heavy metals; and phytoremediation, which plants heavy metal-resistant herbs, shrubs or trees to absorb or stabilize pollutants. However, current methods have some limitations, including a high dependence on soil, which requires a large amount of exogenous soil, increases costs, and may cause damage to the ecological environment in other areas. In addition, the process of soil formation and natural succession of vegetation is slow, making it difficult to quickly restore ecological functions. The survival ability of traditional plants is also limited under extreme pH values, high metal content or drought conditions.

[0003] The extreme conditions of abandoned mine sites (such as high metal content, low organic matter, and drought) limit the effectiveness of traditional remediation methods. As pioneer species, bryophytes can tolerate harsh environments and improve microhabitats, but their application in metal mine remediation has not been systematically studied.

[0004] Therefore, a metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation was proposed. Summary of the Invention

[0005] The present invention aims to solve the problems raised in the background technology and provides a metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation. It aims to solve how to utilize the stress resistance and ecological functions of local moss species in abandoned mines with high metal content, reduce restoration costs and improve success rates, and thus fill the above-mentioned technical gaps, and provide an economical, efficient and sustainable new method for mine ecological restoration. The method is easy to implement and easy to operate. By stacking waste rock in trapezoidal layers, laying substrates, introducing mosses and planting shrubs / trees, the ecological environment restoration of abandoned metal mines is achieved. It is operational, can increase the greening area, and provides an effective method for mine reclamation and ecological restoration and improvement of the ecological environment.

[0006] The specific technical solutions are as follows:

[0007] A metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation includes the following steps:

[0008] Waste rock is stored in a trapezoidal layered stacking method, with each layer designed to be 10m high and stacked upwards layer by layer. During the mining cycle, ecological restoration measures are immediately implemented on the external slopes after each layer of waste rock is completed, achieving a sustainable "mining and restoration" model.

[0009] Determine the planting site on the slope, pre-pave the area with 5-10cm of surface soil left over from mining, and cover it with a 0.5cm thick peat layer;

[0010] According to the planting plan of the moss plant community screened in the greenhouse, the moss plants are planted in the planting area after the improved soil substrate is laid;

[0011] According to the preset planting plan of tree, shrub and grass plant communities, plant the shrub seedlings and tree seedlings separately in the planting areas;

[0012] According to the preset time, mosses, shrubs, trees and herbs in the ecological restoration area are replanted and nurtured so that an ecological plant community is formed in the metal mine waste rock pile, wherein the preset time is preferably two growing seasons.

[0013] The above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, wherein the trapezoidal layered stacking method is used to store waste rock and realize the sustainable model of "mining and restoration at the same time", specifically includes:

[0014] The stacking height of each layer is 10m, with a drainage slope of 2% to 3% between layers. The stacking width of each layer is consistent with the final design floor area, and the stacking method is segmented, with each segment length controlled at 50 to 100m.

[0015] Dump trucks are used to transport waste rock, which is then stacked layer by layer from bottom to top. After each layer is stacked, a roller is used to compact it, with a compaction degree of over 90%.

[0016] The above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, wherein the steps of determining the slope planting points and laying the improved soil matrix specifically include:

[0017] Using the grid method, planting sites were set up on the slope at intervals of 1m x 1m;

[0018] At each planting site, dig a planting hole with a diameter of 10-20 cm and a depth of 20-30 cm;

[0019] The topsoil left over from mining is selected, transported to the area to be repaired and laid in the planting holes. The laying thickness is controlled at 5 to 10 cm, and a 0.5 cm thick peat layer is covered on it.

[0020] The above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, wherein the moss plants are planted according to the moss plant community planting plan screened in the greenhouse, specifically includes:

[0021] Collect the pioneer moss species with strong stress tolerance and rapid growth in the wild, including long-toothed moss, cypress-leaved golden moss, hairy-tipped golden moss, golden moss, and wrinkled-leaved curved-tail moss, retain the bright green part, and use a grinder to crush the moss plants into pieces of 0.5-1.0 cm in size;

[0022] Waste rock was collected from the mine and laid in a plastic tray. It was covered with a 0.5 cm thick soil improvement matrix made of 70% sand and 30% peat soil. Moss fragments were added at a rate of 260 g / m 2 Evenly spread on the surface of the substrate, cultivate in a greenhouse with a temperature of 22℃ / 18℃, an air humidity of 60% / 90%, and a day and night period of 16h / 8h, spray with rain water once every two days, and after 3 to 6 months of cultivation, screen out species with a moss coverage rate of more than 80%, and collect moss plants after large-scale propagation;

[0023] The moss grown in the greenhouse was processed into pieces of 0.5 to 1.0 cm in size, stored at 4 ° C and transported to the mine wasteland, and the weight of the pieces was 260 g / m 2 Spread evenly on the surface of the improved soil.

[0024] In the above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, the shrub seedlings are two-year-old seedlings, the tree seedlings are two-year-old seedlings, and the mosses are transplanted after indoor propagation.

[0025] The above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, wherein the seedlings of the shrub and tree plants are planted in holes, the hole planting parameters are a diameter of 10 to 20 cm, a depth of 20 to 30 cm, and the spacing between adjacent shrub and tree seedlings is 35 cm.

[0026] The above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, wherein the varieties of shrub plants include blueberry and Ledum palustris, and the varieties of tree plants include white birch, willow, and gray pine.

[0027] The above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, wherein the tolerant tree plant varieties are birch, willow, and gray pine, and the better plants are birch and gray pine; the tolerant shrub plants are Ledum palustris and Vaccinium vitis-idaea, and the better plant is Vaccinium vitis-idaea.

[0028] In the above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, the preset time for replanting and nurturing plants in the ecological restoration area is six months to one year.

[0029] The above-mentioned metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, wherein the method is used to form an ecological plant community in the metal mine waste rock pile, which gradually evolves into a near-natural vegetation community system without degradation; wherein, the moss coverage is close to 40%, the survival rate of white birch and gray pine both exceeds 50%, and compared with the treatment without moss coverage, the plant biomass index of white birch and gray pine increases by 4 times and 1 times respectively.

[0030] The present invention has the following beneficial effects:

[0031] 1. It breaks through the single greening model in the greening process of metal mines, provides a model for using moss to restore vegetation in mines, opens up a new path in soil fixation and ecological restoration in metal mines, enriches the means and technologies of ecological restoration in metal mines, and has good promotion and application prospects.

[0032] 2. Select appropriate pioneer species (such as mosses) to establish functionally suitable local pioneer vegetation by "starting" processes such as nutrient cycling and organic carbon accumulation, significantly promote soil development, gradually initiate the process of succession to a more diverse and complex vegetation structure, and improve biodiversity in the mine ecological environment.

[0033] 3. Moss plants can adapt well to the extreme environment of mines. By using various nutritional structures as reproductive bodies, they can quickly spread and colonize disturbed areas. By screening out moss plants that can grow in metal mines and cultivating them in large quantities in greenhouses, combined with soil matrix improvement, the vegetation restoration process that would take more than ten years to complete naturally can be completed in a short period of time, providing good conditions for the fixation and ecological restoration of mine soils.

[0034] 4. Through precise soil covering, the amount of soil used can be reduced compared to the traditional full-yard soil covering method, and peat soil increases soil organic matter. After the introduction of moss, its rhizomes can quickly and effectively fix the soil, prevent soil erosion, improve the local microenvironment, promote the accumulation of carbon and nitrogen in the soil, and improve the survival rate and growth of trees, shrubs and herbaceous plants on the abandoned ore pile. It has the advantages of convenient on-site construction operation, small amount of soil used, good ecological restoration effect, low restoration cost and suitability for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic flow chart of a metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0037] Among them, the drawings are only used for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0038] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inside", "outside" and the like indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0039] In the description of the present invention, unless otherwise expressly specified or limited, when the term "connection" or the like appears to indicate a connection relationship between components, such term should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be internal communication between two components or an interaction between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0040] The metal mine ecological restoration method provided in this embodiment is based on trapezoidal layer stacking and moss inoculation. Figure 1 As shown, the following steps are included:

[0041] S1: The waste rock is stored in a trapezoidal layered stacking method, with each layer designed to be 10m high and stacked upwards layer by layer. During the mining cycle, after each layer of waste rock is stacked, ecological restoration measures are immediately implemented on the external slopes to achieve a sustainable "mining and restoration" model;

[0042] S2: Determine the planting site on the slope, pre-pave the area with 5-10 cm of surface soil left over from mining, and cover it with a 0.5 cm thick peat layer;

[0043] S3: Plant the mosses in the planting area after laying the improved soil substrate according to the planting plan of the moss plant community screened in the greenhouse;

[0044] S4: Plant the shrub seedlings and tree seedlings in the planting areas according to the preset tree, shrub and grass plant community planting plan;

[0045] S5: According to the preset time, the mosses, shrubs, trees and herbs in the ecological restoration area are replanted and nurtured to form an ecological plant community in the metal mine waste rock pile, wherein the preset time is preferably two growing seasons.

[0046] Waste rock is stacked in trapezoidal layers, and restoration is carried out while mining is ongoing. The surface soil and peat layer of the mine are laid, mosses screened in the greenhouse are inoculated, and trees and shrubs are planted and replanted and tended. This allows for simultaneous waste rock stacking and ecological restoration, reducing the difficulty of later restoration. Basic conditions for plant growth are created through substrate improvement. The pioneering role of moss is used to fix the soil and improve the microhabitat. Combined with the planting of trees and shrubs, a three-dimensional vegetation community is formed to promote the rapid recovery and stability of the ecosystem.

[0047] Specifically, in this embodiment, a trapezoidal layered stacking method is used to store waste rock and realize a sustainable model of "mining and repairing at the same time", which specifically includes:

[0048] The stacking height of each layer is 10m, with a drainage slope of 2% to 3% between layers. The stacking width of each layer is consistent with the final design floor area, and the stacking method is segmented, with each segment length controlled at 50 to 100m.

[0049] Dump trucks are used to transport waste rock, which is then stacked layer by layer from bottom to top. After each layer is stacked, a roller is used to compact it, with a compaction degree of over 90%.

[0050] Setting drainage slopes and segment lengths when stacking trapezoidal bodies in layers, and compacting the waste rock after transportation, can ensure the structural stability of the waste rock pile and prevent landslides caused by rainwater erosion; optimize the drainage system to avoid water accumulation affecting plant growth; segmented stacking and compaction treatment improve construction efficiency and provide a safe and flat substrate surface for subsequent repair measures.

[0051] Specifically, in this embodiment, determining the planting site on the slope and laying the improved soil matrix specifically includes:

[0052] Using the grid method, planting sites were set up on the slope at intervals of 1m x 1m;

[0053] At each planting site, dig a planting hole with a diameter of 10-20 cm and a depth of 20-30 cm;

[0054] The topsoil left over from mining is selected, transported to the area to be repaired and laid in the planting holes. The laying thickness is controlled at 5 to 10 cm, and a 0.5 cm thick peat layer is covered on it.

[0055] Using the grid distribution method to determine the planting sites, excavating planting holes of specific sizes, and laying the mine surface soil and peat layer can ensure the uniformity of plant planting and optimize spatial distribution; using the mine legacy soil to reduce the amount of exogenous soil, reduce costs and ecological damage; the peat layer enhances the soil's water retention capacity and organic matter content, improves the fertility and moisture conditions of the substrate, and is conducive to plant rooting.

[0056] Specifically, in this embodiment, the bryophytes are planted according to the planting plan of the bryophyte community screened in the greenhouse, which specifically includes:

[0057] Collect the pioneer moss species with strong stress tolerance and rapid growth in the wild, including long-toothed moss, cypress-leaved golden moss, hairy-tipped golden moss, golden moss, and wrinkled-leaved curved-tail moss, retain the bright green part, and use a grinder to crush the moss plants into pieces of 0.5-1.0 cm in size;

[0058] Waste rock was collected from the mine and laid in a plastic tray. It was covered with a 0.5 cm thick soil improvement matrix made of 70% sand and 30% peat soil. Moss fragments were added at a rate of 260 g / m 2 Evenly spread on the surface of the substrate, cultivate in a greenhouse with a temperature of 22℃ / 18℃, an air humidity of 60% / 90%, and a day and night period of 16h / 8h, spray with rain water once every two days, and after 3 to 6 months of cultivation, screen out species with a moss coverage rate of more than 80%, and collect moss plants after large-scale propagation;

[0059] The moss grown in the greenhouse was processed into pieces of 0.5 to 1.0 cm in size, stored at 4 ° C and transported to the mine wasteland, and the weight of the pieces was 260 g / m 2 Spread evenly on the surface of the improved soil.

[0060] By collecting stress-resistant mosses and crushing them, high-coverage species are screened in the greenhouse using specific substrates, temperature, humidity and light conditions. After low-temperature transportation, they are inoculated into the mine. The screened moss species have strong adaptability to the extreme environment of the mine (such as high metals and drought) and can quickly colonize; the crushing process promotes the diffusion and growth of moss fragments, and greenhouse propagation ensures the number of seedlings; low-temperature transportation maintains the vitality of the moss, and after inoculation, it can quickly cover the substrate, playing a role in consolidating the soil and improving the microenvironment.

[0061] Specifically, in this embodiment, the seedlings of shrub plants are two-year-old seedlings, the seedlings of tree plants are two-year-old seedlings, and the mosses are transplanted after indoor propagation.

[0062] By using two-year-old tree and shrub seedlings, and at the same time adopting indoor propagation and transplantation of mosses, the two-year-old seedlings have a certain growth foundation, which improves the survival rate and stress resistance after transplantation; the mosses propagated indoors can be produced on a large scale to ensure the supply of seedlings for the restoration project and ensure the consistency of the restoration progress and effect.

[0063] Specifically, in this embodiment, the seedlings of shrubs and trees are planted in holes with parameters of 10-20 cm in diameter and 20-30 cm in depth, and the spacing between adjacent seedlings of shrubs and trees is 35 cm.

[0064] Trees and shrubs are planted using specific hole planting parameters and plant spacing. Reasonable hole planting size provides sufficient growth space for the seedling roots and promotes root development; 35cm plant spacing optimizes vegetation density, which not only avoids excessive competition, but also can quickly form closed communities, enhance soil and water conservation capacity and ecosystem stability.

[0065] Specifically, in this embodiment, the shrubs include bilberry and Ledum palustris, and the tree species include birch, willow, and gray pine. By selecting shrubs such as bilberry and Ledum palustris and trees such as birch, willow, and gray pine, the selected plant species are tolerant to environmental conditions such as heavy metal pollution in mines and poor soil quality, allowing them to survive in adverse conditions. The combination of trees and shrubs forms a three-dimensional community structure, improving biodiversity and enhancing ecosystem functions (such as nutrient cycling and soil and water conservation).

[0066] Specifically, in this embodiment, the tolerant tree species are birch, willow, and gray pine, with birch and gray pine being preferred. The tolerant shrub species are Ledum palustris and Vaccinium vulgare, with Vaccinium vulgare being preferred. By selecting birch and gray pine as trees and Vaccinium vulgare as shrubs, the preferred species exhibit greater stress tolerance and more pronounced synergy with mosses, improving soil conditions more quickly and promoting vegetation succession. Their growth characteristics (such as rapid growth and adaptability) can accelerate ecological restoration and enhance the durability of restoration effects.

[0067] Specifically, in this embodiment, the preset time for replanting and nurturing plants in the ecological restoration area is six months to one year. This period provides sufficient growth cycles for the plants, replenishing missing plants in a timely manner and ensuring the integrity of vegetation coverage and community structure. Continuous nurturing promotes robust plant growth, enhances their adaptability to the mining environment, and ensures the ultimate effectiveness of ecological restoration.

[0068] Specifically, in this embodiment, the method is used to form an ecological plant community in the waste rock pile of the metal mine, which gradually evolves into a near-natural vegetation community system in the later stage without degradation; among them, the moss coverage is close to 40%, and the survival rates of white birch and gray pine are both over 50%. Compared with the treatment without moss coverage, the plant biomass index of white birch and gray pine increased by 4 times and 1 times respectively. By repairing and forming a near-natural vegetation community without degradation, improving moss coverage and plant survival rate, it is possible to achieve long-term sustainable restoration of the mine ecosystem and avoid the short-term effects of traditional restoration methods; the stability of the vegetation community is enhanced, and it can independently maintain ecological functions (such as carbon fixation and heavy metal purification), reduce human intervention, and reduce later maintenance costs.

[0069] In addition, in view of the problems faced by ecological restoration of abandoned metal mine sites, such as heavy metal pollution, drought, and soil shortage, the specific implementation methods of the present invention are described in detail below in conjunction with Examples 1-3.

[0070] Example 1

[0071] A metal mining area primarily mines spodumene, generating large amounts of waste rock. This accumulation of waste rock has slowed natural vegetation recovery, weakening ecosystem function. The mining area has a warm-summer humid continental climate, with an average annual high temperature of 0°C and a low temperature of -0.7°C. Annual precipitation ranges from 702 to 749 mm. The growing season typically runs from May to September. The primary tree species are black spruce, Banksia pine, and white birch. Within a 40-kilometer radius of the mining area, dry or open areas are home to longtooth moss, juniper-leaved golden moss, hairy-tipped golden moss, golden moss, and wrinkled-leaved curly moss.

[0072] Waste rock samples were collected from the mining area and the concentrations of calcium, aluminum, vanadium, manganese, iron, molybdenum, barium, copper and zinc were analyzed. The Ca concentration in the waste rock was the highest (11616μg / g), and the heavy metal concentrations decreased in the following order: Fe (837μg / g), Al (778μg / g), Mn (126μg / g), Cu (76μg / g), Ba (32μg / g), Zn (11616μg / g), V (23μg / g) and Mo (0.2μg / g).

[0073] The specific implementation steps are as follows:

[0074] The waste rock is stored in a trapezoidal layered stacking method. The designed height of each layer is 10m, and it is stacked upward layer by layer. The external slope is the area where ecological restoration is planned to be implemented.

[0075] Determine the planting points on the slope and use the grid distribution method to set the planting points at a spacing of 1m×1m. Dig a planting hole with a diameter of 10-20cm and a depth of 20-30cm at each planting point. Pre-lay 5-10cm of surface soil left over from mining in the area where the planting point is located, and cover it with a 0.5cm thick peat layer.

[0076] According to the planting plan of the moss plant community screened in the greenhouse, moss species such as Longtooth Moss were collected and crushed into 0.5-1.0 cm fragments. After cultivation and screening in the greenhouse, the moss fragments were pressurized at 260 g / m 2 Transplant to the planting area with improved soil substrate, and set up a control group without moss plant transplants.

[0077] To construct a pioneer-native tree and shrub plant community, two-year-old tree seedlings (white birch, gray pine) and shrub seedlings (Vaccinium vitis-idaea) were selected and planted in pits with the parameters of 10-20 cm in diameter, 20-30 cm in depth, and 35 cm in spacing.

[0078] Reasonable replanting and tending were carried out for about 3 to 6 months. After two growing seasons, 10 planting areas were randomly selected to measure the vegetation recovery: the moss coverage was close to 40%, and the survival rates of white birch and gray pine were both over 50%. Compared with the treatment without moss coverage, the plant biomass index of white birch and gray pine increased by 4 times and 1 times respectively.

[0079] From the above examples, it can be seen that the ecological restoration method provided by the present invention reduces soil usage, improves plant survival rate and biomass, achieves good ecological restoration effects, and has significant technical advantages and application value through the combination of steps such as layered stacking of trapezoidal bodies, precise soil covering, moss inoculation, and tree and shrub planting.

[0080] Example 2: Ecological restoration of abandoned copper mine sites

[0081] 1. Overview of the mining area

[0082] A copper mine is located in a hilly area in southern my country, experiencing a subtropical monsoon climate with an average annual temperature of 18°C ​​and annual precipitation of 1500–1800 mm, with the rainy season concentrated between April and September. The mine has been mined for over 30 years, and the abandoned waste rock pile is primarily composed of copper-containing sulfide ore and quartzite debris. The waste rock has a pH of 4.2–4.8 (strongly acidic), with copper (Cu) concentrations reaching 210 μg / g, zinc (Zn) concentrations of 185 μg / g, and lead (Pb) concentrations of 92 μg / g. The organic matter content is less than 0.5%, making natural vegetation recovery difficult. Common moss species in the natural vegetation surrounding the mine are Racomitrium canescens, Dicranum undulatum, and Polytrichum commune.

[0083] 2. Waste rock treatment and substrate improvement

[0084] Trapezoidal layered stacking: waste rock is stacked at a height of 10m per layer, with a drainage slope of 2.5% between layers. The length of each segment stacking is 80m, and the compaction degree of each layer reaches 92% to prevent landslides caused by rainwater erosion.

[0085] Substrate laying: Use the grid layout method (1m×1m) to determine the planting site, dig a planting hole with a diameter of 15cm and a depth of 25cm, lay 8cm thick mine surface soil (pH value adjusted to 6.0-6.5), and cover it with a 0.5cm peat layer to neutralize the acidity and increase organic matter.

[0086] 3. Moss Screening and Inoculation

[0087] Greenhouse cultivation: Collect acid-resistant mosses (long-toothed moss, wrinkled-leafed moss) around the mining area, crush them into 0.5-1.0 cm pieces, and press 260g / m 2 Sprinkle the mixture on a substrate of 70% sand and 30% peat in a greenhouse controlled at 25°C / 20°C (day / night), 70% / 85% humidity, 16h / 8h photoperiod, and spray with slightly acidic rainwater (pH 5.5). After four months of cultivation, the coverage of the long-toothed moss reached 85%, and it was selected as the dominant species.

[0088] On-site transplantation: The moss fragments were transported to the mining area at 4°C and evenly spread on the surface of the improved substrate. A moss-free control area was set up simultaneously.

[0089] 4. Planting and tending of trees and shrubs

[0090] Plant selection: Acid-resistant willow (Populus tremuloides) and gray pine (Pinus banksiana) (two-year-old seedlings) were selected as trees, and blueberry (Vaccinium uliginosum) (two-year-old seedlings) were selected as shrubs. The plant spacing was 35 cm, and the hole planting parameters were 15 cm in diameter and 25 cm in depth.

[0091] Nurturing and management: Spray microbial agents every quarter after planting (to promote the solidification of heavy metals), and replant missing plants within two growing seasons.

[0092] 5. Repair effect

[0093] Moss coverage: After two growing seasons, the average moss coverage reached 38%, significantly higher than the control group (12%).

[0094] Plant survival and growth: The survival rate of willow was 62%, and that of gray pine was 58%; compared with the control group, the willow biomass index (VBI) increased by 3.5 times, and the gray pine VBI increased by 1.2 times.

[0095] Soil improvement: The pH value of the surface soil increased to 5.8, the organic matter content increased to 1.2%, and the available copper and zinc contents decreased by 25% to 30%.

[0096] Example 3: Restoration of arid areas of abandoned iron mine sites

[0097] 1. Overview of the mining area

[0098] An iron mine is located in the arid northwestern region of China. Its climate is temperate continental, with an average annual temperature of 7°C, annual precipitation of 180-220 mm, evaporation of 2500 mm, and a large diurnal temperature swing of 15-30°C. The waste rock is primarily hematite and quartzite, with a particle size of 5-100 mm. The soil moisture content is consistently below 5%, with heavy metal iron (Fe) concentrations reaching 1200 μg / g and manganese (Mn) concentrations of 150 μg / g. Vegetation is extremely sparse, with only scattered drought-tolerant herbs. Drought-tolerant mosses found around the mine are Polytrichum juniperinum and P. piliferum.

[0099] 2. Waste rock treatment and substrate improvement

[0100] The trapezoidal bodies are stacked in layers: each layer is 10m high, with a 3% drainage slope between layers (to prevent water accumulation during heavy rains), a segment length of 50m, a compaction degree of more than 90%, and straw mats laid on the outer slopes to temporarily stabilize the soil.

[0101] Substrate laying: Dig planting holes with a diameter of 20 cm and a depth of 30 cm at a spacing of 1 m × 1 m, lay 10 cm thick mine surface soil (mixed with 20% clay to enhance water retention), and cover with a 0.5 cm peat layer + 0.3 cm straw debris (to reduce evaporation).

[0102] 3. Moss Screening and Inoculation

[0103] Greenhouse cultivation: Collect cypress leaf golden moss and hairy golden moss, crush them into 0.8-1.0 cm pieces, and press 280g / m 2 Spread on a 70% sandy soil + 30% peat soil substrate, in a greenhouse controlled at 22°C / 15°C (day / night), 60% / 80% humidity, and an 18h / 6h photoperiod (simulating long days). Sprayed with brackish water (mineralization 2g / L) every three days. After six months of cultivation, the cypress leaf golden moss had a coverage rate of 82%, and was selected as the dominant species.

[0104] On-site transplantation: The moss fragments are transported to the mining area at low temperature, spread and covered with non-woven fabric (moisturizing), and removed after 1 week.

[0105] 4. Planting and tending of trees and shrubs

[0106] Plant selection: Drought-tolerant white birch (Betula papyrifera) and gray pine (Pinus banksiana) (two-year-old seedlings) are used as trees, and Ledum palustre (two-year-old seedlings) are used as shrubs. The spacing between plants is 35 cm, and a 5 cm thick gravel layer is laid at the bottom of the planting hole (to enhance drainage).

[0107] Nursing management: Use a drip irrigation system (replenish water once a month), spray anti-transpiration agents (to reduce water loss), and replant after the first growing season.

[0108] 5. Repair effect

[0109] Moss coverage: After two growing seasons, the coverage of the cypress-leaved golden moss reached 35%, while there was almost no moss growth in the control group.

[0110] Plant survival and growth: The survival rate of white birch was 55%, and the survival rate of gray pine was 52%; compared with the control group, the biomass index (VBI) of white birch increased by 4.2 times, and the VBI of gray pine increased by 1.1 times.

[0111] Improved microenvironment: The moisture content of the surface soil increased to 8%-10%, the temperature difference between day and night decreased by 5-8°C, the soil organic matter content increased to 0.8%, and the activity of iron and manganese ions decreased by 18%-22%.

[0112] The two examples above, targeting abandoned acid copper mines and arid iron mines, respectively, verified the adaptability of the present invention in mines with different climate zones and heavy metal concentrations by adjusting trapezoidal stacking parameters, substrate modification formulas, and moss species selection strategies. The results demonstrated that moss inoculation significantly enhanced soil water retention, improved microhabitats, and promoted tree and shrub survival, resulting in superior restoration results compared to traditional moss-free restoration methods, demonstrating the method's broad applicability and technical advantages.

[0113] In summary, the metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation provided in this embodiment has the following advantages:

[0114] 1. It breaks through the single greening model in the greening process of metal mines, provides a model for using moss to restore vegetation in mines, opens up a new path in soil fixation and ecological restoration in metal mines, enriches the means and technologies of ecological restoration in metal mines, and has good promotion and application prospects.

[0115] 2. Select appropriate pioneer species (such as mosses) to establish functionally suitable local pioneer vegetation by "starting" processes such as nutrient cycling and organic carbon accumulation, significantly promote soil development, gradually initiate the process of succession to a more diverse and complex vegetation structure, and improve biodiversity in the mine ecological environment.

[0116] 3. Moss plants can adapt well to the extreme environment of mines. By using various nutritional structures as reproductive bodies, they can quickly spread and colonize disturbed areas. By screening out moss plants that can grow in metal mines and cultivating them in large quantities in greenhouses, combined with soil matrix improvement, the vegetation restoration process that would take more than ten years to complete naturally can be completed in a short period of time, providing good conditions for the fixation and ecological restoration of mine soils.

[0117] 4. Through precise soil covering, the amount of soil used can be reduced compared to the traditional full-yard soil covering method, and peat soil increases soil organic matter. After the introduction of moss, its rhizomes can quickly and effectively fix the soil, prevent soil erosion, improve the local microenvironment, promote the accumulation of carbon and nitrogen in the soil, and improve the survival rate and growth of trees, shrubs and herbaceous plants on the abandoned ore pile. It has the advantages of convenient on-site construction operation, small amount of soil used, good ecological restoration effect, low restoration cost and suitability for large-scale promotion and application.

[0118] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A metal mine ecological restoration method based on trapezoidal layered stacking and moss inoculation, characterized in that: The following steps are involved: Waste rock is stored using a trapezoidal layered stacking method, with each layer designed to be 10m high and stacked upwards. During the mining cycle, ecological restoration measures are immediately implemented on the external slopes after each layer of waste rock is completed, achieving a sustainable "mining and restoration" model. Determine the planting site on the slope, pre-pave the area with 5-10cm of surface soil left over from mining, and cover it with a 0.5cm thick peat layer; According to the planting plan of the moss plant community screened in the greenhouse, the moss plants are planted in the planting area after the improved soil substrate is laid; According to the preset planting plan of tree, shrub and grass plant communities, plant the shrub seedlings and tree seedlings separately in the planting areas; According to the preset time, mosses, shrubs, trees and herbs in the ecological restoration area will be replanted and nurtured to form an ecological plant community in the metal mine waste rock pile, and the preset time is two growing seasons.

2. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1 is characterized in that: The above-mentioned method of using the trapezoidal layered stacking method to store waste rock and realize the sustainable model of "mining and repairing at the same time" specifically includes: The stacking height of each layer is 10m, with a drainage slope of 2% to 3% between layers. The stacking width of each layer is consistent with the final design floor area, and the stacking method is segmented, with each segment length controlled at 50 to 100m. Dump trucks are used to transport waste rock, which is then stacked layer by layer from bottom to top. After each layer is stacked, a roller is used to compact it, with a compaction degree of over 90%.

3. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1 is characterized in that: The steps of determining the planting sites on the slope and laying the improved soil matrix specifically include: Using the grid method, planting sites were set up on the slope at intervals of 1m x 1m; At each planting site, dig a planting hole with a diameter of 10-20 cm and a depth of 20-30 cm; The topsoil left over from mining is selected, transported to the area to be repaired and laid in the planting holes. The laying thickness is controlled at 5 to 10 cm, and a 0.5 cm thick peat layer is covered on it.

4. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1 is characterized in that: The method of planting bryophytes according to the bryophyte community planting plan screened in the greenhouse specifically includes: Collect the pioneer moss species with strong stress tolerance and rapid growth in the wild, including long-toothed moss, cypress-leaved golden moss, hairy-tipped golden moss, golden moss, and wrinkled-leaved curved-tail moss, retain the bright green part, and use a grinder to crush the moss plants into pieces of 0.5-1.0 cm in size; Waste rock was collected from the mine and laid in a plastic tray. It was covered with a 0.5 cm thick soil improvement matrix made of 70% sand and 30% peat soil. Moss fragments were added at a rate of 260 g / m 2 Evenly spread on the surface of the substrate, cultivate in a greenhouse with a temperature of 22℃ / 18℃, an air humidity of 60% / 90%, and a day and night period of 16h / 8h, spray with rain water once every two days, and after 3 to 6 months of cultivation, screen out species with a moss coverage rate of more than 80%, and collect moss plants after large-scale propagation; The moss grown in the greenhouse was processed into pieces of 0.5 to 1.0 cm in size, stored at 4 ° C and transported to the mine wasteland, and the weight of the pieces was 260 g / m 2 Spread evenly on the surface of the improved soil.

5. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1 is characterized in that: The seedlings of the shrub plants are two-year-old seedlings, the seedlings of the tree plants are two-year-old seedlings, and the mosses are transplanted after indoor propagation.

6. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1 is characterized in that: The seedlings of the shrub and tree plants are planted in a hole planting manner, the hole planting parameters are a diameter of 10 to 20 cm, a depth of 20 to 30 cm, and a spacing of 35 cm between adjacent seedlings of the shrub and tree plants.

7. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1 is characterized in that: The species of the shrub plants include blueberry and Ledum palustris, and the species of the tree plants include white birch, willow and gray pine.

8. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 7 is characterized in that: The tolerant tree plant species are birch, willow and gray pine.

9. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1 is characterized in that: The preset time for replanting and nurturing plants in the ecological restoration area is six months to one year.

10. The metal mine ecological restoration method based on trapezoidal layer stacking and moss inoculation according to claim 1, characterized in that: The method is used to form an ecological plant community in the metal mine waste rock pile, which gradually evolves into a near-natural vegetation community system without degradation. Among them, the moss coverage is close to 40%, and the survival rates of white birch and gray pine are both over 50%. Compared with the treatment without moss coverage, the plant biomass index of white birch and gray pine increases by 4 times and 1 times, respectively.

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