Method for screening and constructing vegetation of ion-type rare earth mine based on niche complementation

Abstract

The application discloses a method for plant combination screening and vegetation construction of ion-type rare earth mines based on niche complementation, and belongs to the technical field of mine ecological restoration, and comprises the following steps: S1, habitat evaluation; S2, construction of a niche index system; S3, candidate plant screening; S4, plant combination optimization; S5, vegetation construction implementation; and S6, dynamic management. The method for plant combination screening and vegetation construction of ion-type rare earth mines based on niche complementation is used, the vegetation survival rate and coverage rate of ion-type rare earth mines are improved, the improvement of soil physical and chemical properties is accelerated, the heavy metal and rare earth element residues are reduced, and water and soil loss is effectively prevented; the constructed vegetation community has the advantages of strong anti-interference ability, good self-maintenance ability, high restoration efficiency, short cycle, and the like; and ecological restoration and efficient resource utilization are considered.

Description

Technical Field

[0001] This invention belongs to the field of mine ecological restoration technology, specifically involving a method for screening and constructing vegetation combinations in ion-type rare earth mines based on niche complementarity. Background Technology

[0002] During the mining of ion-adsorption rare earth mines, surface vegetation and soil structure are damaged. The resulting mining area habitat is characterized by strong acidity (pH value is usually 4.0-5.5), poor nutrient content (organic matter content ≤10g / kg), high levels of heavy metals and rare earth elements, and severe soil erosion, making it difficult for vegetation to recover naturally.

[0003] However, existing mine vegetation restoration technologies often employ single species or empirical plant combinations, resulting in technical shortcomings such as intense inter-species competition, unstable community structure, low restoration efficiency, and poor sustainability. Existing patents primarily focus on soil improvement, stratified vegetation configuration, or microbial synergistic restoration, failing to systematically apply niche complementarity theory to plant combination selection. They lack quantifiable niche assessment indicators and operable dynamic management mechanisms, making it difficult to achieve long-term stable self-maintenance of vegetation communities and thus unable to meet the sustainable needs of ecological restoration in ion-adsorption rare earth mines.

[0004] Therefore, a new method is urgently needed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for screening and constructing vegetation combinations in ion-type rare earth mines based on niche complementarity. This method improves the survival rate and coverage of vegetation in ion-type rare earth mines, accelerates the improvement of soil physicochemical properties, reduces the residue of heavy metals and rare earth elements, and effectively prevents soil erosion. The constructed vegetation community has strong anti-interference ability, good self-sustaining ability, high restoration efficiency, and short cycle. It takes into account both ecological restoration and efficient resource utilization.

[0006] To achieve the above objectives, this invention provides a method for screening and constructing vegetation combinations in ion-type rare earth mines based on niche complementarity, comprising the following steps: S1. Using conventional sampling and surveying methods, conduct a comprehensive survey of the soil physicochemical properties, topography, climate conditions and existing vegetation of ion-adsorption rare earth mines to obtain basic data on the mine habitat; S2. Construct a plant niche characteristic index system. Construct a niche characteristic index system covering four dimensions: resource utilization, environmental adaptation, functional characteristics and interspecific relationships. Use the analytic hierarchy process (AHP) to determine the weights of each dimension and specific index, and formulate quantitative scoring standards for each index. S3. Based on the plant niche characteristic index system in S2, candidate plants are screened. Combining indoor and field experiments, plant niche indices are measured to screen out candidate plants with obvious niche differentiation, strong complementarity and suitability to mining habitats. The niche indices include niche width and niche overlap, which are calculated using the Levins formula and the Schoener formula, respectively. S4. Optimize plant combinations from three dimensions: space, time, and function, to form a three-dimensional configuration pattern of "herbaceous plants-shrubs-trees"; S5. Pre-treat the mine soil, adopt land preparation methods adapted to the mine terrain, plant according to the optimized plant combination and time sequence, and co-inoculate microorganisms to complete the vegetation construction. S6. Regularly monitor the constructed vegetation community and dynamically adjust the vegetation community based on the monitoring results to achieve self-optimization and long-term stable maintenance of the vegetation community.

[0007] Preferably, in S1, the conventional sampling and surveying method specifically includes: Sampling points were set up using a grid sampling method, and multiple parallel soil samples were collected from each sampling point and sent to a CMA-certified testing institution to determine the soil physicochemical properties. GIS technology was used in conjunction with field surveys to analyze the topography and geomorphology. Meteorological data for the past 5 years in the mining area were collected and combined with field observations to complete the climate condition survey. The quadrat method was used to investigate the existing vegetation status.

[0008] Preferably, in S1, the grid size of the grid sampling method is 5m×5m, and 3-5 sampling points are set up in the mining area, tailings area and slope area respectively, and 3 parallel soil samples are collected at each sampling point; The sample plot area of ​​the sampling method is 1m×1m, and 10 sample plots are set up in each area; the soil physicochemical properties include pH value, organic matter content, nitrogen, phosphorus and potassium nutrient content, rare earth element residue and heavy metal content; The topography includes slope, aspect, altitude, and degree of erosion; the climate conditions include average annual temperature, annual precipitation, frost-free period, and sunshine duration.

[0009] Preferably, in S2, the analytic hierarchy process (AHP) is specifically the analytic hierarchy process (AHP), and the weights of each dimension are as follows: The resource utilization dimension is 0.25, the environmental adaptation dimension is 0.35, the functional characteristics dimension is 0.25, and the interspecific relationship dimension is 0.15. The quantitative scoring standard is 1-10 points, and the scoring standard is determined by combining expert scores with indoor and outdoor experimental data.

[0010] Preferably, in S2, the niche characteristic indicators are as follows: Resource utilization dimensions include nutrient requirement type, water use efficiency, and light adaptability; environmental adaptability dimensions include acid tolerance, tolerance to poor soil, heavy metal tolerance, and stress resistance; functional characteristics dimensions include nitrogen fixation capacity, root type, litter decomposition rate, and soil and water conservation capacity; and interspecific relationships dimensions include symbiosis, allelopathy, and competition intensity.

[0011] Preferably, in S3, the biological nitrogen fixation rate of the nitrogen-fixing plants is ≥17%, and the biological nitrogen fixation rate is determined by the Kjeldahl method; the suitable growth pH value of the acid-tolerant plants is 4.0-6.0; the survival rate of the poor-fertility tolerant plants in soil with an organic matter content ≤10g / kg is ≥80%, and the survival rate is determined by continuous observation for 6 months in a field small plot experiment.

[0012] Preferably, in S4, the spatial dimension is optimized as a three-dimensional configuration of upper-layer trees, middle-layer shrubs, and lower-layer herbs, clearly defining the planting density and spacing of each layer of plants; the temporal dimension is optimized as the sequential planting of "pioneer plants, transitional plants, and target plants"; and the functional dimension is optimized as the functional combination of nitrogen-fixing, soil and water conservation, and heavy metal-tolerant plants.

[0013] Preferably, in S5, the soil pretreatment includes: The process involves applying quicklime to adjust soil pH, adding well-rotted organic fertilizer and biochar to improve soil fertility, and inoculating with arbuscular mycorrhizal fungi. The land preparation methods include pit planting, fish-scale pit planting, or strip planting. The microorganisms include arbuscular mycorrhizal fungi and rhizosphere growth-promoting bacteria, with the concentration of the rhizosphere growth-promoting bacteria being 1×10⁻⁶. 8 CFU / mL.

[0014] Preferably, in step S5, the amount of quicklime applied is 100-150 kg / mu, and the soil pH is adjusted to 5.5-6.0; the amount of decomposed organic fertilizer added is 2000 kg / mu, the amount of biochar added is 50 kg / mu, and the tillage depth is 20-25 cm; the amount of arbuscular mycorrhizal fungi inoculated is 50 g / plant, which is mixed with the soil at a mass ratio of 1:10 and then filled into the planting hole; healthy one-year-old seedlings are selected for trees and shrubs, and bermudagrass is sown by broadcasting.

[0015] Preferably, in S6, the periodic monitoring is conducted once at the end of each quarter and once a year for comprehensive monitoring; the monitoring indicators include changes in vegetation coverage, biomass, species diversity and soil physicochemical properties, and each monitoring indicator is measured using the corresponding conventional measurement method; The criteria for dynamic adjustment are as follows: when the survival rate of a species is below 60% or the niche overlap with other species exceeds 0.25, the poorly growing species is replaced and a suitable new species is added. The vegetation coverage was determined by the quadrat method, the biomass by the harvest method, and the species diversity was characterized by the Shannon-Wiener index. The soil physicochemical properties were sent to a testing institution with CMA accreditation for testing. The adapted new species had consistent niche complementarity with the original species and met the S3 screening criteria.

[0016] Therefore, the present invention employs the above-mentioned method for screening and constructing vegetation combinations of ion-type rare earth mines based on niche complementarity. Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) Apply the theory of complementary ecological niches to vegetation restoration in ion-type rare earth mines, establish a quantitative index system of plant ecological niche characteristics, clarify the methods for measuring ecological niche width and ecological niche overlap, replace the traditional empirical plant screening method, improve the scientificity and rationality of plant combination, and solve the problem of blind plant matching in existing technologies. (2) A three-dimensional plant combination optimization model based on space, time and function is proposed, clarifying the planting parameters, timing and functional division of plants in each layer, realizing the efficient complementary use of resources such as light, heat, water and nutrients, reducing the intensity of competition among species, and significantly improving the stability and anti-interference ability of the vegetation community. (3) Construct a closed-loop dynamic management mechanism of “screening-construction-monitoring-adjustment”, clarify the monitoring indicators, monitoring frequency and adjustment standards, realize the self-optimization of vegetation communities, solve the technical shortcomings of one-time restoration and poor sustainability in existing technologies, and ensure the long-term stability of restoration effect; (4) Optimize soil pretreatment and microbial synergistic measures, clarify the selection basis and operation specifications of each parameter, improve plant survival rate and soil improvement efficiency, take into account ecological restoration and efficient resource utilization, and achieve a win-win situation of ecological and economic benefits.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating an embodiment of the present invention's method for screening and constructing vegetation combinations in ion-type rare earth mines based on niche complementarity. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used in the present invention should have the ordinary meaning understood by those skilled in the art.

[0020] Example 1 like Figure 1 As shown, this embodiment provides a method for screening and constructing vegetation combinations of ion-type rare earth mines based on niche complementarity. It should be understood that the specific parameters, models and protocols mentioned in this embodiment are merely examples to help those skilled in the art understand the present invention, and are not intended to limit the present invention.

[0021] An abandoned rare earth mine in southern China was selected as the implementation site. The soil pH in this area is 4.2-5.0, the organic matter content is ≤10g / kg, the residual rare earth element content in the soil is 120-350mg / kg, the heavy metal Cd content is 25-35mg / kg, and the Pb content is 80-100mg / kg. The mine slope is 15-30°, belonging to a moderately eroded area. The average annual temperature in this area is 18-20℃, the annual precipitation is 1200-1500mm, the frost-free period is 280-300 days, and there is sufficient sunshine. The existing vegetation coverage is less than 15%, and it is mainly composed of annual herbaceous plants with poor growth and no dominant species.

[0022] The present invention provides a method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity, comprising the following steps: S1. Habitat assessment was conducted using a grid sampling method with a grid size of 5m×5m. Four sampling points were set up in each of the mining area, tailings area, and slope area. After removing the top 0-5cm of topsoil, soil samples were collected from the 5-20cm soil layer. Three parallel samples were collected from each sampling point and sent to a CMA-certified testing institution to determine the soil pH, organic matter, nitrogen, phosphorus, potassium, and heavy metal (Cd, Pb) content. GIS technology was used to create a topographic map of the mine. The slope and aspect were recorded through field surveys, and the erosion levels (light, moderate, and severe) were classified according to the soil erosion classification and grading standards. Meteorological data (from the local meteorological station) for the past five years were collected for the mining area, including annual average temperature, annual precipitation, and frost-free period. Sunlight duration was also recorded through field observations (9:00-17:00 daily, recorded once per hour). Ten quadrats were set up in each area using the 1m×1m quadrat method to investigate the species, cover, and height of existing vegetation. The results showed that the main native species in the area include Bermuda grass, Lespedeza bicolor, Pinus massoniana, and Amorpha fruticosa. Among them, Bermuda grass had the highest cover, at 8%-12%, but its growth was poor, with a survival rate of only 45%-55%. S2. Construct a niche index system, which covers four dimensions: resource utilization, environmental adaptation, functional characteristics, and interspecific relationships. The weights of each dimension are determined using the Analytic Hierarchy Process (AHP). Environmental adaptation dimension 0.35, resource utilization dimension 0.25, functional characteristics dimension 0.25, interspecific relationships dimension 0.15; establish quantitative scoring standards (1-10 points) for each indicator, among which, for the acid tolerance indicator, pH value 4.0-6.0 is scored as 8-10 points, pH value 6.0-7.0 is scored as 5-7 points, and pH value <4.0 or >7.0 is scored as 1-4 points; In the indicators of tolerance to poor soil, a survival rate of ≥80% in soil with organic matter ≤10g / kg is scored as 8-10 points, a survival rate of 60%-80% is scored as 5-7 points, and a survival rate of <60% is scored as 1-4 points. In the biological nitrogen fixation rate index, a biological nitrogen fixation rate ≥17% is scored as 8-10 points, 12%-17% as 5-7 points, and <12% as 1-4 points; By combining scores from five senior experts in the field (all with registered qualifications) with indoor and outdoor experimental data, specific scoring standards for each indicator were determined, forming a complete niche assessment system with an assessment error of ≤5%. S3. Candidate plant screening, including the following steps: S301. The first step of the initial screening, combined with the habitat survey results of S1, selected 12 native plant species that are distributed in and around the mine and have strong adaptability, taking into account nitrogen-fixing, deep-rooted, pioneer, and soil-improving functional plants. S302. The second step of the screening involved indoor pot experiments. Twelve plant species were planted in simulated mine soil (pH 4.5, organic matter 8 g / kg, Cd content 30 mg / kg). Three replicate pots were set up for each species and cultured for 3 months (culture conditions: temperature 25±2℃, light 12h / d, humidity 60±5%). The Levins formula was used to calculate the niche width and the Schoener formula was used to calculate the niche overlap. The survival rate and growth of each plant were measured. S303. The third step of verification involved setting up 1m×1m quadrats in the mine, planting three quadrats for each plant species, and continuously observing for six months. Ultimately, Bermuda grass, Lespedeza bicolor, Pinus massoniana, and Amorpha fruticosa were selected as candidate species, with the following specific characteristics: Bermuda grass (herbaceous), with a poor soil tolerance score of 9, a niche breadth of 0.92 (calculated using the Levins formula), and an acid tolerance of pH 4.0-6.5, and a significant underground biomass. (Measured using the harvest method), with outstanding soil and water conservation capabilities and a survival rate of 89%; Lespedeza bicolor (shrub), with a biological nitrogen fixation rate of 17.78% (measured using the Kjeldahl method), an acid tolerance pH of 4.2-5.8, a niche width of 0.88 (calculated using the Levins formula), a niche overlap with Amorpha fruticosa of 0.036 (calculated using the Schoener formula), and a survival rate of 87%; Pinus massoniana (tree), tolerant of poor soil, suitable for environments with an average annual temperature of 13-22℃ and an annual precipitation of 800-1800mm, with a niche width of 0. 86 (calculated using the Levins formula), with a survival rate ≥85% in soils with rare earth residues of 120-350 mg / kg; Amorpha fruticosa (shrub), with a biological nitrogen fixation rate of 19.2% (determined by the Kjeldahl method), a heavy metal Cd tolerance concentration ≤50 mg / kg (determined by indoor stress test), and a niche index of 1.0 with Lespedeza bicolor, showing significant complementarity in root niches, and a survival rate of 91%; the average niche overlap of the four plants is ≤0.18, indicating strong complementarity and no serious competitive exclusion relationship, making them suitable for harsh mining habitats; S4. A three-dimensional configuration of "Masson pine, Lespedeza, Amorpha fruticosa, and Bermuda grass" is adopted, and the specific optimization scheme is as follows: In terms of space, the upper layer is planted with Masson pine with a spacing of 2m×3m and a planting density of 167 plants / acre. This parameter is determined based on the growth characteristics of one-year-old Masson pine seedlings and the fertility of the mine soil, which can ensure sufficient light resources for the plants and reduce inter-species competition. The middle layer is planted with Lespedeza and Amorpha fruticosa, with a plant spacing of 1m×1.5m and a planting density of 444 plants / acre. The two are matched in a 1:1 ratio, using a combination of vertical axial root type (Lespedeza) and horizontal axial root type (Amorpha fruticosa), with a root niche index of 1.0 and complementary nitrogen fixation functions. The lower layer is planted with bermudagrass, using a broadcast sowing method at a seeding rate of 20g / m². 2 The seeding rate is determined based on the germination rate of Bermuda grass (≥85%) and the ground cover requirements. Bermuda grass has a clump-forming root system with a high proportion of the ecological niche in the topsoil and an overlap of ≤0.15 with the root ecological niche of the middle shrubs. In terms of timing, in spring (March-April, average daily temperature ≥15℃), Bermuda grass (pioneer plant) is sown first to quickly achieve surface coverage and prevent soil erosion; in summer (June-July, abundant rainfall), Lespedeza and Amorpha fruticosa (transitional plants) are planted to improve seedling survival rate by taking advantage of rainfall; in autumn (September-October, suitable temperature), Masson pine (target plant) is planted to lay the foundation for long-term community stability; in terms of function, Bermuda grass is responsible for surface coverage and soil and water conservation, Lespedeza and Amorpha fruticosa are responsible for nitrogen fixation and soil improvement, and Masson pine is responsible for building the upper structure of the community and improving community stability. The four plant species complement each other in terms of space, time, and function, with an overall fine root niche width index of over 0.085, achieving efficient utilization of light, heat, water, and nutrient resources and reducing interspecific competition. S5. Vegetation creation, which includes the following operations: Soil pretreatment: Based on the soil pH value (4.2-5.0), apply 120 kg / mu of quicklime (this dosage has been verified by indoor tests to adjust the soil pH value to 5.5-6.0, neutralizing soil acidity and avoiding soil compaction caused by excessive quicklime). After evenly spreading, till and mix thoroughly to a depth of 20-25 cm. Add 2000 kg / mu of well-rotted organic fertilizer (≥80% decomposition) and 50 kg / mu of biochar, till and mix thoroughly to improve soil fertility and aeration. Inoculate with arbuscular mycorrhizal fungi at a rate of 50 g / plant. Mix the arbuscular mycorrhizal fungi with soil at a mass ratio of 1:10 and fill the planting hole to enhance soil fertility and aeration. Plant root absorption capacity; land preparation method: for slope areas, fish-scale pit preparation is used, with a pit diameter of 50cm, a pit depth of 40cm, and a pit spacing of 1m×1.5m, adapting to the slope terrain and preventing soil erosion; for flat and gentle slope areas, pit preparation is used, with a pit diameter of 40cm and a pit depth of 30cm, ensuring that the seedling roots can spread out; planting operation: according to the time sequence determined in S4, planting should be carried out on cloudy or light rainy days. For trees and shrubs, select healthy one-year-old seedlings (seedling height ≥30cm, ground diameter ≥0.5cm). When planting, straighten the seedlings, backfill the soil and compact it, and water thoroughly (1-2kg of water per plant); bermudagrass is sown by broadcasting, with a sowing rate of 20g / m². 2 After sowing, cover with 1-2 cm of soil and spray with water to keep moist (maintain soil moisture at 60±5%); simultaneously inoculate with rhizosphere growth-promoting bacteria (concentration 1×10⁻⁶). 8 CFU / mL), apply 500mL of water to each shrub and tree, and spray with a diluted rhizosphere growth-promoting bacteria solution (1:100 dilution ratio) after sowing bermudagrass to promote plant growth and complete vegetation construction; S6. Dynamic management, the specific solution is as follows: The monitoring plan involves monitoring once at the end of each quarter (March, June, September, and December), using the quadrat method to investigate vegetation growth (plant height, canopy coverage, and survival rate). Ten 1m×1m quadrats are set up in each area, and soil samples are collected and sent to a CMA-certified testing institution to determine the soil physicochemical properties. A comprehensive monitoring is conducted once a year in December, including a species diversity survey (characterized by the Shannon-Wiener index) and biomass measurement (using the harvest method). Management measures include timely removal of weeds within the sample plots, once every two months, to prevent weeds from competing with target plants for resources; strengthening slope drainage during the rainy season by setting up drainage ditches (5m apart, 30cm deep) on the slopes to prevent soil erosion. Adjust the criteria: when the survival rate of a species is below 60% or the niche overlap with other species exceeds 0.25, promptly replace it with a complementary alternative species (e.g., when Lespedeza grows poorly, replace it with Magnolia multiflora, which meets the S3 screening criteria, with a niche width of 0.87 and an overlap with other species of ≤0.19). In the later stages of management, two years after vegetation establishment, human intervention is gradually reduced, with supplementary measures such as water replenishment and slope stabilization only implemented after extreme weather events (drought, rainstorms) to achieve self-sustaining of the vegetation community.

[0023] Therefore, this invention adopts the above-mentioned method for screening and constructing vegetation combinations in ion-type rare earth mines based on niche complementarity. This method improves the survival rate and coverage of vegetation in ion-type rare earth mines, accelerates the improvement of soil physicochemical properties, reduces the residue of heavy metals and rare earth elements, and effectively prevents soil erosion. The constructed vegetation community has strong anti-interference ability, good self-maintenance ability, high restoration efficiency, and short cycle. It takes into account both ecological restoration and efficient resource utilization.

[0024] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity, characterized in that, Includes the following steps: S1. Using conventional sampling and surveying methods, conduct a comprehensive survey of the soil physicochemical properties, topography, climate conditions and existing vegetation of ion-adsorption rare earth mines to obtain basic data on the mine habitat; S2. Construct a plant niche characteristic index system. Construct a niche characteristic index system covering four dimensions: resource utilization, environmental adaptation, functional characteristics and interspecific relationships. Use the analytic hierarchy process (AHP) to determine the weights of each dimension and specific index, and formulate quantitative scoring standards for each index. S3. Based on the plant niche characteristic index system in S2, candidate plants are screened. Combining indoor and field experiments, plant niche indices are measured to screen out candidate plants with obvious niche differentiation, strong complementarity and suitability to mining habitats. The niche indices include niche width and niche overlap, which are calculated using the Levins formula and the Schoener formula, respectively. S4. Optimize plant combinations from three dimensions: space, time, and function, to form a three-dimensional configuration pattern of "herbaceous plants-shrubs-trees"; S5. Pre-treat the mine soil, adopt land preparation methods adapted to the mine terrain, plant according to the optimized plant combination and time sequence, and co-inoculate microorganisms to complete the vegetation construction. S6. Regularly monitor the constructed vegetation community and dynamically adjust the vegetation community based on the monitoring results to achieve self-optimization and long-term stable maintenance of the vegetation community.

2. The method for screening and constructing vegetation combinations in ion-type rare earth mines based on niche complementarity according to claim 1, characterized in that, In S1, the conventional sampling and surveying methods specifically include: Sampling points were set up using a grid sampling method, and multiple parallel soil samples were collected from each sampling point and sent to a CMA-certified testing institution to determine the soil physicochemical properties. GIS technology was used in conjunction with field surveys to analyze the topography and geomorphology. Meteorological data for the past 5 years in the mining area were collected and combined with field observations to complete the climate condition survey. The quadrat method was used to investigate the existing vegetation status.

3. The method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity according to claim 2, characterized in that, In S1, the grid size of the grid sampling method is 5m×5m, and 3-5 sampling points are set up in the mining area, tailings area and slope area respectively, and 3 parallel soil samples are collected at each sampling point. The sample plot area of ​​the sampling method is 1m×1m, and 10 sample plots are set up in each area; the soil physicochemical properties include pH value, organic matter content, nitrogen, phosphorus and potassium nutrient content, rare earth element residue and heavy metal content; The topography includes slope, aspect, altitude, and degree of erosion; the climate conditions include average annual temperature, annual precipitation, frost-free period, and sunshine duration.

4. The method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity according to claim 3, characterized in that, In S2, the analytic hierarchy process (AHP) is specifically the AHP method, and the weights of each dimension are as follows: The resource utilization dimension is 0.25, the environmental adaptation dimension is 0.35, the functional characteristics dimension is 0.25, and the interspecific relationship dimension is 0.

15. The quantitative scoring standard is 1-10 points, and the scoring standard is determined by combining expert scores with indoor and outdoor experimental data.

5. The method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity according to claim 4, characterized in that, In S2, the specific niche characteristic indicators are as follows: Resource utilization dimensions include nutrient requirement type, water use efficiency, and light adaptability; environmental adaptability dimensions include acid tolerance, tolerance to poor soil, heavy metal tolerance, and stress resistance; functional characteristics dimensions include nitrogen fixation capacity, root type, litter decomposition rate, and soil and water conservation capacity; and interspecific relationships dimensions include symbiosis, allelopathy, and competition intensity.

6. The method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity according to claim 5, characterized in that, In S3, the biological nitrogen fixation rate of the nitrogen-fixing plants is ≥17%, and the biological nitrogen fixation rate is determined by the Kjeldahl method; the suitable growth pH value of the acid-tolerant plants is 4.0-6.0; the survival rate of the poor-fertility tolerant plants in soil with organic matter content ≤10g / kg is ≥80%, and the survival rate is determined by continuous observation for 6 months in a field small plot experiment.

7. The method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity according to claim 6, characterized in that, In S4, the spatial dimension is optimized to a three-dimensional configuration of upper-layer trees, middle-layer shrubs, and lower-layer herbs, clearly defining the planting density and spacing of plants in each layer; the temporal dimension is optimized to the sequential planting of "pioneer plants, transitional plants, and target plants"; and the functional dimension is optimized to the functional combination of nitrogen-fixing, soil and water conservation, and heavy metal tolerance plants.

8. The method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity according to claim 7, characterized in that, In S5, the soil pretreatment includes: The process involves applying quicklime to adjust soil pH, adding well-rotted organic fertilizer and biochar to improve soil fertility, and inoculating with arbuscular mycorrhizal fungi. The land preparation methods include pit planting, fish-scale pit planting, or strip planting. The microorganisms include arbuscular mycorrhizal fungi and rhizosphere growth-promoting bacteria, with the concentration of the rhizosphere growth-promoting bacteria being 1×10⁻⁶. 8 CFU / mL.

9. The method for screening and constructing vegetation combinations in ion-adsorption rare earth mines based on niche complementarity according to claim 8, characterized in that, In S5, the amount of quicklime applied is 100-150 kg / mu, and the soil pH is adjusted to 5.5-6.0; the amount of decomposed organic fertilizer added is 2000 kg / mu, the amount of biochar added is 50 kg / mu, and the tillage depth is 20-25 cm; the amount of arbuscular mycorrhizal fungi inoculated is 50 g / plant, which is mixed with the soil at a mass ratio of 1:10 and then filled into the planting hole; healthy one-year-old seedlings are selected for trees and shrubs, and bermudagrass is sown by broadcasting.

10. The method for screening and constructing vegetation combinations in ion-type rare earth mines based on niche complementarity according to claim 9, characterized in that, In S6, the regular monitoring is conducted once at the end of each quarter and once a year for comprehensive monitoring; the monitoring indicators include changes in vegetation coverage, biomass, species diversity and soil physicochemical properties, and each monitoring indicator is measured using the corresponding conventional measurement method; The criteria for dynamic adjustment are as follows: when the survival rate of a species is below 60% or the niche overlap with other species exceeds 0.25, the poorly growing species is replaced and a suitable new species is added. The vegetation coverage was determined by the quadrat method, the biomass by the harvest method, and the species diversity was characterized by the Shannon-Wiener index. The soil physicochemical properties were sent to a testing institution with CMA accreditation for testing. The adapted new species had consistent niche complementarity with the original species and met the S3 screening criteria.

Images