A vegetation ecological restoration method for an engineering disturbance area of a low-latitude plateau subalpine meadow

Abstract

This invention discloses a method for vegetation ecological restoration in low-latitude plateau subalpine meadow engineering disturbance areas, belonging to the field of ecological restoration technology. Addressing the topographical differences between flat and embankment slopes in the engineering disturbance area, this invention adopts a "topography-modal" strategy: flat slope units employ a mixed sowing model of leguminous and grassy plants, while embankment units employ a composite model of deep-rooted native plants (such as *Phyllostachys nigra*) and grassy herbs. Seed germination, soaking, and rhizobium inoculation are carried out at the beginning of the rainy season, combined with deep tillage, basal fertilizer application, slope micro-topography construction, mulching for moisture retention, and drainage measures. Subsequent irrigation, fertilization, grazing bans, weeding, and pest and disease control are implemented. This invention enables rapid establishment of vegetation, improved soil structure, enhanced fertility, and long-term slope stability, effectively solving the problems of poor topographic adaptability, monotonous vegetation configuration, and insufficient slope stability in existing technologies. It is particularly suitable for vegetation restoration after engineering disturbance in high-altitude and fragile ecological areas.

Description

Technical Field

[0001] This invention relates to the field of ecological restoration and vegetation restoration technology, and in particular to a method for ecological restoration of vegetation in disturbed areas of low-latitude plateau subalpine meadow projects. Background Technology

[0002] Low-latitude plateau subalpine meadows play a vital role in soil and water conservation, water source protection, biodiversity maintenance, and regional ecological security. However, the high-altitude regions where these ecosystems are located are characterized by cold, dry climates, strong radiation, and high wind speeds, resulting in short growing seasons, low survival rates, and slow growth. Furthermore, factors such as slow soil development, thin soil layers, and exceptional sensitivity to environmental changes further limit the recovery process of vegetation systems after disturbances caused by engineering projects. Under engineering disturbances, the original vegetation communities, topsoil structure, and nutrient cycling processes of subalpine meadows are significantly damaged, leading to exposed surfaces, soil compaction, reduced water-holding capacity, depletion of nutrient pools, and accelerated soil erosion. This poses a serious threat to ecosystem stability and necessitates urgent ecological restoration.

[0003] Existing restoration techniques for disturbed areas often employ single-species sowing, uniform land preparation, and extensive management, failing to adequately consider the differences between flat slopes and embankments in terms of water migration, runoff erosion, freeze-thaw disturbance, soil structural stability, and the difficulty of plant establishment. This often leads to problems such as rapid initial coverage on flat slopes but insufficient fertility later, and low survival rates of shallow-rooted herbs and poor slope stability on embankments. Furthermore, existing methods lack synergistic integration of the nitrogen-fixing and fertilization effects of leguminous plants, the rapid coverage effect of grasses, and the slope-stabilizing effect of deep-rooted native plants. They also lack systematic integration of sowing season, seed treatment, slope micro-topography construction, and subsequent tending and management, making it difficult to form a closed-loop restoration process of "rapid coverage—soil improvement—structural stabilization—continuous community succession." Therefore, there is an urgent need to propose a method for vegetation ecological restoration in disturbed areas of low-latitude plateau and subalpine meadow engineering projects that can be implemented differently for flat and embankments, balancing rapid establishment with long-term stability. Summary of the Invention

[0004] The purpose of this invention is to provide a method for ecological restoration of vegetation in low-latitude plateau subalpine meadow engineering disturbance areas. This method aims to solve the problems of poor terrain adaptability, monotonous vegetation configuration, slow soil improvement, insufficient slope stability, and difficulty in maintaining existing engineering disturbance areas. It achieves rapid vegetation establishment, simultaneous restoration of soil structure and fertility, and long-term slope stability in engineering disturbance areas.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for vegetation ecological restoration in a disturbed area of ​​a low-latitude plateau subalpine meadow project, comprising a cylinder, and including the following steps: Step 1: Unit Survey and Zoning: Conduct on-site surveys of the disturbed areas of the project, and divide them into flat slope units with a slope of no more than 15° and slope units with a slope greater than 15°. Step 2: Determine the vegetation configuration pattern: For flat slope units, adopt the legume-grass mixed sowing restoration pattern; for embankment slope units, adopt the deep-rooted native plants and grass herbaceous plants composite restoration pattern. Step 3: Seed and seedling treatment: Cracking and soaking leguminous seeds, and mixing them evenly with rhizobium agent before sowing; for the use of cold arrow bamboo mother bamboo on slopes, select robust mother bamboo and dig them up with soil balls; Step 4: Land preparation and application of base fertilizer: For flat slope units, deep plow to 20-30 cm at the beginning of the rainy season and apply base fertilizer; for side slope units, construct horizontal steps or fish-scale pits along the contour lines and install interception and drainage facilities. Step 5, Sowing and Transplanting: In the early rainy season, flat slope units are sown by row sowing or broadcast sowing; slope units are first transplanted with arrow bamboo, and then grass and leguminous herb seeds are broadcast between rows or in the grid, and covered with moisture-retaining material after sowing. Step 6, nurturing and management: Keep the soil moist after sowing or transplanting, apply fertilizer and weed in a timely manner after emergence, and prohibit grazing for the first three years; Step 7: Restoration Evaluation and Regulation: Conduct continuous monitoring, using vegetation coverage, soil physicochemical properties, and water-stable aggregate content as core indicators to evaluate the restoration effect, and implement regulation based on the evaluation results.

[0006] Preferably, the legume-grass mixed replanting restoration mode for the flat slope unit in step two is: ryegrass and white clover are mixed at a weight ratio of 6:4; or ryegrass, tall fescue and white clover are mixed at a weight ratio of 5:3:2.

[0007] Preferably, the deep-rooted native plants and grass herbaceous plants composite restoration mode of the slope unit in step two is any one of the following: arrow bamboo + ryegrass, arrow bamboo + tall fescue, or hypericum + ryegrass.

[0008] Preferably, the method for treating legume seeds in step three is as follows: lightly abrading the seed coat with fine sandpaper or soaking in warm water at 40-50℃ for 12-24 hours; the soaking process involves soaking all seeds to be sown for 6-12 hours and then draining them until they are semi-dry; the legume seeds are mixed with rhizobium inoculum and sown within 24 hours; the mother bamboo for the cold arrow bamboo is selected as robust mother bamboo that is more than 2 years old, with intact rhizomes and abundant fibrous roots. When digging, 20-30 cm of the rhizome is retained and 30-40 cm of the rhizome is removed, and the soil ball is retained.

[0009] Preferably, the amount of base fertilizer applied to the flat slope unit in step four is: 1500-2000 kg of well-rotted farmyard manure or 300-500 kg of bio-organic fertilizer per mu, and 20-30 kg of compound fertilizer at the same time; the horizontal step width of the slope unit is 0.5-0.8 m, the step spacing is 1.5-2.0 m, and the fish scale pit is 0.6 m × 0.6 m × 0.4 m; a water interception ditch is set at the top of the slope, and a transverse drainage ditch is set every 20-30 m on the slope surface.

[0010] Preferably, the sowing method for the flat slope unit in step five is as follows: row spacing of 20-30 cm, sowing depth of 1-2 cm, soil covering of 1-1.5 cm, and total sowing amount controlled at 2.5-3.5 kg / mu; the diameter of the planting hole for the cold arrow bamboo in the slope unit is 50%-100% larger than the diameter of the soil ball, and the depth is 25-30 cm. 0.5-1.0 kg of decomposed organic fertilizer or compound fertilizer is added to the hole and mixed with fine topsoil; the covering material for moisture retention is straw mat, straw, or non-woven fabric, with a covering thickness of 2-3 cm; the sowing or transplanting is carried out in the early rainy season in June-July.

[0011] Preferably, in step six, irrigation should be carried out every 2-3 days within 30 days after sowing or transplanting, with each irrigation amount being 3000-4000 L / mu; urea should be applied 5-8 kg / mu 30-45 days after emergence; compound fertilizer should be applied 15-20 kg / mu or well-rotted organic fertilizer 500-700 kg / mu during the peak growing season; weeding should be carried out 2-3 times per year for flat slope units and 1-2 times per year for slope units.

[0012] Preferably, the core indicators mentioned in step seven include: vegetation cover, soil bulk density, soil moisture content, total nitrogen, organic matter, available phosphorus, available potassium and >0.25 mm water-stable aggregate content; the regulation includes supplementing topdressing, reseeding or improving drainage facilities according to the evaluation results.

[0013] Preferably, the disturbance zone of the low-latitude plateau subalpine meadow project is located in an area above 3000 meters above sea level.

[0014] Preferably, during the on-site investigation of the engineering disturbance area in step one, soil samples from the 0-30 cm layer are also collected simultaneously to determine soil bulk density, moisture content, total nitrogen, organic matter, available phosphorus, and available potassium, which serve as the initial background values ​​for restoration evaluation.

[0015] In summary, the present invention has the following beneficial effects: Firstly, this invention adopts a "topography-mode" restoration strategy, which differentiates the limiting factors for flat slopes and embankments. Compared with a uniform sowing method, this approach is more conducive to improving the survival rate of planted plants and the stability of the community.

[0016] Secondly, in the flat slope unit, the mixed sowing of leguminous and grassy plants fully utilizes the biological nitrogen fixation and fertilization effects of leguminous plants and the rapid mulching and root-entwining soil-stabilizing effects of grasses, which can accelerate the reduction of soil bulk density, the increase of moisture content, and the reconstruction of soil nutrient pools. Data from the example show that after three years of using the ryegrass + white clover pattern, the soil bulk density decreased by 21.87%, the total nitrogen content increased to 6.86 g / kg, and the organic matter increased to 262.18 g / kg.

[0017] Thirdly, the slope unit utilizes a synergistic configuration of deep-rooted native plants and fast-growing grasses to construct a root-soil composite that combines shallow interception with deep retention, effectively reducing the risk of slope runoff erosion and the mortality of shallow-rooted vegetation under freeze-thaw conditions. Examples show that after three years of using the *Phyllostachys edulis* + *Lycium chinense* composite model, the soil bulk density on the slope decreased to 0.79 g / cm³, while the moisture content increased to 36.33%.

[0018] Fourth, this invention systematically integrates seed treatment, sowing season, micro-topography construction, mulching for moisture retention, and tending management, enabling synergistic improvement in vegetation cover restoration, soil physicochemical properties, and soil and water conservation functions. After three years, the soil quality index in the flat slope model can reach 0.405–0.875, and in the embankment slope model it can reach 0.365–0.802, significantly better than natural restoration. Attached Figure Description

[0019] Figure 1 This is a comparison chart of soil quality changes in each plot of flat slope and each plot of embankment under different restoration modes in this embodiment of the invention from 2023 to 2025; Figure 2 These are vegetation coverage effect diagrams for each plot on a flat slope and each plot on a side slope under different restoration modes in embodiments of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] Example 1 (flat slope unit - mixed sowing mode of ryegrass + white clover) In a disturbed area of ​​a low-latitude plateau subalpine meadow project, flat slope units (slope ≤ 15°) were divided according to step one of this invention. The 6:4 weight ratio of ryegrass to white clover, as described in step two, was used for sowing. In step three, white clover seeds were mechanically cracked and soaked in warm water for 24 hours, and then treated with rhizobium inoculant before sowing. In step four, deep plowing to a depth of 25 cm was carried out at the beginning of the rainy season, with 1800 kg of well-rotted farmyard manure and 25 kg of compound fertilizer applied per acre. In step five, row sowing was carried out in late June at the beginning of the rainy season, with a row spacing of 25 cm, a seeding rate of 3.0 kg / acre, and a soil covering of 1.2 cm. Step six involved conventional irrigation, topdressing, and grazing ban management. Step seven involved continuous monitoring for three years.

[0022] Results: After three years, soil bulk density decreased from the initial 0.96 g / cm³ to 0.75 g / cm³, a decrease of 21.87%; soil moisture content increased from 30.90% to 36.38%, an increase of 17.74%; total nitrogen increased from 3.38 g / kg to 6.86 g / kg; and organic matter increased from 130.22 g / kg to 262.18 g / kg. Vegetation cover reached over 95%. These results indicate that this model significantly improved soil physical structure and accelerated fertility recovery.

[0023] Example 2 (flat slope unit - mixed sowing pattern of Cosmos spp. and tall fescue) The method was essentially the same as in Example 1, except that a mixture of cosmos and tall fescue was used for vegetation. After three years, monitoring showed that soil bulk density decreased from 0.89 g / cm³ to 0.74 g / cm³, moisture content increased from 27.13% to 33.58%, total nitrogen increased from 3.11 g / kg to 5.66 g / kg, and organic matter increased from 121.17 g / kg to 242.13 g / kg. This indicates that the combination of grasses and broadleaf plants can also achieve good mulch and water retention.

[0024] Example 3 (Slope Unit - Cold Arrow Bamboo Transplantation + Ryegrass Composite Mode) In a slope unit (slope > 15°) within a disturbed area of ​​a low-latitude plateau subalpine meadow project, the *Phyllostachys edulis* + ryegrass composite planting pattern described in step two was adopted. In step three, robust *Phyllostachys edulis* mother bamboo aged two years or older was selected, retaining 25cm of the rhizome, 35cm of the desiccated rhizome, and the root ball. In step four, horizontal steps 0.6m wide and 1.8m apart were constructed along contour lines, with a drainage ditch at the top of the slope. In step five, in late June, planting holes were prepared with a diameter 80% larger than the root ball diameter and a depth of 28cm, with 0.8kg of well-rotted organic fertilizer added to the holes. After transplanting the *Phyllostachys edulis*, ryegrass was sown between rows, covered with 1.5cm of soil, and then covered with 2.5cm of non-woven fabric. Step six involved nurturing and management.

[0025] Results: After three years, soil bulk density decreased from 0.93 g / cm³ to 0.79 g / cm³, moisture content increased from 30.90% to 36.33%, total nitrogen increased from 3.49 g / kg to 5.83 g / kg, and organic matter increased from 147.43 g / kg to 224.36 g / kg. This model combines rapid cover with long-term slope stabilization under slope conditions.

[0026] Example 4 (Slope Unit - Cold-resistant Bamboo + Tall Fescue Composite Mode) The study was essentially the same as in Example 3, except that tall fescue was selected from the grass family. Monitoring three years later showed that soil moisture content increased to 32.32% and soil bulk density decreased to 0.82 g / cm³, further validating that the combination of deep-rooted native plants and fast-growing grasses can effectively construct a "shallow interception-deep retention" structure on slopes.

[0027] Comparative Example (Natural Recovery) In the same engineering disturbance area, a control area that did not use the method of this invention was selected for natural restoration. After three years, the soil bulk density under slope conditions only decreased from 0.94 g / cm³ to 0.89 g / cm³, the vegetation coverage was less than 30%, and the improvement in soil nutrients was significantly lower than that in the embodiments of this invention.

[0028] Overall evaluation like Figure 1 As shown, the soil quality index was used to quantitatively evaluate the restoration effect: after three years, the soil quality index of the flat slope model of this invention reached 0.405–0.875 (good to excellent grade), and that of the slope model reached 0.365–0.802 (medium to good grade), while the soil quality index of the natural restoration area was below 0.3. The results indicate that this invention, through differentiated vegetation configuration based on terrain and model, and comprehensive management throughout the entire process, can simultaneously improve soil structure, water retention capacity, nutrient pool, and vegetation coverage, achieving rapid establishment and long-term stability of vegetation in the engineering disturbance area.

[0029] In addition, such as Figure 2 As shown, the flat slope units and side slope units of the various embodiments of the present invention achieved high levels of vegetation coverage (flat slope > 95%, side slope > 85%) after three years, while the coverage of the naturally restored control area was less than 30%, further verifying the significant advantages of the present invention in rapid vegetation establishment.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A vegetation ecological restoration method for an engineering disturbance area of a low-latitude plateau subalpine meadow, comprising a cylinder, characterized in that, Includes the following steps: Step 1: Unit Survey and Zoning: Conduct on-site surveys of the disturbed areas of the project, and divide them into flat slope units with a slope of no more than 15° and slope units with a slope greater than 15°. Step 2: Determine the vegetation configuration pattern: For flat slope units, adopt the legume-grass mixed sowing restoration pattern; for embankment slope units, adopt the deep-rooted native plants and grass herbaceous plants composite restoration pattern. Step 3: Seed and seedling treatment: Cracking and soaking leguminous seeds, and mixing them evenly with rhizobium inoculant before sowing; for the use of cold arrow bamboo mother bamboo on slopes, select robust mother bamboo and dig them up with soil balls; Step 4: Land preparation and application of base fertilizer: For flat slope units, deep plow to 20-30 cm at the beginning of the rainy season and apply base fertilizer; for side slope units, construct horizontal steps or fish-scale pits along the contour lines and install interception and drainage facilities. Step 5, Sowing and Transplanting: In the early rainy season, flat slope units are sown by row sowing or broadcast sowing; slope units are first transplanted with arrow bamboo, and then grass and leguminous herb seeds are broadcast between rows or in the grid, and covered with moisture-retaining material after sowing. Step 6, nurturing and management: Keep the soil moist after sowing or transplanting, apply fertilizer and weed in a timely manner after emergence, and prohibit grazing for the first three years; Step 7: Restoration Evaluation and Regulation: Conduct continuous monitoring, using vegetation coverage, soil physicochemical properties, and water-stable aggregate content as core indicators to evaluate the restoration effect, and implement regulation based on the evaluation results.

2. The vegetation ecological restoration method in the engineering disturbance area of low-latitude plateau subalpine meadow according to claim 1, characterized in that, The legume-grass mixed replanting restoration mode for the flat slope unit described in step two is as follows: ryegrass and white clover are mixed at a weight ratio of 6:4; or ryegrass, tall fescue and white clover are mixed at a weight ratio of 5:3:

2.

3. The vegetation ecological restoration method of the engineering disturbance area of the low-latitude highland subalpine meadow according to claim 1, characterized in that, The deep-rooted native plants and grass herbaceous plants composite restoration mode of the slope unit mentioned in step two is any one of the following: arrow bamboo + ryegrass, arrow bamboo + tall fescue, or hypericum + ryegrass.

4. The vegetation ecological restoration method of the engineering disturbance area of the low-latitude highland subalpine meadow according to claim 1, characterized in that, The seed-breaking treatment method for legume seeds in step three is as follows: lightly abrade the seed coat with fine sandpaper or soak in warm water at 40-50℃ for 12-24 hours; the soaking process involves soaking all seeds to be sown for 6-12 hours and then draining them until they are semi-dry; after mixing the legume seeds with rhizobium inoculant, sowing should be completed within 24 hours; the mother bamboo for the cold arrow bamboo should be a healthy mother bamboo that is more than 2 years old, with intact rhizomes and abundant fibrous roots. When digging, retain 20-30 cm of the rhizome and 30-40 cm of the rhizome, and retain the soil ball.

5. The vegetation ecological restoration method of the engineering disturbance area of the low-latitude highland subalpine meadow according to claim 1, characterized in that, In step four, the base fertilizer application rate for the flat slope unit is as follows: apply 1500-2000 kg of well-rotted farmyard manure or 300-500 kg of bio-organic fertilizer per mu, and apply 20-30 kg of compound fertilizer at the same time; the horizontal step width of the slope unit is 0.5-0.8 m, the step spacing is 1.5-2.0 m, and the fish scale pit specification is 0.6 m×0.6 m×0.4 m; a water interception ditch is set at the top of the slope, and a transverse drainage ditch is set every 20-30 m on the slope surface.

6. The vegetation ecological restoration method of the engineering disturbance area of the low-latitude highland subalpine meadow according to claim 1, characterized in that, In step five, the sowing method for the flat slope unit is as follows: row spacing of 20-30 cm, sowing depth of 1-2 cm, soil covering of 1-1.5 cm, and total sowing amount controlled at 2.5-3.5 kg / mu; for the slope unit, the diameter of the planting hole for cold arrow bamboo is 50%-100% larger than the diameter of the soil ball, and the depth is 25-30 cm. Add 0.5-1.0 kg of decomposed organic fertilizer or compound fertilizer to the hole and mix it with fine topsoil; the covering and moisture-retaining material is straw mat, straw or non-woven fabric, and the covering thickness is 2-3 cm; the sowing or transplanting is carried out in the early rainy season in June-July.

7. The vegetation ecological restoration method of the engineering disturbance area of the low-latitude highland subalpine meadow according to claim 1, characterized in that, In step six, irrigate every 2-3 days within 30 days after sowing or transplanting, with each irrigation amount being 3000-4000 L / mu; apply urea at 5-8 kg / mu 30-45 days after emergence; apply compound fertilizer at 15-20 kg / mu or well-rotted organic fertilizer at 500-700 kg / mu during the peak growing season; weed 2-3 times per year for flat slope units and 1-2 times per year for sloping units.

8. The vegetation ecological restoration method of the engineering disturbance area of the low-latitude highland subalpine meadow according to claim 1, characterized in that, The core indicators mentioned in step seven include: vegetation cover, soil bulk density, soil moisture content, total nitrogen, organic matter, available phosphorus, available potassium, and the content of water-stable aggregates >0.25 mm; the regulation includes supplementing topdressing, reseeding, or improving drainage facilities based on the evaluation results.

9. A method for vegetation ecological restoration in a low-latitude plateau subalpine meadow engineering disturbance area according to any one of claims 1 to 8, characterized in that, The disturbance area of ​​the low-latitude plateau subalpine meadow project is located in an area above 3,000 meters above sea level.

10. A method for vegetation ecological restoration in a low-latitude plateau subalpine meadow engineering disturbance area according to any one of claims 1 to 8, characterized in that, In step one, during the on-site investigation of the disturbed area, soil samples from the 0-30 cm layer were also collected simultaneously to determine soil bulk density, moisture content, total nitrogen, organic matter, available phosphorus, and available potassium, which served as the initial baseline values ​​for the restoration evaluation.

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