Preparation of composite repair material suitable for freeze-thaw prevention of degraded grass carpet layer in alpine meadow
By preparing multi-layered composite restoration materials that integrate freeze-thaw resistance, hydrothermal regulation, and nutrient supply functions, the freeze-thaw cycle problem of alpine meadow grass carpet layers was solved, achieving long-term stability and ecological restoration effects, and reducing the difficulty of engineering implementation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INSTITUTE OF ENVIRONMENT AND SUSTAINABLE DEVELOPMENT IN AGRICULTURE CAAS
- Filing Date
- 2025-07-29
- Publication Date
- 2026-06-19
AI Technical Summary
Existing technologies lack sufficient freeze-thaw cycle protection mechanisms in alpine meadow grass layers, resulting in insufficient long-term stability and ecological compatibility. They are also difficult to implement in engineering projects and are not suitable for extreme alpine environments.
A composite remediation material was prepared, comprising a seed protection layer, a response layer, a moisture regulation layer, a nutrient matrix layer, and an anchoring layer. Through interfacial polymerization, melt blending, and physical composite technology, a multi-layer structure was formed, integrating freeze-thaw protection, hydrothermal regulation, and nutrient supply functions to adapt to cold environments.
It has achieved long-term freeze-thaw protection in degraded grass carpet layers of alpine meadows, improved soil structure stability and water retention capacity, reduced the difficulty of engineering implementation, and adapted to extreme environments.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of ecological restoration materials technology, specifically relating to the preparation method and application of a composite restoration material suitable for freeze-thaw protection of degraded grass carpet layers in alpine meadows. Background Technology
[0002] The alpine meadow sod layer is a soft, tough, and easily transported topsoil layer formed under natural vegetation in high-altitude cold regions. It comprehensively reflects the soil morphology and formation process of the alpine meadow ecosystem. In my country's soil classification system, the sod surface layer (diagnostic surface layer) refers to the sod-like surface layer of alpine meadow vegetation, formed by the intertwining of living and dead roots, with a thickness ≥5cm, entangled roots accounting for ≥50% by volume, and a bulk density of 0.5g / cm³. 3 ~1.1g / cm 3 It has cold properties.
[0003] The sod layer is the main functional layer of alpine meadow soil, undertaking the vast majority of soil ecological functions and ecosystem services, including maintaining soil productivity, water conservation and regulation, carbon sequestration and climate regulation, soil erosion protection, biodiversity maintenance, and support for pastoral production. The sod layer concentrates most of the root system, organic matter, fine soil material, and nutrients in the meadow soil, serving as a pioneering barrier for the ecological security of the Qinghai-Tibet Plateau.
[0004] However, in recent years, due to climate change, overgrazing, and other unreasonable human activities, one-third of the natural grasslands on the Qinghai-Tibet Plateau have experienced varying degrees of degradation. Overgrazing and severe trampling by livestock have led to the erosion of large areas of alpine meadow grass, while the continuous disturbance and large-scale outbreaks of rodents such as plateau pikas have exacerbated the fragmentation of alpine meadow vegetation, resulting in the exposure and patchy formation of alpine meadows.
[0005] Freeze-thaw cycles are a significant factor in the degradation of the sod cover in alpine meadows. These cycles damage the sod cover through the following mechanisms: 1. Volume change: Soil moisture expands during freezing and contracts during thawing, repeatedly disrupting soil structure; 2. Particle migration: Freeze-thaw cycles promote the vertical migration of soil particles, with fine particles moving downwards and coarse particles moving upwards, leading to soil stratification; 3. Soil erosion: The combined effects of freeze-thaw cycles, precipitation erosion, and rodent activity accelerate the erosion of the sod surface; 4. Soil compaction: Freeze-thaw cycles increase soil bulk density and enhance soil compaction.
[0006] Existing materials and technologies for the restoration of alpine grasslands mainly include: 1. Artificial vegetation erosion-resistant carpets in alpine regions (CN202311741820.1): The preparation of these erosion-resistant carpets includes the following steps: ① selection of carpet species; ② selection of carpet substrate; ③ site selection and land preparation; ④ sowing and cultivation; ⑤ field management, etc. This technology mainly addresses the problem of water erosion, but it is insufficient in protecting against freeze-thaw cycles and is not specifically designed for the special environment of alpine meadows; 2. Restoration methods for degraded alpine grasslands (CN113170705B): Bio-sandbags are prepared and placed in trenches dug in areas where poisonous weeds grow. Bio-skin seed sources are sprayed onto the surface of the bio-sandbags, followed by backfilling with soil, compaction, and laying sand barriers. While this technology is specifically designed for the unique environment of alpine grassland degradation, its construction is complex, material transportation to high-altitude regions is costly, and its long-term stability under freeze-thaw cycles needs further verification. 3. Restoration method for moderately to mildly salinized grasslands (CN115643847A): This method includes the following steps: ① Irrigating the salinized grassland with an amendment solution; ② Laying biomass crusts on the salinized grassland; ③ Placing seeding strips containing salt-tolerant plant seeds on the biomass crusts, followed by covering with soil and irrigation. This technology primarily addresses salinization issues but lacks sufficient protection against freeze-thaw cycles, and its effectiveness may be limited in extreme low-temperature environments.
[0007] Foreign technologies include bioengineered blankets, heat-regulating ground cover materials, and soil stabilizers combined with biocrust technology. However, these technologies have limited adaptability to extreme cold environments and are not specifically tailored to the unique cold environments of the Qinghai-Tibet Plateau. In summary, existing technologies have the following shortcomings: 1. Primarily passive protection, lacking active regulation mechanisms; 2. Insufficient long-term stability, making them difficult to adapt to extreme environments; 3. Insufficient ecological compatibility, leading to significant engineering implementation difficulties. Therefore, there is an urgent need to develop an innovative composite material that integrates freeze-thaw resistance and ecological restoration functions to address the problem of restoring degraded grass cover layers in alpine meadows. Summary of the Invention
[0008] The technical problem to be solved by the present invention is to provide a method for preparing and applying a composite restoration material suitable for preventing freeze-thaw damage in degraded alpine meadow grass layers, which addresses the shortcomings of the prior art. This composite restoration material is used in degraded alpine meadow grass layers to reduce freeze-thaw damage.
[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a composite restoration material suitable for freeze-thaw protection of degraded grass carpet layers in alpine meadows, the method being as follows:
[0010] S1, Seed Protective Layer:
[0011] S101. Mix dolomite powder, deionized water and polyvinyl alcohol evenly, and stir for 30 minutes to obtain a dolomite suspension.
[0012] The dolomite suspension is composed of the following raw materials by mass fraction: 10% dolomite powder, 15% polyvinyl alcohol, and the remainder is deionized water.
[0013] S102. The biodegradable bio-based fiber and the dolomite suspension obtained in S101 are used to form a three-dimensional fiber network with a wavy surface by wet web forming. Then, the cold-resistant plant seeds are evenly distributed in the three-dimensional fiber network with a wavy surface to obtain a seed protective layer.
[0014] The biodegradable bio-based fiber is a mixture of straw fiber and coconut shell fiber;
[0015] The three-dimensional fiber network with a wavy surface contains 80% to 90% biodegradable bio-based fibers by mass.
[0016] S2, Response Layer:
[0017] S201. The core material is dispersed in the shell material using an interfacial polymerization method. Acetic acid with a mass concentration of 1.67 mol / L is added, the pH value is adjusted to 4.5, and after reacting for 20 min, phase change material microcapsules are obtained.
[0018] The core material is liquid paraffin, and the shell material is a mixture of biodegradable gum arabic and gelatin;
[0019] The phase change material microcapsules are composed of the following raw materials by mass fraction: 50% core material and 50% shell material;
[0020] S202. After uniformly mixing the nano-silica and the phase change material microcapsules obtained in S201, the mixture is dispersed in polylactic acid resin by melt blending and hot-pressed to obtain the responsive layer.
[0021] The response layer is composed of the following raw materials by mass fraction: 80%~90% phase change material microcapsules, 5%~10% nano silica, and the balance being polylactic acid resin;
[0022] S3, Moisture Regulation Layer:
[0023] First, bentonite is laid as the bottom layer, followed by biochar, zeolite and polyacrylamide in sequence, and finally powdered silicon-calcium-potassium-magnesium fertilizer is sprinkled on top. After pressing, a moisture regulation layer with a porous gradient structure and pore size gradually decreasing from top to bottom is obtained.
[0024] The bentonite has a particle size of 0.1 mm to 0.5 mm, the biochar has a particle size of 0.5 mm to 2 mm, and the zeolite has a particle size of 2 mm to 5 mm.
[0025] The moisture control layer is composed of the following raw materials by mass fraction: 25%~35% bentonite, 20%~25% biochar, 25%~35% zeolite, 5% polyacrylamide, and the balance is powdered silicon-calcium-potassium-magnesium fertilizer.
[0026] S4, Nutrient substrate layer:
[0027] The nutrient substrate layer is obtained by mixing the main material of the nutrient substrate layer, the slow-release compound fertilizer and the symbiotic microbial community of the roots of cold-resistant plants evenly and then granulating it.
[0028] The main material of the nutrient substrate layer is a mixture of humic acid and biochar;
[0029] The nutrient substrate layer is composed of the following raw materials by mass fraction: 70%~80% of the main material of the nutrient substrate layer, 15%~25% of slow-release compound fertilizer, and the remainder is the symbiotic microbial community of the roots of cold-resistant plants.
[0030] S5, Anchoring Layer:
[0031] S501. After molding the bio-based polymer, the molded bio-based polymer is obtained.
[0032] The bio-based polymer is a mixture of modified starch and microcrystalline cellulose;
[0033] S502. The soil stabilizer is uniformly filled into the molded bio-based polymer obtained in S501 to obtain the anchoring layer.
[0034] The soil stabilizer is liquid sodium silicate;
[0035] The mass fraction of the soil stabilizer in the anchoring layer is 35%~30%;
[0036] S6. The anchoring layer obtained in S5, the nutrient substrate layer obtained in S4, the moisture regulation layer obtained in S3, the response layer obtained in S2, and the seed protection layer obtained in S1 are laid sequentially from bottom to top. The layers are physically composited using hot melt adhesive to obtain a composite restoration material suitable for freeze-thaw protection of degraded grass mats in alpine meadows.
[0037] Preferably, the cold-resistant plant seeds in S102 are a mixture of Kentucky bluegrass seeds, Leymus chinensis seeds, and Agrostis chinensis seeds; the wave crest height of the three-dimensional fiber network with a wavy surface is 3mm~5mm, and the wave spacing is 15mm~20mm.
[0038] Preferably, the distribution density of the cold-resistant plant seeds in the three-dimensional fiber network with a wavy surface in S102 is 4000 g / m². 3 .
[0039] Preferably, the melt blending temperature in S202 is 180°C; the hot pressing conditions are: temperature 120°C, pressure 5MPa, and time 15min.
[0040] Preferably, the effective component content of the silicon-calcium-potassium-magnesium fertilizer in S3 is: 25% silicon dioxide, 20% calcium oxide, 5% magnesium oxide, and 1% potassium humate; the effective component content of the slow-release compound fertilizer in S4 is: 14% nitrogen, 14% phosphorus, and 14% potassium.
[0041] Preferably, the symbiotic microbial community of the cold-resistant plant roots described in S4 is a mixed microbial community of Bacillus subtilis and Trichoderma harzianum.
[0042] Preferably, the molding conditions described in S501 are: temperature of 60°C, pressure of 5MPa, and time of 10min.
[0043] Preferably, the thickness of the seed protection layer in S1 is 1.5cm to 2.0cm; the thickness of the response layer in S2 is 0.8cm to 1.2cm; the thickness of the moisture regulation layer in S3 is 1.0cm to 2.0cm; the thickness of the nutrient substrate layer in S4 is 2.0cm to 3.0cm; and the thickness of the anchoring layer in S5 is 1.0cm to 1.5cm.
[0044] This invention also provides the application of the above-mentioned composite restoration material for preventing freeze-thaw damage to degraded grass layers in alpine meadows. The composite restoration material for preventing freeze-thaw damage to degraded grass layers in alpine meadows is used to reduce freeze-thaw damage.
[0045] Compared with the prior art, the present invention has the following advantages:
[0046] 1. The composite restoration material prepared by this invention is suitable for freeze-thaw protection of degraded grass mats in alpine meadows. It integrates freeze-thaw protection, hydrothermal regulation, nutrient supply and ecological restoration functions. It can actively respond to and buffer environmental changes and regulate the hydrothermal balance of the material.
[0047] 2. The composite restoration material prepared by this invention is suitable for freeze-thaw protection of degraded grass mat layers in alpine meadows. It has a stable structure, long-lasting function, can achieve long-term restoration effect, and is adapted to alpine environments.
[0048] 3. The composite restoration material prepared by this invention for preventing freeze-thaw damage to degraded grass mat layers in alpine meadows adopts a modular design, which makes it easy to lay and reduces the difficulty of engineering implementation, making it suitable for application in alpine regions.
[0049] The present invention will be further described in detail below with reference to the embodiments. Detailed Implementation
[0050] Example 1
[0051] This embodiment describes a method for preparing a composite remediation material suitable for freeze-thaw protection of degraded grass carpet layers in alpine meadows. The method is characterized by the following:
[0052] S1, Seed Protective Layer:
[0053] S101. Mix dolomite powder, deionized water and polyvinyl alcohol evenly, and stir for 30 minutes to obtain a dolomite suspension.
[0054] The dolomite suspension is composed of the following raw materials by mass fraction: 10% dolomite powder, 15% polyvinyl alcohol, and the remainder is deionized water.
[0055] S102. The biodegradable bio-based fibers are dispersed in the dolomite suspension obtained in S101, and then pressed into a mesh structure in a paper sheet forming machine (Shandong Animate Instrument Co., Ltd.) for making nonwoven fabrics through a porous sieve. The mesh is then pressed into shape on a corrugated mold and dried at 80℃ to obtain a three-dimensional fiber mesh with a corrugated surface. The peak height of the corrugated three-dimensional fiber mesh is 3mm~5mm, and the wave spacing is 15mm~20mm. Then, a mixture of Kentucky bluegrass seeds, Leymus chinensis seeds, and Agrostis chinensis seeds is prepared at a concentration of 4000g / m³. 3 The distribution density is uniformly distributed in the three-dimensional fiber network, resulting in a seed protection layer with a thickness of 1.5cm~2.0cm;
[0056] The biodegradable bio-based fiber is a mixture of straw fiber and coconut shell fiber;
[0057] The three-dimensional fiber network with a wavy surface contains 80% to 90% biodegradable bio-based fibers by mass.
[0058] S2, Response Layer:
[0059] S201. Preparation of phase change material microcapsules by interfacial polymerization: using liquid paraffin as the core material and biodegradable gum arabic and gelatin as the shell material, the core material is dispersed in the shell material aqueous solution by the complex coagulation method. Acetic acid with a mass concentration of 1.67 mol / L is added to adjust the pH value to 4.5, and the reaction is carried out for 20 min to obtain phase change material microcapsules with a particle size of 20 μm to 30 μm.
[0060] The phase change material microcapsules are composed of the following raw materials by mass fraction: 50% core material and 50% shell material;
[0061] S202. After uniformly mixing the nano-silica and the phase change material microcapsules obtained in S201, the mixture is uniformly dispersed in molten polylactic acid resin (Zhejiang Hisun Biomaterials Co., Ltd.) at 180°C using a high-speed disperser via melt blending. After hot pressing at 120°C, 5MPa, and 15min, a response layer with a thickness of 0.8cm~1.2cm is obtained.
[0062] The response layer is composed of the following raw materials by mass fraction: 80%~90% phase change material microcapsules, 5%~10% nano silica, and the balance being polylactic acid resin;
[0063] S3, Moisture Regulation Layer:
[0064] A moisture regulation layer was prepared using a layered laying method: First, bentonite with a particle size of 0.1 mm to 0.5 mm was laid at the bottom layer. Then, biochar with a particle size of 0.5 mm to 2 mm, zeolite with a particle size of 2 mm to 5 mm, and polyacrylamide gel were laid in sequence. Finally, powdered silicon-calcium-potassium-magnesium fertilizer (Jiangsu Degao Bioengineering Co., Ltd.) was sprinkled on top. Through layered pressing, a moisture regulation layer with a thickness of 1.0 cm to 2.0 cm and a porous gradient structure was formed, with the pore size gradually decreasing from top to bottom (from 5 mm to 0.1 mm).
[0065] The effective ingredient content of the powdered silicon-calcium-potassium-magnesium fertilizer is: 25% silicon dioxide, 20% calcium oxide, 5% magnesium oxide, and 1% potassium humate; it can improve the material's water retention, drought resistance, and cold resistance.
[0066] The moisture control layer is composed of the following raw materials by mass fraction: 25%~35% bentonite, 20%~25% biochar, 25%~35% zeolite, 5% polyacrylamide, and the balance is powdered silicon-calcium-potassium-magnesium fertilizer.
[0067] S4, Nutrient substrate layer:
[0068] After the main material of the nutrient substrate layer, the slow-release compound fertilizer (Dahan Garden Technology Co., Ltd.), and the symbiotic bacteria of the roots of cold-resistant plants are mixed evenly, the raw material is obtained. The raw material is added to a rotary drum granulator and granulated for 10 minutes at a speed of 15 rpm and a water spray volume of 8% of the raw material mass. Then it is dried at 60℃ for 2 hours to obtain a nutrient substrate layer with a particle size of 2mm~5mm and a thickness of 2.0cm~3.0cm.
[0069] The main material of the nutrient substrate layer is a mixture of humic acid and biochar;
[0070] The effective ingredient content of the controlled-release compound fertilizer is 14% nitrogen, 14% phosphorus, and 14% potassium.
[0071] The nutrient substrate layer is composed of the following raw materials by mass fraction: 70%~80% of the main material of the nutrient substrate layer, 15%~25% of slow-release compound fertilizer, and the remainder is the symbiotic microbial community of the roots of cold-resistant plants.
[0072] The symbiotic microbial community of the roots of the cold-resistant plants is a mixed community of Bacillus subtilis and Trichoderma harzianum;
[0073] S5, Anchoring Layer:
[0074] S501. The bio-based polymer is molded at a temperature of 60℃, a pressure of 5MPa, and a time of 10min to obtain the molded bio-based polymer.
[0075] The bio-based polymer is arranged in a hexagonal close-packed pattern with a grid spacing (side length of the hexagon) of 5cm to 8cm and a grid tensile strength of 3.0kN / m.
[0076] The bio-based polymer is a mixture of modified starch (Weifang Senruit Biotechnology Co., Ltd.) and microcrystalline cellulose (Huzhou Linghu Xinwang Chemical Co., Ltd.);
[0077] S502. Soil stabilizer is filled into the molded bio-based polymer obtained in S501 to obtain an anchoring layer with a thickness of 1.0cm~1.5cm.
[0078] The soil stabilizer is liquid sodium silicate (Henan Borun Casting Materials Co., Ltd.).
[0079] The mass fraction of the soil stabilizer in the anchoring layer is 35%~30%;
[0080] S6. The anchoring layer obtained in S5, the nutrient substrate layer obtained in S4, the moisture regulation layer obtained in S3, the response layer obtained in S2, and the seed protection layer obtained in S1 are laid sequentially from bottom to top. The layers are physically composited using hot melt adhesive to obtain a composite restoration material suitable for freeze-thaw protection of degraded grass mats in alpine meadows.
[0081] Example 2
[0082] This embodiment describes the application of the composite restoration material prepared in Example 1, which is suitable for preventing freeze-thaw damage to degraded grass layers in alpine meadows. The composite restoration material is used in degraded grass layers in alpine meadows to reduce freeze-thaw damage.
[0083] 1. Preparation of the alpine meadow experimental area:
[0084] The degraded alpine meadow in Nagqu Prefecture, Tibet Autonomous Region, was selected as the experimental area, with an area of approximately 100 m². 2The surface debris, including stones and dead branches, of the degraded grass layer in the alpine meadow experimental area was cleaned up. Then, the severely degraded areas in the alpine meadow experimental area were simply leveled and obvious pits were filled to obtain the experimental area.
[0085] 2. Suitable for laying composite restoration materials for freeze-thaw protection of degraded grass mat layers in alpine meadows:
[0086] The composite remediation material obtained in Example 1, S6, suitable for freeze-thaw protection of degraded alpine meadow meadows, was cut to a size of 1m × 1m. This cut composite remediation material was then laid on the surface of a degraded alpine meadow experimental area in Nagqu Prefecture, Tibet Autonomous Region. During the laying process, the overlap length of adjacent composite remediation materials was 5cm to 10cm to ensure continuous coverage. The coverage rate of the composite remediation material was over 95%, covering an area of approximately 50m². 2 The control area is approximately 50m² 2 .
[0087] 3. Suitable for fixing and anchoring composite restoration materials used for freeze-thaw protection of degraded grass mat layers in alpine meadows:
[0088] Biodegradable anchors (golf tacks, Huizhou Shenger Sporting Goods Co., Ltd.), 15cm in length and 0.8cm in diameter, are fixed along the edges and center of the laid composite repair material. One biodegradable anchor is fixed every 50cm along the edge of the composite repair material, and the anchoring density in the center of the composite repair material is 4-6 anchors / m². 2 In areas with steep slopes (slope > 15°) within the alpine meadow test area, the anchoring density was increased to 8 anchors / m. 2 .
[0089] 4. Post-construction maintenance of composite restoration materials suitable for freeze-thaw protection of degraded grass mat layers in alpine meadows:
[0090] For the composite restoration material suitable for freeze-thaw protection of degraded sod layers in alpine meadows that has been laid and anchored, water it once a day for the first 3 days after laying, with each watering being 2L / m². 2 The vegetation restoration status will be monitored monthly using the composite restoration material suitable for freeze-thaw protection of degraded alpine meadow grass. The vegetation coverage, species composition, and growth status will be recorded. Fences will be set up around the test area where the composite restoration material suitable for freeze-thaw protection of degraded alpine meadow grass will be laid to prevent livestock from entering and ensure the initial restoration effect.
[0091] After a complete growth and freeze-thaw cycle (May 2024 to May 2025), the composite remediation material showed good performance in preventing freeze-thaw damage to degraded grass carpet layers in alpine meadows.
[0092] Soil structure protection: Maintain soil bulk density at 0.8 g / cm³ 3 ~1.0g / cm 3 Compared to the control area (1.3 g / cm³), 3 ~1.5g / cm 3 Significantly reduced;
[0093] Vegetation restoration effect: Vegetation coverage increased by 25%;
[0094] Moisture retention capacity: Soil moisture content increased by approximately 30% compared to the control area;
[0095] Reduced soil freeze-thaw cycles: The number of freeze-thaw cycles decreased from 83 in the control area to 56 during the monitoring period.
[0096] Therefore, the composite remediation material prepared in this invention, suitable for preventing freeze-thaw damage in degraded alpine meadow grass layers, can effectively protect soil structure, improve soil moisture retention capacity, and reduce freeze-thaw events when used in degraded alpine meadow grass layers.
[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.
Claims
1. A method for preparing a composite restoration material suitable for freeze-thaw protection of degraded grass mat layers in alpine meadows, characterized in that, The method is as follows: S1, Seed Protective Layer: S101. Mix dolomite powder, deionized water and polyvinyl alcohol evenly, and stir for 30 minutes to obtain a dolomite suspension. The dolomite suspension is composed of the following raw materials by mass fraction: 10% dolomite powder, 15% polyvinyl alcohol, and the remainder is deionized water. S102. The biodegradable bio-based fiber and the dolomite suspension obtained in S101 are used to form a three-dimensional fiber network with a wavy surface by wet web forming. Then, the cold-resistant plant seeds are evenly distributed in the three-dimensional fiber network with a wavy surface to obtain a seed protective layer. The biodegradable bio-based fiber is a mixture of straw fiber and coconut shell fiber; The three-dimensional fiber network with a wavy surface contains 80% to 90% biodegradable bio-based fibers by mass. S2, Response Layer: S201. The core material is dispersed in the shell material using an interfacial polymerization method. Acetic acid with a mass concentration of 1.67 mol / L is added, the pH value is adjusted to 4.5, and after reacting for 20 min, phase change material microcapsules are obtained. The core material is liquid paraffin, and the shell material is a mixture of biodegradable gum arabic and gelatin; The phase change material microcapsules are composed of the following raw materials by mass fraction: 50% core material and 50% shell material; S202. After uniformly mixing the nano-silica and the phase change material microcapsules obtained in S201, the mixture is dispersed in polylactic acid resin by melt blending and hot-pressed to obtain the responsive layer. The response layer is composed of the following raw materials by mass fraction: 80%~90% phase change material microcapsules, 5%~10% nano silica, and the balance being polylactic acid resin; S3, Moisture Regulation Layer: First, bentonite is laid as the bottom layer, followed by biochar, zeolite and polyacrylamide in sequence, and finally powdered silicon-calcium-potassium-magnesium fertilizer is sprinkled on top. After pressing, a moisture regulation layer with a porous gradient structure and pore size gradually decreasing from top to bottom is obtained. The bentonite has a particle size of 0.1 mm to 0.5 mm, the biochar has a particle size of 0.5 mm to 2 mm, and the zeolite has a particle size of 2 mm to 5 mm. The moisture control layer is composed of the following raw materials by mass fraction: 25%~35% bentonite, 20%~25% biochar, 25%~35% zeolite, 5% polyacrylamide, and the balance is powdered silicon-calcium-potassium-magnesium fertilizer. S4, Nutrient substrate layer: The nutrient substrate layer is obtained by mixing the main material of the nutrient substrate layer, the slow-release compound fertilizer and the symbiotic microbial community of the roots of cold-resistant plants evenly and then granulating it. The main material of the nutrient substrate layer is a mixture of humic acid and biochar; The nutrient substrate layer is composed of the following raw materials by mass fraction: 70%~80% of the main material of the nutrient substrate layer, 15%~25% of slow-release compound fertilizer, and the remainder is the symbiotic microbial community of the roots of cold-resistant plants. S5, Anchoring Layer: S501. After molding the bio-based polymer, the molded bio-based polymer is obtained. The bio-based polymer is a mixture of modified starch and microcrystalline cellulose; S502. The soil stabilizer is uniformly filled into the molded bio-based polymer obtained in S501 to obtain the anchoring layer. The soil stabilizer is liquid sodium silicate; The mass fraction of the soil stabilizer in the anchoring layer is 30%~35%; S6. The anchoring layer obtained in S5, the nutrient substrate layer obtained in S4, the moisture regulation layer obtained in S3, the response layer obtained in S2, and the seed protection layer obtained in S1 are laid sequentially from bottom to top. The layers are physically composited using hot melt adhesive to obtain a composite restoration material suitable for freeze-thaw protection of degraded grass mats in alpine meadows.
2. The preparation method of a composite restoration material suitable for freeze-thaw protection of degraded grass carpet in alpine meadows according to claim 1, characterized in that, The cold-resistant plant seeds mentioned in S102 are a mixture of Kentucky bluegrass seeds, Leymus chinensis seeds, and Agrostis chinensis seeds; the three-dimensional fiber network with a wavy surface has a peak height of 3mm~5mm and a wave distance of 15mm~20mm.
3. The preparation method of a composite restoration material suitable for freeze-thaw protection of degraded grass carpet in alpine meadows according to claim 1, characterized in that, The distribution density of the cold-resistant plant seeds described in S102 within the wavy three-dimensional fiber network on the surface is 4000 g / m². 3 .
4. The preparation method of the composite repair material suitable for freeze-thaw prevention of degraded grass carpet in alpine meadow according to claim 1, characterized in that, The melt blending temperature described in S202 is 180℃; the hot pressing conditions are: temperature 120℃, pressure 5MPa, and time 15min.
5. The preparation method of the composite repair material suitable for freeze-thaw prevention of degraded grass carpet in alpine meadow according to claim 1, characterized in that, The effective ingredient content of the powdered silicon-calcium-potassium-magnesium fertilizer described in S3 is: 25% silicon dioxide, 20% calcium oxide, 5% magnesium oxide, and 1% potassium humate; the effective ingredient content of the slow-release compound fertilizer described in S4 is: 14% nitrogen, 14% phosphorus, and 14% potassium.
6. The preparation method of a composite restoration material suitable for freeze-thaw protection of degraded grass carpet in alpine meadows according to claim 1, characterized in that, The symbiotic microbial community of the roots of cold-resistant plants described in S4 is a mixed community of Bacillus subtilis and Trichoderma harzianum.
7. The preparation method of a composite restoration material suitable for freeze-thaw protection of degraded grass carpet in alpine meadows according to claim 1, characterized in that, The molding conditions described in S501 are: temperature 60℃, pressure 5MPa, and time 10min.
8. The method for preparing a composite restoration material suitable for freeze-thaw protection of degraded grass carpet in alpine meadows according to claim 1, characterized in that, The thickness of the seed protection layer in S1 is 1.5cm to 2.0cm; the thickness of the response layer in S2 is 0.8cm to 1.2cm; the thickness of the moisture regulation layer in S3 is 1.0cm to 2.0cm; the thickness of the nutrient substrate layer in S4 is 2.0cm to 3.0cm; and the thickness of the anchoring layer in S5 is 1.0cm to 1.5cm.
9. The application of a composite restoration material prepared by the preparation method according to any one of claims 1-8, suitable for freeze-thaw protection of degraded grass carpet layers in alpine meadows, characterized in that, The composite restoration material, suitable for preventing freeze-thaw damage in degraded alpine meadow grass layers, is used to reduce freeze-thaw events in degraded alpine meadow grass layers.