A method for reconstructing an ecological seawall and a method for planting plants in a rigid seawall grid plate

Abstract

The application belongs to the technical field of ecological reconstruction of seawalls, and discloses a reconstruction method of an ecological seawall and a planting method of plants in a hard seawall grid plate, a planting method of plants in a seawall ecological reconstruction grid plate, which comprises the following steps: S1: salt-tolerant plant selection: selecting native salt-tolerant plant varieties in a treatment area; S2: filling of ecological concrete in the grid and backfilling of planting materials: comprehensively considering the maximum high tide level and the wave-splashing range of the treatment area in 50 years; S3: improvement: after backfilling of ecological concrete to a depth of 1 / 2 of the grid plate, backfilling of planting materials to a depth of 1 / 3 of the grid plate and compaction, and finally backfilling of planting materials containing seeds of the plant varieties selected in step S1; the planting materials are 1m 3 40-60g of AB bacteria (reference patent CN103626584B) are mixed in the planting soil; the plant planting method in the hard seawall grid plate has the advantage of improving the survival rate of plants.

Description

Technical Field

[0001] This invention belongs to the field of ecological transformation technology of seawalls, and in particular, a method for transforming ecological seawalls and a method for planting plants in the grid panels of hardened seawalls. Background Technology

[0002] A significant factor influencing the ecological restoration of seawalls is the impact and destructive force of ocean waves on the shoreline. Tidal and wind forces exert a strong impact and destructive effect on seawalls, leading to the frequent use of rigid structures based on stones and concrete in seawall construction and ecological transformation. However, this structure reduces the original shoreline's tidal absorption capacity, obstructs energy and material exchange between land and sea, weakens the self-purification capacity of coastal waters, and hinders human contact with the ocean, thus damaging the landscape and aesthetic value of the coastline to some extent. Therefore, it is essential to respect the existing foundation conditions and adhere to the principles of adapting to local conditions and utilizing local materials when designing existing shoreline forms and protective structures to enhance or strengthen the ecological environment. Chinese patent document CN116591099A discloses a method and system for ecological transformation of seawalls. The system comprises an upper slope, a lower slope, and a transition platform between the upper and lower slopes. The transition platform features an intertidal ecological zone formed by artificial reef ecological frames. The vertical center of the intertidal ecological zone corresponds to the normal water level. The horizontal cross-section of the artificial reef ecological frame is rectangular, with four side plates forming the circumference and a base plate integrated with the side plates. The top is open, and the side plates have through holes. Adjacent through holes on adjacent artificial reef ecological frames are connected. A stone accumulation zone is located at the base of the lower slope, and a slope planting layer or a trapezoidal wetland is located on the upper slope. The method involves ecological transformation of seawalls through the aforementioned system. Chinese patent document CN217923363U discloses a multifunctional ecological seawall system, primarily used in shallow bays. This system includes an ecological seawall main body, a vegetation community zone, a biological reef area, a seaweed farm, and an ecological submerged breakwater, arranged sequentially from land to sea. This invention provides a multifunctional ecological seawall system suitable for ecological construction projects of seawalls that are severely impacted by waves, subject to erosion, and lacking adequate seawall protection. By ecologically modifying the structure and materials of the seawall itself, it effectively increases habitat complexity and enhances marine biodiversity. Artificial ecological reefs and seaweed beds not only improve water quality, but their complex spatial structure also provides habitats for various marine organisms such as fish, crustaceans, and benthic invertebrates. Furthermore, the ecological submerged seawall serves as a primary disaster mitigation strategy for the entire system, achieving synergistic effects between ecological conservation and disaster reduction.

[0003] These existing technologies offer suggestions for the ecological transformation of seawalls, but they do not address specific planting methods for plants within the seawall grid panels. This results in difficulties in seed germination and low survival rates for plants on the hardened seawalls in the treatment area, increasing the difficulty of ecological transformation of seawalls. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for modifying ecological seawalls and a method for planting plants within rigid seawall grid panels.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A method for modifying an ecological seawall and a method for planting vegetation within a rigid seawall grid panel include the following steps:

[0007] S1: Screening of salt-tolerant plants: Select native salt-tolerant plant varieties suitable for the treatment area based on historical survey data and relevant literature review;

[0008] S2: Ecological concrete filling and backfill planting materials within the grid: taking into account the maximum high tide level (hereinafter referred to as: high tide level) and splash range of the treatment area once every 50 years;

[0009] S3: Improvement: After backfilling with ecological concrete to a depth of 1 / 2 of the grating, backfill with planting material to a depth of 1 / 3 of the grating and compact it. Finally, backfill with planting material containing the mixed-sown native plant seeds selected in step S1; the planting material is per 1m 3 Mix 40-60g of AB bacteria into the planting soil (refer to patent CN103626584B);

[0010] The aforementioned eco-friendly concrete involves coating the surface of aggregate particles with a thin layer of cement paste, without requiring the cement to fill the gaps between the aggregate particles; per 1m 3 The quality of eco-friendly concrete is the sum of the compacted bulk density of aggregates, the amount of cement per cubic meter, additives, and water. Its specific components are: cement, crushed stone, mixing water, aggregate additives, and void filler nutrients. The standard mix design is as follows:

[0011] per 1m 3 Ecological concrete consists of 210-350 kg of cement, 1420-1685 kg of crushed stone, 60.4-70 L of water, 30-50 kg of aggregate additives, and 15-20 kg of void filler nutrients. The preparation method is as follows: cement and mixing water are mixed to form a uniform slurry. Then, crushed stone and aggregate additives are added sequentially to form a uniform concrete. After 15 days, the void filler nutrients are evenly poured into the concrete.

[0012]

[0013] The nutrient-filling material for the voids includes planting soil, AB bacteria, plant fiber, slow-release compound fertilizer, and water-retaining agent, wherein each 1m 3The planting soil contains 40-60g of AB bacteria, 20-50g of plant fiber, 5-12g of slow-release compound fertilizer, and 2-4g of water-retaining agent. The preparation method for the gap-filling nutrients is as follows: First, mix the planting soil, AB bacteria, slow-release compound fertilizer, and water-retaining agent evenly. Then, soak the plant fiber in water and mix it with the AB bacteria. Gradually add an appropriate amount of water to the mixture, mix evenly, and then dry it to a moisture content of 20%-40%.

[0014] Furthermore, the cement used is ordinary Portland cement; the coating thickness of the thin cement slurry is 1.0 mm.

[0015] Furthermore, based on the highest tide level in the region that occurs once every 50 years, different types and proportions of salt-tolerant plants are planted in different areas. The specific selection method is based on the degree of salt tolerance of the plants, and the number of seeds of plants with high salt tolerance accounts for at least 50%.

[0016] Furthermore, the backfilling and mixing of salt-tolerant plant seeds is as follows: the prepared salt-tolerant plant seeds are mixed according to the mixing ratio (the specific mixing ratio can only be determined by investigating the local plant species), and then mixed with the planting soil and AB bacteria. The seeds account for 5%-10% of the mass of the planting soil and AB bacteria mixture. After being moistened with water, the mixture is filled into the grid board, where the moisture content of the mixed material is 70%-80%.

[0017] Furthermore, before large-scale planting, planting trials were conducted in typical areas of hardened seawalls.

[0018] Furthermore, if some salt-tolerant plants fail to germinate, they can be appropriately reseeded, and a safety assessment of the plant species should be conducted. They should not be planted out of season to avoid the invasion of alien species.

[0019] Furthermore, the compressive strength of the ecological concrete is slightly lower, controlled at 3-7 MPa, and the porosity is 21%-30%.

[0020] The advantages and positive effects of this invention are as follows:

[0021] 1. In the method of this invention, ecological concrete is filled into the grid panels of the artificial seawall. Ecological concrete has good resistance to high-speed water erosion, and the pores within it are filled with nutrients composed of planting soil, AB bacteria, plant fibers, long-acting compound fertilizer, and water-retaining agents. While blocking and delaying the penetration and erosion of seawater into the planting layer, the pores also provide a connection space for water, air, and plant roots, allowing time for adaptation in the early stages of plant growth, ensuring normal plant growth, and achieving an early survival rate of over 88%.

[0022] 2. The high water level design in this invention is based on the 50-year maximum high tide level (hereinafter referred to as: high tide level) as the dividing line. Different types and proportions of native salt-tolerant plants are planted in different areas, which can maximize the survival rate of salt-tolerant plants, avoid the invasion of alien species and reduce the cost of ecological transformation of hardened seawalls; provide favorable conditions for plant growth, and make the survival rate of plants in the later stage more than 75%.

[0023] 3. The method of the present invention can predict the overall repair effect of hardened seawalls based on planting experiments in typical areas, which can greatly reduce the cost of trial and error; it can provide the most favorable growth environment for salt-tolerant plants and reduce their risk of being contaminated by exogenous pollutants.

[0024] 4. In this invention, if some salt-tolerant plants fail to germinate, they can be reseeded appropriately, and a safety assessment of the plant species should be conducted. Planting should not be done out of season, and the invasion of alien species should not be caused. The planting of salt-tolerant plants follows natural laws and biological characteristics, and reduces the cost of ecological transformation of hardened seawalls.

[0025] 5. In this invention, the prepared salt-tolerant plant seeds are mixed according to a specific mixing ratio (the exact mixing ratio can only be determined by investigating the local plant species), and then mixed with planting soil and AB bacteria (the mass ratio of the seed-planting soil to the AB bacteria mixture is 5%-10%, per 1m³). 3 The planting soil contains 40-60g of AB bacteria. After being moistened with water, it is filled into the grid board, with the mixed material having a moisture content of 70%-80%. This ensures full contact between the seeds and the planting material, guaranteeing seed germination and improving the survival rate of salt-tolerant plants. Furthermore, the planting soil must be free of rocks, tree roots, lumps of clay, garbage, and other harmful substances to provide the most favorable growing environment for salt-tolerant plants and reduce the risk of contamination from external pollutants.

[0026] 6. This invention utilizes native salt-tolerant plants from the treated area for the ecological transformation of seawalls. Taking into account the 50-year return period's highest tide level (hereinafter referred to as: high tide level) and the splash range, native salt-tolerant plants are planted to increase the biodiversity of existing hardened seawalls. Firstly, ecological concrete is filled within the grid panels. This is beneficial because its excellent air and water permeability allows for the integration of engineering protection and ecological restoration. Its gaps provide connectivity for water, air, and plant roots, while minimizing seawater infiltration into the upper planting layer, maximizing the space for root penetration and growth. Secondly, planting soil and AB bacteria are backfilled on top of the ecological concrete to a depth of approximately one-third of the grid panel's depth. The planting soil is rich in organic matter, improving soil structure and enhancing water and fertilizer retention. The AB bacteria successfully introduce halophilic bacteria, which can reduce the salinity of cement, optimize the physicochemical properties of salinity, and possess metabolic activity. They can resist high mechanical and chemically induced stresses and have a long lifespan, enabling them to grow in cement environments. Ultimately, based on the on-site investigation and laboratory selection results, native salt-tolerant plants were planted.

[0027] 7. The compressive strength of the ecological concrete in this invention is slightly lower, controlled at 3-7 MPa, and the porosity is 21%-30%. A structural type emphasizing vegetation slope protection was selected, which simultaneously considers structural slope protection and slope greening, in the expectation that early vegetation will form as soon as possible. Attached Figure Description

[0028] Figure 1 This is a photograph of the ecological concrete test block of the present invention: porosity 20%-30% (left) and vegetation coverage 95% (right).

[0029] Figure 2 These are comparative test photos of the ecological concrete experimental blocks used in this invention;

[0030] Figure 3 This is a diagram showing the root penetration and growth of the ecological concrete test block in this invention.

[0031] Figure 4 This is a schematic diagram of the ecological transformation system for seawalls in this invention;

[0032] Figure 5 This is a photograph of the actual ecological concrete pouring at the restoration site in this invention.

[0033] Figure 6 This is a photograph of the actual soil used to repair the holes in the grid plate and level the planting soil in this invention.

[0034] Figure 7 This is a photograph of plant budding at the restoration site (July 10, 2023) used in this invention.

[0035] Figure 8This is a photograph of the restored plant growth at the site (July 24, 2023) used in this invention. Detailed Implementation

[0036] The present invention will be further described below with reference to the embodiments. The following embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0037] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0038] This invention addresses the ecological transformation of rigid artificial seawalls along the Bohai Bay coast, providing a method for planting vegetation within a grid panel that facilitates ecological seawall development. The method includes the following steps:

[0039] S1: Screening of native salt-tolerant plants: Selecting native salt-tolerant plant varieties suitable for the treatment area based on historical survey data and relevant literature review;

[0040] S2: The grid is filled with ecological concrete and backfilled with planting materials: taking into account the maximum high tide level and the splash range;

[0041] S3: Improvement: After backfilling with ecological concrete to a depth of 1 / 2 of the grating, backfill with planting material to a depth of 1 / 3 of the grating and compact it. Finally, backfill with planting material containing the mixed-sown native plant seeds selected in step S1; the planting material is per 1m 3 Mix 40-60g of AB bacteria into the planting soil;

[0042] The aforementioned eco-friendly concrete involves coating the surface of aggregate particles with a thin layer of cement paste, without requiring the cement to fill the gaps between the aggregate particles; per 1m 3 The quality of ecological concrete should be the sum of the compacted bulk density of aggregates, the amount of cement per cubic meter, additives, and water. Its specific components are: cement, crushed stone, mixing water, aggregate additives, and void filler nutrients. The standard mix design is as follows:

[0043]

[0044] The method for preparing the ecological concrete is as follows: cement and mixing water are mixed to form a uniform slurry. Then, crushed stone and aggregate additives are added in sequence to form a uniform concrete. After 15 days, void-filling nutrients are evenly poured into the concrete.

[0045] The nutrient-filling material for the voids includes planting soil, AB bacteria, plant fiber, slow-release compound fertilizer, and water-retaining agent, wherein each 1m 3The planting soil contains 40-60g of AB bacteria, 20-50g of plant fiber, 5-12g of slow-release compound fertilizer, and 2-4g of water-retaining agent. The preparation method for the gap-filling nutrients is as follows: First, mix the planting soil, AB bacteria, slow-release compound fertilizer, and water-retaining agent evenly. Then, soak the plant fiber in water and mix it with the AB bacteria. Gradually add an appropriate amount of water to the mixture, mix evenly, and then dry it to a moisture content of 20%-40%.

[0046] Preferably, eco-friendly concrete should use hard, durable, and clean crushed stone.

[0047] Preferably, the mixing water should be drinking water that meets national standards and can be used to mix eco-friendly concrete. The use of surface water, groundwater, and treated or disposed industrial wastewater must comply with the technical requirements of the "Standard for Water Used in Concrete Mixing" JGJ63.

[0048] The selection of raw materials for the eco-friendly concrete in this application mainly focuses on the cement strength grade, type, particle size, and gradation of the coarse aggregate. Therefore, eco-friendly concrete should be prepared using high-strength cement and aggregates with a wide gradation (generally, the aggregates are two-dimensional: 5-20mm, 20-40mm, with a maximum particle size of 40mm). 1m 3 The total amount of aggregate used in eco-friendly concrete is taken from the value of the aggregate's compacted bulk density. Sampling tests showed that the compacted bulk density of crushed stone is 1685 kg / m³. 3 .

[0049] The cement dosage in this application can be appropriately increased while ensuring optimal water content. This increases the consistency and thickness of the cement paste film around the aggregate, effectively improving the strength of the no-fines permeable concrete. However, excessive cement dosage will increase the paste volume, reduce porosity, and decrease permeability. Furthermore, the cement dosage is affected by the aggregate particle size. If the aggregate particle size is small and the specific surface area is large, the cement dosage should be appropriately increased. Typically, the cement dosage is around 210 kg / m³. 3 ~350kg / m 3 Within the range.

[0050] The water-cement ratio in this application affects both the strength and permeability of eco-concrete. The water-cement ratio of eco-concrete is between 0.25 and 0.40. If the cement paste is evenly coated on the surface of the aggregate particles without dripping, the water-cement ratio is considered suitable. Finally, a mix design trial was conducted, and the resulting eco-concrete was observed to ensure that the cement paste was evenly coated on the surface of the aggregate particles without dripping, and that the aggregates were bonded together to form a cohesive whole (see...). Figure 1 The ecological concrete mixing method uses a 500-type forced mixer. Trial batches are performed at 0.5 cubic meters per batch.

[0051] The aggregate additive in this application is Greening Additive A, a patented product (publication number: CN103626584A) provided by Hubei Jinyuan Green Channel Ecological Environment Co., Ltd. It reacts chemically with cement, regulating the cement's pH value and creating a porosity of 20%-30%, suitable for plant growth. The plant coverage can reach over 95% (see...). Figure 1 (See the comparative test photos of the ecological concrete test blocks and the root penetration of the ecological concrete test blocks.) Figure 2 , Figure 3 As shown in the figure, the addition of greening additive A to ecological concrete results in significantly better plant growth compared to ordinary concrete.

[0052] The flexural and compressive strengths of the cement in the embodiments of this application are shown in Table 1:

[0053] Table 1 Flexural and compressive strengths of cement

[0054]

[0055] The chemical composition and physical properties of the cement in the embodiments of this application are shown in Table 2.

[0056] Table 2 Chemical composition and physical properties of cement

[0057]

[0058]

[0059] Example 1

[0060] The method for modifying the ecological seawall and the method for planting plants within the rigid seawall grid panels in this embodiment include the following steps:

[0061] S1: Screening of salt-tolerant plants: Based on historical survey data and relevant literature, native salt-tolerant plant varieties suitable for the treatment area were selected. In this embodiment, Suaeda salsa, Suaeda salsa, Leymus chinensis and ryegrass were selected as planting varieties.

[0062] S2: The grid is filled with ecological concrete and backfilled with planting materials: taking into account the maximum high tide level and the splash range;

[0063] S3: Improvement: After backfilling with ecological concrete to a depth of 1 / 2 of the grating, backfill with planting material to a depth of 1 / 3 of the grating and compact it. Finally, backfill with planting material containing the mixed-sown native plant seeds selected in step S1; the planting material is per 1m 3 Mix 40-60g of AB bacteria into the planting soil (refer to patent CN103626584B);

[0064] The specific components of the ecological concrete are cement, crushed stone, mixing water, aggregate additives, and void-filling nutrients. Each 1m³ 3 The components are: 283 kg of cement, 1539 kg of crushed stone (aggregate particle size in the range of 20-40 mm), 65 L of mixing water, 40 kg of vegetation concrete additive, and 18 kg of void filling nutrients.

[0065] The preparation method of ecological concrete in this embodiment is as follows: First, the aggregate is poured into a mixing device, and 50% of the water-cement ratio is added to moisten the surface of the aggregate. Then, cement is added and mixed. Next, 50% of the water-cement ratio is added successively and the mixture is stirred to form mixture A, until the aggregate is fully coated with cement paste and there is no dripping on the surface. Pre-weighed aggregate additives are gradually added to mixture A, and thorough stirring is required during the mixing process to form uniform concrete. After 15 days, high-pressure jetting equipment can be used to inject void-filling nutrients into the concrete to ensure that the void-filling nutrients are evenly distributed in the concrete.

[0066] The nutrient-filling material for the voids includes planting soil, AB bacteria, plant fiber, slow-release compound fertilizer, and water-retaining agent, wherein each 1m 3 The planting soil contains 40-60g of AB bacteria, 20-50g of plant fiber, 5-12g of slow-release compound fertilizer, and 2-4g of water-retaining agent. In this embodiment, the preparation method for the gap-filling nutrients is as follows: First, mix the planting soil, AB bacteria, slow-release compound fertilizer, and water-retaining agent evenly. Then, soak the plant fiber in water for 30 minutes to allow it to fully absorb water and soften. Mix the soaked plant fiber evenly with the other raw materials. Gradually add an appropriate amount of water to the mixture, ensuring that the moisture is evenly distributed and that the mixture is not overly wet. Finally, dry the mixture to a moisture content of 20%-40% to ensure it is suitable for filling.

[0067] In this embodiment, the planting soil in the gap-filling nutrient material is supplemented with humus and sludge (mass ratio of 3:1:1), and all soil particles have a diameter of no more than 5 mm; the plant fiber is made from crushed crop straw such as rice straw, wheat, and corn, with a length of 5-25 mm; the granular compound fertilizer is composed of nitrogen, phosphorus, and potassium; and the water-retaining agent is composed of polyacrylamide, sodium polyacrylate, sodium carboxymethyl cellulose, sodium carboxymethyl starch, and sawdust.

[0068] The method of mixed sowing of native salt-tolerant plants in this embodiment is as follows: (e.g.) Figure 4 As shown, Suaeda salsa is planted at and below the maximum high tide level of the artificial seawall on the seaward side, and Suaeda salsa, Suaeda salsa, Leymus chinensis and Lernaea ryegrass are planted above the high tide level, with a seed ratio of (10-12):(3-4):(2.6-3):(2.4-3).

[0069] The ecological concrete construction process in this embodiment includes slope trimming, formwork installation, mixing, transportation, pouring, jointing, curing, and formwork removal (see...). Figure 5 Ideally, slope trimming includes removing weeds and loose stones to make the slope surface as flat as possible. When installing formwork, pay attention to its location and height to avoid significantly affecting the pouring and molding of porous concrete on site. Ecological concrete should be mixed at a concrete batching plant capable of achieving the intended performance according to the mix design requirements. The batching plant should preferably use a high-efficiency forced mixer. Ecological concrete can be transported using mixer trucks or dump trucks. Concrete transportation time should not affect pouring and molding; concrete transported by mixer trucks should be unloaded within 1.5 hours, and concrete transported by dump trucks should be unloaded within 1.0 hour. The main equipment for ecological concrete pouring includes inclined conveyor belts for conveying concrete and cylindrical leveling machines for spreading and compacting. Expansion joints and contraction joints should be installed according to design requirements. After the ecological concrete is poured, to prevent rapid drying, the poured surface should be immediately covered with a film or similar material for curing. Ecological concrete has poor adhesion, so the formwork must be kept in place during construction until the concrete reaches sufficient strength. Generally, it should not be removed until 3 days after construction.

[0070] The optimal construction seasons for ecological concrete riverbank greening are March to May and October to November, with ambient temperatures ideally between 15℃ and 25℃, and not below 10℃ or above 30℃. Construction is prohibited during or before heavy rain to prevent seed and planting soil loss. After covering the ecological concrete surface with soil, watering should be carried out to maintain soil moisture and promote seed germination and growth. The leveling process for the planting soil and AB bacteria is detailed in [link to relevant documentation]. Figure 6 .

[0071] Example 2

[0072] The method for modifying the ecological seawall and the method for planting plants within the rigid seawall grid panels in this embodiment include the following steps:

[0073] S1: Screening of salt-tolerant plants: Based on historical survey data and relevant literature, native salt-tolerant plant varieties suitable for the treatment area were selected. In this embodiment, Suaeda salsa, Suaeda salsa, Leymus chinensis and ryegrass were selected as planting varieties.

[0074] S2: The grid is filled with ecological concrete and backfilled with planting materials: taking into account the maximum high tide level and the splash range;

[0075] S3: Improvement: After backfilling with ecological concrete to a depth of 1 / 2 of the grating, backfill with planting material to a depth of 1 / 3 of the grating and compact it. Finally, backfill with planting material containing the mixed-sown native plant seeds selected in step S1; the planting material is per 1m 3Mix 40-60g of AB bacteria into the planting soil;

[0076] The specific components of the ecological concrete are cement, crushed stone, mixing water, aggregate additives, and void-filling nutrients. Each 1m³ 3 The components are: 320 kg cement, 1539 kg crushed stone (aggregate particle size in the range of 5-20 mm), 68 L mixing water, 40 kg vegetation concrete additive, and 20 kg void-filling nutrients. The preparation method is the same as in Example 1.

[0077] The preparation method of the gap-filling nutrient in this embodiment is the same as that in Example 1.

[0078] In this embodiment, the mixed sowing method of native salt-tolerant plants is to plant Suaeda salsa at and below the maximum high tide level of the artificial seawall on the seaward side of the seawall, and Suaeda salsa, Suaeda salsa, Leymus chinensis and Lernaea ryegrass at the high tide level, with the seed number ratio being (10-12):(3-4):(2.6-3):(2.4-3).

[0079] The construction process of the ecological concrete and planting soil in this embodiment is the same as that in Embodiment 1.

[0080] Example 3

[0081] The method for modifying the ecological seawall and the method for planting plants within the rigid seawall grid panels in this embodiment include the following steps:

[0082] S1: Screening of salt-tolerant plants: Based on historical survey data and relevant literature review, native salt-tolerant plant varieties suitable for the treatment area were selected. In this embodiment, Suaeda salsa, Suaeda salsa, Leymus chinensis, Ryegrass, Tall Fescue and Iris tectorum were selected as planting varieties.

[0083] S2: The grid is filled with ecological concrete and backfilled with planting materials: taking into account the maximum high tide level and the splash range;

[0084] S3: Improvement: After backfilling with ecological concrete to a depth of 1 / 2 of the grating, backfill with planting material to a depth of 1 / 3 of the grating and compact it. Finally, backfill with planting material containing the mixed-sown native plant seeds selected in step S1; the planting material is per 1m 3 Mix 40-60g of AB bacteria into the planting soil;

[0085] The specific components of the ecological concrete are cement, crushed stone, mixing water, aggregate additives, and void-filling nutrients. The specific proportions are the same as in Example 2.

[0086] The preparation method of the gap-filling nutrient in this embodiment is the same as that in Example 1.

[0087] In this embodiment, the mixed sowing method of native salt-tolerant plants is to plant Suaeda salsa at and below the maximum high tide level of the artificial seawall on the seaward side of the seawall, and Suaeda salsa, Suaeda salsa, Leymus chinensis, Ryegrass and Tall Festuca acuminata at and above the maximum high tide level, with the seed number ratio being (10-12):(3-4):(2-3):(2-2.4):(0.6-1).

[0088] In this embodiment, *Iris tectorum* seedlings are transplanted above the highest tide level, averaging 3-4 seedlings per grid. This is because the upright growth of *Iris tectorum* leaves effectively reduces water evaporation and mitigates wave erosion of other seedlings within the grid. Furthermore, the flowers of *Iris tectorum* are creamy white, light blue, blue, or bluish-purple, making them aesthetically pleasing.

[0089] The construction process of the ecological concrete and planting soil in this embodiment is the same as that in Embodiment 1.

[0090] Performance testing experiments:

[0091] Detection method:

[0092] Three test areas of equal size were divided into three zones according to the grid panels in the restoration area. Each test area had 20 experimental points. Plants were planted at the experimental points using the ecological seawall modification method described in Examples 1-3 and the planting method within the hardened seawall grid panels. After the plants sprouted (see...),... Figure 7 Remove the covering, and after one month and three months of plant growth (see...). Figure 8 The number of surviving plants in each experimental area was counted, and the plant survival rate was calculated according to the following formula. The test results are shown in Table 3.

[0093] Plant survival rate = (number of surviving plants in each experimental area) / 20 × 100%.

[0094] Table 3. Survival rate of plants in the experimental areas of Examples 1-3

[0095] Serial Number January survival rate % March survival rate % Example 1 88.7 75.3 Example 2 90.7 80.6 Example 3 96.3 82.1

[0096] Comparing Examples 1 and 2 with Table 3, it can be seen that when the particle size of the crushed stone in the ecological concrete is smaller, the specific surface area of ​​the aggregate is larger, and the mass of cement mixing water and void-filling nutrients increases, the consistency and thickness of the cement paste film layer around the aggregate also increase, which can effectively improve the strength of the ecological concrete. In the later stages, a better growth environment for the plants was maintained, and the survival rate in March reached as high as 80.6%.

[0097] Comparing Examples 2 and 3 with Table 3, it can be seen that adding Iris tectorum and tall fescue to the planting varieties significantly improved the survival rate in January. This is because tall fescue has nitrogen-fixing properties, and Iris tectorum not only has the ability to withstand severe saline-alkali stress, but also has a well-developed umbrella-shaped root system with dense and extensive fibrous roots, giving it a strong ability to bind soil and retain water.

[0098] In summary, the ecological seawall modification method and the planting method within the hardened seawall grid panels proposed in this application can greatly improve the early-stage survival rate of plants, as well as the later-stage survival rate, and has high practical value.

[0099] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for planting plants within a rigid seawall grating, characterized in that: Includes the following steps: S1: Screening of salt-tolerant plants: Select native salt-tolerant plant varieties suitable for the treatment area based on historical survey data and relevant literature review; S2: Ecological concrete and backfill planting materials are used to fill the grid: taking into account the maximum high tide level and splash range of the treatment area once every 50 years. S3: Improvement: After backfilling with ecological concrete to a depth of 1 / 2 of the grating, backfill with planting material to a depth of 1 / 3 of the grating and compact it. Finally, backfill with planting material containing seeds of the mixed native salt-tolerant plant varieties selected in step S1; the planting material is per 1m 3 Mix 40-60g of AB bacteria into the planting soil; The ecological concrete is made by coating the surface of aggregate particles with a thin layer of cement slurry; per 1m 3 The quality of eco-friendly concrete is the sum of the compacted bulk density of aggregates, the amount of cement per cubic meter, additives, and water. Its specific components are: cement, crushed stone, mixing water, aggregate additives, and void filler nutrients. The standard mix design is as follows: per 1m 3 Ecological concrete consists of 210-350 kg of cement, 1420-1685 kg of crushed stone, 60.4-70 L of water, 30-50 kg of aggregate additives, and 15-20 kg of void filler nutrients. The preparation method of ecological concrete is as follows: cement and water are mixed to form a uniform slurry, then crushed stone and aggregate additives are added in sequence to form a uniform concrete. After 15 days, void filler nutrients are evenly poured into the concrete. The nutrient-filling material for the voids includes planting soil, AB bacteria, plant fiber, slow-release compound fertilizer, and water-retaining agent, wherein each 1 m 3 The planting soil contains 40-60g of AB bacteria, 20-50g of plant fiber, 5-12g of slow-release compound fertilizer, and 2-4g of water-retaining agent. The preparation method of the gap-filling nutrients is as follows: first, mix the planting soil, AB bacteria, slow-release compound fertilizer, and water-retaining agent evenly, then soak the plant fiber in water and mix it evenly; gradually add water to the mixture and mix evenly, then dry it to 20%-40% humidity. The cement used is ordinary Portland cement; the thickness of the thin cement slurry coating is 1.0 mm; Based on the highest tide level in the region that occurs once every 50 years, different types and proportions of salt-tolerant plants are planted in different areas. The specific selection method is based on the salt tolerance of the plants, and the number of seeds of plants with high salt tolerance accounts for at least 50%. The backfilling and mixing of salt-tolerant plant seeds is as follows: Mix the prepared salt-tolerant plant seeds according to the mixing ratio, and then mix them with planting soil and AB bacteria. The seeds account for 5%-10% of the mass of the planting soil and AB bacteria mixture. After wetting with water, fill the grid board. The moisture content of the mixed material is 70%-80%. Before large-scale planting, planting trials were conducted in typical areas of hardened seawalls; If some salt-tolerant plants fail to germinate, they can be reseeded appropriately, and a safety assessment of the plant species should be conducted. They should not be planted out of season to avoid the invasion of alien species.

2. The planting method according to claim 1, characterized in that: The compressive strength of the ecological concrete is slightly lower, controlled at 3-7 MPa, and the porosity is 21%-30%.

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