Ecological restoration method for degraded coastal salt marsh wetland

Abstract

The invention discloses a degraded coastal salt marsh wetland ecological restoration method which comprises the following steps: S1, selecting a restoration area, and performing ecological environment investigation on the restoration area; s2, the restoration area is divided into a halophyte floating island area, a submerged plant restoration area and a salt marsh wetland restoration area, the halophyte floating island area and the submerged plant restoration area form a clear water conservation pond, and the clear water conservation pond provides a tidal water source for the salt marsh wetland restoration area; s3, performing microtopography improvement on the salt marsh wetland restoration area to enable the ground slope of the salt marsh wetland restoration area from the land to the sea surface to be less than or equal to 6 degrees, and performing soil restoration on the salt marsh wetland restoration area; and S4, according to the current tidal creek form on the nearby coastal salt marsh wetland, calculating the suitable density of the tidal creek and the main flow direction of the tidal creek in the salt marsh wetland recovery area. According to the method, the coastal salt marsh wetland can be ecologically restored, only microtopography transformation is needed, the influence on ecology is small, the restoration effect is good, operation is easy, and the cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of coastal salt marsh wetland restoration, and in particular to a method for ecological restoration of degraded coastal salt marsh wetlands. Background Art

[0002] Coastal salt marsh wetlands are located in the salt-fresh water confluence area of ​​the ocean and land ecosystems. Due to the interaction of regular or irregular ocean tides and terrestrial freshwater runoff, this area has formed a typical wetland ecosystem with a huge natural physical environment stress gradient and obvious vegetation zoning. At present, due to the obstruction of hydrological connectivity, the reduction of habitat connectivity of local species, the weakening of seed flow connectivity, and the imbalance of soil water and salt, the habitat quality of local species has declined and degraded. The vegetation restoration technology for local species in degraded coastal salt marsh wetlands has become an important and challenging scientific problem.

[0003] Coastal salt marsh wetlands are important ecological resources, and they play a very important role in regulating regional climate, strengthening flood and drought resistance, controlling pollution, improving wetland environment, and increasing tourism revenue. In recent years, the intensification of human activities has led to serious damage and even loss of salt marsh wetlands. In order to protect this precious resource, there is an urgent need for practical ecological restoration technologies to restore severely degraded coastal salt marsh wetland areas. Summary of the invention

[0004] The invention provides a method for ecological restoration of degraded coastal salt marsh wetlands, which can be used for ecological restoration of coastal salt marsh wetlands. It only requires micro-topography transformation, has little impact on the ecology, has good restoration effect, is simple to operate, and is low in cost.

[0005] In order to achieve the above object, the present invention provides a method for ecological restoration of degraded coastal salt marsh wetlands, which comprises the following steps:

[0006] S1. Select a restoration area and conduct an ecological environment survey on the restoration area;

[0007] S2. Dividing the restoration area into a halophyte floating island area, a submerged plant restoration area and a salt marsh wetland restoration area, wherein the halophyte floating island area and the submerged plant restoration area constitute a clear water conservation pond, and the clear water conservation pond provides a tidal water source for the salt marsh wetland restoration area;

[0008] S3. Conduct micro-topography improvement on the salt marsh wetland restoration area, so that the ground slope from land to sea in the salt marsh wetland restoration area is ≤6°, and perform soil restoration on the salt marsh wetland restoration area;

[0009] S4. Calculate the suitable density of tidal channels and the main flow direction of tidal channels in the salt marsh restoration area according to the existing tidal channel morphology in the nearby coastal salt marsh wetlands;

[0010] S5. Construct plant communities in the salt marsh wetland restoration area, including aquatic plants and halophytes;

[0011] S6. Plant growth detection: use sample plots to monitor plant density, plant height and biomass. For areas with low plant density or no plants, analyze the reasons and carry out appropriate replanting in the next year.

[0012] As a further description of the above technical solution:

[0013] In step S3, the micro-topography improvement of the salt marsh wetland restoration area includes the following steps:

[0014] S31, plowing the land in the salt marsh wetland restoration area, and leveling the plowed land to obtain a base soil layer;

[0015] S32, laying a salt-isolating layer on the base soil layer, and horizontally laying a first plant straw layer on the salt-isolating layer;

[0016] S33, laying a planting soil layer on the first plant straw layer;

[0017] S34, vertically inserting a second plant straw layer on the planting soil layer.

[0018] As a further description of the above technical solution:

[0019] The salt-isolating layer is a coarse sand layer or a crushed stone layer or a mixed layer of coarse sand and crushed stone.

[0020] As a further description of the above technical solution:

[0021] The first plant straw layer and the second plant straw layer are both wetland plant straws.

[0022] As a further description of the above technical solution:

[0023] The wetland plant straws include one or more of reed straws, sedge straws, Spartina alterniflora straws, Scirpus maritima straws, Phragmites australis straws and Suaeda salsa straws.

[0024] As a further description of the above technical solution:

[0025] The ecological environment survey includes a comprehensive survey of the climate conditions, soil conditions, water resources, vegetation, and animal and plant resources of the target wetland.

[0026] As a further description of the above technical solution:

[0027] The halophytes are one or two of Suaeda salsa, Ligusticum chuanxiong and Apocynum venetum; the aquatic plants are one or more of Snapdragon, Phragmites australis and Tripterygium wilfordii; and the planting method is a combination of sowing and vegetative body transplantation.

[0028] As a further description of the above technical solution:

[0029] The soil restoration includes: restoring the soil by using a thin layer of dredged mud covering method.

[0030] As a further description of the above technical solution:

[0031] The ground slope of the salt marsh wetland restoration area from land to sea is 4°.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] 1. In the present invention, the restoration area is divided into a halophyte floating island area, a submerged plant restoration area and a salt marsh wetland restoration area. The halophyte floating island area and the submerged plant restoration area constitute a clean water conservation pond. The clean water conservation pond provides a tidal water source for the salt marsh wetland restoration area, can regulate the hydraulic retention time, measure the effluent water quality, summarize the best zoning plan, and construct a composite ecological purification system to avoid domestic sewage from polluting the salt marsh wetland restoration area again.

[0034] 2. In the present invention, a variety of aquatic plants and halophytes are mixed to construct wetland plant communities, which improves the plant diversity of the wetland and at the same time improves the pollutant purification capacity of the wetland; the planting method adopts a combination of sowing and nutrient body transplantation, which greatly improves the success rate of wetland ecological restoration; planting multiple plants at the same time can accelerate the succession of plant communities and promote the function of wetland soil ecosystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 This is a flow chart of a method for ecological restoration of degraded coastal salt marsh wetlands.

[0037] Figure 2 This is a cross-sectional view of a salt marsh restoration area in a method for ecological restoration of degraded coastal salt marsh wetlands.

[0038] Figure 3 This is an overhead view of the salt marsh restoration area in a method for ecological restoration of degraded coastal salt marsh wetlands.

[0039] Legend:

[0040] 1. Base soil layer; 2. Salt isolation layer; 3. First plant straw layer; 4. Planting soil layer; 5. Second plant straw layer. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0044] In the description of the embodiments of the present invention, it should be noted that the terms "upper", "inner", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0045] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] See also Figure 1-3 The present invention provides a method for ecological restoration of degraded coastal salt marsh wetlands, comprising:

[0047] S1. Select a restoration area and conduct an ecological environment survey on the restoration area;

[0048] S2. Dividing the restoration area into a halophyte floating island area, a submerged plant restoration area and a salt marsh wetland restoration area, wherein the halophyte floating island area and the submerged plant restoration area constitute a clear water conservation pond, and the clear water conservation pond provides a tidal water source for the salt marsh wetland restoration area;

[0049] S3. Conduct micro-topography improvement on the salt marsh wetland restoration area, so that the ground slope from land to sea in the salt marsh wetland restoration area is ≤6°, and perform soil restoration on the salt marsh wetland restoration area;

[0050] S4. Calculate the suitable density of tidal channels and the main flow direction of tidal channels in the salt marsh restoration area according to the existing tidal channel morphology in the nearby coastal salt marsh wetlands;

[0051] S5. Construct plant communities in the salt marsh wetland restoration area, including aquatic plants and halophytes;

[0052] S6. Plant growth detection: use sample plots to monitor plant density, plant height and biomass. For areas with low plant density or no plants, analyze the reasons and carry out appropriate replanting in the next year.

[0053] In step S3, the micro-topography improvement of the salt marsh wetland restoration area includes the following steps:

[0054] S31, plowing the land in the salt marsh wetland restoration area, and leveling the plowed land to obtain a base soil layer 1;

[0055] S32, laying a salt-isolating layer 2 on the base soil layer 1, and horizontally laying a first plant straw layer 3 on the salt-isolating layer 2;

[0056] S33, laying a planting soil layer 4 on the first plant straw layer 3;

[0057] S34, vertically inserting a second plant straw layer 5 on the planting soil layer 4.

[0058] The salt-isolating layer effectively prevents the formation of capillary action between the saline-alkali soil layer and the guest soil layer, that is, it effectively cuts off the channel for salt from the saline-alkali soil layer to enter the planting soil layer, avoiding the subsequent salinization of the planting soil layer.

[0059] The vertical plant straws are arranged in a grid shape, which can block the soil, improve the soil's impact resistance, and prevent soil loss. The later decomposition of the plant straw can effectively improve the physical texture conditions of the soil, prevent soil compaction, increase soil permeability, increase the nutrient supply of the soil in the restoration area, and provide nutrients such as nitrogen and phosphorus for the planted vegetation species.

[0060] The salt-isolating layer is a coarse sand layer or a crushed stone layer or a mixed layer of coarse sand and crushed stone. Materials can be obtained according to local conditions to reduce costs.

[0061] The first plant straw layer and the second plant straw layer are both wetland plant straws.

[0062] The wetland plant straws include one or more of reed straws, sedge straws, Spartina alterniflora straws, Scirpus maritima straws, Phragmites australis straws and Suaeda salsa straws.

[0063] The wetland plant community is constructed by mixing a variety of aquatic plants and halophytes, which improves the plant diversity of the wetland and the pollutant purification capacity of the wetland. The planting method adopts the combination of sowing and vegetative body transplantation, which greatly improves the success rate of wetland ecological restoration.

[0064] The ecological environment survey includes a comprehensive survey of the climate conditions, soil conditions, water resources, vegetation, and animal and plant resources of the target wetland. The selection of restoration areas specifically involves a comprehensive understanding of the state of the target wetland before damage, the cause of damage, and the degree of human interference during the restoration process, so as to select the area that needs ecological restoration; this can increase the success rate of wetland restoration.

[0065] The halophytes are one or two of Suaeda salsa, Ligusticum chuanxiong and Apocynum venetum; the aquatic plants are one or more of Snapdragon, Phragmites australis and Tripterygium wilfordii; and the planting method is a combination of sowing and vegetative body transplantation.

[0066] The soil restoration includes: using dredged mud thin layer covering method to restore soil. Marine dredged mud is used for ecological restoration and ecological reconstruction of coastal wetlands. Dredged mud contains rich secondary minerals and humus colloids, which can form a granular structure of soil and is the material basis for ecological restoration of sinking and erosive coastal wetlands. At the same time, dredged mud can effectively reinforce the coast and stabilize the erosive coast. After the coastal wetland ecosystem is formed, the vegetation root system in the wetland can effectively stabilize the silt, while creating a diverse habitat and improving the ecological environment quality of the coast and offshore waters.

[0067] The ground slope of the salt marsh wetland restoration area from land to sea is 4°, which is convenient for drainage.

[0068] Working principle: The restoration area is divided into halophyte floating island area, submerged plant restoration area and salt marsh wetland restoration area. The halophyte floating island area and submerged plant restoration area constitute a clear water conservation pond, which provides tidal water sources for the salt marsh wetland restoration area, can regulate the hydraulic retention time, measure the effluent water quality, summarize the best zoning plan, and build a composite ecological purification system to avoid domestic sewage from polluting the salt marsh wetland restoration area again. The wetland plant community is constructed by mixing a variety of aquatic plants and halophytes, which improves the plant diversity of the wetland and the pollutant purification capacity of the wetland; the planting method adopts the combined use of sowing and nutrient body transplantation, which greatly improves the success rate of wetland ecological restoration; planting a variety of plants at the same time can accelerate the succession of plant communities and promote the function of wetland soil ecosystems.

[0069] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for ecological restoration of degraded coastal salt marsh wetlands, characterized in that: The following steps are involved: S1. Select a restoration area and conduct an ecological environment survey on the restoration area; S2. Dividing the restoration area into a halophyte floating island area, a submerged plant restoration area and a salt marsh wetland restoration area, wherein the halophyte floating island area and the submerged plant restoration area constitute a clear water conservation pond, and the clear water conservation pond provides a tidal water source for the salt marsh wetland restoration area; S3. Conduct micro-topography improvement on the salt marsh wetland restoration area, so that the ground slope from land to sea in the salt marsh wetland restoration area is ≤6°, and perform soil restoration on the salt marsh wetland restoration area; S4. Calculate the suitable density of tidal channels and the main flow direction of tidal channels in the salt marsh restoration area according to the existing tidal channel morphology in the nearby coastal salt marsh wetlands; S5. Construct plant communities in the salt marsh wetland restoration area, including aquatic plants and halophytes; S6. Plant growth detection: use sample plots to monitor plant density, plant height and biomass. For areas with low plant density or no plants, analyze the reasons and carry out appropriate replanting in the next year.

2. The method for ecological restoration of degraded coastal salt marsh wetlands according to claim 1, characterized in that: In step S3, the micro-topography improvement of the salt marsh wetland restoration area includes the following steps: S31, plowing the land in the salt marsh wetland restoration area, and leveling the plowed land to obtain a base soil layer; S32, laying a salt-isolating layer on the base soil layer, and horizontally laying a first plant straw layer on the salt-isolating layer; S33, laying a planting soil layer on the first plant straw layer; S34, vertically inserting a second plant straw layer on the planting soil layer.

3. A method for ecological restoration of degraded coastal salt marsh wetlands according to claim 2, characterized in that: The salt-isolating layer is a coarse sand layer or a crushed stone layer or a mixed layer of coarse sand and crushed stone.

4. The method for ecological restoration of degraded coastal salt marsh wetlands according to claim 2, characterized in that: The first plant straw layer and the second plant straw layer are both wetland plant straws.

5. A method for ecological restoration of degraded coastal salt marsh wetlands according to claim 4, characterized in that: The wetland plant straws include one or more of reed straws, sedge straws, Spartina alterniflora straws, Scirpus maritima straws, Phragmites australis straws and Suaeda salsa straws.

6. The method for ecological restoration of degraded coastal salt marsh wetlands according to claim 1, characterized in that: The ecological environment survey includes a comprehensive survey of the climate conditions, soil conditions, water resources, vegetation, and animal and plant resources of the target wetland.

7. The method for ecological restoration of degraded coastal salt marsh wetlands according to claim 1, characterized in that: The halophytes are one or two of Suaeda salsa, Ligusticum chuanxiong and Apocynum venetum; the aquatic plants are one or more of Snapdragon, Phragmites australis and Tripterygium wilfordii; and the planting method is a combination of sowing and vegetative body transplantation.

8. The method for ecological restoration of degraded coastal salt marsh wetlands according to claim 1, characterized in that: The soil restoration includes: restoring the soil by using a thin layer of dredged mud covering method.

9. The method for ecological restoration of degraded coastal salt marsh wetlands according to claim 1, characterized in that: The ground slope of the salt marsh wetland restoration area from land to sea is 4°.

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