Spartina alterniflora treatment method based on mechanical cutting and tidal water level adjustment

Abstract

The invention discloses a spartina alterniflora management method based on mechanical mowing and tidal water level regulation, which comprises the following steps: using mechanical mowing equipment to mow spartina alterniflora in the growth peak period of spartina alterniflora, and cutting the overground part to the height less than 5cm; dividing the treatment area into high, medium and low tidal flat according to the tidal flat elevation, and establishing a dam filled with sand and covered with degradable cloth in each area; adjusting the height of the dam according to the tidal cycle and the tidal flat elevation, so that the high tidal flat area is submerged by natural saline water at least twice a month during the large tide; after the spartina alterniflora is treated, the sandy dam and the anti-scouring cloth are gradually removed, the original ecological system of the wetland is restored, and local plants are planted to promote natural restoration. According to the method, low-cost, high-efficiency and eco-friendly long-term treatment of the spartina alterniflora can be realized in a large-area mud flat area, so that the operability, sustainability and environmental friendliness of the treatment effect are remarkably improved, and the method has wide popularization and application values.

Description

Technical Field

[0001] The invention relates to the technical field of wetland ecological restoration, and in particular to a method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation, which is suitable for large-area ecological control in coastal wetlands, saline-alkali tidal flats and intertidal zones. Background Art

[0002] Spartina alterniflora is a perennial herb of the Poaceae family, with the characteristics of a well-developed root system, strong reproductive ability and rapid spread.

[0003] In order to control the spread of Spartina alterniflora, a variety of prevention and control methods have been proposed, including physical control, chemical control and biological control, but these methods still have many problems in practical application. Chemical methods usually use herbicide spraying. Although it is easy to operate and effective in the short term, it is easy to pollute the soil and water bodies and have a negative impact on the surrounding ecological environment. Physical control mainly includes manual mowing, plowing, cofferdam flooding and other methods, but these methods require a lot of manpower and material resources when applied on a large scale, with low efficiency and unsatisfactory control effects; in addition, the high cost and operational complexity of physical methods limit their application in large-scale control.

[0004] Several methods for comprehensive management of Spartina alterniflora have been proposed in existing patents, but there are still some shortcomings. For example, the patent application publication number is CN113712018A, and the name is a comprehensive method for managing Spartina alterniflora by freshwater flooding. The method combines dikes, freshwater flooding, tillage and covering with biological mulch to inhibit the expansion of Spartina alterniflora. However, it mainly relies on the continuous supply of freshwater resources and is difficult to promote in areas where freshwater resources are scarce. In addition, large areas of tidal flats require a lot of manual operation and mechanical equipment investment, resulting in high management costs and difficulty in continuous implementation. The invention with patent application publication number CN110268892A is entitled "A method for comprehensive control of Spartina alterniflora by terraced flooding and mowing". The method inhibits the growth of Spartina alterniflora by constructing terraced dams and combining tidal flooding with mowing technology, and has a certain control effect. Although the method makes full use of tidal water for natural water replenishment, thereby reducing the need for artificial irrigation, its mowing operation mainly relies on manual labor and is less efficient. In addition, the dam material is made of earth or PVC pipes, and this material selection may have durability problems in long-term use. More importantly, the invention lacks clear and specific measures in terms of ecological restoration, which may have an adverse impact on the recovery of the wetland ecosystem after treatment, reducing its sustainability and potential for promotion and application. The patent application publication number is CN103749424A, and the patent name is a method for controlling the flooding of Spartina alterniflora by cofferdams on sandy beaches. The invention relies on stainless steel plate cofferdams and deep excavation to form a closed structure. Although the water level can be adjusted by tides, its construction is complicated and costly, and it is difficult to promote on large sandy beaches. At the same time, the long-term existence of steel plate cofferdams may interfere with the beach ecosystem, and it is difficult to maintain and easily corroded by seawater. In addition, the method lacks flexibility, and the cofferdam is difficult to adjust or remove after installation. It is difficult to restore the natural state after the treatment is completed, which limits its environmental friendliness and wide applicability. The patent application publication number is CN101176442A, and the patent name is a method for controlling the invasion of Spartina alterniflora by integrated technology of mowing and water level regulation. The method requires digging a water storage ditch to collect and store tidal water. The construction is complicated and costly, and it is impossible to achieve automatic water replenishment. It relies on multiple manual operations for water replenishment, resulting in increased labor costs and waste of resources. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation comprises the following specific steps:

[0008] S1: Mechanical mowing: Use a mechanical mowing device with adjustable height to mow the Spartina alterniflora during the growth period of the grass, and cut the above-ground part to a height of less than 5 cm;

[0009] S2: Zoning embankment construction: According to the elevation of the tidal flat, the treatment area is divided into high, medium and low tidal flats, and embankments filled with sand and covered with biodegradable fabrics are built in each area to prevent wave erosion and soil loss;

[0010] S3: Tidal water level regulation: Adjust the height of the levee according to the tidal cycle and the elevation of the tidal flat so that the high tide beach area is flooded with natural salt water at least twice a month during the high tide, achieving natural water replenishment without the need for artificial freshwater irrigation;

[0011] S4: Ecological restoration: After completing the treatment of Spartina alterniflora, gradually remove the sandy embankments and anti-scour fabrics, restore the original wetland ecosystem, and plant native plants to promote natural recovery.

[0012] As a further technical solution of the present invention, in S1, the mechanical mowing equipment is a height-adjustable lawn mower that can adapt to the terrain of different tidal flat areas to reduce damage to non-target plants.

[0013] As a further technical solution of the present invention, in S1, the residues of Spartina alterniflora after mechanical mowing can be directly covered on the ground surface as an organic covering layer to improve the soil and reduce water evaporation.

[0014] As a further technical solution of the present invention, in S2, the partitioned embankment is constructed by filling with sand and covering the surface with degradable fabric, which can be naturally degraded after the treatment is completed without additional treatment.

[0015] As a further technical solution of the present invention, in S3, the height of the dam is adjusted according to the tidal water level and the elevation of the tidal flat, wherein the height of the low tidal flat dam is 1.2 meters, the height of the mid-tidal flat dam is 0.8 meters, and the height of the high tidal flat dam is 0.5 meters, so as to ensure natural salt water replenishment during high tides.

[0016] As a further technical solution of the present invention, in S3, when the tidal water level is adjusted, a water level sensor and an automatic drainage device are set inside the dam to monitor and adjust the water level in real time to ensure the optimal flooding depth and duration.

[0017] As a further technical solution of the present invention, in S4, after the treatment is completed, local plants such as Suaeda salsa and Scutellaria maritima are planted to promote the recovery of the ecosystem and improve the biodiversity of the wetland.

[0018] As a further technical solution of the present invention, during the treatment period, the soil salinity, vegetation growth and water bird habitat in the area are monitored every quarter to evaluate the treatment effect and adjust subsequent management measures.

[0019] As a further technical solution of the present invention, the treatment method is applicable to large areas of coastal wetland tidal flats, especially areas with scarce fresh water resources and high-salinity soil.

[0020] The beneficial effects of the present invention are:

[0021] 1. By introducing mechanized mowing technology, environmentally friendly zoned dam design and a natural regulation system based on tidal water levels, the efficiency and automation level of Spartina alterniflora management have been significantly improved, effectively reducing manual operation costs and dependence on freshwater resources.

[0022] 2. At the same time, the innovative use of the periodic changes in tidal water levels has achieved natural salt water replenishment in the treatment area, avoiding the high cost of freshwater irrigation and environmental pollution caused by chemical agents in existing methods.

[0023] 3. Sand and degradable fabrics are used as dam materials, which can effectively prevent erosion and facilitate removal after treatment is completed, thus minimizing interference with the wetland ecosystem and facilitating the natural recovery of native plants and ecosystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention provides a flow chart of a method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0026] Please see attached Figure 1 A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation comprises the following specific steps:

[0027] S1: Mechanical mowing: Use mechanical mowing equipment with adjustable height to mow S. alterniflora during its peak growth period, cutting the above-ground part to a height of less than 5 cm to weaken its regeneration ability;

[0028] Mechanical mowing equipment is a height-adjustable mower that can adapt to the terrain of different tidal flat areas to reduce damage to tidal flat soil and non-target plants;

[0029] The residues of Spartina alterniflora after mechanical mowing can be directly covered on the ground as an organic mulch to improve the soil and reduce water evaporation, and can also serve as a nutrient supplement.

[0030] S2: Zoning embankment construction: According to the elevation of the tidal flat, the treatment area is divided into high, medium and low tidal flats. By measuring the height of the tidal flat and the tidal changes, the boundaries of each area are determined so that effective treatment can be carried out according to different tidal conditions. In addition, embankments filled with sand and covered with degradable fabrics are built in each area to prevent wave erosion and soil loss.

[0031] The construction of the zoned dam is filled with sand and covered with degradable fabric on the surface to prevent seawater scouring from damaging the dam structure. The degradable fabric can be naturally degraded after the treatment is completed, without the need for additional treatment, reducing the impact on the ecological environment;

[0032] During the dam construction process, drainage holes can be set at the bottom of the dam to quickly drain water when the tide recedes, preventing excessive water accumulation in the dam and affecting subsequent ecological recovery.

[0033] S3: Tidal water level regulation: Adjust the height of the levee according to the tidal cycle and the elevation of the tidal flat so that the high tide beach area is flooded with natural salt water at least twice a month during the high tide, achieving natural water replenishment without the need for artificial freshwater irrigation;

[0034] The height of the dam is adjusted according to the tidal water level and the elevation of the tidal flat, with the low tidal flat dam height being 1.2 meters, the mid tidal flat dam height being 0.8 meters, and the high tidal flat dam height being 0.5 meters, to ensure that the high tidal flat dam can be naturally submerged during high tides to achieve natural salt water replenishment. This design does not require artificial irrigation and makes full use of tidal water level changes to inhibit the growth of Spartina alterniflora.

[0035] When the tidal water level is adjusted, water level sensors and automatic drainage devices are installed inside the dam to monitor and adjust the water level in real time to ensure the optimal flooding depth and duration.

[0036] S4: Ecological restoration: After completing the treatment of Spartina alterniflora, gradually remove the sandy embankments and anti-scour fabrics, restore the original wetland ecosystem, and plant native plants to promote natural recovery.

[0037] Levee dismantling and fabric recycling: After 6-12 months of treatment, the Spartina alterniflora gradually withers under the stress of flooding and salt water, and the sandy levee can be dismantled. First, remove the biodegradable fabric on the surface of the levee, roll it up and dispose of it. Use mechanical equipment to dismantle the sandy levee to ensure that no secondary damage is caused to the surrounding mudflats and native plants during the dismantling process.

[0038] Restoration and monitoring of the ecosystem: After the dam is removed, soil improvement and native plant planting will be carried out in the treatment area to accelerate the ecological restoration process. It is recommended to plant local plants that adapt to saline-alkali environments, such as Suaeda salsa and Scutellaria marissima, to increase vegetation coverage and stability, promote ecosystem restoration, and improve wetland biodiversity. The ecological restoration effect can be evaluated by regularly monitoring plant growth, soil salt content, and water bird habitats. If there are signs of recurrence of Spartina alterniflora, management measures can be adjusted according to the monitoring results, and mechanical cutting and tidal regulation can be carried out in a timely manner to ensure long-term treatment effects.

[0039] Maintenance of treatment effects: Monitoring stations are set up in the treatment area to regularly collect data, including soil salinity, water level changes and vegetation growth conditions; drones or remote sensing technology are used for regional monitoring to promptly detect signs of resurgence of Spartina alterniflora.

[0040] In a preferred embodiment, during the treatment period, soil salinity, vegetation growth and water bird habitat in the area are monitored quarterly to evaluate the treatment effect and adjust subsequent management measures.

[0041] In a preferred embodiment, the treatment method is applicable to large areas of coastal wetland tidal flats, especially areas with scarce fresh water resources and high-salinity soils.

[0042] Example 1

[0043] A one-year experiment on the control of Spartina alterniflora was conducted in the coastal wetlands of Yuyao City, Zhejiang Province. The coastal wetlands of Yuyao City are typical tidal mudflat areas, which are significantly affected by the rise and fall of sea water. The invasion of Spartina alterniflora is relatively serious, posing a significant threat to the local ecological environment and biodiversity. This implementation case shows the effect of the method based on the combination of mechanical mowing, zoning dam construction and tidal water level regulation proposed by the present invention in practical application.

[0044] 1. Experimental area and preliminary preparation

[0045] 1.1 Overview of the test area:

[0046] The test area is located in the coastal wetland of Yuyao City, Zhejiang Province. The density of Spartina alterniflora in the test area is high, which has a serious impact on the local plant community and water bird habitat. The tidal frequency in the selected area is 2 high tides per month, and the highest tide can flood the high tide beach area.

[0047] 1.2 Preliminary preparations:

[0048] Detailed topographic surveys and tidal water level monitoring were carried out in the test area to determine the boundaries of high, medium and low tidal flats. Based on the measurement data, the test area was divided into three sub-areas (high, medium and low tidal flats). Special mechanical mowing equipment was introduced to carry out preliminary mowing of Spartina alterniflora in the test area to ensure the effective implementation of subsequent control measures.

[0049] (II) Specific implementation steps

[0050] 2.1 Mechanical mowing operation:

[0051] In early May before the start of the experiment, mechanical mowing equipment was used to mow the Spartina alterniflora, and the above-ground parts were cut to a height of less than 5 cm.

[0052] 2.2 Zoning dam construction:

[0053] According to the elevation of the tidal flat and the tidal water level, sandy dams are built in the high, medium and low tidal flat areas. The height of the dams is as follows: low tidal flat: the dam height is 1.2 meters, so that the treatment area is always soaked in salt water; medium tidal flat: the dam height is 0.8 meters, ensuring that the medium tide submerges the Spartina alterniflora in the area; high tidal flat: the dam height is 0.5 meters, which is only submerged during high tide, and tidal water replenishment can be achieved twice a month. The surface of the dam is covered with degradable fabric to prevent the dam from being damaged by waves. The fabric is made of environmentally friendly materials to ensure that it can be naturally degraded after the treatment is completed.

[0054] 2.3 Tidal water level regulation:

[0055] Taking advantage of the tidal cycle of Yuyao City, the area inside the dyke of the high tide beach is flooded with salt water through the natural tidal rise and fall during the monthly high tide. The area is soaked in salt water at least twice a month. No additional artificial water replenishment is required during this process, and natural water level regulation is achieved. Water level sensors are installed inside the dyke to monitor water level changes in real time to ensure that the flooding time and depth can effectively inhibit the regeneration of Spartina alterniflora.

[0056] 3. Governance Effect and Monitoring

[0057] 3.1 Governance effect evaluation:

[0058] Six months after the treatment was implemented (November), the growth of Spartina alterniflora in each sub-area was monitored. The results showed that the growth of Spartina alterniflora in each tidal flat area was significantly inhibited, and the biomass was reduced by more than 90%.

[0059] 3.2 Ecological restoration and vegetation diversity:

[0060] Nine months after the treatment was completed (February of the following year), some of the dams and coverings were removed. It was found that native plant communities, such as Suaeda salsa and Scirpus mariqueter, began to recover naturally in the treatment area. Waterbird monitoring results showed that the number of waterbirds in the treatment area increased by 30%, including protected birds such as bean geese and black-headed gulls that returned to the area.

[0061] 3.3 Long-term maintenance and management:

[0062] It is planned to carry out mechanical mowing once a year after the trial to prevent the recurrence of Spartina alterniflora. Water level monitoring and ecological assessment will be carried out every quarter to ensure the sustainability of the treatment effect. The tidal water level, soil salinity and plant growth conditions in the area will be tracked over a long period of time, and the dam height and water level regulation strategy will be adjusted when necessary to ensure the long-term control effect of Spartina alterniflora.

[0063] The implementation case in the coastal wetland of Yuyao City, Zhejiang Province shows that the management method based on mechanical mowing and tidal water level regulation proposed in this invention can effectively control the growth of Spartina alterniflora while reducing the negative impact on the ecological environment. The combination of mechanized operation and natural tides not only improves the management efficiency, but also greatly reduces labor costs and freshwater resource consumption, providing an efficient and sustainable solution for the ecological restoration of large areas of coastal wetlands.

[0064] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0065] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation, characterized in that: The specific steps include: S1: Mechanical mowing: Use a mechanical mowing device with adjustable height to mow the Spartina alterniflora during the growth period of the grass, and cut the above-ground part to a height of less than 5 cm; S2: Zoning embankment construction: According to the elevation of the tidal flat, the treatment area is divided into high, medium and low tidal flats, and embankments filled with sand and covered with biodegradable fabrics are built in each area to prevent wave erosion and soil loss; S3: Tidal water level regulation: Adjust the height of the levee according to the tidal cycle and the elevation of the tidal flat so that the high tide beach area is flooded with natural salt water at least twice a month during the high tide, achieving natural water replenishment without the need for artificial freshwater irrigation; S4: Ecological restoration: After completing the treatment of Spartina alterniflora, gradually remove the sandy embankments and anti-scour fabrics, restore the original wetland ecosystem, and plant native plants to promote natural recovery.

2. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 1, characterized in that: In S1, the mechanical mowing device is a height-adjustable lawn mower that can adapt to the terrain of different tidal flat areas to reduce damage to non-target plants.

3. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 2, characterized in that: In S1, the residues of Spartina alterniflora after mechanical mowing can be directly covered on the ground surface as an organic covering layer to improve the soil and reduce water evaporation.

4. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 1, characterized in that: In S2, the partitioned embankment is constructed by filling with sand and covering the surface with degradable fabric, which can be naturally degraded after the treatment is completed without additional treatment.

5. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 1, characterized in that: In S3, the height of the dam is adjusted according to the tidal water level and the elevation of the tidal flat, wherein the height of the low tidal flat dam is 1.2 meters, the height of the mid-tidal flat dam is 0.8 meters, and the height of the high tidal flat dam is 0.5 meters, to ensure natural salt water replenishment during high tides.

6. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 5, characterized in that: In S3, when the tidal water level is adjusted, a water level sensor and an automatic drainage device are set inside the dam to monitor and adjust the water level in real time to ensure the optimal flooding depth and duration.

7. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 1, characterized in that: In S4, after the treatment is completed, the restoration of the ecosystem is promoted and the biodiversity of the wetland is improved by planting native plants such as Suaeda salsa and Scutellaria maritima.

8. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 1, characterized in that: During the treatment period, soil salinity, vegetation growth and water bird habitat in the area will be monitored every quarter to evaluate the treatment effect and adjust subsequent management measures.

9. A method for controlling Spartina alterniflora based on mechanical mowing and tidal water level regulation according to claim 1, characterized in that: The treatment method is applicable to large areas of coastal wetland mudflats, especially those with scarce freshwater resources and high-salinity soils.

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