Integrated removal and treatment method for spartina alterniflora in mudflat wetland

Abstract

The invention discloses an integrated removal and treatment method for spartina alterniflora in a mudflat wetland. The integrated removal and treatment method sequentially comprises the steps that a construction operation area is divided; mowing the spartina alterniflora for more than three times in the construction operation area, and airing the crushed straws; performing anaerobic landfill on the straws into the first landfill ditch; carrying out more than two times of root system ploughing on the construction operation area which is already cut; a second landfill ditch with the depth not smaller than two meters is dug, and the ploughed spartina alterniflora root system is placed into the second landfill ditch; and covering soil and compacting the second landfill ditch. According to the method, the formation of mature seeds of the spartina alterniflora can be effectively prevented, the sexual propagation path of the spartina alterniflora can be effectively cut off, the surface of the first landfill ditch after landfill is no longer suitable for growth of the spartina alterniflora, mowing and ploughing are carried out in different areas at the same time, the spartina alterniflora is prevented from sprouting again, the treatment efficiency of the wetland spartina alterniflora is further improved, and the economic benefit is increased. Vegetative propagation of spartina alterniflora is avoided, repeated treatment of spartina alterniflora is avoided, and the treatment cost of spartina alterniflora is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wetland ecological restoration, and particularly relates to an integrated control method for Spartina alterniflora in tidal flat wetlands. Background Art

[0002] Spartina alterniflora is a perennial salt marsh herb of the genus Spartina in the family Poaceae. It is native to the Atlantic coast and the Gulf of Mexico. Due to its characteristics such as well-developed roots, salt and flood tolerance, strong reproductive ability, fast population spread, and strong invasiveness, it has now become the most typical and harmful alien invasive plant in the coastal wetland ecosystem of China.

[0003] The existing control methods for Spartina alterniflora include physical methods, chemical methods, and biological replacement methods. The chemical method is generally to spray herbicides. Although it is simple and easy to implement and has low cost, it has certain adverse effects on the soil, water body, surrounding organisms, etc., and is not suitable for the control of Spartina alterniflora in large areas (such as coastal wetlands). The biological replacement method is mostly used for the prevention and control of Spartina alterniflora in mangrove wetlands, and there are no native plants that can successfully replace Spartina alterniflora in salt marsh wetlands. The existing research on the control of Spartina alterniflora mainly focuses on physical control methods. For example, a method for comprehensively controlling Spartina alterniflora by mowing and plowing disclosed in Chinese CN112514713A mows the above-ground plants of Spartina alterniflora from the flowering stage to the early booting stage, so that it cannot produce mature seeds, thereby preventing Spartina alterniflora from sexually reproducing and spreading over long distances through seeds; in winter, the Spartina alterniflora that germinates again after mowing is plowed and the roots are broken, destroying the rhizomes of Spartina alterniflora in the dormant period, so that the rhizomes cannot reproduce asexually in the second year, and Spartina alterniflora is controlled by the combination of mowing and plowing. In the above method for controlling Spartina alterniflora, mowing is usually carried out from May to October every year, and plowing is carried out from November after mowing to January of the following year. The time interval between mowing and plowing is too long. Spartina alterniflora can regenerate 7 - 10 days after mowing, and the residual stalks germinate quickly again. Plowing turns the deep seeds to the surface layer, and the germination density increases instead in the following year, resulting in doubling of the labor and capital investment for the control of Spartina alterniflora due to repeated control. Summary of the Invention

[0004] Aiming at the defects existing in the prior art, the present application provides an integrated control method and method for Spartina alterniflora in tidal flat wetlands to solve the technical problems such as incomplete control of Spartina alterniflora in the prior art and the increase in the control cost of Spartina alterniflora caused by repeated control.

[0005] In order to achieve the above object of the invention, the technical solution provided by the present invention is as follows:

[0006] An integrated control method for Spartina alterniflora in tidal flat wetlands, comprising the following steps:

[0007] S1. Divide the wetland into multiple construction operation areas, and the area of each operation area does not exceed 100 ha;

[0008] S2. Mow the Spartina alterniflora in the construction operation area, sun-dry and crush the cut straws. When the above-ground part of the mowed Spartina alterniflora regrows to a height of 15 - 20 cm, mow the Spartina alterniflora again. The Spartina alterniflora in each construction operation area is mowed more than three times;

[0009] S3. Fill the dried and crushed straws into the first landfill trench for anaerobic landfill;

[0010] S4. During the ebb tide period, conduct root plowing on the construction operation areas that have been mowed more than three times, so that the surface layer of the construction operation areas is peeled off. The Spartina alterniflora in each construction operation area is plowed more than two times, and the remaining rhizomes in the soil that cannot be removed are chopped. At the same time, perform S2 and S3 in other construction operation areas;

[0011] S5. Excavate multiple second landfill trenches in the construction operation area. The depth of the second landfill trench is not less than 2 m. Collect the Spartina alterniflora roots exposed on the ground after plowing and put them into the second landfill trench;

[0012] S6. Fill the soil excavated from the second landfill trench into the second landfill trench to cover the Spartina alterniflora roots. Stack the excess soil evenly within the excavation range of the second landfill trench. Cover the second landfill trench with soil and compact it until there is no obvious subsidence when a person or machine walks on the covered soil layer and the soil surface is not loose. The covering material does not contain other weed seeds and Spartina alterniflora seeds.

[0013] In one embodiment, the height of the remaining above-ground part of the Spartina alterniflora after mowing in S2 does not exceed 10 cm, and the single-stem residue of the crushed straw does not exceed 5 cm.

[0014] In one embodiment, when mowing the Spartina alterniflora in S2, first perform mechanical mowing on the Spartina alterniflora, and perform manual supplementary mowing on the Spartina alterniflora in areas where mechanical mowing is not possible.

[0015] In one embodiment, S3 specifically includes the following steps:

[0016] S301. Set out and locate the first landfill trench, and excavate the surface soil of the first landfill trench;

[0017] S302. Place the surface soil on one side of the first landfill trench;

[0018] S303. Excavate the deep soil of the first landfill trench,

[0019] S304. Place the deep soil on the other side of the first landfill trench, and a woven geotextile is arranged between the deep soil and the other side of the first landfill trench;

[0020] S305. Fill the bottom of the first landfill trench with air-dried and crushed straw;

[0021] S306. Fill the first landfill trench with the topsoil excavated in S302 to cover the air-dried and crushed straw in the first landfill trench;

[0022] S307. Fill the first landfill trench with the deep soil excavated in S303 to cover the topsoil in the first landfill trench;

[0023] S308. Level and stack the surplus soil within the excavation range of the first landfill trench.

[0024] In one implementation, the number of the first landfill trenches in the construction operation area in S3 is equal to the number of mowing times in S2. Immediately after each mowing and drying of the straw, the straw is anaerobically landfilled.

[0025] In one implementation, the depth of root plowing in S4 is not less than 30 cm, and the thickness of the soil layer covering the Spartina alterniflora roots in S6 is at least 50 cm.

[0026] In one implementation, S4, S5, and S6 are completed within one tidal cycle.

[0027] In one implementation, the surface soil of the first landfill trench and the second landfill trench both form an earth ridge slightly higher than the ground.

[0028] In one implementation, it further includes S7. Establish a normalized monitoring and early warning mechanism, set up monitoring units, and conduct tracking monitoring on the wetland in the completed treatment area through on-site monitoring and / or UAV remote sensing. The monitoring content includes the recurrence area and recurrence density of Spartina alterniflora in the completed treatment area, collect the patches where recurrence occurs, and set up quadrats for the patches to count the number of recurrence Spartina alterniflora plants, so as to calculate the number of recurrence plants per hectare of the patch. Remove Spartina alterniflora in time when it is found. If sporadic new plants appear, take measures such as digging and pulling out for timely treatment. If patchy populations appear, use chemical control measures for timely treatment.

[0029] In one implementation, monitor once within 1 month after the completion of S6, and monitor no less than 4 times from April to November every year, and make written and image records.

[0030] In S2, a Spartina alterniflora mowing device for tidal flat wetlands is used to mow Spartina alterniflora within the construction operation area. The Spartina alterniflora mowing device for tidal flat wetlands includes an excavator and a mowing assembly. The excavator can be placed on a dredger for work. The excavator includes a vehicle body, a telescopic rotating arm, and a bucket. One end of the telescopic rotating arm is fixed to the vehicle body, and a bucket is fixed to the other end of the telescopic rotating arm. The mowing assembly is arranged at the front end of the bucket to cut the stems and leaves of Spartina alterniflora.

[0031] In one implementation, the mowing assembly includes a blade and a fixing frame. The blade is rectangular. One end of the blade is fixedly arranged on the bucket, and the other end of the blade is away from the bucket. The mowing assembly can be separated from the bucket. One side of the blade is a cutting edge, and the other side is a blade back. The cutting edge of the blade faces outward. The fixing frame is arranged on the blade back side. The fixing frame includes a first fixing rod and a second fixing rod. A plurality of first fixing rods are fixedly arranged at intervals along the length direction of the blade on the upper surface of the blade back. One end of the second fixing rod is fixed to the blade, and the other end of the second fixing rod is fixed to the bucket.

[0032] Compared with the prior art, the present application has at least the following beneficial effects:

[0033] In the integrated control method of Spartina alterniflora in tidal flat wetlands of the present application, the wetland is first divided into multiple construction operation areas, which can minimize the mowing time of Spartina alterniflora. Each single mowing within each construction operation area is completed within 7 days, and then Spartina alterniflora is mowed three or more times in S2, thereby effectively preventing the formation of mature seeds of Spartina alterniflora, cutting off its sexual reproduction pathway, and preventing the seeds from spreading to other areas with the tide or wind, etc., thereby reducing its spreading range. Before Spartina alterniflora has fully recovered its growth, the above-ground part is continuously damaged, making it difficult for it to accumulate enough nutrients for regeneration and gradually weakening its growth potential. In the present application, different construction operation areas can carry out mowing and ploughing simultaneously, shortening the control time of Spartina alterniflora in tidal flat wetlands.

[0034] When anaerobically landfilling straw, the surface soil and deep soil are successively excavated during the process of digging the first landfill trench, and the surface soil and deep soil are placed separately. When covering the straw, the surface soil is covered first and then the deep soil, so that the surface of the first landfill trench after landfilling is no longer suitable for the growth of Spartina alterniflora.

[0035] In the present application, the roots and rhizomes of Spartina alterniflora are chopped and broken by ploughing, so that they are separated from the soil, destroying their functions of absorbing water and nutrients, making it difficult for Spartina alterniflora to continue growing, and cutting off its asexual reproduction pathway. When ploughing the roots in a certain construction operation area, mowing and anaerobic landfilling are carried out simultaneously in other construction operation areas, which not only shortens the time interval between mowing and ploughing, avoids the re-germination of fast-growing Spartina alterniflora, but also improves the control efficiency of Spartina alterniflora in wetlands.

[0036] In this application, the roots of Spartina alterniflora after plowing are buried in a first landfill trench with a depth of not less than 2 m, so that they can decompose rapidly under anoxic conditions, preventing the asexual reproduction of Spartina alterniflora, avoiding repeated treatment of Spartina alterniflora, and reducing the treatment cost of Spartina alterniflora. Brief Description of the Drawings

[0037] Figure 1 It is a schematic flow chart of the method for treating Spartina alterniflora in wetlands in the embodiment of this application;

[0038] Figure 2 It is a schematic diagram of the division of the construction operation area in the embodiment of this application;

[0039] Figure 3 It is a schematic flow chart of the anaerobic landfill of straw in the embodiment of this application;

[0040] Figure 4 It is a schematic structural diagram of the mowing device for Spartina alterniflora in tidal flat wetlands in the embodiment of this application;

[0041] Figure 5 It is a top view of the mowing device for Spartina alterniflora in tidal flat wetlands in the embodiment of this application;

[0042] Figure 6 It is a schematic structural diagram of the mowing assembly in the embodiment of this application;

[0043] Figure 7 It is a top view of the mowing assembly in the embodiment of this application;

[0044] Figure 8 It is Figure 6 View A-A of.

[0045] Reference Signs: 1, excavator; 101, vehicle body; 102, telescopic rotating arm; 103, bucket; 2, mowing assembly; 201, blade; 202, fixing frame; 203, first fixing plate; 204, second fixing plate; 205, first fixing rod; 206, second fixing rod; 207, third fixing rod. Detailed Description of the Embodiment

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be described below through specific embodiments shown in the drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0047] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms "a", "the", and "said" used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0048] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to a determination".

[0049] In the description of the present invention, unless otherwise specified and defined, it should be noted that the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a mechanical connection, or it may be the communication inside two components. It may be directly connected, or it may be indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms may be understood according to specific circumstances.

[0050] To better understand the technical solution of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0051] Taking part of the Nanhui Dongtan Wetland in Shanghai as an example, this embodiment provides a method for controlling Spartina alterniflora in wetlands, as Figure 1 shown, including the following steps:

[0052] S1. Divide the wetland into multiple construction operation areas, and the area of each operation area does not exceed 100 ha.

[0053] As Figure 2 shown, in this embodiment, according to the distribution of Spartina alterniflora and the elevation of the tidal flat, part of the Nanhui Dongtan Wetland is divided into 6 construction operation areas, and the area of each area does not exceed 100 ha, so as to carry out construction operations in sub-areas subsequently and also be able to shorten the mowing time as much as possible.

[0054] S2. Mow the Spartina alterniflora in the construction operation area, dry and crush the cut straws. When the above-ground part of the mowed Spartina alterniflora grows back to a height of 15 - 20 cm, mow the Spartina alterniflora again, and mow the Spartina alterniflora in each construction operation area more than three times.

[0055] In this embodiment, the height of the above-ground residual stubble of Spartina alterniflora after mowing does not exceed 10 cm. When mowing Spartina alterniflora, mechanical mowing is first carried out on Spartina alterniflora to improve production efficiency, and manual supplementary mowing is carried out on Spartina alterniflora in areas where mechanical mowing is not possible to ensure that the height of the above-ground residual stubble of Spartina alterniflora does not exceed 10 cm. Areas where mechanical mowing is not possible include areas where Spartina alterniflora has fallen down, areas around scattered stones or artificial blocks. Each single mowing within each construction operation area is completed within 7 days to effectively prevent the formation of mature seeds of Spartina alterniflora, cut off its sexual reproduction pathway, and prevent the seeds from spreading to other areas with the tide or wind, etc., thereby reducing its spreading range. Before Spartina alterniflora has fully recovered its growth, continuously damage its above-ground part to make it difficult to accumulate enough nutrients for regeneration and gradually weaken its growth potential. The single-stalk residue of the crushed straw is no more than 5 cm.

[0056] Drying the straw includes the following steps: In a ventilated, sunny and dry site, the straw is evenly spread out with a moderate thickness to avoid excessive stacking affecting the drying effect, and it is regularly turned over to ensure even drying, so that the water content of the straw is reduced to a relatively low level, which is conducive to subsequent crushing and treatment and prevents mildew and rot.

[0057] Crushing the dried straw includes the following steps: Using a suitable crushing device, the straw is crushed into smaller sizes with uniform particle sizes, which is convenient for subsequent resource utilization such as returning to the field and composting, and avoids being too thick to decompose or too fine to increase the treatment cost due to over-crushing. After crushing, it is collected and stored in a dry place to prevent secondary moisture absorption.

[0058] In this embodiment, as shown in Figures 4 - 8 the mowing device for Spartina alterniflora in tidal flat wetlands is used to mow Spartina alterniflora in the construction operation area. The mowing device for Spartina alterniflora in tidal flat wetlands includes an excavator 1 and a mowing component 2. The excavator 1 can work on a dredger. The excavator 1 includes a vehicle body 101, a telescopic rotating arm 102 and a bucket 103. One end of the telescopic rotating arm 102 is fixed on the vehicle body 101, and a bucket 103 is fixed at the other end of the telescopic rotating arm 102. The mowing component 2 is arranged at the front end of the bucket 103 to cut the stems and leaves of Spartina alterniflora. The mowing component 2 includes a blade 201. The blade 201 is rectangular. One end of the blade 201 is fixedly arranged on the bucket 103, and the other end of the blade 201 is far from the bucket 103. The mowing component 2 can be separated from the bucket 103.

[0059] One end of the blade 201 is fixed to the side of the bucket 103, and the blade 201 is perpendicular to the side of the bucket 103. To ensure the stability of the mowing assembly 2 when mowing the stems and leaves, the blade 201 is fixed to the bucket 103 by welding. A first fixing plate 203 is welded to the fixed end of the blade 201. The side surface of the first fixing plate 203 is welded to the side of the bucket 103. The lower side of the first fixing plate 203 is welded and connected to the upper surface of the blade 201. A second fixing plate 204 is further provided between the blade 201 and the first fixing plate 203. The second fixing plate 204 is in the shape of a right-angled triangle. One right-angled side of the second fixing plate 204 is welded and connected to the first fixing plate 203, and one right-angled side of the second fixing plate 204 is welded and connected to the upper surface of the blade 201, thereby ensuring the welding stability between the blade 201 and the bucket 103.

[0060] In order to move the cut stems and leaves to one side when the telescopic rotating arm 102 rotates to drive the mowing assembly 2 to work, and also to prevent the blade 201 from shifting when the mowing assembly 2 rotates, in this embodiment, the mowing assembly 2 further includes a fixing frame 202. One side of the blade 201 is the cutting edge, and the other side is the back of the blade. The cutting edge of the blade 201 faces outward. The fixing frame 202 is arranged on the back side of the blade. The fixing frame 202 includes a first fixing rod 205 and a second fixing rod 206. A plurality of first fixing rods 205 are fixedly arranged at intervals along the length direction of the blade 201 on the upper surface of the back of the blade. One end of the second fixing rod 206 is fixed to the blade 201, and the other end of the second fixing rod 206 is fixed to the bucket 103. In this embodiment, the fixing frame 202 further includes a third fixing rod 207. The upper end of the first fixing rod 205 is fixedly connected to the third fixing rod 207 by welding, and the first fixing rod 205 is perpendicularly welded to the blade 201 to increase the stability of the fixing frame 202 and prevent the cut stems and leaves from falling off the blade surface when the blade 201 rotates.

[0061] In order to enable the excavator 1 to move better on the tidal flat wetland, the excavator 1 is a crawler excavator.

[0062] S3. Fill the dried and crushed straw into the first landfill trench for anaerobic landfill.

[0063] As Figure 3 shown, in this embodiment, S3 specifically includes the following steps:

[0064] S301. Lay out and position the first landfill trench, and excavate the surface soil of the first landfill trench;

[0065] S302. Place the surface soil on one side of the first landfill trench;

[0066] S303. Excavate the deep soil of the first landfill trench,

[0067] S304. Place the deep soil on the other side of the first landfill trench, and a woven geotextile is arranged between the deep soil and the other side of the first landfill trench to prevent the deep soil from being mixed with the topsoil.

[0068] S305. Fill the bottom of the first landfill trench with the dried and crushed straw.

[0069] S306. Fill the first landfill trench with the topsoil excavated in S302 to cover the dried and crushed straw in the first landfill trench.

[0070] S307. Fill the first landfill trench with the deep soil excavated in S303 to cover the topsoil in the first landfill trench.

[0071] S308. Level and stack the excess soil within the excavation range of the first landfill trench.

[0072] In this embodiment, when anaerobically landfilling the straw, the topsoil that is usually rich in humus, microorganisms and nutrients is filled first, and then the deep soil with a relatively compact structure and lower nutrient content is filled, so that the surface of the first landfill trench after landfilling is no longer suitable for the growth of Spartina alterniflora. The number of the first landfill trenches in the construction operation area is equal to the number of mowing times in S2. Immediately after mowing and drying the straw each time, the straw is anaerobically landfilled.

[0073] S4. During the ebb tide period, conduct root plowing on the construction operation areas that have been mowed three or more times, so that the top layer of the construction operation areas is peeled off. The Spartina alterniflora in each construction operation area is plowed more than twice, and the remaining rhizomes in the soil that cannot be removed are chopped. At the same time, S2 and S3 are carried out in other construction operation areas.

[0074] The depth of root plowing is not less than 30 cm. In this embodiment, the depth of root plowing is 30 - 50 cm. Plowing during the ebb tide can expose the roots of Spartina alterniflora to the air, facilitating more thorough excavation and cutting of the roots. In addition, the dry soil conditions contribute to the fragmentation and loosening of the plowed soil, which is beneficial to burying the roots deeply and achieving a better control effect to prevent the re-germination of Spartina alterniflora.

[0075] S5. Excavate multiple second landfill trenches in the construction operation area. The depth of the second landfill trenches is not less than 2 m. Collect the roots of Spartina alterniflora exposed on the ground after plowing and put them into the second landfill trenches.

[0076] S6. Fill the soil excavated from the second landfill trenches into the second landfill trenches to cover the roots of Spartina alterniflora. Level and stack the excess soil within the excavation range of the second landfill trenches. Compact the soil covering the second landfill trenches until there is no obvious subsidence when a person or machine walks on the covering soil layer and the soil surface is not loose. The covering material does not contain other weed seeds and Spartina alterniflora seeds.

[0077] Through the cooperation of S5 and S6, the roots of Spartina alterniflora are filled into the deep pits, and the soil covering is compacted to make the soil covering closely combined, reducing the air content in the soil. Due to the high water content in the soil of the tidal flat wetland, the anaerobic asphyxiation death is accelerated when the roots and rhizomes are landfilled, achieving the purpose of blocking the oxygen transmission of Spartina alterniflora. However, it is not overly compacted to avoid affecting the physical properties of the soil and subsequent ecological restoration. In this embodiment, the soil covering layer above the roots of Spartina alterniflora in S6 needs to be at least 50 cm thick, and steps S4, S5 and S6 are completed within one tidal cycle, which is convenient for construction.

[0078] The surface soil of the first landfill trench and the second landfill trench both form a soil ridge slightly higher than the ground surface to facilitate drainage.

[0079] To avoid the recurrence of Spartina alterniflora, this embodiment also includes S7, establishing a normalized monitoring and early warning mechanism, setting up monitoring units, and tracking and monitoring the wetland in the already treated area through on-site monitoring and / or drone remote sensing, etc. The main contents of the monitoring include the recurrence area and recurrence density (unit: plants / hectare) of Spartina alterniflora in the already treated area, collecting the patches where recurrence occurs, and setting up quadrats for the patches to count the number of recurrence Spartina alterniflora plants to estimate the number of recurrence plants per hectare of the patch. If Spartina alterniflora is found, it should be removed in time. If sporadic new plants appear, measures such as digging and pulling out should be taken for timely treatment; if patchy populations appear, chemical control measures should be preferably used for timely treatment. Among them, the monitoring frequency is determined according to the completion time, the growth cycle of Spartina alterniflora, the tidal conditions, etc. It is monitored once within 1 month after the completion of S6, and key monitoring is carried out during the growth period from April to November every year. The monitoring is carried out 4 times from April to November every year, and written and image records are made.

[0080] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the invention or perform equivalent substitution on some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. An integrated control method for Spartina alterniflora in tidal flat wetlands, characterized in that, It includes the following steps: S1. Divide the wetland into multiple construction operation areas, and the area of each operation area does not exceed 100 ha; S2. Mow the Spartina alterniflora in the construction operation area, spread, dry, and crush the cut straws. When the above-ground part of the mowed Spartina alterniflora regrows to a height of 15 - 20 cm, mow the Spartina alterniflora again. The Spartina alterniflora in each construction operation area is mowed more than three times; S3. Fill the dried and crushed straws into the first landfill trench for anaerobic landfill; S4. During the ebb tide period, conduct root plowing on the construction operation areas that have been mowed more than three times, so that the surface layer of the construction operation areas is peeled off. The Spartina alterniflora in each construction operation area is plowed more than two times, and the remaining rhizomes in the soil that cannot be removed are chopped. At the same time, conduct S2 and S3 in other construction operation areas; S5. Excavate multiple second landfill trenches in the construction operation area. The depth of the second landfill trench is not less than 2 m. Collect the Spartina alterniflora roots exposed on the ground after plowing and turn them into the second landfill trench; S6. Fill the soil excavated from the second landfill trench into the second landfill trench to cover the Spartina alterniflora roots. Stack the excess soil evenly within the excavation range of the second landfill trench. Conduct soil covering and compaction on the second landfill trench until there is no obvious subsidence when a person or machine walks on the soil covering layer and the soil surface is not loose. The soil covering material does not contain other weed seeds and Spartina alterniflora seeds.

2. The integrated control method for Spartina alterniflora in tidal flat wetlands according to claim 1, characterized in that, In S2, the residual height of the above-ground part of the mowed Spartina alterniflora does not exceed 10 cm, and the single-stalk residue of the crushed straw does not exceed 5 cm.

3. The integrated control method of Spartina alterniflora in tidal flat wetlands according to claim 2, characterized in that, When mowing the Spartina alterniflora in S2, first conduct mechanical mowing on the Spartina alterniflora, and conduct manual supplementary mowing on the Spartina alterniflora in the areas where mechanical mowing is not possible.

4. The integrated control method for Spartina alterniflora in tidal flat wetlands according to claim 1, wherein, S3 specifically includes the following steps: S301. Set out and locate the first landfill trench, and excavate the surface soil of the first landfill trench; S302. Place the surface soil on one side of the first landfill trench; S303. Excavate the deep soil of the first landfill trench, S304. Place the deep soil on the other side of the first landfill trench, and a woven geotextile is arranged between the deep soil and the other side of the first landfill trench; S305. Fill the dried and crushed straws into the bottom of the first landfill trench; S306. Fill the surface soil excavated in S302 into the first landfill trench to cover the dried and crushed straws in the first landfill trench; S307. Fill the deep soil excavated in S303 into the first landfill trench to cover the surface soil in the first landfill trench; S308. Stack the excess soil evenly within the excavation range of the first landfill trench.

5. The integrated Spartina alterniflora control method for tidal flat wetlands according to claim 4, wherein In S3, the number of the first landfill trenches in the construction operation area is equal to the number of mowing times in S2. After each mowing of the straws, immediately conduct anaerobic landfill on the straws.

6. The integrated control method for Spartina alterniflora in tidal flat wetlands according to claim 1, wherein, In S4, the depth of root plowing is not less than 30 cm, and the soil covering layer on the Spartina alterniflora roots in S6 needs to be at least 50 cm thick.

7. The method for integrated control of Spartina alterniflora in tidal flat wetlands according to claim 1, characterized in that, S4, S5, and S6 are completed within one tidal cycle.

8. The integrated control method for Spartina alterniflora in tidal flat wetlands according to claim 6, characterized in that, The surface soil of the first landfill trench and the second landfill trench both form a soil ridge slightly higher than the ground.

9. The integrated control method for Spartina alterniflora in tidal flat wetlands according to claim 1, wherein, It also includes S7, establishing a normalized monitoring and early warning mechanism, setting up monitoring units, and tracking and monitoring the treated wetland areas through on-site monitoring and / or drone remote sensing. The monitoring content includes the recurrence area and recurrence density of Spartina alterniflora in the treated areas. Collect the patches where recurrence occurs, set up quadrats for the patches to count the number of Spartina alterniflora plants in recurrence, so as to estimate the number of plants in recurrence per hectare of the patch. Remove Spartina alterniflora in time when it is found. If there are sporadic newly emerged plants, take measures such as digging and pulling out for timely treatment. If there are patchy populations, use chemical control measures for timely treatment.

10. The integrated control method for Spartina alterniflora in tidal flat wetlands according to claim 9, characterized in that, Monitor once within 1 month after the completion of S6, and the number of monitoring times from April to November each year shall be no less than 4 times, and keep written and image records.

11. The method for integrated control of Spartina alterniflora in tidal flat wetlands according to claim 1, characterized in that, In S2, a Spartina alterniflora mowing device for tidal flat wetlands is used to mow Spartina alterniflora in the construction operation area. The Spartina alterniflora mowing device for tidal flat wetlands includes an excavator and a mowing assembly. The excavator can work on a dredger. The excavator includes a vehicle body, a telescopic and rotating arm, and a bucket. One end of the telescopic and rotating arm is fixed on the vehicle body, and a bucket is fixed at the other end of the telescopic and rotating arm. The mowing assembly is arranged at the front end of the bucket to cut the stems and leaves of Spartina alterniflora. The mowing assembly includes a blade and a fixing frame. The blade is rectangular. One end of the blade is fixedly arranged on the bucket, and the other end of the blade is far from the bucket. The mowing assembly can be separated from the bucket. One side of the blade is the cutting edge, and the other side is the back of the blade. The cutting edge of the blade faces outward. The fixing frame is arranged on the back side of the blade. The fixing frame includes a first fixing rod and a second fixing rod. A plurality of first fixing rods are fixedly arranged at intervals along the length direction of the blade on the upper surface of the back of the blade. One end of the second fixing rod is fixed on the blade, and the other end of the second fixing rod is fixed on the bucket.

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