Ecological control and mangrove forest recovery method for spartina alterniflora

Abstract

The invention relates to the field of marine ecological restoration, and provides a spartina alterniflora ecological control and mangrove forest restoration method. The method comprises the following steps: firstly, reasonably partitioning a treatment area and determining a landing point, before the spartina alterniflora germinates and seeds are mature, cradling by using a special cradling ship, controlling the stubble height, then cleaning, ploughing to damage root systems, leveling a field, and covering by using PLA composite weeding cloth with photosensitive and temperature-sensitive characteristics. Then, dynamically optimizing the nursery stock planting density according to the soil salinity and the tide frequency, forming holes in the weeding cloth for planting, and performing layered planting according to the elevation difference of the intertidal zone to form an isolation forest belt; and finally, evaluating the ecological restoration effect by adopting a multispectral remote sensing technology in combination with unmanned aerial vehicle aerial photography. According to the method, the spartina alterniflora is efficiently removed and treated, the new germination rate is remarkably reduced, environment friendliness is achieved, the cost effectiveness is high, mangrove forest ecological restoration is powerfully promoted, the amphibious biodiversity is improved, and an effective scheme is provided for coastal wetland ecological restoration.

Description

Technical Field

[0001] The present invention relates to the field of marine ecological restoration, and particularly to a method for ecological control of Spartina alterniflora and restoration of mangroves. Background Art

[0002] Spartina alterniflora is native to the Atlantic coast of the Americas and the Gulf of Mexico. Since its introduction into China in the late 1970s, it has spread rapidly along the coast. Due to its extremely strong reproductive ability, including seed reproduction and asexual reproduction, and its strong adaptability to the environment, it can grow in a variety of tidal flat environments, resulting in its wide distribution in coastal wetlands in China.

[0003] The proliferation of Spartina alterniflora has caused many serious harms to the coastal wetland ecosystem. In terms of biodiversity, it has changed the topography and geochemical properties of the tidal flats, destroying the habitats of native benthic organisms, birds, etc. The number of many native species has decreased significantly, and biodiversity has dropped significantly. For example, in some areas, the invasion of Spartina alterniflora has led to the loss of foraging and habitat areas for some rare birds, and the population of these birds has decreased significantly. In terms of waterways, the large growth of Spartina alterniflora has slowed down the water flow velocity in the intertidal zone and aggravated sediment deposition, resulting in the shallowing and blockage of waterways, seriously affecting maritime transportation and the normal operation of ports. For fishery production, Spartina alterniflora has changed the ecological environment of the tidal flats, affecting the migration and reproduction of aquatic organisms such as fish, shrimps, and crabs, reducing fishery resources, and affecting the economic income of fishermen. At the same time, the invasion of Spartina alterniflora has also led to the degradation of the coastal wetland ecosystem, and the decline of its ecological service functions such as carbon sequestration and water purification capacity.

[0004] Currently, the control methods for Spartina alterniflora mainly include physical control, chemical control, and biological control, etc. Physical control methods such as manual mowing can, to a certain extent, control the growth of the above-ground part of Spartina alterniflora, but the damage to the underground roots is limited. Spartina alterniflora is extremely easy to germinate again, and the labor cost is high and the efficiency is low. Although the efficiency of mechanical mowing has been improved, it is also difficult to completely remove the roots, and it may damage the soil structure of the tidal flats. Chemical control methods use herbicides, which can quickly kill Spartina alterniflora, but the residues of herbicides will pollute the soil, water body, and organisms, destroying the ecological balance and not meeting the requirements of ecological environmental protection. Biological control methods are currently still in the research and exploration stage, and no mature and effective technical system has been formed, making it difficult to be applied on a large scale.

[0005] In the aspect of mangrove ecological restoration, traditional restoration methods often ignore the interference of Spartina alterniflora and directly plant mangrove plants, resulting in the growth of mangrove seedlings being competitively inhibited by Spartina alterniflora, with low survival rates and poor restoration effects.

[0006] Patent document CN202210257293.6 discloses a method for clearing Spartina alterniflora and replacing and restoring it with mangroves, which includes the following steps: (1) determination of the clearing area; (2) mowing of Spartina alterniflora; (3) clearing of Spartina alterniflora; (4) leveling of the tidal flat; (5) construction of artificial tidal channels; (6) high-density transplantation of mangrove seedlings. The method of the present invention first uses physical means to treat Spartina alterniflora, which can completely clear Spartina alterniflora, and then by transplanting native mangrove seedlings, it can effectively inhibit the regeneration of Spartina alterniflora and achieve the purpose of clearing Spartina alterniflora and replacing and restoring mangroves. However, this method requires the construction of a new dike, which has already changed the natural properties of the tidal flat and is costly, so it cannot be widely promoted on a large scale.

[0007] Patent document CN202010341751.5 discloses a method for clearing Spartina alterniflora. It uses a method of first treating Spartina alterniflora and then burying it, and then putting mature plants, seedlings of Rhizophoraceae and associated marine animals. It can completely clear Spartina alterniflora, destructively treat the rhizomes of Spartina alterniflora and deeply bury and fertilize them, and with film covering, it can effectively prevent Spartina alterniflora from growing again. Cooperating with the reasonable placement of mature plants, seedlings of Rhizophoraceae and associated marine animals, it can achieve the effect of safely, effectively and durably clearing Spartina alterniflora. However, this method has a large cost, and does not consider the problem that film covering may degrade too early, resulting in the regrowth of Spartina alterniflora, or degrade too slowly, affecting the root expansion of mangroves.

[0008] Therefore, it has important practical significance to develop a method that can not only effectively control Spartina alterniflora but also achieve the ecological restoration of mangroves. Summary of the Invention

[0009] The purpose of the present invention is to provide a method for ecological control of Spartina alterniflora and mangrove restoration, aiming to completely control the growth and spread of Spartina alterniflora, improve the regional ecosystem, restore native biodiversity, ensure the ecological safety of native tidal flats, and enhance the biodiversity of land and water organisms.

[0010] To achieve the above purpose, the present invention provides a method for ecological control of Spartina alterniflora and mangrove restoration, including the following steps:

[0011] S1, reasonably divide and partition the treatment area to determine the temporary landing point of Spartina alterniflora;

[0012] S2, before Spartina alterniflora germinates until its seeds mature, use a Spartina alterniflora mowing boat to mow Spartina alterniflora;

[0013] S3, N days after mowing, use a rotary tiller to fully cut and break the roots and bury them in the silt on the spot, repeat the rotary tilling step once, and the traveling direction of the rotary tiller for the second time is perpendicular to that of the first time, and level the tilled site;

[0014] S4. Use a PLA composite weed control cloth with photosensitive and thermosensitive properties to cover and fix the Spartina alterniflora area, and the covered area of the weed control cloth exceeds the area of the treatment area.

[0015] S5. Based on the beach elevation of the treatment area, dynamically optimize the planting density of mangrove seedlings, make holes on the weed control cloth according to the planting density of mangrove seedlings; select appropriate mangrove seedlings and plant them into the holes, and cover with soil; insert bamboo poles beside the seedlings to prevent the seedlings from lodging.

[0016] S6. According to the elevation difference in the intertidal zone, design a hierarchical planting plan for seedling plants, select appropriate seedlings and plant them into the holes to form an isolation forest belt.

[0017] S7. Use multi-spectral remote sensing technology to regularly monitor the vegetation coverage, soil moisture and the resurgence of Spartina alterniflora in the treatment area, generate a three-dimensional terrain model in combination with UAV aerial photography, and evaluate the ecological restoration effect.

[0018] Furthermore, the cutter head of the Spartina alterniflora mowing boat is made of high-strength alloy material, uses a detachable modular design and can adjust the cutting depth; an intelligent control system is integrated in the Spartina alterniflora mowing boat to monitor the growth density and height of Spartina alterniflora in real time, automatically adjust the cutting depth of the cutter head and the traveling path to ensure the maximization of mowing efficiency and the precise control of the stubble height.

[0019] Furthermore, when mowing Spartina alterniflora, the residual stem height is controlled at 1 - 3 cm; the tillage depth of the tiller is 30 - 50 cm; the weed control cloth is a PLA weed control cloth with a lap width of 5 - 10 cm and is sewn on site with a packing machine; the weed control cloth covers 10 - 15 cm beyond the treatment area and is fixed in the soil with bamboo poles around; the thickness of the PLA weed control cloth is 0.1 - 0.3 mm and its tensile strength is not less than 50 MPa.

[0020] Furthermore, the PLA composite weed control cloth with photosensitive and thermosensitive properties has a three-layer structure, which is divided into a photosensitive layer, a thermosensitive layer and a reinforcing layer from the outside to the inside.

[0021] Furthermore, the photosensitive layer is prepared by using PLA (polylactic acid) as the main matrix material and adding photosensitive polymers or photosensitive nanoparticles; the thermosensitive layer is prepared by using PLA (polylactic acid) as the main matrix material and adding thermosensitive polymers or thermosensitive microcapsules; the reinforcing layer is prepared by using PLA (polylactic acid) as the main matrix material and adding hemp fibers.

[0022] Furthermore, in step S5, based on the beach elevation of the treatment area, dynamically optimizing the planting density of mangrove seedlings specifically means that in the area 1 m outside the outer edge of the treatment area or where the tidal inundation frequency > 47.5%, the planting spacing of mangrove seedlings is selected to be 500 - 800 mm * 500 - 800 mm.

[0023] Furthermore, in step S6, according to the elevation difference in the intertidal zone, the specific stratified planting plan for mangrove seedlings is as follows: plant Avicennia marina, Rhizophora stylosa, etc. in the low tide zone, plant Kandelia obovata, Bruguiera sexangula, etc. in the middle tide zone, and plant Bruguiera gymnorrhiza, etc. in the high tide zone to form complementary ecological niches and enhance the stability of the community.

[0024] Furthermore, inoculate obligate degrading bacteria, such as lignin-degrading bacteria or allelochemical-decomposing bacteria in the soil after ploughing to accelerate the decomposition of Spartina alterniflora residues and secrete herbicidal substances to inhibit its regeneration.

[0025] Furthermore, when planting mangrove seedlings, synchronously apply microbial inoculants such as nitrogen-fixing bacteria and phosphorus-solubilizing bacteria to improve the stress resistance of the seedlings and promote soil nutrient cycling.

[0026] Furthermore, the surface of the weed control cloth is designed with a gradient microporous structure, and the pore size gradually increases from the inside to the outside. The inner layer has a smaller pore size, which can effectively block the germination of its seeds; the outer layer has a larger pore size, which promotes gas exchange and water penetration between the soil and the outside.

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0028] 1. Systematic governance and ecological compatibility: From zonal mowing, root damage to mangrove restoration, a full-process closed-loop of "removal - restoration - maintenance" is formed to ensure the thoroughness of Spartina alterniflora control. The photosensitive / temperature-sensitive PLA composite weed control cloth realizes dynamic degradation regulation through a three-layer structure (photosensitive layer, temperature-sensitive layer, reinforcing layer), and the surface of the weed control cloth is designed with a gradient microporous structure, which not only inhibits the regrowth of Spartina alterniflora but also avoids traditional plastic pollution, and the degradation period is synchronized with the growth of mangroves.

[0029] 2. Technological innovation and efficiency improvement: The high-strength alloy mowing boat integrated with an intelligent control system can real-time monitor the density and height of Spartina alterniflora, automatically adjust the cutting depth and path, improve efficiency, and the double vertical ploughing combined with the introduction of lignin-degrading bacteria destroys the underground roots of Spartina alterniflora and accelerates the decomposition of residues.

[0030] 3. Precise planting and ecological niche optimization: Based on the beach elevation of the control area, dynamically optimize the planting density of seedlings. In the outer edge of the control area or areas with a lower frequency of tidal inundation, increase the planting spacing of mangrove seedlings. Stratified planting of Kandelia obovata, Avicennia marina, Bruguiera gymnorrhiza, etc. according to the elevation difference in the intertidal zone forms complementary ecological niches, enhances the stability of the community, and improves the resource utilization efficiency of the ecosystem.

[0031] 4. Real-time Monitoring and Scientific Evaluation: Use multi-spectral remote sensing technology to regularly monitor the vegetation coverage, soil moisture, and the resurgence of Spartina alterniflora in the treatment area. Combine with UAV aerial photography to generate a three-dimensional terrain model, comprehensively and accurately evaluate the ecological restoration effect, provide support for the management department to formulate scientific treatment and protection strategies, facilitate the optimization of treatment plans, and improve treatment efficiency. Specific Embodiment

[0032] The following combines examples to further describe in detail the specific embodiments of the present invention. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0033] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groups.

[0035] It should also be further understood that the term "and / or" used in the description of this application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0036] In the embodiment, the indication of directions (such as up, down, left, right, front, and back) is used to explain that the structures and movements of various components of the present invention are not absolute but relative. When these components are in the indicated positions, these explanations are appropriate. If the descriptions of the positions of these components change, then the indications of these directions also change accordingly.

[0037] In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific embodiments of the present invention will be described below.

[0039] Steps for Controlling Spartina alterniflora

[0040] Regional Division and Determination of Landing Points: Reasonably divide and partition the treatment area. According to factors such as the terrain, area, and distribution density of Spartina alterniflora in the treatment area, divide the treatment area into several small regions to facilitate subsequent treatment operations. At the same time, determine the temporary landing points for Spartina alterniflora. The landing points should be selected at positions with higher terrain, convenient transportation, and less impact on the surrounding environment to facilitate the transportation of the cut Spartina alterniflora ashore.

[0041] Spartina alterniflora mowing: Before Spartina alterniflora germinates until its seeds mature, use a multi-blade Spartina alterniflora mowing boat with a detachable modular design and adjustable cutting depth for mowing. The design of this mowing boat can flexibly adjust the cutting depth according to the growth of Spartina alterniflora and soil conditions to ensure that the height of the basal stubble is controlled within 1 - 3 cm. The multi-blade design can improve the mowing efficiency and mow a large area of Spartina alterniflora at one time. During the mowing process, ensure the uniformity of mowing and avoid missed mowing. An intelligent control system is integrated into the Spartina alterniflora mowing boat to real-time monitor the growth density and height of Spartina alterniflora, automatically adjust the cutting depth of the blades and the traveling path to ensure the maximization of mowing efficiency and the precise control of stubble height.

[0042] Spartina alterniflora cleaning: The mowed Spartina alterniflora is transported to a temporary landing point by suitable transportation tools, such as small barges or tracked transport vehicles, and then transferred to a garbage transfer station for treatment. During transportation, prevent the scattering of Spartina alterniflora to cause secondary pollution.

[0043] Root treatment: Five days after mowing, use a rotary tiller to till the growth area of Spartina alterniflora. The rotary tilling depth of the rotary tiller should reach 30 - 50 cm. By fully chopping the roots and burying them in the silt on the spot, the underground root structure of Spartina alterniflora is damaged to reduce its new germination rate. At the same time, this treatment method can also reduce soil carbon loss and protect the soil ecological environment. To further improve the root damage effect, the tilling can be repeated once, and the traveling direction of the machine for the second time should be perpendicular to that of the first time to ensure that the underground roots are fully damaged. After tilling, inoculate specific degrading bacteria, such as lignin-degrading bacteria or root allelochemical-decomposing bacteria, into the soil to accelerate the decomposition of Spartina alterniflora residues and secrete weed-inhibiting substances to inhibit its regeneration.

[0044] Site leveling: The site after tilling will be uneven and needs to be leveled. Use a grader or other leveling equipment to evenly distribute the silt and debris on the site surface to make the site meet the flatness requirements suitable for subsequent planting of mangrove plants.

[0045] Weed cloth covering: Splice the PLA composite weed cloth with photosensitive and thermosensitive properties according to the size of the Spartina alterniflora control area. For smaller control areas, it can be processed and spliced on-site into the required size; for large-scale control areas, it needs to be processed by the manufacturer into larger pieces of weed cloth according to the actual on-site size and sewn on-site. Use a packing machine to sew the weed cloth on-site, and control the lap width within 5 - 10 cm to ensure the tightness of the weed cloth. Then, cover the Spartina alterniflora area with the PLA composite weed cloth with photosensitive and thermosensitive properties. The coverage range of the weed cloth should exceed the treatment area by 10 - 15 cm, and fix the weed cloth around with bamboo poles in the soil. And when installing the weed cloth, it should be slightly loose to adapt to the swelling and shrinking of the soil and the growth of plants.

[0046] The PLA composite weeding cloth with photosensitive and thermosensitive properties has a three-layer structure, which is divided into a photosensitive layer, a thermosensitive layer, and a reinforcing layer from the outside to the inside. The photosensitive layer is prepared by using PLA (polylactic acid) as the main matrix material and adding photosensitive polymers or photosensitive nanoparticles, such as photosensitive polyurethane, photosensitive titanium dioxide nanoparticles, etc. These additives can undergo chemical reactions or structural changes under the illumination of specific wavelengths of light, thereby affecting the degradation rate of PLA; the thermosensitive layer is prepared by using PLA (polylactic acid) as the main matrix material and adding thermosensitive polymers or thermosensitive microcapsules, such as thermosensitive poly(N-isopropylacrylamide), thermosensitive paraffin microcapsules, etc. These additives will undergo phase changes or structural changes at specific temperatures, thereby changing the degradation rate of PLA; the reinforcing layer is prepared by using PLA (polylactic acid) as the main matrix material and adding hemp fibers. The surface of the weeding cloth is designed with a gradient microporous structure, with smaller pore diameters in the inner layer, which can effectively block the germination of its seeds; the pore diameters in the outer layer are larger, which promotes the gas exchange and water penetration between the soil and the outside world.

[0047] Under the action of light, the photosensitive layer can adjust the degradation rate of the weeding cloth according to the change of light intensity. When the light is sufficient, the photosensitive material undergoes a specific reaction, accelerating the degradation, so that the weeding cloth gradually loses its blocking effect on the germination of Spartina alterniflora seeds within an appropriate time, and at the same time releases space for the growth of mangrove seedlings. When the light is weak, the degradation rate slows down, ensuring that the weeding cloth maintains its inhibitory effect on Spartina alterniflora for a long time and avoiding the resurgence of Spartina alterniflora caused by premature degradation. The thermosensitive layer functions according to the temperature change. When the temperature is high, the thermosensitive material changes its structure, increasing the degradation rate of the weeding cloth. Because the growth of mangrove seedlings is faster in a high-temperature environment and more soil space and nutrients are needed, accelerating the degradation at this time can meet the requirements; when the temperature is low, the degradation rate decreases, maintaining the coverage and protection of the weeding cloth on the soil, preventing the growth of weeds, and creating a stable growth environment for mangrove seedlings. Through the synergistic effect of the photosensitive layer and the thermosensitive layer, the weeding cloth can accurately adjust the degradation rate according to the local light and temperature conditions, better adapting to the needs of different environments and plant growth stages. The three-layer structure cooperates with each other, making the degradation process more coordinated. The photosensitive layer and the thermosensitive layer start to degrade under the action of external environmental factors, while the reinforcing layer maintains the structural stability in the initial stage of degradation. As the degradation progresses, the reinforcing layer also gradually degrades, providing a certain amount of organic matter for the soil. This coordination ensures that while effectively inhibiting the growth of Spartina alterniflora, the weeding cloth can gradually degrade, integrate into the soil, reduce the impact on the environment, and meet the requirements of ecological environmental protection.

[0048] Steps for mangrove ecological restoration

[0049] Open - hole planting preparation: Based on the elevation of the beach surface in the treatment area, dynamically optimize the planting density of seedlings. In the area 1m outside the outer edge of the treatment area or where the tidal inundation frequency > 47.5%, the planting spacing of mangrove seedlings is selected as 500 - 800mm * 500 - 800mm. Open holes on the weed - control cloth based on the planting density. The diameter of the open hole is 8 - 10cm larger than the root ball of the seedling, and the size of the hole should be such that the root system is not damaged when the root soil mass is placed in it. In the area 1m outside the outer edge of the treatment area or where the tidal inundation frequency > 47.5%, seawater immersion is frequent. A relatively large planting spacing can reduce the mutual influence between seedlings caused by waterlogging. When the tide ebbs each time, there is enough space for water to drain quickly, avoiding the decay of the seedling roots due to long - term waterlogging and lack of oxygen. The large planting spacing ensures that when the wind and waves come, there will not be a strong overall resistance surface formed due to overly dense seedlings. The wind and waves can be dispersed in the gaps between the seedlings, reducing the impact force on individual seedlings. The wind and wave force borne by each seedling is reduced, lowering the risk of the seedlings being uprooted or broken by the wind and waves, and improving the stability of the entire treatment area in the harsh marine environment. At the same time, the spacing of 500 - 800mm × 500 - 800mm allows each tree seedling to obtain sufficient sunlight. In the intertidal zone with limited light resources, mutual shading between seedlings is avoided, ensuring that each seedling can efficiently carry out photosynthesis, produce enough organic matter for growth and maintaining life activities. At the same time, the root systems of seedlings are more reasonably distributed in the soil at this spacing, reducing competition for nutrients, and each seedling can obtain sufficient nitrogen, phosphorus, potassium and other nutrient elements from the soil to ensure growth requirements.

[0050] Seedling selection: According to the elevation differences in the intertidal zone, a stratified planting plan for nursery plants is designed. Specifically, Avicennia marina, Rhizophora stylosa, etc. are planted in the low-tide zone; Kandelia obovata, Bruguiera gymnorrhiza, etc. are planted in the mid-tide zone; and Bruguiera sexangula, etc. are planted in the high-tide zone, forming complementary ecological niches and enhancing the stability of the community. The environmental conditions vary significantly at different elevations in the intertidal zone. In the low-tide zone, the seawater immersion time is relatively long. The finger-like respiratory roots of Avicennia marina extend vertically from the horizontal cable roots, and maintain root oxygen supply through lenticels and well-developed aerenchyma, adapting to the periodic hypoxic environment. The arched stilt roots of Rhizophora stylosa cooperate with the lenticels on the root surface and the internal longitudinal aerenchyma to achieve gas transport during the tidal intermission. In the mid-tide zone, the waterlogging time is moderate, and Kandelia obovata and Bruguiera gymnorrhiza grow well here. The knee-shaped respiratory roots of Kandelia obovata and the plank roots of Bruguiera gymnorrhiza can efficiently absorb oxygen during ebb tides, and their leaf salt glands can actively excrete salts, adapting to the salinity fluctuations in the mid-tide zone. Viviparous propagules (hypocotyls) can take root during the short ebb-tide window period to avoid being washed away by the tide. The sediment stability in the mid-tide zone is relatively high, which is conducive to the fixation of seedlings. At the same time, the nutrient input is sufficient to support their growth requirements. In the high-tide zone, the seawater immersion time is short, the soil salinity is high, the periodic drought is severe, and the oxygen is sufficient. Bruguiera sexangula forms a well-developed aerenchyma through aerial roots to enhance the water transport efficiency; the thick cutin layer and sunken stomata on the leaves significantly reduce transpiration water loss. The roots of Bruguiera sexangula have the ability to selectively absorb ions, excrete excess salts through salt glands, and accumulate osmoregulatory substances such as proline to maintain cell osmotic balance. The structure of the xylem vessels can slow down cavitation and ensure water transport under drought conditions. In addition, the viviparous characteristics of the seeds enable them to have stress-resistant structures when detaching from the parent plant, significantly improving the settlement success rate of seedlings in arid tidal flats. This stratified planting makes full use of the ecological resources in different tidal zones, constructs a complex and stable ecosystem, and provides diverse habitats and foraging places for many organisms. Generally, 1-2-year-old seedlings with a high degree of lignification are used, and the seedling height is preferably 50 cm - 80 cm. In special cases, such as areas with poor soil conditions or a large amount of Spartina alterniflora residues, larger-sized perennial seedlings can be used. The selected seedlings should be robust and free from pests and diseases to improve the planting survival rate.

[0051] Planting operation: Select container seedlings for planting in the holes. During planting, the nutrient cups (bags) should be removed to avoid restricting the root systems of the seedlings. The height of the soil covering should not exceed 10 cm above the upper surface of the seedling nutrient bags to ensure that the root systems of the seedlings can fully contact the soil and absorb nutrients and water.

[0052] Wind protection and seedling fixation: Insert bamboo poles beside the seedlings and tie the seedlings to the bamboo poles to prevent the seedlings from lodging. The length and insertion depth of the bamboo poles should be selected according to the local wind conditions and soil texture to ensure that the seedlings can be effectively fixed.

[0053] Feedback on restoration effect: The multi-spectral remote sensing technology is used to regularly monitor the vegetation coverage, soil moisture and the resurgence of Spartina alterniflora in the treatment area. Combined with UAV aerial photography, a three-dimensional terrain model is generated to evaluate the ecological restoration effect. The information obtained through multi-spectral remote sensing and UAV aerial photography can help the management department comprehensively understand the ecological status of the treatment area and provide support for formulating scientific treatment and protection strategies. According to the vegetation coverage and the resurgence of Spartina alterniflora, human, material and financial resources are reasonably arranged to conduct targeted treatment and monitoring of key areas. The monitoring data is used to evaluate the effects of different treatment measures, summarize experiences and lessons, provide references for subsequent ecological restoration work, continuously optimize the treatment plan, and improve the treatment efficiency and ecological restoration effect.

[0054] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

Claims

1. A method for ecological control of Spartina alterniflora and restoration of mangroves, characterized in that, It includes the following steps: S1. Reasonably divide and partition the treatment area, and determine the temporary landing points of Spartina alterniflora; S2. Before Spartina alterniflora germinates until its seeds mature, use a Spartina alterniflora mowing boat to mow Spartina alterniflora; S3. After mowing for N days, use a tiller to fully cut and break the roots and bury them in the silt on the spot. Repeat the tilling step once. The traveling direction of the tiller for the second time is perpendicular to that of the first time, and level the tilled site; S4. Cover and fix the Spartina alterniflora area with a PLA composite weeding cloth with photosensitive and thermosensitive properties. The coverage area of the weeding cloth exceeds the area of the treatment area; S5. Based on the beach elevation of the treatment area, dynamically optimize the planting density of mangrove seedlings. Drill holes in the weeding cloth according to the seedling planting density; Select suitable mangrove seedlings and plant them into the drilled holes, and cover them with soil; Insert bamboo poles beside the mangrove seedlings to prevent the seedlings from lodging; S6. According to the elevation difference of the intertidal zone, design a layered planting plan for mangrove seedlings, select suitable mangrove seedlings and plant them into the drilled holes to form an isolation forest belt; S7. Adopt multi-spectral remote sensing technology to regularly monitor the vegetation coverage, soil moisture and the resurgence of Spartina alterniflora in the treatment area, generate a three-dimensional terrain model in combination with UAV aerial photography, and evaluate the ecological restoration effect.

2. The method for ecological control of Spartina alterniflora and restoration of mangroves according to claim 1, characterized in that, The cutter head of the Spartina alterniflora mowing boat is made of high-strength alloy material, uses a detachable modular design and can adjust the cutting depth; An intelligent control system is integrated in the Spartina alterniflora mowing boat to real-time monitor the growth density and height of Spartina alterniflora, and automatically adjust the cutting depth of the cutter head and the traveling path to ensure the maximization of mowing efficiency and precise control of the stubble height.

3. The method for ecological control of Spartina alterniflora and restoration of mangroves according to claim 1, wherein When mowing Spartina alterniflora, the residual stem height is controlled at 1-3 cm; The tilling depth of the tiller is 30-50 cm; The weeding cloth is a PLA weeding cloth, the lapping width is 5-10 cm, and it is sewn on site with a packing machine; The weeding cloth covers 10-15 cm beyond the treatment area, and is fixed in the soil with bamboo poles around; The thickness of the PLA weeding cloth is 0.1-0.3 mm, and its tensile strength is not less than 50 MPa.

4. The Spartina alterniflora ecological control and mangrove restoration method according to claim 1, characterized in that The PLA composite weeding cloth with photosensitive and thermosensitive properties has a three-layer structure, which is divided into a photosensitive layer, a thermosensitive layer and a reinforcing layer from the outside to the inside.

5. The Spartina alterniflora ecological control and mangrove restoration method according to claim 4, characterized in that, The photosensitive layer is prepared by using PLA (polylactic acid) as the main matrix material and adding photosensitive polymers or photosensitive nanoparticles; The thermosensitive layer is prepared by using PLA (polylactic acid) as the main matrix material and adding thermosensitive polymers or thermosensitive microcapsules; The reinforcing layer is prepared by using PLA (polylactic acid) as the main matrix material and adding hemp fibers.

6. The Spartina alterniflora ecological control and mangrove restoration method according to claim 1, characterized in that In step S5, based on the beach elevation of the treatment area, dynamically optimize the planting density of mangrove seedlings. Specifically, based on the beach elevation of the treatment area, dynamically optimize the seedling planting density. In the area 1 m outside the treatment area or where the tidal inundation frequency > 47.5%, the planting spacing of mangrove seedlings is selected as 500-800 mm * 500-800 mm.

7. The method for ecological control of Spartina alterniflora and restoration of mangroves according to claim 1, wherein In step S6, according to the elevation differences in the intertidal zone, the specific stratified planting plan for mangrove seedlings is as follows: Avicennia marina, Rhizophora stylosa, etc. are planted in the low-tide zone; Kandelia obovata, Bruguiera gymnorrhiza, etc. are planted in the mid-tide zone; and Bruguiera sexangula, etc. are planted in the high-tide zone, forming complementary ecological niches and enhancing the stability of the community.

8. The Spartina alterniflora ecological control and mangrove restoration method according to claim 4, characterized in that, Introduce obligate degrading bacteria, such as lignin-degrading bacteria or root allelochemical-decomposing bacteria, into the plowed soil to accelerate the decomposition of Spartina alterniflora residues and secrete herbicidal substances to inhibit its regeneration.

9. The method for ecological control of Spartina alterniflora and restoration of mangroves according to claim 4, wherein When planting mangrove seedlings, synchronously apply microbial inoculants such as nitrogen-fixing bacteria and phosphorus-solubilizing bacteria to enhance the stress resistance of the seedlings and promote soil nutrient cycling.

10. The method for ecological control of Spartina alterniflora and restoration of mangroves according to claim 1, characterized in that, The surface of the weed control fabric is designed with a gradient microporous structure, with the pore size gradually increasing from the inside to the outside. The inner layer has a smaller pore size, which can effectively block the germination of its seeds; the outer layer has a larger pore size, which promotes gas exchange and water penetration between the soil and the outside.