A method for preparing sea sedge mats for coastal mudflat vegetation restoration

Abstract

This invention relates to the field of plant cultivation technology, and more particularly to a method for preparing *Scirpus triqueter* mats for coastal tidal flat vegetation restoration. The method includes: sowing *Scirpus triqueter* bulbs in a growth substrate for cultivation, and spraying paclobutrazol solution during the cultivation process; wherein the growth substrate comprises quartz sand, vermiculite, and peat moss in a volume ratio of 2-5:1-4:4. The structure of this growth substrate facilitates the twining and penetration of *Scirpus triqueter*, cross-linking into a dense and compact mat, enhancing the anchorage ability of transplanted *Scirpus triqueter* in the tidal flat, and, combined with paclobutrazol, improving the stress resistance of transplanted *Scirpus triqueter*. This results in *Scirpus triqueter* mats prepared by the above method having a higher survival rate and growth capacity in the tidal flat environment, making them suitable for the restoration of vegetation in coastal tidal flat wetlands.

Description

Technical Field

[0001] This invention relates to the field of plant cultivation technology, and in particular to a method for preparing sea burdock mats for coastal mudflat vegetation restoration. Background Technology

[0002] Sea sedge ( Bolboschoenoplectus mariqueter *Scirpus triqueter* is a typical native species of coastal salt marsh wetlands in East China and one of the few vascular plants in the subtropical low tide zone capable of establishing natural communities. Due to its strong salt and flood tolerance, *Scirpus triqueter* is widely used as a community-building species in coastal wetland vegetation restoration projects, playing a significant engineering value in stabilizing tidal flat substrate, inhibiting erosion, and promoting the restoration of wetland ecological functions.

[0003] However, in actual tidal flat vegetation restoration practices, the restoration effect of *Scirpus triqueter* is often severely constrained by habitat hydrodynamic conditions. On the one hand, coastal tidal flats are subject to periodic tidal inundation and continuous scouring by receding tides, resulting in soft substrates and significant elevation changes. Conventionally planted seeds or bulb seedlings have shallow root systems and small anchorage areas, making it difficult to effectively anchor them to the tidal flat substrate in a short period. They are easily uprooted or washed away by wind and waves, leading to low survival rates and severe patchy distribution. On the other hand, extreme weather events such as typhoons and storm surges can cause severe hydrodynamic impacts in a short time, causing newly transplanted seedlings or immature plant communities to be completely stripped away, directly leading to the failure of restoration projects.

[0004] Therefore, improving the adhesion and rapid coverage of *Scirpus triqueter* seedlings on tidal flats is one of the key technical challenges currently facing coastal salt marsh vegetation restoration projects. Summary of the Invention

[0005] This invention provides a method for preparing sea burr mats for coastal wetland vegetation restoration, which solves the problems of slow growth of sea burr and loose connection with the soil during coastal wetland vegetation restoration, making it susceptible to wind and wave impact and thus leading to restoration failure. By fixing and intertwining the roots of the bulb seedlings and the bulb seedlings with the substrate to form a dense structure, the resistance to wind and wave erosion can be greatly improved, thus improving the restoration effect.

[0006] In a first aspect, the present invention provides a method for preparing a mat made of *Scirpus triquetrum*, the method comprising: sowing the bulbs of *Scirpus triquetrum* in a growth substrate for cultivation, and spraying paclobutrazol solution during the cultivation process; The growth substrate comprises quartz sand, vermiculite, and peat moss in a volume ratio of 2-5:1-4:4.

[0007] Coastal mudflats are susceptible to wind and wave erosion, which limits the growth of *Scirpus triqueter* used for vegetation restoration, especially during occasional typhoons, which can cause transplanted *Scirpus triqueter* to be uprooted and die. Therefore, this invention employs a method of preparing *Scirpus triqueter* into a sturdy, dense mat to improve its resistance to wind and waves after transplantation, thereby increasing its overall survival rate and growth capacity. This invention discovers that using the aforementioned volume ratio of quartz sand, vermiculite, and peat moss as a growth substrate, the synergistic effect of these components fully utilizes the hardness and rough surface of the quartz sand particles, allowing the *Scirpus triqueter* roots to entwine, penetrate, and cement the sand particles, forming a stable structure. Furthermore, the peat moss fills the gaps, resulting in a dense, compact mat with high tensile strength that is not easily broken when rolled up.

[0008] Furthermore, among the aforementioned growth substrates, quartz sand does not decompose or pulverize, vermiculite has a stable structure, and peat decomposes slowly. The physical structure of the entire substrate system remains almost unchanged over several months, making it suitable for maintaining the overall structure of the mat for a relatively long period after transplanting, thus providing ample time for the deep rooting and growth of *Scirpus triqueter*.

[0009] Preferably, the growth substrate comprises quartz sand, vermiculite, and peat moss in a volume ratio of 3-4:2-3:4. More preferably, the quartz sand is approximately 20-40 mesh, and the vermiculite has a particle size of 1-3 mm.

[0010] Preferably, the bulb is planted at a depth of 2-4 cm.

[0011] The above-mentioned sowing depth was chosen because if the bulbs are buried too deep, the bulb seedlings will have difficulty germinating and their growth will be affected; if they are buried too shallow, they will easily lose moisture during cold storage and stratification, causing the bulbs to lose their vitality.

[0012] Preferably, the bulbs are planted at a density of 1700 bulbs per m². -2 .

[0013] Appropriate sowing density is more conducive to the firmness and solidity of straw mats; too dense a density will restrict growth, while too sparse a density will result in insufficient strength of the straw mats.

[0014] Preferably, the concentration of the paclobutrazol solution is 50-200 mg·L⁻¹. -1 .

[0015] Preferably, paclobutrazol solution is sprayed when the plant height reaches 13-15 cm, and sprayed continuously for 2-4 days.

[0016] Preferably, during the foliar spraying period, spray once a day, each time at a dose of 75-100 mL·m -2 Apply paclobutrazol solution at the appropriate dosage.

[0017] Preferably, after spraying, the plants are cultivated until they reach a height of 20-25 cm.

[0018] This invention has found that spraying paclobutrazol, especially using the above-mentioned dosage and method, can effectively improve the stress resistance of *Scirpus triqueter*, particularly its ability to resist seawater flooding, and improve its survival rate and growth capacity after transplantation.

[0019] Preferably, the cultivation includes: first storing the bulbs in a cool, ventilated, and rain-protected environment at 0-10℃, maintaining the absolute moisture content of the substrate at 25%~35% until the bulbs germinate; when the average daily temperature is ≥10℃ for 5 consecutive days, the germinated bulbs, along with the substrate and container, are then transferred to an environment with photosynthetically active radiation ≥50% under natural light, ventilation, and rain protection for cultivation. The above storage and cultivation steps are all commonly used methods for breaking dormancy and formulating formulations in the field. Those skilled in the art can choose other methods to obtain similar effects according to actual needs.

[0020] Preferably, during the bulb cultivation process after germination, water is added to the substrate to maintain the water level 1-2 cm above the substrate surface.

[0021] Preferably, the sea burdock mat is used for coastal mudflat vegetation restoration.

[0022] Under conditions of high seeding density of *Rubus triquetrum* bulbs and a suitable mixing ratio of quartz sand and vermiculite, the roots, rhizomes, and substrate of each *Rubus triquetrum* plant intertwine to form a dense and stable *Rubus triquetrum*-substrate complex, which can effectively resist tidal erosion and improve the survival rate and spread rate of *Rubus triquetrum*.

[0023] In a second aspect, the present invention provides a method for vegetation restoration of coastal mudflats, the method comprising: preparing a sea burr mat using the method described in the first aspect, and transplanting the sea burr mat to the coastal mudflats where vegetation restoration is required.

[0024] Preferably, the transplantation involves laying the sea buckthorn mats flat on the mudflats, with a spacing of 0.8 to 1.2 m between the mats.

[0025] After transplantation, the grass mats will continue to grow and expand. Maintaining sufficient spacing can make better use of the expanded range of each meadow and improve the efficiency of vegetation restoration.

[0026] The present invention has the following beneficial effects: The present invention provides a method for preparing *Scirpus triquetrum* mats for coastal tidal flat vegetation restoration. This method involves controlling the ratio of quartz sand and vermiculite in the culture medium, the thickness of the substrate, and the sowing density of *Scirpus triquetrum* bulbs. It also includes the application of paclobutrazol to cultivate the mats, thereby improving the anchorage and dispersal capabilities of *Scirpus triquetrum*. This method is simple, easy to implement, and has controllable conditions, resulting in significant effects. It can greatly improve the survival rate and growth capacity of *Scirpus triquetrum* seedlings in tidal flat habitats, thus enhancing the restoration effectiveness of coastal tidal flat wetland vegetation. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 It is a transplantable sea buckthorn mat obtained according to the method described in Embodiment 10 of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] The method for preparing *Scirpus triquetrum* mats provided by this invention includes the following steps: I. Bulb Preparation: Collect underground bulbs of typical sea sedge populations from coastal mudflat wetlands in November and December, or obtain mature bulbs grown from artificially cultivated sea sedge. Select plump and undamaged bulbs as experimental materials.

[0031] II. Substrate Preparation: Thoroughly mix 20-mesh quartz sand, 1-3 mm vermiculite, and peat moss in ratios of 5:1:4, 4:2:4, 3:3:4, 2:4:4, and 1:5:4 respectively to prepare the growth substrate. Fill the substrate into a plastic box with dimensions of 50 cm in length, 36.5 cm in width, and 12.5 cm in height, with a substrate depth of 2-5 cm.

[0032] III. Bulb Sowing and Low-Temperature Stratification: The bulbs collected in Step 1 are buried in the substrate described in Step 2 at intervals of 2.1-2.7 cm, to a depth of 2 cm. Approximately 1100-2000 bulbs per plastic box are sown per box. -2 Store in a cool, ventilated, and rain-protected environment at 0-10℃, maintaining a substrate moisture content of around 30%.

[0033] 4. When the average daily temperature is ≥ 10 ℃ for 5 consecutive days, transfer the plastic boxes containing the bulbs as described in step 3 to a well-lit, well-ventilated, and rain-sheltered environment to begin cultivation. The required photosynthetically active radiation (PAR) should be ≥ 50% of the natural light level. Add tap water and replenish the water regularly until it is 1-2 cm above the substrate surface.

[0034] V. Spraying paclobutrazol solution: When the plant height reaches 13-15 cm, spray the seedlings in the plastic boxes with paclobutrazol solution for 3 consecutive days, once a day, at a dosage of 90 ml / m² each time. -2 The dosage is 100 mg·L. -1 Paclobutrazol solution; when the plant height reaches 20-25 cm, the cultivation of sea buckthorn turf is completed.

[0035] Example 1 I. Seed Collection: Select healthy and large-scale *Scirpus triquetrum* communities in coastal wetlands of East China (Yangtze River Estuary, Hangzhou Bay, etc.) to collect *Scirpus triquetrum* bulbs, or obtain mature bulbs from artificially cultivated *Scirpus triquetrum*. Select plump and undamaged bulbs as experimental materials.

[0036] II. Substrate preparation: Mix 20-mesh quartz sand, 1-3 mm vermiculite and peat moss thoroughly in a volume ratio of 5:1:4 to prepare the growth substrate. Fill the substrate into a plastic box with dimensions of 50 cm in length, 36.5 cm in width and 12.5 cm in height, and the substrate depth should be 2 cm.

[0037] III. Bulb Sowing: Evenly distribute the bulbs collected in step one (1100 bulbs / m²). -2 Bury it in the substrate described in step two to a depth of 2 cm, and store it in a cool, ventilated, and rain-protected environment at 0-10℃, keeping the absolute moisture content of the substrate at about 30%.

[0038] 4. When the average daily temperature is ≥ 10 ℃ for 5 consecutive days, transfer the plastic boxes containing the bulbs as described in step 3 to a well-lit, well-ventilated, and rain-sheltered environment to begin cultivation. The required photosynthetically active radiation (PAR) should be ≥ 50% of the natural light level. Add tap water and replenish the water regularly until it is 1-2 cm above the substrate surface.

[0039] V. Spraying paclobutrazol solution: When the plant height reaches 13-15 cm, spray the seedlings in the plastic boxes with paclobutrazol solution for 3 consecutive days, once a day, at a dosage of 90 ml / m³ each time. -2 The dosage is 100 mg·L. -1 Paclobutrazol solution; when the plant height reaches 20-25 cm, the cultivation of sea buckthorn turf is completed.

[0040] The cultivation steps of Examples 2-16 are the same as those of Example 1, except that the preparation ratio of each component of the substrate, the thickness of the substrate, and the density of sowing *Scirpus triqueter* bulbs are different, as detailed in Table 1.

[0041] Table 1

[0042] Test case The sea burr mats prepared in Examples 1-16 were transplanted to coastal tidal flat wetlands requiring vegetation restoration (elevation 2.4-3.0 m, monthly vertical sedimentation greater than 0 and less than 10 cm, salinity <10‰, and continuous flooding depth <8 cm).

[0043] The grass mats prepared in Examples 1-16 were laid flat on the mudflats, with a 1 m gap between them, and were marked with labels. The labels were checked regularly to prevent them from being lost.

[0044] Four months after growth, the cover, number of tillers and plant height of *Scirpus triqueter* were investigated within a 1×1 m area centered on the grass mat. The results are shown in Table 2.

[0045] Table 2

[0046] Table 2 shows that the ratio of quartz sand to vermiculite to peat significantly affects the growth and expansion capacity after transplantation. The two groups with ratios of 3:3:4 and 4:2:4 performed significantly better than the two groups with high quartz sand (5:1:4) and high vermiculite (2:4:4). This indicates that a serious imbalance in the ratio of quartz sand to vermiculite (too high or too low) is not conducive to the establishment and expansion of *Scirpus triqueter* on the tidal flats. A ratio closer to 1:1 (3:3:4) or 2:1 (4:2:4) is more conducive to the formation of a grass mat with high coverage and high tillering.

[0047] Considering the overall coverage, number of tillers, and plant height, implementation method 10 performed best. The morphology of the straw mat before transplanting in this embodiment is as follows: Figure 1 As shown, its crown coverage after transplanting was 91.5%, and the number of tillers was 145.7 plants per square meter. 2The plant height was 69.3 cm, and all three indicators were among the highest, indicating that this combination could form the grass mat community with the highest coverage and the densest tillering within 4 months after transplanting, which is most conducive to the rapid vegetation restoration of coastal mudflats.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of preparing a sea rush mat, characterized by, The method includes: sowing the bulbs of *Scirpus triquetrum* in a growth substrate for cultivation, and spraying paclobutrazol solution during the cultivation process; The growth substrate comprises quartz sand, vermiculite, and peat moss in a volume ratio of 2-5:1-4:

4.

2. The method of claim 1, wherein the sea rothboellia trispatha mat is prepared by the steps of: The bulbs are sown at a depth of 2-5 cm.

3. The method of preparing a sea rush mat according to claim 1 or 2, characterized in that, The sowing density of the bulb is 1100-2000 pieces / m 2 .

4. The method of claim 1, 2 or 3, wherein the sea rush mat is prepared by the steps of: The concentration of the paclobutrazol solution is 50-200 mg L -1 .

5. The method of claim 1 to 4, wherein the sea rush mat is prepared by the steps of: When the plant height reaches 13-15 cm, start spraying paclobutrazol solution and spray continuously for 2-4 days. Preferably, during the spraying, 1 spraying is carried out every day, and each spraying is 75~100 mL·m 2 Paclobutrazol solution.

6. The method of claim 5, wherein the sea rothboellia trisulca mat is prepared by the steps of: After spraying, continue cultivation until the plants reach a height of 20-25 cm.

7. The method of claim 1, 2, 3, 4, 5, or 6, wherein the Spartina alterniflora mat is prepared by the steps of: The cultivation process includes: first, storing the bulbs in a cool, ventilated, and rain-protected environment at 0-10℃, maintaining the absolute moisture content of the substrate at 25%~35% until the bulbs germinate; then, when the average daily temperature is ≥10℃ for 5 consecutive days, transferring the germinated bulbs, along with the substrate and container, to an environment with photosynthetically active radiation ≥50% under natural light, ventilation, and rain protection for cultivation. Preferably, during the bulb cultivation process after germination, water is added to the substrate to maintain the water level 1-2 cm above the substrate surface.

8. The method of claim 1 to 7, wherein the sea rush mat is prepared by the steps of: The sea burdock mat is used for coastal mudflat vegetation restoration.

9. A method for coastal beach vegetation restoration, characterized by, The method includes: preparing sea burr mats using the method described in any one of claims 1 to 8, and transplanting the sea burr mats to coastal mudflats where vegetation restoration is required.

10. The method of claim 9, wherein, The transplantation involves laying the sea buckthorn mats flat on the mudflats, maintaining a spacing of 0.8 to 1.2 m between the mats.

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