A transplanting device and restoration method for intertidal Japanese eelgrass plants

Abstract

This invention provides a transplanting device and restoration method for intertidal Japanese eelgrass plants, belonging to the field of ecological restoration technology. The transplanting device is an open frame with biodegradable rope perforations on two opposite sides, with biodegradable ropes connected to these perforations. A downwardly sloping mud-blocking plate is also provided around the perimeter of the device. This transplanting device reduces damage to the intertidal topography. After transplanting Japanese eelgrass, it effectively resists the impact of tides on the transplanted plants, promoting the growth of new roots and solving the problem of difficulty in fixing transplanted plants. Successfully transplanted Japanese eelgrass plants can quickly form communities through their own reproductive capacity, optimizing the surrounding habitat, improving environmental quality, and exerting significant ecological value.

Description

Technical Field

[0001] This invention belongs to the field of ecological restoration technology, and in particular relates to a device and method for transplanting and restoring intertidal Japanese eelgrass plants. Background Technology

[0002] Japanese eelgrass (Zostera japonica), also known as dwarf eelgrass, is an important primary producer in the intertidal ecosystem, possessing high ecological and economic value. It provides habitats and brooding grounds for intertidal organisms, and its detritus is an important food source for nearshore life. Furthermore, Japanese eelgrass communities play a crucial role in regulating suspended solids, dissolved oxygen, chlorophyll, heavy metals, and nutrients in the water, slowing water flow, and acting as a wavebreak and embankment stabilizer.

[0003] In recent decades, due to changes in the natural environment and human interference, the resources of Japanese eelgrass have been declining, and in some coastal areas, Japanese eelgrass beds have even disappeared completely, seriously affecting the stability of the intertidal ecosystem. As people's understanding of the ecological functions of seagrass beds has increased, the protection of seagrass beds and the restoration of their communities have received attention from scholars both domestically and internationally, leading to the development of numerous seagrass bed restoration technologies and devices. Seagrass transplantation is currently the most widely used and researched seagrass restoration method. It employs special methods and devices to transplant natural seagrass to the restoration area, utilizing the asexual reproduction of seagrass to achieve the purpose of seagrass restoration. Depending on the transplanting unit, it is divided into three types: turf method, turf block method, and rhizome method. Among them, the turf method and turf block method are more destructive to the natural seagrass bed. The rhizome method, which relies on manual collection of transplanting units, greatly reduces the damage to the natural seagrass bed because it does not include the substrate, and is currently the main method for seagrass bed restoration. Compared to other seaweed restoration efforts, the intertidal zone where Japanese eelgrass lives has more complex tidal movements, making it challenging to fix the Japanese eelgrass in the substrate. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a transplanting device and repair method for intertidal Japanese eelgrass plants, so as to improve the transplanting efficiency and survival rate of Japanese eelgrass.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A transplanting device for intertidal Japanese eelgrass plants, the device being an open frame with top and bottom openings, wherein biodegradable rope holes are provided on two opposite sides and biodegradable ropes are connected to opposite biodegradable rope holes; a downwardly inclined mud-blocking plate is also provided around the periphery of the device.

[0007] Preferably, the device is 56-60cm long and wide, 14-16cm high, and 1-1.5cm thick on each side; the bottom of the side is also provided with a chamfer of 30-60°.

[0008] Preferably, each side has 5-6 biodegradable rope holes, the biodegradable rope holes are 1.8-2cm from the bottom of the device, and the distance between adjacent biodegradable rope holes on the same side is 8-10cm.

[0009] Preferably, the mud-blocking plate is 4.5-5cm wide, 0.5-0.7cm thick, 7-9cm away from the top of the device, and has a vertical tilt angle of 37±5°.

[0010] Preferably, the device has a handle on each of the two sides without the biodegradable rope perforation. The handle is 10-12cm long, 4-5cm wide, 2-3cm concave, and 2-3cm from the top of the device.

[0011] The present invention also provides an application of the transplanting device described above in the transplanting and restoration of Japanese eelgrass plants in the intertidal zone.

[0012] The present invention also provides a method for transplanting and restoring intertidal Japanese eelgrass plants, comprising the following steps: collecting plants during the growing season of wild Japanese eelgrass, with multiple wild Japanese eelgrass plants forming a transplanting unit and fixing them to a biodegradable rope of the transplanting device, and placing the transplanting device on the exposed mudflats after the tide recedes.

[0013] Preferably, 6-10 wild Japanese eelgrass plants constitute one transplanting unit, and the fixed distance between the transplanting units on the biodegradable rope is 8-10cm, with each device fixing ≥25 transplanting units.

[0014] Preferably, the average tidal height of the intertidal zone is ≤1.2m, the proportion of bottom sand in the tidal flat is >90%, and the salinity is 30-35psu.

[0015] Preferably, after the transplanting device is placed for 3 months, the biodegradable rope degrades, the transplanting device is recycled, and the Japanese eel grass reproduces on its own.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention provides a device for transplanting Japanese eelgrass plants in the intertidal zone. This device can reduce damage to the intertidal topography, and after transplanting Japanese eelgrass, it can also effectively resist the impact of tides on the transplanted plants, which is conducive to the growth of new roots of the transplanted plants and solves the problem of the difficulty in fixing the transplanted plants.

[0018] This invention also provides a method for restoring intertidal Japanese eelgrass plants using the above-mentioned device. After successful transplantation, the Japanese eelgrass plants can quickly form communities by relying on their own population reproduction capabilities, optimize the surrounding habitat, improve environmental quality, and exert great ecological value. Attached Figure Description

[0019] Figure 1 The intertidal Japanese eelgrass transplanting device of the present invention is shown in the figure. 1 is the outer frame body, 2 is the biodegradable rope perforation, 3 is the biodegradable rope, 4 is the mud-blocking plate, and 5 is the handle.

[0020] Figure 2 This is a top view of the intertidal Japanese eelgrass plant transplanting device of the present invention after the transplanting unit is fixed. In the figure, 1 is the outer frame body, 3 is the biodegradable rope, 4 is the mud barrier plate, 5 is the handle, and 6 is the Japanese eelgrass plant transplanting unit. Detailed Implementation

[0021] The intertidal zone Japanese eelgrass transplanting device provided by this invention is a frame 1 with open top and bottom, wherein biodegradable rope holes 2 are provided on two opposite sides, and biodegradable ropes 3 are connected to the opposite biodegradable rope holes; the device is also surrounded by a downwardly inclined mud-blocking plate 4, such as... Figure 1 As shown. During the transplantation of Japanese eelgrass plants in the intertidal zone, the transplanting unit 6 of the Japanese eelgrass plant is fixed to the biodegradable rope 3, as shown. Figure 2 As shown.

[0022] The transplanting device of the present invention will sink due to its own weight after being placed on the mudflat. The roots of the Japanese eelgrass transplanting unit on the biodegradable rope will sink into the bottom due to the sinking movement of the device. After sinking to a certain depth, the mud plate stops the sinking movement of the transplanting device. At this time, the Japanese eelgrass plants are controlled to be planted at a depth of 2-4 cm, thereby strengthening the fixation of the plants and promoting the sprouting of new roots of the transplanted plants.

[0023] Japanese eelgrass plants primarily survive in low-lying areas with seawater retention after tides recede. Under high summer temperatures, if transplanted Japanese eelgrass is exposed to sunlight, the survival rate is less than 10%. Only by surviving in low-lying areas with seawater retention after tides recede can Japanese eelgrass exhibit higher resistance to high temperatures and strong radiation, thus increasing the survival rate of transplanted plants. The transplanting device of this invention traps seawater within the device during low tide, providing a suitable living environment for the transplanted plants and significantly improving their survival rate.

[0024] The transplanting device of this invention also blocks the mud and sand carried by the tide. The mud and sand will accumulate outside the device, raising the terrain outside the device and improving the plant's habitat. After the device is retrieved, it can provide suitable conditions for the subsequent survival of the transplanted plants.

[0025] The transplanting device of this invention can be directly placed into the restoration area, and two people can transplant 1000-2000m² per day. 2 This significantly shortened the repair time and saved labor costs in the affected areas.

[0026] In this invention, the device is preferably 56-60cm long and 58-60cm wide, more preferably 58-60cm high; 14-16cm high, more preferably 14-15cm high; and each side is 1-1.5cm thick. The bottom of the side is also provided with a chamfer of 30-60°, more preferably 45°, which is conducive to the transplanting device sinking into the bottom sand of the tidal flat.

[0027] In this invention, preferably, 5-6 biodegradable rope holes are provided on the side of the device, the biodegradable rope holes are 1.8-2cm away from the bottom of the device, and the distance between each biodegradable rope hole on the same side is 8-10cm; more preferably, the diameter of the biodegradable rope holes is 0.5-1cm.

[0028] In this invention, the mud-blocking plate is preferably 4.5-5cm wide and 0.5-0.7cm thick, with the connection point to the frame 7-9cm from the top of the device, and the vertical tilt angle is 37±5°, which can control the self-sinking depth of the transplanting device.

[0029] In this invention, the preferred device has a handle 5 on each of the two sides without the biodegradable rope hole. The handle is 10-12cm long, 4-5cm wide, 2-3cm concave, and 2-3cm from the top of the device, making it more convenient for manual handling.

[0030] In this invention, the transplanting device material is preferably a material with a density greater than seawater and corrosion resistant, and is further preferably an environmentally friendly material. As one possible implementation method, the transplanting device material of this invention is basalt fiber.

[0031] In this invention, the biodegradable rope is preferably hemp rope, and as one possible implementation, the biodegradable rope material of this invention is jute fiber.

[0032] This invention also provides a method for transplanting and restoring intertidal Japanese eelgrass plants. The method utilizes the aforementioned transplanting device to transplant Japanese eelgrass plants, comprising the following steps: collecting plants during the wild Japanese eelgrass growing season; multiple wild Japanese eelgrass plants are grouped into a transplanting unit and fixed to a biodegradable rope of the transplanting device; and placing the transplanting device on the exposed mudflats after low tide. As one possible implementation, hemp rope is used to secure the transplanting unit to the biodegradable rope at the binding point.

[0033] In this invention, wild Japanese eelgrass plants are collected during their growing season. As one possible implementation method, wild, naturally occurring Japanese eelgrass plants are collected in June. In April and May, the plants are smaller, making transplanting difficult; in July and August, some plants enter their flowering period, and the hot weather at this time is also unfavorable for transplant survival. As another possible implementation method, after collecting the wild Japanese eelgrass plants, they are rinsed clean with seawater from the site.

[0034] In this invention, it is preferred that 6-10 Japanese eelgrass plants form a transplanting unit, more preferably 8 Japanese eelgrass plants form a transplanting unit, and even more preferably, the rhizomes are tied together with biodegradable rope to form a transplanting unit with a length of 1 cm or more.

[0035] In this invention, when the collection site and the transplanting site are not in the same sea area, the prepared transplanting unit is immersed in an insulated box containing seawater and transported to the transplanting sea area at a temperature of 4-10°C.

[0036] In this invention, it is preferable to shorten the leaves of the Japanese eelgrass plant by 20%-40% during transplanting, and more preferably shorten them by 1 / 3 of their total length. During transplanting, the root system of the Japanese eelgrass plant is damaged, reducing its ability to supply inorganic salts to the leaves, and consequently reducing the total leaf area, which is beneficial to improving the transplant survival rate.

[0037] In this invention, it is preferred that the fixed distance between the transplanting units on the biodegradable rope is 8-10cm, and each device fixes ≥25 transplanting units; it is further preferred that each transplanting device has a total of ≥180 Japanese eelgrass plants.

[0038] In this invention, the average tidal height of the intertidal zone is preferably ≤1.2m, the proportion of bottom sand in the tidal flat is >90%, and the salinity is 30-35psu; the spacing of the transplanting devices is preferably 56-60cm, and more preferably 55cm, to facilitate the passage of staff and subsequent maintenance.

[0039] In this invention, it is preferable that the transplanting device is placed for 3 months until the biodegradable rope degrades, then the transplanting device is recycled, and the Japanese eelgrass reproduces on its own. The recycled transplanting device can then be reused.

[0040] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0041] Example 1

[0042] A device for transplanting and restoring intertidal Japanese eelgrass plants, the structure of which is as follows:

[0043] The material is basalt fiber; the device is an open frame, 60cm long and wide, and 14cm high. The side frame of the device is 1cm thick, and the bottom of the device has a chamfered angle of 45° inward or outward. There are 5 biodegradable rope holes on each of the left and right sides of the device, with a hole diameter of 1cm. The biodegradable rope holes are 2cm away from the bottom of the device and spaced 10cm apart. Biodegradable ropes are inserted between the corresponding biodegradable rope holes on the two sides. The biodegradable rope material is jute fiber. The device is surrounded by a downward-sloping mud-blocking plate, 5cm long and 0.5cm thick, with a downward vertical tilt angle of 37±5°, and 7cm away from the top of the device. There is a handle on each of the two sides of the device without biodegradable rope holes, 10cm long, 4cm wide, 2cm concave, and 2cm away from the top.

[0044] Example 2

[0045] A device for transplanting and restoring intertidal Japanese eelgrass plants, the structure of which is as follows:

[0046] The material is basalt fiber; the device is an open frame, 56cm long and wide, and 16cm high. The side frame of the device is 1.5cm thick, and the bottom of the device has a chamfered angle of 30° inward or outward. There are 5 biodegradable rope holes on each of the left and right sides of the device, with a hole diameter of 0.5cm. The biodegradable rope holes are 1.8cm from the bottom of the device and spaced 9cm apart. Biodegradable ropes are inserted between the corresponding biodegradable rope holes on the two sides. The biodegradable rope material is jute fiber. The device is surrounded by a downward-sloping mud-blocking plate, 4.5cm long and 0.7cm thick, with a downward vertical tilt angle of 37±5°, and 9cm from the top of the device. There is a handle on each of the two sides of the device without biodegradable rope holes, 12cm long, 5cm wide, 3cm concave, and 3cm from the top.

[0047] Example 3

[0048] A device for transplanting and restoring intertidal Japanese eelgrass plants, the structure of which is as follows:

[0049] The material is basalt fiber; the device is an open frame, 58cm long and wide, and 15cm high. The side frame of the device is 1.2cm thick, and the bottom of the device has a chamfered angle of 60° inward or outward. There are 6 biodegradable rope holes on each of the left and right sides of the device, with a hole diameter of 0.8cm. The biodegradable rope holes are 1.9cm from the bottom of the device and spaced 8cm apart. Biodegradable ropes are inserted between the corresponding biodegradable rope holes on the two sides. The biodegradable rope material is jute fiber. The device is surrounded by a downward-sloping mud-blocking plate, 4.8cm long and 0.6cm thick, with a downward vertical tilt angle of 37±5°, and 8cm from the top of the device. There is a handle on each of the two sides of the device without biodegradable rope holes, 11cm long, 4.5cm wide, 2.5cm concave, and 2.5cm from the top.

[0050] Example 4

[0051] A method for transplanting and restoring intertidal Japanese eelgrass plants, using the transplanting device of Example 1, includes the following steps:

[0052] (1) In June, wild Japanese eelgrass is in its growth period. Collect the plants and clean them with seawater. Randomly select 8 Japanese eelgrass plants to make a transplanting unit. Tie the transplanting unit with hemp rope 1cm above the root base. If the collection site and the transplanting site are not in the same sea area, immerse the prepared transplanting unit in a seawater incubator and transport it to the transplanting sea area at 4-10℃.

[0053] (2) On the shore of the transplanting sea area, the plants were processed on site. The total length of the leaves of the transplanting unit was shortened by 1 / 3 and tied to the biodegradable rope of the transplanting device at 10cm intervals. Each transplanting device fixed 25 transplanting units, totaling 200 Japanese eel grass plants.

[0054] (3) Select an intertidal zone with an average tide height of ≤1.2m. The bottom of the tidal flat is mainly composed of sand and silt, accounting for more than 90%, with a salinity of 30-35psu. Place the transplanting device after the tide recedes and when the tidal flat is exposed. The transplanting device should be placed at 55cm intervals to allow people to pass through normally and facilitate later maintenance.

[0055] (4) After the transplanting device was placed for 3 months, the hemp rope rotted and the transplanted Japanese eel grass plants began to reproduce on their own. The transplanting device was then recycled and reused.

[0056] From June to October 2023, the method described in this embodiment was used for the ecological restoration of *Erigeron jasminoides* in the coastal mudflats of Kenli District, Dongying City. The intertidal zone in Dongying is characterized by sandy silt, uneven terrain, and strong tidal movements. Hot summer weather caused the original *Erigeron jasminoides* community to be concentrated only in low-lying areas of the intertidal zone, and its resource quantity was declining. To improve the habitat of *Erigeron jasminoides* and increase its resource quantity, this restoration employed a *Erigeron jasminoides* transplanting and fixing device. The devices were manually placed directly into the restoration area, with each device spaced 50 cm apart. Subsequent maintenance showed that one month after transplanting, the survival rate of the transplanted *Erigeron jasminoides* plants reached over 90%, and the loss of transplanted units due to seawater erosion was significantly reduced. Three months after transplanting, the transplanted plants were capable of asexual reproduction.

[0057] Example 5

[0058] A method for transplanting and restoring intertidal Japanese eelgrass plants includes the following steps:

[0059] A method for transplanting and restoring intertidal Japanese eelgrass plants, using the transplanting device of Example 2, includes the following steps:

[0060] (1) In June, wild Japanese eelgrass is in the vigorous growth period. Collect the plants and clean them with seawater on site. Randomly select 10 Japanese eelgrass plants to make a transplanting unit. Tie the transplanting unit with hemp rope 1cm above the root base. If the collection site and the transplanting site are not in the same sea area, immerse the prepared transplanting unit in a seawater incubator and transport it to the transplanting sea area at 4-10℃.

[0061] (2) On the shore of the transplanting sea area, the plants were processed on site. The total length of the leaves of the transplanting unit was shortened by 20%, and they were tied to the biodegradable rope of the transplanting device at 8cm intervals. Each transplanting device fixed 25 transplanting units, totaling 250 Japanese eel grass plants.

[0062] (3) Select an intertidal zone with an average tide height of ≤1.2m. The bottom of the tidal flat is mainly composed of sand and silt, accounting for more than 90%, with a salinity of 30-35psu. Place the transplanting device after the tide recedes and when the tidal flat is exposed. The transplanting device should be placed at 50cm intervals to allow people to pass through normally and facilitate later maintenance.

[0063] (4) After the transplanting device was placed for 3 months, the hemp rope rotted and the transplanted Japanese eel grass plants began to reproduce on their own. The transplanting device was then recycled and reused.

[0064] Example 6

[0065] A method for transplanting and restoring intertidal Japanese eelgrass plants includes the following steps:

[0066] A method for transplanting and restoring intertidal Japanese eelgrass plants, using the transplanting device of Example 3, includes the following steps:

[0067] (1) In June, wild Japanese eelgrass is in its peak season. Collect the plants and clean them with seawater. Randomly select 6 Japanese eelgrass plants to make a transplanting unit. Tie the transplanting unit with hemp rope 1cm above the root base. If the collection site and the transplanting site are not in the same sea area, immerse the prepared transplanting unit in a seawater incubator and transport it to the transplanting sea area at 4-10℃.

[0068] (2) On the shore of the transplanting sea area, the plants were processed on site. The total length of the leaves of the transplanting unit was shortened by 40%, and they were tied to the biodegradable rope of the transplanting device at 10cm intervals. Each transplanting device fixed 30 transplanting units, totaling 180 Japanese eel grass plants.

[0069] (3) Select an intertidal zone with an average tide height of ≤1.2m. The bottom of the tidal flat is mainly composed of sand and silt, accounting for more than 90%, with a salinity of 30-35psu. Place the transplanting device after the tide recedes and when the tidal flat is exposed. The transplanting device should be placed at 60cm intervals to allow people to pass through normally and facilitate later maintenance.

[0070] (4) After the transplanting device was placed for 3 months, the hemp rope rotted and the transplanted Japanese eel grass plants began to reproduce on their own. The transplanting device was then recycled and reused.

[0071] Example 7

[0072] The Influence of Different Transplanting Times on the Survival Rate of Japanese Eelgrass

[0073] In June, seagrass beds were restored using the pinning method. One month later, the survival rate of transplanted plants was as high as 76.9%. In July and August, the pinning method was tested again. One month later, the survival rates were 58.9% and 40.6% respectively, neither of which were as good as the transplanting results in June.

[0074] Plants are too small to be transplanted in May.

[0075] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for transplanting intertidal Japanese eelgrass plants, characterized in that, The transplanting device is a frame with open top and bottom, with biodegradable rope holes on two opposite sides and biodegradable ropes connected to the opposite biodegradable rope holes; the transplanting device is also surrounded by a downwardly inclined mud-blocking plate. The transplanting device is 56-60cm long and wide, 14-16cm high, and 1-1.5cm thick on each side; the bottom of the side is also provided with a chamfer of 30-60°. Each side is provided with 5-6 biodegradable rope holes, the biodegradable rope holes are 1.8-2cm away from the bottom of the transplanting device, and the distance between adjacent biodegradable rope holes on the same side is 8-10cm. The mud-blocking plate is 4.5-5cm wide and 0.5-0.7cm thick, located 7-9cm from the top of the transplanting device, with a vertical tilt angle of 37±5°.

2. The transplanting device according to claim 1, characterized in that, The transplanting device has a handle on each of the two sides without the biodegradable rope perforation. The handle is 10-12cm long, 4-5cm wide, 2-3cm concave, and 2-3cm from the top of the transplanting device.

3. The application of the transplanting device according to claim 1 or 2 in the transplanting and restoration of Japanese eelgrass plants in the intertidal zone.

4. A method for transplanting and restoring intertidal Japanese eelgrass plants, characterized in that, The process includes the following steps: collecting wild Japanese eelgrass plants during their growing season; using multiple wild Japanese eelgrass plants as a transplanting unit and fixing them to the biodegradable rope of the transplanting device described in claim 1 or 2; and placing the transplanting device on the exposed mudflats after the tide has receded.

5. The repair method according to claim 4, characterized in that, Six to ten wild Japanese eelgrass plants constitute one transplanting unit. The fixed distance between the transplanting units on the biodegradable rope is 8 to 10 cm. Each transplanting device has ≥25 transplanting units.

6. The repair method according to claim 4, characterized in that, The intertidal zone has an average tidal height of ≤1.2m, a bottom sand content of >90%, and a salinity of 30-35psu.

7. The repair method according to claim 4, characterized in that, After the transplanting device is placed for 3 months, the biodegradable rope degrades, the transplanting device is recycled, and the Japanese eel grass reproduces on its own.

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