A mangrove ecological restoration method to improve biodiversity

Abstract

The present invention belongs to the technical field of mangrove ecological restoration, and discloses a method for improving biodiversity of mangrove ecological restoration, including: a. In a mangrove restoration area with relatively low terrain, according to the current status of the beach landform in the restoration area, it is sorted into strips or blocks of land with different heights, respectively used for planting mangroves or retaining them as tidal channels and waters; b. In a mangrove restoration area with relatively high terrain, it is respectively used for planting mangroves and retaining the beach state; c. Combined with the specific topography and landforms of the mangrove restoration area, the above two methods a and b are used in combination; the present invention plans the mangrove restoration area into different plots according to the specific topography and landforms, so as to adapt to the requirements of the organisms there for growth, reproduction and habitat, and improve the diversity of organisms. It is consistent with the basic principles of overall protection of the environment, respect for nature, scientific restoration, adapting measures to local conditions, and orderly advancement, and promotes the overall protection of the mangrove ecosystem.

Description

Technical Field

[0001] The invention relates to the technical field of mangrove ecological restoration, and in particular to a mangrove ecological restoration method for improving biodiversity. Background Art

[0002] Wetlands are one of the ecosystems with important environmental functions and habitats for many organisms on Earth. The wetland environment is composed of wetland hydrology, wetland biogeochemical cycles, and the adaptation and transformation of organisms to wetlands. In the wetland environment, various factors interact and depend on each other, and together constitute the overall function of the wetland environment. As a transition zone between water and land, wetlands have huge environmental regulation functions and ecological benefits. Together with forests and oceans, they are known as the world's three major ecosystems. They play an irreplaceable role in maintaining biodiversity, flood control and drought relief, regulating climate, degrading pollutants, beautifying the environment, and providing production and living materials. They are one of the most important natural resources and living environments for mankind and are known as the "Kidneys of the Earth."

[0003] Mangroves are woody plant communities widely distributed in the intertidal zones of tropical and subtropical coasts. They are wetland ecosystems composed of evergreen trees and shrubs, mainly formed by mangrove plants. They are important habitats for a large number of endangered and rare waterfowl, as well as breeding grounds for marine organisms such as fish, shrimp, crabs and shellfish. Mangroves, as one of the important types of marine wetlands, have been included in the Ramsar Wetland Classification System and the China Wetland Resources Survey Classification System. Mangrove wetlands play an extremely important role in protecting marine ecology, mainly including maintaining biodiversity, breaking waves and protecting banks, promoting siltation and land reclamation, and purifying the atmosphere and seawater. However, affected by the development of the coastal zone and the utilization of resources, the total area of ​​mangroves in my country has dropped from 50,000 hm2 in the early days of the founding of the People's Republic of China. 2 It dropped to 22,000 hm2 in 2000. 2 Although the country has attached great importance to the protection and restoration of mangroves since 2000, and the area of ​​mangroves has gradually increased, its restoration has only stopped at increasing the mangrove planting area and improving the afforestation survival rate, without fully considering the needs of other organisms in the ecosystem. As a result, after large-scale afforestation, the sustainable development of the ecosystem has been restricted.

[0004] In order to solve the above problems, a Chinese patent (patent publication number: CN112790059B) discloses a method for mangrove ecological restoration, including investigating and measuring the environmental characteristics of the mangrove restoration area, and then dividing the mangrove restoration area according to the data obtained from the investigation to determine the area that needs ecological restoration; placing composite microbial strains or planting native mangrove plants that purify sewage in the area that needs water environment ecological restoration to improve water quality; performing soil restoration in the area that needs soil ecological restoration; planting native mangrove seedlings and reinforcing them in the area that needs ecological restoration according to the size of wind and waves; regularly monitoring and maintaining the mangrove restoration area to observe the growth status of plants. The above scheme uses microbial ecological control to remove organic matter, nitrogen, phosphorus and other pollutants in the water body and adsorb heavy metal ions; determines the type and planting density of mangrove plants according to the size of wind and waves; combines microbial restoration technology and mangrove planting technology according to water quality characteristics, soil characteristics and wind and wave size to improve the diversity of ecosystem species and improve the ecological environment; However, this method does not specifically consider the actual topography and landforms of the mangrove restoration area, and different topography and landforms play an important role in the reproduction and habitat of different organisms. Therefore, the present invention provides a method for planning a mangrove restoration area into different plots according to its specific topography and landforms, so as to adapt to the requirements of the organisms there for growth, reproduction and habitat. Summary of the invention

[0005] The present invention aims to provide a mangrove ecological restoration method for improving biodiversity. According to the specific topography and landforms of the mangrove restoration area, it is planned into different plots to meet the requirements of the organisms there for growth, reproduction and habitat, thereby improving the diversity of organisms. This is consistent with the basic principles of overall environmental protection, respect for nature, scientific restoration, adapting to local conditions and orderly advancement, and promotes the overall protection of the mangrove ecosystem.

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

[0007] A method for mangrove ecological restoration to improve biodiversity includes the following three methods:

[0008] a. In the relatively low-lying mangrove restoration area, the land will be organized into strips or blocks of different heights according to the current status of the tidal flat landforms in the restoration area. Mangroves will be planted in the tidal flats suitable for mangrove growth, and the lower plots will be reserved as tidal channels and waters for marine life and birds to survive, inhabit or forage;

[0009] b. In mangrove restoration areas with relatively high terrain, the tidal flats suitable for mangrove planting will be organized into strips or blocks, with some plots planted with mangroves and the other plots retained as tidal flats for birds or marine benthic animals to survive, inhabit or forage; the plots planted with mangroves and the plots retained as tidal flats will be arranged intermittently;

[0010] c. Combine the above methods a and b in light of the specific topography of the mangrove restoration area, so that the mangrove planting area accounts for 65-75% of the restoration area, and the rest is exposed mudflats, tidal gullies and water areas.

[0011] Furthermore, the width of the plot for planting mangroves is greater than 10 meters, and shrub species of 3 to 5 meters are planted around the plot, and the planting density of shrub species is 0.5×0.5m or 0.5×1.0m; trees or small trees are planted in the middle of the plot, and the planting density is 1.0×1.0m or 2.0×2.0m.

[0012] Furthermore, the shrub species planted around the mangroves include one or more of Paulownia, Avicennia marina, and Acanthus truncatula, and the planting density is determined by the size of the wind and waves:

[0013] For plots with low wind and waves and no obvious tidal scouring, the planting density is 0.5×1.0m;

[0014] For plots with strong winds and waves and obvious tidal erosion, the planting density is 0.5×0.5m.

[0015] Furthermore, the tree species or small tree species planted in the middle of the mangrove forest include one or more of Rhizophora mangrovea, Candelaria officinalis, Bruguiera gymnorrhiza, and Sea Lily, and the planting density is determined by the size of the wind and waves:

[0016] For plots with low wind and waves and no obvious tidal erosion, the planting density is 2.0×2.0m;

[0017] For plots with strong winds and waves and obvious tidal erosion, the planting density is 1.0×1.0mm.

[0018] Furthermore, the depth of the tidal gullies and water areas is retained at 1.0 to 1.5 m during high tide, and the water depth is maintained at 0.2 to 0.5 m after low tide; 0.1 to 0.3 m thick discarded oyster shells are laid on the sloping beach 0.3 to 0.5 m above the edge of the tidal gullies and water areas to reduce sediment loss in the mangrove planting belt.

[0019] The beneficial effects of the technical scheme are as follows: the technical scheme provided by the present invention plans the mangroves to be restored into plots of different shapes according to the specific topography and landforms thereof in combination with their spatial positions; mangroves are planted in plots suitable for the growth of mangroves, wherein shrub species are planted around the plots, and trees or small trees are planted in the middle of the plots, and the planting density of the shrub species and tree species planted are related to the wind and waves, and the larger the wind and waves, the larger the planting density, so as to ensure the survival ability of the mangroves and the prepared tree species; at the same time, tidal gullies, water areas or reserved tidal flat plots are set up, and the water depth of the tidal gullies and water areas is retained for birds or marine benthic animals to survive, inhabit or forage, and the abandoned oyster shells in the restoration area are fully utilized to press the tidal gullies and the slopes at the edge of the water areas to reduce the loss of sediments in the mangrove planting belt; this method is consistent with the basic principles of overall protection of the environment, respect for nature, scientific restoration, adapting measures to local conditions, and orderly advancement, and promotes the overall protection of the mangrove ecosystem. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the restoration experiment effect of method a in a mangrove ecological restoration method for improving biodiversity according to the present invention;

[0021] Figure 2 This is a schematic diagram of the restoration experiment effect of method b in a mangrove ecological restoration method for improving biodiversity according to the present invention; DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0023] like Figure 1 and Figure 2 As shown in the figure, a mangrove ecological restoration method for improving biodiversity includes the following three methods:

[0024] a. In the relatively low-lying mangrove restoration area, according to the current status of the tidal flat landform in the restoration area, it will be organized into strips or blocks of different heights. Mangroves will be planted in the tidal flats suitable for mangrove growth, and the lower plots will be reserved as tidal gullies and water areas for marine life and birds to survive, inhabit or forage; the depth of the tidal gullies and water areas reserved during high tide is 1.0 to 1.5 meters, and the water depth is maintained at 0.2 to 0.5 meters after low tide; 0.1 to 0.3 meters thick discarded oyster shells will be laid on the upper 0.3 to 0.5 meters of the slope at the edge of the tidal gullies and water areas to reduce the loss of sediments on the mangrove planting belt;

[0025] b. In mangrove restoration areas with relatively high terrain, the tidal flats suitable for mangrove planting will be organized into strips or blocks, with some plots planted with mangroves and the other plots retained as tidal flats for birds or marine benthic animals to survive, inhabit or forage; the plots planted with mangroves and the plots retained as tidal flats will be arranged intermittently;

[0026] c. Combine the above methods a and b in light of the specific topography of the mangrove restoration area, so that the mangrove planting area accounts for 65-75% of the restoration area, and the rest is exposed mudflats, tidal gullies and water areas.

[0027] Among them, the width of the plot used for planting mangroves is greater than 10 meters, and shrubs of 3 to 5 meters are planted around the plot. The shrubs planted around the mangroves include one or more of Paulownia, Avicennia marina, and Acanthus truncatula. The planting density of the shrubs is 0.5×0.5m or 0.5×1.0m, as follows:

[0028] For plots with low wind and waves and no obvious tidal scouring, the planting density is 0.5×1.0m;

[0029] In plots with strong winds and waves and obvious tidal scouring, the planting density is 0.5×0.5m;

[0030] In the middle of the plot, trees or small trees are planted, including one or more of Rhizophora mangrovea, Candel, Bruguiera gymnorrhiza, and Sea Lotus, with a planting density of 1.0×1.0m or 2.0×2.0m, as follows:

[0031] For plots with low wind and waves and no obvious tidal erosion, the planting density is 2.0×2.0m;

[0032] For plots with strong winds and waves and obvious tidal erosion, the planting density is 1.0×1.0mm.

[0033] Using the above method, the inventors implemented it in the northeastern harbor of Hainan Island and the western harbor of South Island respectively:

[0034] Example 1

[0035] 450 mu of mangrove ecological restoration was carried out on the open beach with gentle slope in the northeastern harbor of Hainan Island. The original beach in the project area was compact muddy sediment, containing certain gravel or unweathered basalt blocks, and there were few animals on the beach. The tidal channel and mangrove planting belt were formed by digging trenches and filling the beach on the spot. The mangrove planting belt should be 20-30m wide. True mangrove plants such as autumn candel, red sea olive and Bruguiera gymnorrhiza were planted in the middle of the mangrove planting belt with a planting density of 1.0×1.5m. Tung trees were planted around the planting belt with a planting density of 0.5×1.0m and a planting belt width of 3m; the top width of the waterway is 10-12m, the bottom width is 2-3m, and the depth is 1.5m. The upper part of the waterway slope is paved with 0.5m wide and 0.2m thick discarded oyster shells.

[0036] A survey conducted one year after the project was completed showed that the mudflat sediments were soft and the survival rate of mangrove afforestation was 86%. Biodiversity surveys were conducted for three consecutive years, and the number of bird species, crab species, and mollusk species in the project area increased by 17, 8, and 21 respectively.

[0037] Example 2

[0038] The 6,000-mu aquaculture ponds at the rear edge of the western harbor of Hainan Island were selected to be converted back to forest and wetlands. 4,025 mu of ponds were converted back to forest and 1,975 mu of ponds were converted back to wetlands in the project area. The areas of forest and wetlands were planned in blocks of varying sizes. At the lowest tide, the water depth of the wetland block was maintained at 0.2-0.5m; the width of the tidal gully in the forest area was 8-10m, the depth was 1.0-1.5m, and the area accounted for about 8% of the forest area; the blank beach without mangroves planted accounted for about 20% of the forest area. The blank beach was distributed in the mangrove planting belt in a strip shape, with a width of 10m and the same length as the mangrove belt. The mangrove planting belt is 15-30m wide. The selected tree species include red sea olive, autumn candel, Bruguiera gymnorrhiza, sea lotus, etc., with a planting density of 1.0×1.5m, and the shrub species include tung tree, white bone soil, mouse lily, etc., with a planting density of 1.0×1.0m.

[0039] A survey conducted six months after the implementation of the project showed that the survival rate of mangroves reached 92%, and the number of bird species, fish species, crab species, and mollusk species in the project area increased by 16, 12, 5, and 13 respectively.

[0040] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the technical solution of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for restoring mangrove ecology to improve biodiversity, characterized by: There are three methods: a. In the relatively low-lying mangrove restoration area, the land will be organized into strips or blocks of different heights according to the current status of the tidal flat landforms in the restoration area. Mangroves will be planted in the tidal flats suitable for mangrove growth, and the lower plots will be reserved as tidal channels and waters for marine life and birds to survive, inhabit or forage; b. In mangrove restoration areas with relatively high terrain, the tidal flats suitable for mangrove planting will be organized into strips or blocks, with some plots planted with mangroves and the other plots retained as tidal flats for birds or marine benthic animals to survive, inhabit or forage; the plots planted with mangroves and the plots retained as tidal flats will be arranged intermittently; c. Combine the above two methods (a) and (b) in light of the specific topography of the mangrove restoration area, so that the mangrove planting area accounts for 65-75% of the restoration area, and the rest is exposed mudflats, tidal gullies and water areas; The width of the plot used for planting mangroves is greater than 10 meters, and 3-5m shrub species are planted around the plot, with a planting density of 0.5×0.5m or 0.5×1.0m; trees or small trees are planted in the middle of the plot, with a planting density of 1.0×1.0m or 2.0×2.0m.

2. A method for improving biodiversity in mangrove ecological restoration according to claim 1, characterized in that: The shrub species planted around the mangroves include one or more of Paulownia, Avicennia marina, and Acanthus truncatula. The planting density is determined by the size of the wind and waves: For plots with low wind and waves and no obvious tidal scouring, the planting density is 0.5×1.0m; For plots with strong winds and waves and obvious tidal erosion, the planting density is 0.5×0.5m.

3. A method for restoring mangrove ecosystems to improve biodiversity according to claim 1, characterized in that: The trees or small trees planted in the middle of the mangroves include one or more of the following: Rhizophora rubra, Candel, Bruguiera gymnorrhiza, and Sea Lily. The planting density is determined by the size of the wind and waves: For plots with low wind and waves and no obvious tidal erosion, the planting density is 2.0×2.0m; For plots with strong winds and waves and obvious tidal erosion, the planting density is 1.0×1.0m.

4. A method for restoring mangrove ecology to improve biodiversity according to claim 1, characterized in that: During high tide, the water depth of tidal gullies and water areas is maintained at 1.0-1.5m, and after low tide, the water depth is maintained at 0.2-0.5m; 0.1-0.3m thick discarded oyster shells are laid on the sloping beach 0.3-0.5m above the edge of the tidal gully and water area to reduce the loss of sediments on the mangrove planting belt due to scouring by water flow during low tide.

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