Degenerated wetland near-natural recovery method based on provenance production improvement

Abstract

The invention discloses a degraded wetland near-natural restoration method based on provenance production improvement, belongs to the technical field of wetland ecological engineering, and solves the restrictive problems of plant provenance deficiency caused by exogenous interference and low sustainable efficiency after wetland restoration. The method comprises the following steps: 1, defining provenance deletion and recovering wetland site selection; 2, creating a grid habitat of the target wetland; 3, collecting and cultivating a breeding matrix; 4, performing segmented management and control on hydrological conditions; and 5, seed source production monitoring and propagation mediation. The method is suitable for a degraded wetland near-natural recovery scene with provenance production obstacles.

Description

Technical Field

[0001] The invention belongs to the technical field of wetland ecological engineering, and specifically relates to a near-natural restoration technology for degraded wetlands. Background Art

[0002] As a unique and irreplaceable natural ecosystem on the earth's surface, wetlands have multiple ecological and social service functions, and play an important role in maintaining the integrity of biodiversity and optimizing the local ecological environment. Wetland plants, as one of the basic components of wetland ecosystems, are the main contributors to the net primary productivity of wetland ecosystems. They play an active role in supplying food sources, providing habitats, and maintaining regional ecological balance.

[0003] However, due to the combined influence of multiple factors such as agricultural and animal husbandry development, wetland degradation has become increasingly prominent, and the degradation of native vegetation caused by the lack of seed sources has seriously restricted the structural stability and function of wetland ecosystems, and will eventually threaten national ecological security and human social well-being. Therefore, how to effectively improve the production capacity of plant seed sources in degraded wetlands has become a key technical issue that needs to be urgently solved in the field of wetland ecological protection.

[0004] At present, the main ways to improve seed production include whole-plant transplanting and ecological water replenishment. The whole-plant transplanting technology has a clear principle and strong operability, and can increase seed production in a short period of time. However, this method only relies on the asexual reproduction strategy of plants to achieve short-term colony expansion and requires frequent manual maintenance and management, and seed production activities are not sustainable; ecological water replenishment methods can provide sufficient water supply during the plant seed production process, thereby stimulating the germination of soil seed banks and the sprouting of plant rhizomes to achieve the restoration goal, but this method requires a large amount of natural water resources, the restoration cost is high, and it cannot avoid the problem of secondary vegetation succession caused by changes in hydrological conditions.

[0005] Therefore, how to effectively integrate measures such as hydrological restoration and germplasm introduction to promote seed production and achieve near-natural restoration of degraded wetlands has become a key scientific issue that urgently needs to be addressed in the field of wetland ecological protection. Summary of the invention

[0006] The present invention proposes a near-natural restoration method for degraded wetlands based on improved seed production, which aims to solve the limiting problems of plant seed loss caused by exogenous interference and low sustainable efficiency after wetland restoration.

[0007] The present invention proposes a near-natural restoration method for degraded wetlands based on seed production improvement, which comprises the following steps: S1: Delineation of seed loss and selection of wetland restoration sites, including: Investigate the surface plant community and soil seed bank of the proposed restoration area one year before restoration, and define the standards for wetland degradation and seed source loss. The standards are: the dominant species is annual plants, the surface vegetation density is less than 10-20 plants / square meter, the number of soil seed species is less than 5, and the similarity between the surface plant community and the soil seed bank is less than 0.1; delineate the target restoration plots in February of the restoration year, and there are adjacent water bodies around the target restoration plots; S2: Construction of target wetland grid habitat, including: From late March to early April of the restoration year, the soil in the target restoration plot is turned over with a turning depth of 0-30 cm; an interactive water transfer overflow ring network is constructed; the interactive water transfer overflow ring network is constructed as follows: in the target restoration plot, U-shaped water transfer network lines are set at intervals of 10 meters in the longitudinal and transverse directions to form several grid-shaped restoration plots, and the depth of the U-shaped water transfer network line is 20 cm and the width is 40 cm; the soil generated by digging the U-shaped water transfer network line is used to build an ecological dam at the edge of the target restoration plot, and 3 controllable semi-underground water transfer culverts are set on the ecological dam on the side of the adjacent water body, and the interval between each controllable semi-underground water transfer culvert is 30 meters; a natural reservoir is dug at the periphery of the ecological dam on the side of the adjacent water body, and the natural reservoir is 10 meters wide, 100 meters long and 1 meter deep; during the restoration period, surface water and groundwater from the adjacent water body are extracted, and the natural reservoir is continuously filled with water by overflow; S3: Propagation substrate collection and cultivation, including: From mid-April to late April of the restoration year, soil resources and rhizomes of non-clustered sedge grass were collected intermittently in the adjacent natural wetlands; the collection depth of the soil resources was 0-10 cm, and the collection depth of the non-clustered sedge grass rhizomes was 0-30 cm; a sedge grass mound with a height of 30-40 cm and a diameter of 40-50 cm was selected, and it was vertically divided into three equal parts, and one mound was retained in situ, and the rest of the mounds were used for subsequent transplanting; the collected soil resources were evenly covered on the surface of several grid-shaped restoration plots, and sedge grass roots were evenly placed with a placement density of 10-20 stems / square meter; then the soil was turned twice with a turning depth of 0-10 cm; and the sedge grass mound mound was transplanted in each grid-shaped restoration plot; S4: Segmented management of hydrological conditions, including: After the second rotation is completed, a controllable semi-underground water culvert is used to introduce water from the natural reservoir into the interactive water overflow ring network to replenish water to the target restoration plot; S5: Seed production monitoring and dissemination mediation, including: Collect sedge seeds, protect them from light and keep them sterile, then sow them in the gaps of transplanted sedge mounds; carry out soil seed bank and seed spike development monitoring in early May and early July of the restoration year and in early May and early July of the following year; when the target restoration plots meet the restoration assessment standards, remove the ecological dam and controllable semi-underground water culverts to complete the near-natural restoration of the degraded wetland.

[0008] Furthermore, a preferred solution is provided: the type of the adjacent water body is a freshwater river, lake, or reservoir.

[0009] Furthermore, a preferred solution is provided: the total nitrogen content of the adjacent water body is lower than 1.5 mg / L, the total phosphorus content is lower than 0.5 mg / L, and the total organic carbon content is lower than 1.8 mg / L.

[0010] Furthermore, a preferred solution is provided: the distance between the target restoration plot and the adjacent water body is 60-80 meters, and the average altitude of the target restoration plot is 0.2-0.5 meters higher than the adjacent water body.

[0011] Furthermore, a preferred solution is provided: the historical grazing period of the target restoration plot is less than 10-15 years, the grazing density is less than 10-15 animals / mu, the soil salt content is less than 60mmol / L, and the soil alkalinity is less than 7%-9%.

[0012] Furthermore, a preferred solution is provided: the adjacent natural wetlands are dominated by Gnaphalium sphaerocephalum, Ula grass, Gray-veined Gnaphalium, and Gnaphalium sphaerocephalum.

[0013] Furthermore, a preferred solution is provided: in S3, the sedge grass mounds are transplanted at a density of 1-2 mounds / square meter and at intervals greater than 1 meter; the sedge grass mounds are buried 5 cm underground and exposed 25-35 cm above the ground.

[0014] Furthermore, a preferred solution is provided: water is replenished to the target restoration plots as follows: the first water replenishment is in the form of overflow until the surface is flooded by 1-2 cm, and the water is replenished in a cycle of 20-25 days until the surface is flooded by 1-2 cm; water is replenished in mid-July until the surface is flooded by 5-10 cm and maintained until mid-October, and the controllable semi-underground water culvert is closed after replenishing in mid-October until the surface is flooded by 15-20 cm.

[0015] Furthermore, a preferred solution is provided: collecting sedge seeds and performing light-proof and sterile treatment includes: collecting sedge seeds after the seed ears mature in the year of restoration, with the total amount collected being 30%-40% of the total yield of the year; placing the collected sedge seeds in a light-proof 4°C sterile environment and storing them continuously until May of the following year.

[0016] Furthermore, a preferred solution is provided: the evaluation criteria for the target restoration plots are: In the restoration year, each plant develops 2-3 spikes, the biomass of each spike is 15-20 mg, and the number of species in the soil seed bank is more than 10; in the second year after restoration, each plant develops 3-4 spikes, the biomass of each spike is 20-30 mg, and the number of species in the soil seed bank is more than 15; After three years of artificially mediated management of the target restoration plots, the vegetation coverage was greater than 60%, the plant community density was greater than 160 plants / square meter, and the similarity between the surface plant community and the soil seed bank was greater than 0.3.

[0017] Compared with the prior art, the advantages of the present invention are: 1. The present invention has clear principles, is easy to implement and has low cost.

[0018] The method described in the present invention is in line with the concept of ecological near-natural restoration. It realizes the segmented rhythmic control of the hydrological situation of the restored wetland by setting up an interactive water transfer overflow ring network, and promotes the improvement of seed production by introducing multi-source time-sharing germplasm, thereby realizing near-natural restoration of degraded wetlands. After the method described in the present invention is implemented, multi-source seed production and propagation and planting can be realized in the same year, and the complete life history process of dominant plant seed production-propagation-germination-planting can be reconstructed in a short period of time, without the need for frequent manual maintenance, and is suitable for wide promotion and application in the restoration process of seed-deficient degraded wetlands caused by agricultural and animal husbandry activities.

[0019] 2. The present invention can effectively improve the seed production capacity of degraded wetlands.

[0020] The present invention effectively integrates the sexual and asexual reproduction strategies of dominant plants and companion plants by introducing soil seed banks, rhizomes of dominant plants and sedge grass mounds in the target restoration plots, which can expand the source of germplasm production in degraded wetlands in a short period of time and thus improve the seed production capacity. In addition, the present invention covers technical points such as multiple soil rotation, which can shorten the seed slow-release cycle by reducing soil environmental improvement and bionic covering, thereby improving the seed production capacity.

[0021] 3. The present invention can effectively stimulate the production efficiency of seed sources in degraded wetlands.

[0022] The method described in the present invention presets a grid-shaped water delivery overflow ring network in the target restoration plot and adopts segmented hydrological situation control measures, which can fully meet the differentiated demand for water in the multi-stage development process of plants, thereby alleviating the glycolysis rate and sugar consumption in the plant body, reducing the risk of plant respiratory substrate depletion and accumulation of harmful substances, thereby promoting plant growth and development and energy conduction, and strengthening the development of axillary meristems, inflorescence structure formation and grain development. At the same time, the present invention introduces sedge grass mounds into the target restoration plot, and creates a heterogeneous habitat while supplementing the source of germplasm production. The differentiated hydrological environment formed by it can meet the heterogeneous demand for habitat conditions for seed germination of plants of different life forms, thereby improving the efficiency of seed production. In addition, the method described in the present invention adopts artificial mediated propagation means to ensure the level of seed vitality and target the orientation and form of seed planting, which can obtain suitable water and heat resources to the greatest extent, thereby promoting the mobilization of stored nutrients and accelerating intergenerational information transmission, effectively improving the efficiency of seed production activities.

[0023] 4. The method described in the present invention is safe and effective, and does not pose any ecological safety risks.

[0024] The water used in the present invention is natural surface water and groundwater. The water is settled in the reservoir to remove suspended matter and solid pollutants in the early stage of use. At the same time, no organic pollutants are used in the construction of the target restoration plot, and there is no risk of eutrophication and non-point source pollution. At the same time, the germplasm resources used in the present invention are collected in an intermittent form in the adjacent natural wetlands, and there is no risk of any alien species invasion and local ecological environment damage.

[0025] The present invention is applicable to near-natural restoration scenarios of degraded wetlands where there are obstacles to seed production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a schematic diagram of the near-natural restoration structure of the target restoration plot according to the first specific implementation mode of the present invention, wherein 1 is an ecological dam; 2 is a grid-shaped restoration plot; 3 is a controllable semi-underground water culvert; 4 is a natural reservoir; 5 is a U-shaped water transmission network line; 6 is a temporary water transmission pipeline; 7 is an adjacent water body; Figure 2It is a side view of the near-natural restoration structure of the target restoration plot according to the first specific implementation mode of the present invention, wherein 8 is a twice shallowly turned soil layer; 9 is a rotary turned soil layer; 10 is a sedge grass mound; Figure 3 A bar graph of the surface vegetation coverage of the target restoration plots within different restoration years as described in the second specific implementation mode of the present invention; Figure 4 A bar graph of surface vegetation density of target restoration plots within different restoration years as described in the second specific implementation mode of the present invention; Figure 5 A bar graph of the similarity of above-ground and underground vegetation in target restoration plots within different restoration years as described in the second specific implementation mode of the present invention; The different lowercase letters in the figure represent that the surface vegetation coverage, surface vegetation density, and above-ground-underground vegetation similarity of the target restoration plots within different restoration years are significantly different at the hypothesized level of 0.05, among which a is significantly different from b, c, d, and e; b is significantly different from a, c, d, and e; c is significantly different from a, b, d, and e; d is significantly different from a, b, c, and e; and e is significantly different from a, b, c, and d. DETAILED DESCRIPTION

[0028] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0029] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0030] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific implementation methods disclosed below.

[0033] Implementation method 1: Reference Figure 1 , Figure 2 This embodiment will be described.

[0034] This implementation method proposes a near-natural restoration method for degraded wetlands based on improved seed production. The specific implementation steps are as follows: 1. Definition of seed source deficiency and site selection for wetland restoration: Assess the environmental background conditions and historical disturbance level of the area to be restored, and select degraded wetlands adjacent to water bodies as target restoration sites. It is required to investigate the species composition of surface vegetation and soil seed bank in the proposed restoration area one year before restoration, and use the dominant species of surface plant communities and soil seed banks as annual plants, surface vegetation density less than 10-20 plants / square meter, and the number of soil seed bank species less than 5 as the standard for defining wetland degradation; it is required that the similarity between surface plant communities and soil seed banks in the target restoration plots be less than 0.1 as the standard for defining seed source loss; it is required to delineate target restoration plots with a margin specification of 100 meters × 100 meters in February of the restoration year to facilitate grid habitat creation and subsequent operation and maintenance; it is required that the grazing period of livestock in the target restoration plots be less than 10-15 years, and the grazing density be less than 10-15 heads / mu, so as to avoid the depletion of basic seed sources and irreversible degradation of soil physical and chemical properties caused by heavy grazing; it is required that the soil salt content of the target restoration plots be less than 60mmol / L, and the soil alkalinity be less than 7-9%, so as to avoid the depletion of basic seed sources and irreversible degradation of soil physical and chemical properties caused by heavy grazing; Avoid ion toxicity and permeability damage caused by soil salinization to the production of non-salt-tolerant plant seed sources and seed germination processes; require that there is no water accumulation in the target restoration plots to facilitate the creation of grid habitats and hydrological environment regulation during the near-natural restoration process; require that the selected target restoration plots be 0.2-0.5 meters higher than the adjacent natural water bodies to reduce the construction difficulty and subsequent operation and maintenance costs during the water transfer process; require that the target restoration plots be 60-80 meters away from the adjacent water bodies 7 to avoid the risk of extreme flooding caused by flooding events; require that the adjacent water bodies 7 of the target restoration plots be freshwater rivers, lakes, reservoirs, and the total nitrogen, total phosphorus and total organic carbon contents in the water bodies be lower than 1.5 mg / L, 0.5 mg / L and 1.8 mg / L, respectively, to ensure the water demand in the near-restoration process of the degraded wetlands and the continuous supply of natural water sources after restoration, while avoiding the risk of secondary pollution in the restoration area caused by eutrophication of water bodies.

[0035] 2. Construction of grid habitat in target wetlands: From late March to early April, the physical environment of the surface soil of the target restoration plots was repaired and an interactive water overflow ring network was set up. It is required to use small mechanical facilities to turn over the soil at a depth of 0-30 cm in the target restoration plots to alleviate the deterioration of the physical structure of the surface soil caused by livestock grazing, thereby improving the soil permeability and water retention; it is required to set up interactive water overflow ring networks at intervals of 10 meters, and set up U-shaped water transmission network lines 5 with a depth of 20 cm and a width of 40 cm to strengthen the hydrological connectivity within the target restoration plots and alleviate the local soil erosion and landform erosion caused by direct water supply; it is required to use the earthwork generated by excavating the U-shaped water transmission network line 5 to pile up 20 cm high and 30 cm wide living water pipes at the edge of the target restoration plots. It is required to build an ecological dam 1 to prevent the backflow of external water bodies and the interference of short-term hydrological conditions on the vegetation in the target restoration plot; it is required to set up three controllable semi-underground water culverts 3 at intervals of 30 meters at the ecological dam on the natural water body side of the target restoration plot, so as to adjust the time and scale of water input during the near-natural restoration and subsequent maintenance of the degraded wetland; it is required to dig a natural reservoir 4 with a width of 10 meters, a length of 100 meters and a depth of 1 meter on the periphery of the ecological dam on the natural water body side of the target restoration plot, and temporarily set up surface water extraction pipelines and groundwater overflow to store water, so as to supply the water required for the restoration of the target restoration plot and the needs of staged water replenishment.

[0036] 3. Collection and cultivation of propagation substrate: From mid to late April, soil seed banks, rhizomes of Eupatorium plants and Eupatorium grass mounds were collected, and the cultivation of propagation substrates was carried out in combination with secondary shallow turning of the topsoil. It is required to collect propagation substrate resources in the adjacent natural sedge wetland in an intermittent manner to avoid the ecological damage of natural wetland vegetation caused by centralized germplasm resource collection; it is required that the dominant species in the natural sedge wetland are tuber sedge, Ula grass, gray vein sedge, and clump sedge to ensure that sedge grass mounds can be naturally formed after the plant propagation substrate is transplanted; it is required to collect soil resources at a depth of 0-10 cm; it is required to collect non-clustered sedge rhizome resources at a depth of 0-30 cm; it is required to use sedge grass mounds with a height of 30-40 cm and a diameter of 40-50 cm as the mound collection object, and to divide the mound into three equal parts in the form of vertical cutting, and retain one part of the mound in situ, so as to maintain the in situ vegetation ecological process and provide sufficient propagation substrate supply for the target restoration plot; it is required to separate the collected soil into 5 cm The grid-shaped restoration plots formed by the water overflow ring network in the target restoration plots are evenly covered with soil, and the roots of sedge grass are evenly placed at a density of 10-20 stems / square meter. Then, a micro-rotation device is used to rotate the soil for the second time at a depth of 0-10 cm to simulate the soil seed bank and the natural concentrated distribution depth of the target plant roots in a bionic way, thereby reducing the risk of tillering blockage caused by the burial depth in the early stage of seed and root tillering; it is required to transplant sedge grass mounds at a density of 1-2 mounds / square meter in each grid-shaped restoration plot, and the distance between the mounds should be greater than 1 meter, so as to reserve the seed rain propagation and the ecological niche space for vegetation development; it is required that the underground burial depth of the sedge grass mounds during the transplanting process is 5 cm, and the surface exposure height is 25-35 cm, so as to simulate the natural development form of the grass mound and ensure the normal germination of the plants on the top of the mound.

[0037] 4. Segmented control of hydrological situation: Carry out initial water replenishment after the cultivation of the propagation substrate, and after the initial water replenishment, intermittent water replenishment is performed at a cycle of 20-25 days to the initial hydrological state. It is required to use a controllable semi-underground water culvert to introduce water from the natural reservoir to carry out water replenishment work, so as to ensure that the introduced water enters the target restoration plot through the preset grid-shaped water overflow ring network; it is required to carry out initial water replenishment work immediately after the second rotation is completed, so as to provide suitable hydrological conditions for the root sprouting of sedge grass and facilitate the later transplanting of sedge grass mounds; it is required to replenish water after the second rotation until the surface is flooded by 1-2 cm, so as to provide an oxygen-rich soil moisture environment for the development of the propagation substrate and promote rapid plant development; it is required to replenish water in sections at intervals of 20-25 days to the initial hydrological state, so as to effectively improve the stability of soil aggregates and Stimulate soil respiration, thereby promoting plants to absorb and utilize nutrients from the soil to supply seed spike development and seed growth; require water replenishment in mid-July until the surface is flooded 5-10 cm and maintained until mid-October, so as to induce plants to adopt an "escape strategy" through flooding stress, thereby increasing the development of the aboveground parts of plants and biomass accumulation, and at the same time provide a water medium for seed propagation in the target restoration plots; require water replenishment in mid-October until the surface is flooded 15-20 cm and then close the controllable semi-underground water culvert to provide a suitable hydrological environment for vegetation roots and stems to overwinter and avoid drought stress in the spring of the following year caused by winter water infiltration.

[0038] 5. Seed production monitoring and dissemination mediation: Carry out monitoring of sedge seed production in the restoration year and in May and early July of the following year, and carry out auxiliary seed propagation measures in the following year. It is required that in the restoration year, a single plant develops 2-3 seed ears, the biomass of a single ear is 15-20mg, and the number of species in the soil seed bank is more than 10; in the following year, a single plant develops 3-4 ears, the biomass of a single ear is 20-30mg, and the number of species in the soil seed bank is more than 15 as the staged seed production improvement standard, so as to provide sufficient seed supply sources for the near-natural restoration of the target plots; it is required to manually collect sedge seeds with a total amount of 30%-40% of the total annual production after the seed ears mature, and keep them in a light-proof 4℃ sterile environment until May of the following year to ensure that the seeds maintain a high level of vitality and can be used for later artificial bionic propagation mediation; it is required to transplant in May of the following year. The gaps between the sedge grass mounds are sown in a concentrated spot pattern with 10 to 20 seeds to simulate the sedge seed dispersal process and promote the rapid colonization and concentrated development of clustered sedge; the recovery status of the target restoration plot is evaluated after 3 years of artificial mediated management, and the vegetation coverage greater than 60%, the plant community density greater than 160 plants / square meter, and the similarity between the surface plant community and the soil seed bank greater than 0.3 are used as restoration assessment standards; the ecological dam and 3 controllable semi-underground water culverts are removed after the vegetation development conditions meet the restoration assessment standards, so as to continue the natural hydrological connection between the target restoration plot and the surrounding natural wetlands, thereby realizing the fully natural development of the degraded wetlands.

[0039] The method described in this implementation mode has clear principles and strong operability. It can promote the improvement of plant seed production efficiency through segmented control of hydrological conditions, and the design concept is consistent with the concept of near-natural restoration, without any engineering safety hazards and ecological interference risks. The method described in this implementation mode can be used to carry out near-natural restoration of degraded wetlands, and the success rate of restoring plant seed production can reach 100%, the success rate of self-propagation of restored plant communities can reach 100%, and the probability of sustainable development of restored wetland ecology can reach 100%.

[0040] Implementation method 2: Reference Figure 3 , Figure 4 , Figure 5 This embodiment will be described.

[0041] This embodiment is a further example of the method for near-natural restoration of degraded wetlands based on enhanced seed production described in Embodiment 1.

[0042] This implementation method carries out near-natural restoration of degraded wetlands with seed-deficient sources in a certain plain in the western region. During the near-natural restoration of degraded wetlands, the following methods are used: 1. Definition of seed source deficiency and site selection for wetland restoration: In May and July of the year before restoration, soil seed bank sample collection and cultivation and surface plant community survey were carried out in a degraded wetland along the river in a nature reserve. The surface plant density in this area is less than 10 plants / square meter. The surface plant community and soil seed bank are dominated by annual plants such as gray-green quinoa, and the similarity between the surface plant community and the soil seed bank is 0.08, which is a degraded wetland with seed source deficiency. On March 12 of the restoration year, a 100m×100m degraded wetland with a height of 0.5m above the adjacent water body and a distance of 75m was designated as the target restoration plot. The historical grazing period of this plot is 8 years, during which the grazing intensity is 12 / mu, the soil salt content is 45mmol / L, and the soil alkalinity is 6.8. The water body adjacent to the plot is a freshwater river with a total nitrogen content of 1.2±0.1 mg / L, a total phosphorus content of 0.3±0.1 mg / L, and a total organic carbon content of 1.8±0.2 mg / L.

[0043] 2. Construction of grid habitat in target wetlands: From March 29 to April 2 of the restoration year, a small tiller was used to turn over the 0-30 cm soil in the target restoration plot, and a U-shaped water channel with a depth of 20 cm and a width of 40 cm was dug at intervals of 10 meters to construct a grid-based water overflow ring network. The earthwork generated by digging the water channel was used to build an ecological dam with a height of 20 cm and a width of 30 cm at the edges of the target restoration plot, and three controllable semi-underground water culverts were set up at intervals of 30 meters at the ecological dam on the natural water body side of the target restoration plot. A natural reservoir with a width of 10 meters, a length of 100 meters, and a depth of 1 meter was dug outside the ecological dam on this side, and water was stored by extracting natural water bodies and groundwater overflow for subsequent segmented hydrological situation control.

[0044] 3. Collection and cultivation of propagation substrate: From April 15 to 21 of the restoration year, soil at a depth of 0-10 cm and rhizomes of tuber sedge grass at a depth of 0-30 cm were collected intermittently in the adjacent natural sedge grass wetland. After vertically cutting the sedge grass mound with a height of 30-40 cm and a diameter of 40-50 cm into three equal parts, one mound was retained in place and the rest was used as a breeding matrix resource. After the sedge grass roots were evenly placed in the grid-shaped restoration plot at a density of 15 stems / square meter, the soil at a depth of 0-10 cm was turned twice using a micro-rotation device, and then the sedge grass mound was transplanted at a density of 2 mounds / square meter and a spacing of 1.5 meters according to the cultivation standard of 5 cm underground burial depth and 25-35 cm exposed on the surface.

[0045] IV. Segmented Control of Hydrological Situation On April 18 of the year of repair, after the second rotation was completed, the water in the natural water reservoir was introduced into the grid-shaped water overflow ring network through a controllable semi-underground water culvert to replenish water until the surface was flooded by 1-2 cm, and then replenished again at intervals of 22 days to a state of 1-2 cm flooding. During the non-water replenishment period, the soil in the target plot gradually dried up. On July 16 of the year of repair, after the seeds of the tubercle sedge completely fell off, water was replenished to a surface flooding depth of 10 cm and the flooding state was maintained until October 16. After that, water was replenished to a surface flooding depth of 20 cm and the controllable semi-underground water culvert was closed.

[0046] 5. Monitoring of seed ear development and transmission mediation The development of the seed spikes of Gastrodia elata was continuously monitored from July 1 to 6 of the restoration year, and about 35% of the total yield of Gastrodia elata in that year was collected and stored in a sterile environment at 4°C. From May 2 to 7 of the restoration year, 20 seeds were sown in a concentrated spot pattern in the gaps between the transplanted Gastrodia elata mounds to promote the rapid clustering of Gastrodia elata, and the development of the seed spikes of Gastrodia elata was monitored again from July 1 to 6. In May and July of the fourth year after restoration, an assessment survey of the ecological characteristics of the soil seed bank and surface vegetation was conducted, and the vegetation coverage greater than 60%, the plant community density greater than 160 plants / square meter, and the similarity between the surface plant community and the soil seed bank greater than 0.3 were used as restoration assessment criteria.

[0047] After evaluation, the vegetation coverage in the target restoration plot is 70%, the plant community density is 82±4 plants / square meter, and the similarity between the surface plant community and the soil seed bank is 0.36, which meets the standards for restoration of degraded wetlands. The ecological dam and the controllable semi-underground water culvert have been removed, thereby achieving the fully natural self-development of the degraded wetland. The invention method achieves the near-natural restoration goal of increasing the efficiency of plant seed production by 100%, the success rate of self-propagation of restored plant communities by 100%, and the success rate of fully natural development of degraded wetlands by 100%. It has achieved the near-natural restoration of degraded wetlands on the basis of improved seed production.

[0048] Those skilled in the art will appreciate that the above are only preferred embodiments of the present invention, and the various embodiments of the present disclosure and / or the features described in the claims may be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or perform equivalent substitutions on some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0049] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0050] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0051] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present disclosure rather than to limit its protection scope. Although the present disclosure has been described in detail with reference to the above implementation modes, ordinary technicians in the relevant field should understand that after reading the present disclosure, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation modes of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the disclosed claims to be approved.

Claims

1. A near-natural restoration method for degraded wetlands based on seed production improvement, characterized in that: The method comprises: S1: Delineation of seed loss and selection of wetland restoration sites, including: In the year before restoration, the surface plant community and soil seed bank of the proposed restoration area were investigated to define the standards for wetland degradation and seed source loss. The standards were: the dominant species were annual plants, the surface vegetation density was less than 10-20 plants / square meter, the number of soil seed species was less than 5, and the similarity between the surface plant community and the soil seed bank was less than 0.1; in February of the restoration year, the target restoration plots were delineated, and there were adjacent water bodies around the target restoration plots (7); S2: Construction of target wetland grid habitat, including: From late March to early April of the restoration year, the soil in the target restoration plot is turned over to a depth of 0-30 cm; an interactive water transfer overflow ring network is constructed; the interactive water transfer overflow ring network is constructed in the following manner: in the target restoration plot, U-shaped water transfer network lines (5) are arranged at intervals of 10 meters in the longitudinal and transverse directions to form a plurality of grid-shaped restoration plots (2), the U-shaped water transfer network lines (5) having a depth of 20 cm and a width of 40 cm; the soil generated by digging the U-shaped water transfer network lines (5) is used to dig the soil around the target restoration plot. An ecological dam (1) is built at the edge, and three controllable semi-underground water culverts (3) are installed on the ecological dam (1) on the side adjacent to the water body (7), with each controllable semi-underground water culvert (3) being spaced 30 meters apart; a natural water reservoir (4) is excavated at the periphery of the ecological dam (1) on the side adjacent to the water body (7), wherein the natural water reservoir (4) is 10 meters wide, 100 meters long, and 1 meter deep; during the recovery period, surface water and groundwater from the adjacent water body (7) are extracted, and the natural water reservoir (4) is continuously stored with water by overflow; S3: Propagation substrate collection and cultivation, including: From mid-April to late April of the restoration year, soil resources and non-clustered sedge rhizome resources are intermittently collected in the adjacent natural wetland; the soil resources are collected at a depth of 0-10 cm, and the non-clustered sedge rhizome resources are collected at a depth of 0-30 cm; a sedge grass mound with a height of 30-40 cm and a diameter of 40-50 cm is selected, and it is vertically divided into three equal parts, one mound is retained in situ, and the remaining mounds are used for subsequent transplanting; the collected soil resources are evenly covered on the surface of several grid-shaped restoration plots (2), and sedge grass roots are evenly placed at a density of 10-20 stems / square meter; then the soil is turned twice, and the turning depth is 0-10 cm; and the sedge grass mound is transplanted in each grid-shaped restoration plot (2); S4: Segmented management of hydrological conditions, including: After the second rotation is completed, the controllable semi-underground water culvert (3) is used to introduce the water in the natural reservoir (4) into the interactive water overflow ring network to replenish water to the target restoration plot; S5: Seed production monitoring and dissemination mediation, including: Collect sedge seeds, protect them from light and keep them sterile, then sow them in the gaps of transplanted sedge mounds; carry out soil seed bank and seed spike development monitoring in early May and early July of the restoration year and in early May and early July of the following year; when the target restoration plots meet the restoration assessment standards, remove the ecological dam and controllable semi-underground water culverts to complete the near-natural restoration of the degraded wetland.

2. A near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1, characterized in that: The types of adjacent water bodies (7) are freshwater rivers, lakes, and ponds.

3. The near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1 is characterized in that: The total nitrogen content of adjacent water bodies (7) is less than 1.5 mg / L, the total phosphorus content is less than 0.5 mg / L, and the total organic carbon content is less than 1.8 mg / L.

4. The near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1 is characterized in that: The distance between the target recovery plots is 60-80 meters from the adjacent water body (7), and the average altitude of the target recovery plot is 0.2-0.5 meters higher than the adjacent water body (7).

5. The near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1 is characterized in that: The historical grazing period of the target restoration plot is less than 10-15 years, the grazing density is less than 10-15 pcs / mu, the soil salt content is less than 60mmol / L, and the soil alkalinization degree is less than 7%-9%.

6. The near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1 is characterized in that: The adjacent natural wetlands are dominant species of cyst sedge grass, umlain grass, gray vein grass, and clump sedge grass.

7. The near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1 is characterized in that: In the S3, the transplanted sedge grass grass hills are transplanted at a density of 1-2 piles / square meter, and the interval is greater than 1 meter; the underground buried depth of the sedge grass grass hills is 5 cm, and the surface exposed height is 25-35 cm.

8. The near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1 is characterized in that: The specific steps for replenishing water to the target restoration plots are as follows: the first replenishment is to replenish water in the form of overflow until the surface water is 1-2 cm, and then replenish water in a cycle of 20-25 days until the surface water is 1-2 cm; replenish water in mid-July until the surface water is 5-10 cm and maintain it until mid-October; replenish water in mid-October until the surface water is 15-20 cm, and then close the controllable semi-underground water culvert (3).

9. The near-natural restoration method for degraded wetlands based on seed production improvement according to claim 1 is characterized in that: Collecting sedge seeds and treating them in a light-proof and sterile manner includes: collecting sedge seeds after the seed spikes mature in the year of restoration, with the total amount collected being 30%-40% of the total yield of the year; placing the collected sedge seeds in a light-proof 4°C sterile environment and storing them until May of the following year.

10. The near-natural restoration method of degraded wetlands based on seed production improvement according to claim 1, characterized in that: The evaluation criteria for target restoration plots are: In the restoration year, each plant develops 2-3 spikes, the biomass of each spike is 15-20 mg, and the number of species in the soil seed bank is more than 10; in the second year after restoration, each plant develops 3-4 spikes, the biomass of each spike is 20-30 mg, and the number of species in the soil seed bank is more than 15; After three years of artificial mediation management of the target restoration plot, the vegetation coverage is greater than 60%, the plant community density is greater than 160 plants / square meter, and the similarity between the surface plant community and the soil seed bank is greater than 0.3.

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