Degenerated sand vegetation restoration method based on donation soil seed bank

Abstract

The invention belongs to the technical field of degenerated sand land treatment, and particularly relates to a degenerated sand land vegetation restoration method based on a donation soil seed bank. Comprising the steps of donation soil seed bank acquisition, donation soil seed bank soil matrix improvement and donation soil seed bank transplanting and laying. The method comprises the following steps: firstly, selecting a top-level or near-top-level natural community of a habitat vegetation succession sequence as a donation source area of a donation soil seed bank, obtaining surface soil of a habitat earth surface containing the seed bank, wherein transplanted soil contains a soil seed bank, nutrient propagules such as root systems and subterranean stems of plants, soil organisms and the like; and then transplanting to the surface of the degraded sand land, realizing vegetation recovery of the degraded sand land by utilizing the transplanted soil seed bank and soil through a natural germination and growth process, and recovering the vegetation coverage to the community level of the donation source area in the second year and the third year after implementation, and enabling the plant variety number to be close to the species number of the donation source area.

Description

Technical Field

[0001] The invention belongs to the technical field of degraded sand land management, and in particular relates to a degraded sand land vegetation restoration method based on a donated soil seed bank. Background Art

[0002] Land sandification and degradation is one of the important manifestations of desertification hazards. It causes hazards such as sand dune activation, grassland destruction, and farmland and forest degradation, which seriously threaten human survival and development space. Using soil seed banks to restore vegetation naturally is an effective technical approach to near-natural vegetation restoration. The soil seed bank is the sum of all viable seeds in the soil and litter on the soil surface. The soil seed bank is a potential plant community and a "potential provider" of genetic diversity of plant populations. It can reflect the history of vegetation and determine the succession direction of vegetation communities, and plays an important role in the community. In areas such as desertified and degraded land, engineering relic land, and severely degraded vegetation, the soil seed bank is severely damaged, or the density of the soil seed bank is too low to support the natural recovery of vegetation. In this case, vegetation restoration is usually carried out by adding foreign seeds to promote the restoration of vegetation in desertified and degraded land. However, it is difficult to accurately select the type and quantity of plant seeds to be added, as well as the addition ratio of different species. At the same time, the added plant seeds will also be restricted by the soil environment of the degraded sandy land, resulting in poor restoration effect and even difficulty in establishing vegetation coverage. Therefore, there is an urgent need for a vegetation restoration method that can overcome the shortcomings of seed addition technology. Summary of the invention

[0003] In view of the current situation of insufficient rapid treatment technology for degraded sandy land, the purpose of the present invention is to provide a method for restoring vegetation in degraded sandy land based on a donated soil seed bank. The present invention achieves the goal of rapid restoration of vegetation in degraded sandy land by donating a soil seed bank based on the natural succession law of vegetation in sandy land.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for restoring vegetation in degraded sandy land based on a donated soil seed bank, comprising obtaining the donated soil seed bank, improving the soil matrix of the donated soil seed bank, and transplanting and laying the donated soil seed bank.

[0006] The method for obtaining a donated soil seed bank includes selecting a donated source area and obtaining the donated soil seed bank, wherein the selection of the donated source area is based on the vegetation succession sequence of the donated area, and the near-top or top vegetation community of the vegetation succession in the habitat is used as the donated source area; the acquisition of the donated soil seed bank is to obtain the surface soil in the donated source area as the transplanted soil seed bank.

[0007] Furthermore, the method for obtaining the donated soil seed bank is as follows:

[0008] (1) Select the near-top or top communities of the vegetation succession sequence in the recipient area as the donation source area;

[0009] (2) Keep the surface soil of the donation area in its original state for sampling;

[0010] (3) The sampling depth of surface soil in the donation source area is 5 cm;

[0011] (4) Strip or sheet sampling is adopted in the donation source area, with a strip width of 20 cm and a spacing of more than 100 cm between each sampling strip;

[0012] (5) After sampling from the donor source area, the sampling zone is covered and protected.

[0013] The method for improving the soil matrix of the donated soil seed bank is as follows: add 5‰ soil water retaining agent, 3‰ soil adhesive, 3‰ urea and 1‰ diammonium phosphate to the surface soil obtained from the donated soil seed bank, and fully mix the above-mentioned added ingredients with the surface soil obtained from the donated source area.

[0014] The method for laying the donated soil seed bank is as follows: after clearing the surface debris in the donated area, the donated soil seed bank soil with improved matrix is ​​immediately and evenly laid on the surface of the donated area, and spray irrigation is immediately carried out after laying, thereby achieving the restoration of degraded sand vegetation.

[0015] Furthermore, the method for laying the donated soil seed bank is:

[0016] (1) The donated soil seed bank soil after matrix improvement is immediately and evenly spread on the surface of the donated area with a thickness of 5 cm;

[0017] (2) Spray irrigation shall be carried out immediately after the donated soil is laid in the recipient area, and the irrigation amount shall be such that the soil infiltration depth is 5 cm.

[0018] The advantages of the present invention compared with the prior art are:

[0019] 1. The present invention first selects the top or near-top natural community of the vegetation succession sequence of the habitat as the donation source area of ​​the donation soil seed bank, obtains the surface soil of the habitat containing the seed bank, and the transplanted soil contains the soil seed bank, plant roots and underground stems and other vegetative reproduction bodies, soil organisms, etc., and then transplants it to the surface of the degraded sandy land. The transplanted soil seed bank and its soil are used to achieve vegetation restoration of the degraded sandy land through a natural germination and growth process. In the second and third years after implementation, the vegetation coverage can be restored to the community level of the donation source area, and the number of plant species is close to the number of species in the donation source area.

[0020] 2. The method of the present invention can achieve rapid vegetation restoration across succession sequences, promote the direct development of degraded sandy land into near-top or top-level stable communities, and meet the requirements for sandy land vegetation restoration under specific environmental requirements, such as the rapid management needs of degraded sandy land around parks, roads, railways, and power transmission lines.

[0021] 3. The method of the present invention can effectively solve the problem of insufficient seed addition technology. Donating soil seed bank refers to a vegetation restoration method in which the surface soil containing the soil seed bank is transferred from the top or near-top natural community of the adjacent vegetation succession sequence and laid in the degraded area. Donating soil seed bank is to transfer the complete soil seed bank. The transplanted surface soil of the donation source area contains the seed bank and soil environment (nutrients, soil organisms, etc.), avoiding the problem of the number of species added to the seed bank, the species ratio and the soil environment. This method can be used in areas where the original vegetation has completely disappeared, such as severely desertified and degraded land, mining wasteland, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the technical process of restoring vegetation in degraded sandy land by donating soil seed banks according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of soil acquisition for a donated soil seed bank according to an embodiment of the present invention.

[0024] Figure 3 Schematic diagram of the soil matrix improvement process of the donated soil seed bank according to an embodiment of the present invention.

[0025] Figure 4 Schematic diagram of the process of transplanting a donated soil seed bank to a donated area according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Example 1

[0027] The typical degraded sandy land in Horqin Sandy Land was used as the recipient area to carry out vegetation restoration of the donated soil seed bank. The process is shown in Figure 1 The degradation succession sequence of Horqin sandy land can generally be divided into the severe degradation stage (vegetation coverage 5-10%), the moderate degradation stage (vegetation coverage 10-20%), the mild degradation stage (vegetation coverage 20-35%) and the stable stage (vegetation coverage 35-60%) (approximately the top community state); this embodiment takes the severely degraded sandy land as the recipient area, and the fixed dune area of ​​the near-top community of the natural succession of the sandy land vegetation as the donation source area.

[0028] 1. Methods for obtaining donated soil seed banks

[0029] (1) Selecting the source area for soil seed bank donation: clarifying the vegetation succession sequence of the sandy land under the habitat conditions of the donation area, that is, screening out the near-top or top plant communities of the habitat in the adjacent area from the natural succession process of the degraded sandy land to the stable near-top or top community. In this embodiment, the long-term stable fixed dune area of ​​the Horqin Sandy Land is used as the source area for soil seed bank donation of this technology.

[0030] (2) Soil acquisition from the donated soil seed bank: The donated soil seed bank is to obtain the surface soil in the donated source area. In order to reduce the damage to the habitat of the donated source area, the strip and sheet soil sampling methods are adopted. The sampling belts are randomly set according to the spatial distribution of the plants. The original state of the surface soil is kept for soil sampling. The soil sampling depth is set to 5 cm, the width of the soil sampling belt is 20 cm, and the length of the soil sampling belt is set according to the actual situation on site. Each sampling belt is kept at a distance of more than 100 cm (see Figure 2 ), and after soil is taken, the surface of the borrowing area is covered with dead branches and leaves to promote the natural recovery of vegetation in the donation area.

[0031] 2. Donate soil seed bank soil matrix improvement

[0032] The surface soil (including the seed bank) obtained from the donation source area (fixed sand in this embodiment) is immediately transferred to the donation area (severely degraded sand in this embodiment) and placed in an open container. Then, according to the volume ratio of the donated soil, 5‰ of soil water retainer (Liaoning Boke Biotechnology Co., Ltd., Boke water retainer (for agriculture and forestry)), 3‰ of soil adhesive (Nanjing Saipu Polymer Materials Co., Ltd., FLOBOND A30), 3‰ of urea, and 1‰ of diammonium phosphate are added to the donated soil, and the mixture is fully mixed and stirred to form the donated soil seed bank material after the soil is improved (see Figure 3 ).

[0033] 3. Donated soil seed bank transplant laying

[0034] In the severely degraded sandy areas of the donated area, the surface debris of the donated area is first cleaned, and then the surface soil (seed bank) of the donated source area mixed with soil improvement elements is evenly spread on the surface of the donated area with a thickness of 5 cm. After spreading, spray irrigation is immediately carried out, and the irrigation amount is limited to the soil that is soaked to a depth of 5 cm (see Figure 4 ).

[0035] Comparative Example 1

[0036] Comparison of sampling methods for donated soil seed banks: Taking fixed sand dunes as the research object, different sampling depths and widths were set to compare and select the appropriate sampling depth and sampling bandwidth.

[0037] 1. Comparative selection of sampling depths in the donated soil seed source area: By setting four sampling depths, namely 0-3cm, 0-5cm, 0-10cm, and 0-15cm treatments, the integrity of the soil seed bank and the distribution density of the soil seed bank are considered, see Table 1. Based on the comparative analysis of the species structure (number of species) and seed density of the soil seed bank of each treatment, it is found that the soil in the 0-5cm treatment can contain all the soil seed bank species of this type, and at the same time, the seed density has basically reached the peak value of the soil seed bank of this type, so this 0-5 cm depth is selected as the appropriate sampling depth. In this mode, all soil seed bank species can be obtained, and the seed density also meets the requirements.

[0038] Table 1 Effect of soil seed bank sampling depth on seed bank characteristics in fixed dune areas

[0039] Sampling depth Number of species <![CDATA[Seed density (ind.m -2 )]]> 0-3cm 6 2284±869 0-5cm 9 2833±789 0-10cm 9 2853±733 0-15cm 9 2641±562

[0040] 2. Comparative selection of sampling band width in the donated soil seed source area: 4 sampling band widths are set, namely 20cm, 40cm, 60cm, and 80cm treatments, and their effects on the restoration of surface vegetation in the donated source area are compared, as shown in Table 2. According to the comparative analysis of the vegetation restoration effect (vegetation coverage, number of species) of each treatment after 1-3 years, it is found that with the increase of the sampling band width, the plant colonization speed decreases. Under the condition of 80cm bandwidth, a large surface exposure will be formed on the surface of the donated source area, and the vegetation colonization speed is the slowest. After the third year, only 15-25% of the vegetation coverage can be formed, which is easy to form wind erosion pits and cause the activation of surface sand; the 20cm bandwidth treatment has the lowest degree of damage to the surface of the donated source area, and an effective vegetation coverage can be formed 2-3 years after sampling. The vegetation colonization speed is the fastest, which effectively reduces the risk of surface wind and sand activation, and also takes into account the convenience and efficiency of sampling. Therefore, the source area soil sampling band width selected in the present invention is 20cm.

[0041] Table 2 Effect of soil seed bank sampling width on surface vegetation in the source area in fixed dune areas

[0042]

[0043] 3. Comparison and selection of the thickness of the donated soil seed bank in the donated area:

[0044] Four donation soil seed bank laying thicknesses of 0 cm, 2.5 cm, 5 cm and 7.5 cm were set respectively, and the effects of different laying thicknesses on plant seed germination and seedling growth and the soil utilization efficiency of the donation soil seed bank were compared, as shown in Table 3. The comparison found that the laying thickness of the donation soil seed bank significantly affected the number of seed germination and seedling biomass. The treatments with 2.5 cm, 5 cm and 7.5 cm donation soil seed banks had an average germination rate of 644 plants / m-2 、1142 strains·m -2 and 1172 strains·m -2 The results showed that the number of seeds germinated in the 5cm and 7.5cm donated soil seed bank was significantly higher than that in the 2.5cm donated soil seed bank (P<0.05). At the same time, the plant biomass was 117.26 g·m in the 2.5cm, 5cm and 7.5cm treatments, respectively. -2 、155.71g·m -2 、161.48g·m -2 The biomass of the 7.5cm and 5cm donated soil seed bank treatments was significantly higher than that of the 2.5cm treatment, and there was no significant difference between the 5cm and 7.5cm paving thickness treatments. Considering the restoration effect and implementation cost, the 5cm donated soil seed bank paving thickness can meet the needs of effectively restoring degraded dune vegetation and can effectively improve the utilization efficiency of the donated source soil seed bank soil.

[0045] In summary, the sampling depth of the soil seed bank in the donation source area affects the integrity and seed bank density of the obtained soil seed bank, the width of the sampling belt affects the subsequent restoration process of the surface of the donation source area, and the laying thickness of the donated soil seed bank in the donated area affects the vegetation restoration effect and the utilization rate of the donated soil. Specifically: the integrity and seed bank density of the soil seed bank are an influencing factor of the method of the present invention. For different sampling depth methods of the donation source area, the integrity of the soil seed bank and the number of seeds contained are compared and analyzed. The results show that under the sampling depth of 0-5cm, the samples taken can fully contain the soil seed bank in the donation area, and there is no significant difference with the sampling depths of 0-10cm and 0-15cm, which can meet the needs of the donated soil seed bank. At the same time, considering the distribution density of the soil seed bank, the density of the soil seed bank in the 0-5cm treatment basically reaches the peak value, ensuring the quantity requirements of the soil seed bank.

[0046] The impact on the vegetation environment after obtaining the donated soil in the donation source area is an important factor in the method of the present invention, so as to prevent the degradation of vegetation in the donation source area or the harm of wind and sand activities after obtaining the soil seed bank; the method of 20cm sampling bandwidth adopted by the present invention, compared with the method of 40-80cm sampling bandwidth, can quickly restore the surface vegetation coverage after sampling and prevent wind and sand activation, while the method of too wide sampling band can easily cause the formation of surface wind erosion pits and wind and sand activation, causing vegetation degradation in the donation source area.

[0047] The laying thickness of the transplanted soil seed bank in the donated area affects the vegetation restoration effect and the utilization efficiency of the donated soil seed bank. By comparing different laying thickness methods, it was found that the 2.5 cm laying thickness reduced the number of seed germination and vegetation biomass of the transplanted soil seed bank, while the 5 cm and 7.5 cm laying thickness treatments were significantly higher than the 2.5 cm treatment in terms of seed germination number and plant biomass, and there was no significant difference between the two. Considering the utilization efficiency of donated soil and reducing the construction earthwork volume, the 5 cm laying thickness has the best restoration effect.

[0048] Through the above comparative analysis, the specific method of the present invention can comprehensively and effectively achieve the goal of vegetation restoration in degraded sandy land.

[0049] Effect of donated soil seed bank on vegetation restoration on degraded sandy land

[0050] The donated soil seed vegetation restoration method of Example 1 can achieve rapid restoration of degraded sandy land vegetation. In the second year after implementation, the vegetation coverage increased from the original 10% to 25%, and in the third year, the vegetation coverage reached 40-50%. The structure and quantity of plant species also reached the level of the donated source area (fixed sandy land), basically achieving effective control of wind and sand hazards, directly transforming from severely degraded sandy land to the fixed sandy land stage, and realizing the leapfrog restoration of degraded sandy land vegetation succession. It is an efficient degraded sandy land vegetation restoration technology.

Claims

1. A method for restoring vegetation on degraded sandy land based on a donated soil seed bank, characterized in that: It includes the acquisition of donated soil seed bank, the improvement of soil matrix of donated soil seed bank and the transplantation and laying of donated soil seed bank.

2. The method for restoring vegetation in degraded sandy land based on a donated soil seed bank according to claim 1, characterized in that: The method for obtaining a donated soil seed bank includes selecting a donation source area and obtaining soil for the donated soil seed bank, wherein the selection of the donation source area is based on the vegetation succession sequence of the donated area, and the near-top or top vegetation community of the vegetation succession in the habitat is used as the donation source area; the soil for the donated soil seed bank is obtained by obtaining the surface soil in the donation source area as the soil for the transplanted soil seed bank.

3. The method for restoring vegetation in degraded sandy land based on a donated soil seed bank according to claim 1, characterized in that: The method for improving the soil matrix of the donated soil seed bank is as follows: add 5‰ soil water retaining agent, 3‰ soil adhesive, 3‰ urea and 1‰ diammonium phosphate to the surface soil obtained from the donated soil seed bank, and fully mix the above-mentioned added ingredients with the surface soil obtained from the donated source area.

4. The method for restoring vegetation in degraded sandy land based on a donated soil seed bank according to claim 1, characterized in that: The method for laying the donated soil seed bank is as follows: after clearing the surface debris in the donated area, the donated soil seed bank soil with improved matrix is ​​immediately and evenly laid on the surface of the donated area, and spray irrigation is immediately carried out after laying, thereby achieving the restoration of degraded sand vegetation.

5. The method for restoring vegetation in degraded sandy land based on a donated soil seed bank according to claim 2, characterized in that: The method of obtaining soil for the donated soil seed bank is as follows: (1) Select the near-top or top communities of the vegetation succession sequence in the recipient area as the donation source area; (2) Keep the surface soil of the donation area in its original state for sampling; (3) The sampling depth of surface soil in the donation source area is 5 cm; (4) Strip or sheet sampling is adopted in the donation source area, with a strip width of 20 cm and a spacing of more than 100 cm between each sampling strip; (5) After sampling from the donor source area, the sampling zone is covered and protected.

6. The method for restoring vegetation in degraded sandy land based on a donated soil seed bank according to claim 4, characterized in that: The method of laying the donated soil seed bank is: (1) The donated soil seed bank soil after matrix improvement is immediately and evenly spread on the surface of the donated area with a thickness of 5 cm; (2) Spray irrigation shall be carried out immediately after the donated soil is laid in the recipient area, and the irrigation amount shall be such that the soil infiltration depth is 5 cm.

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