Method for ecological restoration of saline-alkali land in lake shrinkage area

Abstract

The application discloses a kind of lake atrophy area saline-alkali soil vegetation ecological restoration method, comprising the following steps: S1, repair area division: S1-1, sampling point layout;S1-2, sample collection detection;S1-3, detection result analysis;S2, near lake bare area repair;S3, suedia canariensis repair area repair;S4, wetland repair area repair.The application carries out detailed block division to lake atrophy area, so that more targeted repair policy is made, the block that meets the requirement of fertility is cultivated and reformed, and other blocks are respectively subjected to ecological restoration by corresponding method, the ecological utilization of lake atrophy area is improved, and the ecological management of lake atrophy area has certain guiding significance and economic value.

Description

Technical Field

[0001] This invention relates to the field of lake management technology, specifically to a method for ecological restoration of vegetation in saline-alkali land in lake shrinkage areas. Background Technology

[0002] Saline-alkali land resulting from the shrinking of lakes in arid regions represents a new type of challenging site, urgently requiring forest and grassland vegetation restoration and adaptive management to mitigate climate change risks. Research indicates that vegetation restoration, as a key measure to enhance the resilience of ecosystems in lake-shrinking areas, plays a crucial role in maintaining habitats, conserving soil, and protecting water quality. On the one hand, different vegetation restoration measures can influence the soil organic carbon pool, physicochemical properties, microbial community composition, and carbon and nitrogen cycles around lakes; on the other hand, changes in soil pH and nutrient content have a positive feedback effect on the vegetation restoration process. Therefore, vegetation restoration and soil conservation are mutually reinforcing processes, playing a vital role in maintaining the stability of lake ecological functions. Different vegetation restoration models can promote changes in soil bacterial and fungal communities, thereby significantly accelerating soil nutrient transformation processes; reports also indicate that vegetation restoration can induce succession in soil crust and surface microbial communities, triggering changes in soil microbial community functions and physicochemical properties.

[0003] Currently, comprehensive management of lake shrinkage areas is inadequate. Generally, it involves planting large amounts of vegetation along the lake shore, but this not only fails to alleviate the continued shrinkage of the lakes but also fails to make good use of the shrunken areas. Therefore, a scientific and rational comprehensive management method is needed to improve the ecological protection of lake shrinkage areas. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for ecological restoration of vegetation in saline-alkali land in lake shrinkage areas.

[0005] The technical solution of this invention is:

[0006] A method for ecological restoration of vegetation in saline-alkali land in lake shrinkage areas includes the following steps:

[0007] S1. Repair Area Division:

[0008] S1-1. Sampling point layout: Several sampling point strips are laid out in a direction perpendicular to the lake shoreline of the lake shrinkage area. Several sampling points are laid out at equal intervals on each sampling point strip for soil collection.

[0009] S1-2, Sample collection and testing: pH value and soil fertility of soil samples collected from sampling points are tested;

[0010] S1-3. Analysis of test results: Since the soil alkalinity increases gradually outward from the lake shrinkage area, the pH value of each sampling point on a sampling strip is summarized and divided into three equal parts from low to high to obtain two threshold points. The first threshold point is closer to the lake shoreline, and the second threshold point is farther away from the lake shoreline. The lake shrinkage area enclosed by the first threshold points on each sampling strip is called the near-lake bare area. The lake shrinkage area enclosed by the second threshold points on each sampling strip is called the Suaeda salsa remediation area. The lake shrinkage area enclosed by the outermost sampling point on each sampling strip is called the wetland remediation area.

[0011] S2, Restoration of bare areas near the lake:

[0012] S2-1, Block Division: The near-lake bare area is divided into several first sub-blocks according to the sampling point strips;

[0013] S2-2, Fertility assessment: If more than half of the sampling points in the first sub-block have soil fertility that meets the national soil fertility standard level 1 of the national soil survey, then the soil fertility of the first sub-block is considered to be up to standard and can be used as arable land after leveling and weeding.

[0014] S2-3, Ecological Restoration: If the fertility of the first sub-block does not meet the standard, the vegetation coverage of the first sub-block will be optimized. The vegetation coverage of the first sub-block will be calculated. If the vegetation coverage is >30%, some vegetation will be removed to ensure that the vegetation coverage is ≤30%. If the vegetation coverage is ≤20%, aquatic plants will be planted in the first sub-block to ensure that 20% < vegetation coverage ≤30%.

[0015] S3, Repair of the Suaeda salsa restoration area:

[0016] S3-1, Block Division: Divide the sampling point strips in the Suaeda salsa remediation area into several second sub-blocks;

[0017] S3-2. Fertility assessment: If more than half of the sampling points in the second sub-block have soil fertility that meets the national soil fertility standard level 2 of the national soil survey, then the second sub-block is considered to have met the fertility standard and can be used as arable land after leveling and weeding.

[0018] S3-3, Ecological Restoration: If the fertility of the second sub-block does not meet the standard, the vegetation coverage of the second sub-block will be optimized. The vegetation coverage of the second sub-block will be calculated. If the vegetation coverage is >50%, the vegetation in the second sub-block will be allowed to grow naturally. If the vegetation coverage is ≤40%, Suaeda salsa will be planted in the second sub-block to ensure that 40% < vegetation coverage.

[0019] S4. Wetland restoration area restoration:

[0020] S4-1, Block Division: Divide the sampling point strips in the wetland restoration area into several third sub-blocks;

[0021] S4-2. Fertility assessment: If more than half of the sampling points in the third sub-block have soil fertility that meets the national soil fertility standard level 3 of the national soil survey, then the soil fertility of the third sub-block is considered to be up to standard and can be used as arable land after leveling and weeding.

[0022] S4-3. Ecological Restoration: If the fertility of the third sub-block does not meet the standard, the vegetation coverage of the third sub-block will be optimized. The vegetation coverage of the third sub-block will be calculated. If the vegetation coverage is >70%, the vegetation in the third sub-block will be allowed to grow naturally. If the vegetation coverage is ≤60%, aquatic plants will be planted in the third sub-block to ensure that 60% < vegetation coverage.

[0023] Furthermore, in S1, there are 5 to 20 sampling point strips, each sampling point strip has 9 to 30 sampling points, the spacing between sampling point strips is 50 to 5000 m, the spacing between sampling points is 10 to 100 m, and the soil sampling depth is 5 to 20 cm.

[0024] Note: By setting up sampling points, we can understand the degree and trend of salinization in the entire shrinking area of ​​the lake, thus providing a theoretical basis for the subsequent formulation of relevant measures.

[0025] Furthermore, the aquatic plants in S2-3 and S4-3 include reeds, rushes, cattails, tamarisk, sparganiums, and water onions.

[0026] Note: Planting aquatic plants can protect biodiversity in shrinking lake areas.

[0027] Furthermore, in S2-2, the soil fertility levels are classified as follows:

[0028] Soil fertility testing includes five indicators: organic matter, total nitrogen, total phosphorus, available phosphorus, and total potassium. The standards for these five indicators to reach Level 1 of the national soil fertility standard are as follows: organic matter > 40 g / kg, total nitrogen > 2 g / kg, total phosphorus > 1 g / kg, available phosphorus > 40 g / kg, and total potassium > 25 g / kg. In step S2-2, if any two indicators at a sampling point reach Level 1, the soil fertility at that sampling point can be considered to have reached Level 1 of the national soil fertility standard.

[0029] Note: For bare areas near lakes, a higher fertility level is required to make them arable land due to their proximity to the lake. The purpose of selecting two fertility indicators is to select suitable crops for planting based on the fertility level corresponding to the indicators.

[0030] Furthermore, in S3-2, the soil fertility levels are classified as follows:

[0031] Soil fertility testing includes five indicators: organic matter, total nitrogen, total phosphorus, available phosphorus, and total potassium. The standards for these five indicators to reach Level 2 of the national soil fertility standard are as follows: 30g / kg < organic matter ≤ 40g / kg, 1.5g / kg < total nitrogen ≤ 2g / kg, 0.8g / kg < total phosphorus ≤ 1g / kg, 20g / kg < available phosphorus ≤ 40g / kg, and 20g / kg < total potassium ≤ 25g / kg. In step S3-2, if any three indicators at a sampling point reach Level 2, the soil fertility at that sampling point can be considered to have reached Level 2 of the national soil fertility standard.

[0032] Note: For the Suaeda salsa restoration area, the main focus is on planting Suaeda salsa, supplemented by other crops. Therefore, the required number of fertility indicators is greater than that for the bare areas near the lake.

[0033] Furthermore, in S4-2, the soil fertility levels are classified as follows:

[0034] Soil fertility testing includes five indicators: organic matter, total nitrogen, total phosphorus, available phosphorus, and total potassium. The standards for these five indicators to reach Level 3 of the national soil fertility standard are as follows: 20g / kg < organic matter ≤ 30g / kg, 1g / kg < total nitrogen ≤ 1.5g / kg, 0.6g / kg < total phosphorus ≤ 0.8g / kg, 10g / kg < available phosphorus ≤ 20g / kg, and 15g / kg < total potassium ≤ 20g / kg. In step S4-2, if any four indicators at a sampling point reach Level 3, the soil fertility at that sampling point can be considered to have reached Level 3 of the national soil fertility standard.

[0035] Note: In wetland restoration areas, which are far from lakes, more arable land can be developed, but the salinity is higher. The requirements for fertility indicators can be appropriately reduced, but more areas that meet the required fertility indicators should be selected to keep the fertility of each block as similar as possible, so that the same crop can be planted, which is convenient for management.

[0036] Furthermore, in steps S2-2, S3-2, and S4-2, after leveling and weeding, it is necessary to apply a tillage enzyme to the soil. The preparation method of the tillage enzyme is as follows:

[0037] Mix fruits, aquatic plant stems and leaves and water in a weight ratio of 1:2~3:10~15, place them in a sealed container and ferment for 90~100 days, and take the upper liquid to obtain the enzyme for arable land.

[0038] Among them, the fruits are one or more of the following: sea buckthorn, crabapple, apple pear, blueberry, plum, apricot, crisp jujube, and cantaloupe; the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3.

[0039] In S2-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the first sub-block at 50-60%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:50 and added to the soil to increase the soil moisture content by 1-3%. This process is repeated every 5-7 days, increasing the soil moisture content by 0.2-0.4% each time, for a total of 5 times.

[0040] In S3-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the second sub-block at 45-55%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:80 and added to the soil to increase the soil moisture content by 2-4%. This is then applied every 5-7 days, increasing the soil moisture content by 0.5-1% each time, for a total of 5 applications.

[0041] In S3-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the third sub-block at 40-50%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:100 and added to the soil to increase the soil moisture content by 3-5%. This process is repeated every 5-7 days, increasing the soil moisture content by 0.6-1.2% each time, for a total of 5 times.

[0042] Note: Different ratios of enzymes for arable land are used for different regions. This is because the further away from the lake, the higher the salinity, and the greater the amount of enzymes required for arable land. At the same time, the initial water content of bare areas near the lake is high, so the amount applied each time should not be too high. The initial water content of wetland restoration areas is not high, and the area is relatively large, so the amount applied each time can be appropriately increased.

[0043] Furthermore, in S3-3 and S4-3, a soil conditioner is applied to the soil before planting vegetation, and the method for preparing the soil conditioner is as follows:

[0044] The enzyme residue, aquatic plant stems and leaves, and clay minerals are mixed in a weight ratio of 1:4~6:7~9, crushed, dried, and then passed through a 30-mesh sieve.

[0045] The enzyme residue is the lower layer residue produced during the preparation of the enzyme for arable land, the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3, and the clay minerals are kaolinite, montmorillonite, illite or sepiolite.

[0046] The application rate of the soil conditioner is 20-25 kg / mu.

[0047] Note: Soil conditioners can effectively improve the soil environment, which is beneficial to the activities of soil microorganisms and other organisms. Clay minerals can also reduce the content of heavy metals in the soil.

[0048] Furthermore, in S3-3, Suaeda salsa is harvested every 3 to 6 months.

[0049] Note: Harvesting the salt-containing alkali grass can prevent the high-salt alkali grass residue from causing salt accumulation in the lake area.

[0050] The beneficial effects of this invention are:

[0051] (1) The present invention provides a method for ecological restoration of saline-alkali land vegetation in a lake shrinkage area. By dividing the lake shrinkage area into detailed blocks, a more targeted restoration policy can be formulated. For blocks that meet the fertility requirements, farmland can be transformed, and for other blocks, corresponding methods can be used for ecological restoration. This improves the ecological utilization of the lake shrinkage area, realizes the principle of adapting to local conditions, and has certain guiding significance and economic value for the ecological management of the lake shrinkage area.

[0052] (2) The present invention provides a method for ecological restoration of saline-alkali land vegetation in a lake shrinkage area. It controls the vegetation coverage rate in each of the divided areas to avoid further loss of water resources and further shrinkage of the slope. In particular, the bare areas near the lake need to be controlled at a low vegetation coverage rate to avoid putting too much pressure on the water resources in the lake. Areas far from the lake can choose a higher vegetation coverage rate because these areas can generally utilize more abundant groundwater and surface water resources. Increasing the vegetation coverage rate is conducive to improving the species diversity of the area.

[0053] (3) The present invention provides a method for ecological restoration of vegetation in saline-alkali land in a lake shrinkage area. The use of arable land enzymes can help the soil that is about to be used as arable land to further restore and improve it, alleviate salinization, increase organic matter content, and have a certain antibacterial effect. At the same time, some of the enzyme residues used to prepare arable land enzymes can be used as one of the raw materials for soil conditioners. The materials are easy to obtain and can maximize the soil restoration effect in wetland restoration areas. In the end, the purpose of simultaneously promoting restoration in three areas—near lake bare areas, Suaeda salsa restoration areas, and wetland restoration areas—is achieved. Attached Figure Description

[0054] Figure 1 This invention provides a method for ecological restoration of saline-alkali land vegetation in lake shrinkage areas. (Diagram showing the delineation of lake shrinkage areas.)

[0055] Figure 2 This is the correlation coefficient between vegetation restoration effectiveness and soil pH, nutrients, and particle size composition in an experimental example of a method for ecological restoration of saline-alkali land in a lake shrinkage area according to the present invention.

[0056] Figure 3 This is a schematic diagram of the alkali-covered shoal restoration area and the wetland restoration area in an experimental example of a method for ecological restoration of saline-alkali land vegetation in a lake shrinkage area according to the present invention;

[0057] Figure 4 This is a schematic diagram of the alkaline shed restoration area and the near-lake bare area in an experimental example of a method for ecological restoration of saline-alkali land vegetation in a lake shrinkage area according to the present invention.

[0058] Among them, 1-near-lake bare area, 2-alkali tarpaulin restoration area, 3-wetland restoration area. Detailed Implementation

[0059] Example 1

[0060] A method for ecological restoration of vegetation in saline-alkali land in lake shrinkage areas includes the following steps:

[0061] S1. Repair Area Division:

[0062] S1-1, Sampling point layout: such as Figure 1 As shown, five sampling strips were laid out perpendicular to the shoreline of the lake in the shrinking lake area. Fifteen sampling points were evenly spaced on each sampling strip for soil collection. The spacing between the sampling strips was 2000m, the spacing between the sampling points was 60m, and the soil collection depth was 10cm.

[0063] S1-2, Sample collection and testing: pH value and soil fertility of soil samples collected from sampling points are tested;

[0064] S1-3. Analysis of Detection Results: Because the soil alkalinity increases gradually with pH values ​​from the perpendicular to the lake shrinkage area outwards, the pH values ​​of all sampling points on a single sampling strip were summarized and divided into three equal parts from low to high, resulting in two threshold points. The first threshold point is closer to the lake shoreline, and the second threshold point is farther from the lake shoreline. Connecting the first threshold points on each sampling strip sequentially forms the lake shrinkage area, designated as near-lake bare area 1. Connecting the second threshold points on each sampling strip sequentially forms the lake shrinkage area, designated as Suaeda salsa remediation area 2. Connecting the outermost sampling point on each sampling strip sequentially forms the lake shrinkage area, designated as wetland remediation area 3. Figure 1 As shown;

[0065] S2, Restoration of bare areas near the lake:

[0066] S2-1, Block Division: The near-lake bare area 1 is divided into several first sub-blocks according to the sampling point strips;

[0067] S2-2, Fertility assessment: If more than half of the sampling points in the first sub-block have soil fertility that meets the national soil fertility standard level 1 of the national soil survey, then the soil fertility of the first sub-block is considered to be up to standard and can be used as arable land after leveling and weeding.

[0068] Soil fertility levels are classified as follows:

[0069] Soil fertility testing includes five indicators: organic matter, total nitrogen, total phosphorus, available phosphorus, and total potassium. The standards for these five indicators to reach Level 1 of the national soil fertility standard are as follows: organic matter > 40 g / kg, total nitrogen > 2 g / kg, total phosphorus > 1 g / kg, available phosphorus > 40 g / kg, and total potassium > 25 g / kg. In step S2-2, if any two indicators at a sampling point reach Level 1, the soil fertility at that sampling point can be considered to have reached Level 1 of the national soil fertility standard.

[0070] S2-3, Ecological Restoration: If the fertility of the first sub-block does not meet the standard, the vegetation coverage of the first sub-block will be optimized. The vegetation coverage of the first sub-block will be calculated. If the vegetation coverage is >30%, some vegetation will be removed to ensure that the vegetation coverage is 30%. If the vegetation coverage is ≤20%, aquatic plants such as reeds, rushes, cattails, and tamarisk will be planted in the first sub-block to ensure that the vegetation coverage is 24%.

[0071] S3, Suaeda salsa restoration area 2 restoration:

[0072] S3-1, Block division: Divide the sampling point strip of the Suaeda salsa restoration area 2 into several second sub-blocks;

[0073] S3-2. Fertility assessment: If more than half of the sampling points in the second sub-block have soil fertility that meets the national soil fertility standard level 2 of the national soil survey, then the second sub-block is considered to have met the fertility standard and can be used as arable land after leveling and weeding.

[0074] Soil fertility levels are classified as follows:

[0075] Soil fertility testing includes five indicators: organic matter, total nitrogen, total phosphorus, available phosphorus, and total potassium. The standards for these five indicators to reach Level 2 of the national soil fertility standard are as follows: 30g / kg < organic matter ≤ 40g / kg, 1.5g / kg < total nitrogen ≤ 2g / kg, 0.8g / kg < total phosphorus ≤ 1g / kg, 20g / kg < available phosphorus ≤ 40g / kg, and 20g / kg < total potassium ≤ 25g / kg. In step S3-2, if any three indicators at a sampling point reach Level 2, the soil fertility at that sampling point can be considered to have reached Level 2 of the national soil fertility standard.

[0076] S3-3, Ecological Restoration: If the fertility of the second sub-block does not meet the standard, the vegetation coverage of the second sub-block will be optimized. The vegetation coverage of the second sub-block will be calculated. If the vegetation coverage is >50%, the vegetation in the second sub-block will be allowed to grow naturally. If the vegetation coverage is ≤40%, Suaeda salsa will be planted in the second sub-block to ensure that the vegetation coverage reaches 45%. Suaeda salsa will be harvested every 3 months.

[0077] S4, Wetland Restoration Zone 3 Restoration:

[0078] S4-1, Block division: Divide the three sampling point strips in the wetland restoration area into several third sub-blocks;

[0079] S4-2. Fertility assessment: If more than half of the sampling points in the third sub-block have soil fertility that meets the national soil fertility standard level 3 of the national soil survey, then the soil fertility of the third sub-block is considered to be up to standard and can be used as arable land after leveling and weeding.

[0080] Soil fertility levels are classified as follows:

[0081] Soil fertility testing includes five indicators: organic matter, total nitrogen, total phosphorus, available phosphorus, and total potassium. The standards for these five indicators to reach level 3 of the national soil fertility standard are as follows: 20g / kg < organic matter ≤ 30g / kg, 1g / kg < total nitrogen ≤ 1.5g / kg, 0.6g / kg < total phosphorus ≤ 0.8g / kg, 10g / kg < available phosphorus ≤ 20g / kg, and 15g / kg < total potassium ≤ 20g / kg. In step S4-2, if any four indicators at a sampling point reach level 3, the soil fertility at that sampling point can be considered to have reached level 3 of the national soil fertility standard.

[0082] S4-3, Ecological Restoration: If the fertility of the third sub-block does not meet the standard, the vegetation coverage of the third sub-block will be optimized. The vegetation coverage of the third sub-block will be calculated. If the vegetation coverage is >70%, the vegetation in the third sub-block will be allowed to grow naturally. If the vegetation coverage is ≤60%, aquatic plants such as reeds, rushes, cattails, and tamarisk will be planted in the third sub-block to ensure that the vegetation coverage reaches 65%.

[0083] In S2-2, S3-2, and S4-2, after leveling and weeding, it is necessary to apply tillage enzymes to the soil. The preparation method of tillage enzymes is as follows:

[0084] Mix fruits, aquatic plant stems and leaves and water in a weight ratio of 1:2.5:13, place them in a sealed container and ferment for 95 days. Take the upper liquid to obtain the enzyme for arable land.

[0085] Among them, the fruits are sea buckthorn and sand pear, and the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3;

[0086] In S2-2, after leveling and weeding, water is first added to the soil to keep the soil moisture content in the first sub-block at 55%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:50 and added to the soil to increase the soil moisture content by 2%. This is then applied every 6 days, increasing the soil moisture content by 0.3% each time, for a total of 5 times.

[0087] In S3-2, after leveling and weeding, water is first added to the soil to keep the soil moisture content in the second sub-block at 50%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:80 and added to the soil to increase the soil moisture content by 3%. This is then applied every 6 days, increasing the soil moisture content by 0.7% each time, for a total of 5 times.

[0088] In S3-2, after leveling and weeding, water is first added to the soil to keep the soil moisture content in the third sub-block at 45%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:100 and added to the soil to increase the soil moisture content by 4%. This is then applied every 6 days, increasing the soil moisture content by 1% each time, for a total of 5 times.

[0089] In S3-3 and S4-3, a soil conditioner is applied to the soil before planting vegetation. The preparation method of the soil conditioner is as follows:

[0090] The enzyme residue, aquatic plant stems and leaves, and clay minerals are mixed in a weight ratio of 1:5:8, crushed, dried, and then passed through a 30-mesh sieve.

[0091] The enzyme residue is the lower layer residue produced during the preparation of enzymes for arable land; the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3; and the clay minerals are kaolinite and sepiolite.

[0092] The application rate of soil conditioner is 23 kg / mu.

[0093] Example 2

[0094] The difference between this embodiment and Embodiment 1 is that:

[0095] In S1-1, 10 sampling point strips were laid out in a direction perpendicular to the shoreline of the lake in the shrinking lake area. Nine sampling points were evenly spaced on each sampling point strip for soil collection. The spacing between the sampling point strips was 5000m, the spacing between the sampling points was 100m, and the soil collection depth was 20cm.

[0096] Example 3

[0097] The difference between this embodiment and Embodiment 1 is that:

[0098] In S1-1, 20 sampling point strips were laid out in a direction perpendicular to the shoreline of the lake in the shrinking lake area. 30 sampling points were evenly spaced on each sampling point strip for soil collection. The spacing between the sampling point strips was 50m, the spacing between sampling points was 10m, and the soil collection depth was 5cm.

[0099] Note: Appropriate parameters should be selected based on the size of the shrunken area of ​​the lake to be restored.

[0100] Example 4

[0101] The difference between this embodiment and Embodiment 1 is that:

[0102] In S2-3, if the vegetation coverage rate is ≤20%, the first sub-block will be planted with aquatic plants such as reeds, purslane, and water onions to ensure a vegetation coverage rate of 30%.

[0103] Example 5

[0104] The difference between this embodiment and Embodiment 1 is that:

[0105] In S3-3, if the vegetation coverage is ≤40%, then Suaeda salsa is planted in the second sub-block to ensure that the vegetation coverage reaches 50%. Suaeda salsa is harvested every 6 months.

[0106] Example 6

[0107] The difference between this embodiment and Embodiment 1 is that:

[0108] In S4-3, if the vegetation coverage is ≤60%, then aquatic plants such as reeds, purslane, and water onions will be planted in the third sub-block to ensure that the vegetation coverage reaches 70%.

[0109] Example 7

[0110] The difference between this embodiment and Embodiment 1 is that:

[0111] In S2-2, S3-2, and S4-2, after leveling and weeding, it is necessary to apply tillage enzymes to the soil. The preparation method of tillage enzymes is as follows:

[0112] Mix fruits, aquatic plant stems and leaves and water in a weight ratio of 1:2:10, place them in a sealed container and ferment for 90 days, and take the upper liquid to obtain the enzyme for arable land.

[0113] Among them, the fruits are apples, pears and blueberries, and the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3;

[0114] In S2-2, after leveling and weeding, water is first added to the soil to keep the soil moisture content in the first sub-block at 60%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:50 and added to the soil to increase the soil moisture content by 1%. This is then applied every 5 days, increasing the soil moisture content by 0.2% each time, for a total of 5 times.

[0115] In S3-2, after leveling and weeding, water is first added to the soil to keep the soil moisture content in the second sub-block at 55%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:80 and added to the soil to increase the soil moisture content by 2%. This is then applied every 5 days, increasing the soil moisture content by 0.5% each time, for a total of 5 times.

[0116] In S3-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the third sub-block at 50%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:100 and added to the soil to increase the soil moisture content by 3%. This is then applied every 5 days, increasing the soil moisture content by 0.6% each time, for a total of 5 times.

[0117] Example 8

[0118] The difference between this embodiment and Embodiment 1 is that:

[0119] In S2-2, S3-2, and S4-2, after leveling and weeding, it is necessary to apply tillage enzymes to the soil. The preparation method of tillage enzymes is as follows:

[0120] Mix fruits, aquatic plant stems and leaves and water in a weight ratio of 1:3:15, place them in a sealed container and ferment for 100 days. Take the upper liquid to obtain the enzyme for tillage.

[0121] Among them, the fruits are plums, apricots, crisp dates and cantaloupes, and the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3;

[0122] In S2-2, after leveling and weeding, water is first added to the soil to keep the soil moisture content in the first sub-block at 50%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:50 and added to the soil to increase the soil moisture content by 3%. This is then applied every 7 days, increasing the soil moisture content by 0.4% each time, for a total of 5 times.

[0123] In S3-2, after leveling and weeding, water is first added to the soil to keep the soil moisture content in the second sub-block at 45%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:80 and added to the soil to increase the soil moisture content by 4%. This is then applied every 7 days, increasing the soil moisture content by 1% each time, for a total of 5 times.

[0124] In S3-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the third sub-block at 40%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:100 and added to the soil to increase the soil moisture content by 5%. This is then applied every 7 days, increasing the soil moisture content by 1.2% each time, for a total of 5 times.

[0125] Note: If the initial moisture content of the plot is relatively high, avoid further increasing the moisture content when adding the soil-cultivating enzyme, and appropriately shorten the addition interval. If the initial moisture content of the plot is relatively low, the moisture content can be further increased when adding the soil-cultivating enzyme, and the addition interval can be appropriately extended.

[0126] Example 9

[0127] The difference between this embodiment and Embodiment 1 is that:

[0128] In S3-3 and S4-3, a soil conditioner is applied to the soil before planting vegetation. The preparation method of the soil conditioner is as follows:

[0129] The enzyme residue, aquatic plant stems and leaves, and clay minerals are mixed in a weight ratio of 1:4:7, crushed, dried, and then passed through a 30-mesh sieve.

[0130] The enzyme residue is the lower layer residue produced during the preparation of enzymes for arable land, the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3, and the clay mineral is montmorillonite.

[0131] The application rate of soil conditioner is 20 kg / mu.

[0132] Example 10

[0133] The difference between this embodiment and Embodiment 1 is that:

[0134] In S3-3 and S4-3, a soil conditioner is applied to the soil before planting vegetation. The preparation method of the soil conditioner is as follows:

[0135] The enzyme residue, aquatic plant stems and leaves, and clay minerals are mixed in a weight ratio of 1:6:9, crushed, dried, and then passed through a 30-mesh sieve.

[0136] The enzyme residue is the lower layer residue produced during the preparation of enzymes for arable land, the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3, and the clay mineral is illite.

[0137] The application rate of soil conditioner is 25 kg / mu.

[0138] Experimental Example

[0139] Below, we will conduct a field experiment using a real-world example to demonstrate the method in Embodiment 1 of this invention. The site was selected in the shrinking area of ​​Dalinor Lake. Sampling points were set up and samples were collected according to the method in S1. Based on the pH value of the sampling points, the area was divided into a near-lake bare area, a Suaeda salsa restoration area, and a wetland restoration area. Partial point information for each area is shown in the table below:

[0140] Table 1. Basic Information on Different Ecological Restoration Zones

[0141]

[0142] We then calculated the average soil pH and soil nutrient content of the three ecological restoration areas, as shown in the table below:

[0143] Table 2. Average soil pH and soil nutrient content in different ecological restoration zones

[0144]

[0145] Subsequently, we assessed the fertility of each point in each ecological restoration area according to the fertility assessment methods in S2-2, S3-2 and S4-2, and found that: one block in the near-lake bare area 1 meets the requirements for arable land, two blocks in the Suaeda salsa restoration area 2 meet the requirements for arable land, and one block in the wetland restoration area 3 meets the requirements for arable land.

[0146] The soil pH value in the lake shrinkage area is 10.30~10.68, which is strongly alkaline and is a severely saline-alkali land. The soil pH value of each type of sample plot shows the following trend: wetland restoration area > Suaeda salsa restoration area > near lake bare land, showing a trend of increasing with altitude as the distance from the lake shoreline increases.

[0147] We then carried out ecological restoration in the corresponding areas according to the restoration methods in S2-3, S3-3, and S4-3. The growth height of vegetation in each restored area was statistically analyzed, and the results are shown in the table below:

[0148] Table 3. Vegetation growth status in different ecological restoration plots

[0149]

[0150] Soil pH in the shrinking area of ​​Dalinor Lake showed a positive correlation with total carbon content, total nitrogen content, organic matter content, and silt content, with correlation coefficients (R) ranging from 0.26 to 0.47; and a negative correlation with sand content and vegetation cover, with R values ​​of -0.26 for both. Figure 2As shown, vegetation cover was positively correlated with soil organic matter content, total carbon content, total nitrogen content, and sand content, with R values ​​ranging from 0.22 to 0.63. Soil organic matter and total carbon content had a significant impact on vegetation cover. It was negatively correlated with soil total sulfur content, total phosphorus content, pH value, and silt content, with correlation coefficients ranging from -0.21 to -0.53. Average plant height was positively correlated with soil total carbon, total nitrogen, organic matter, pH value, and sand content, with R values ​​ranging from 0.11 to 0.66. Overall, the main influencing factors were similar to those of vegetation cover.

[0151] In the Dalinor watershed, rising temperatures and increased vegetation cover are believed to have contributed to lake shrinkage, and the decrease in annual precipitation is consistent with this shrinkage trend. Related studies indicate that the groundwater runoff in Dalinor Lake is far greater than its surface runoff, and land surface evapotranspiration is a key process connecting vegetation and groundwater. Evapotranspiration intensity increases with increasing vegetation cover. After implementing relevant ecological restoration measures, remote sensing monitoring shows that while vegetation cover has increased, the lake shrinkage trend has slowed, and groundwater recharge has also improved. The ecological protection and restoration efforts have yielded significant results, demonstrating the effectiveness of the method described in this invention.

[0152] Meanwhile, for the areas that were converted into arable land, taking the bare area near the lake 1 as an example, after about one month of application of arable land enzymes for improvement, the soil pH dropped from 10.3 to 7.76, and the soil salinization was significantly improved. The arable land enzymes contain a large amount of organic acids after fermentation and also exhibit strong acidic properties. After being applied to the soil, they can react with the alkaline components in the soil and effectively reduce the soil pH. In addition, the fruits selected for the arable land enzymes, such as sea buckthorn and sand pear, are common fruits near the location of Dalinor Lake.

[0153] For soils that have undergone soil amendment remediation, taking wetland remediation area 3 as an example, the average plant height increased by 0.09m compared with soil plots that have not undergone soil amendment remediation. This indicates that the nutrients can effectively improve the soil environment, reduce the availability of heavy metals, increase the diversity of organisms and microorganisms in the soil, and promote plant growth.

[0154] like Figure 3 and 4 As shown, the regional division of the entire lake shrinkage area after restoration is very obvious. The vegetation coverage rate of wetland restoration area 3 behind Suaeda salsa restoration area 2 meets the requirements. The bare area near the lake in front of Suaeda salsa restoration area 2, which is close to the lake, has also been designated for vegetation coverage or improved into arable land.

Claims

1. A method for ecological restoration of vegetation in saline-alkali land in lake shrinkage areas, characterized in that, Includes the following steps: S1. Repair Area Division: S1-1. Sampling point layout: Several sampling point strips are laid out in a direction perpendicular to the lake shoreline of the lake shrinkage area. Several sampling points are laid out at equal intervals on each sampling point strip for soil collection. S1-2, Sample collection and testing: pH value and soil fertility of soil samples collected from sampling points are tested; S1-3, Analysis of test results: Since the soil alkalinity increases gradually from the direction perpendicular to the lake shrinkage area outwards, the pH value of each sampling point on a sampling point strip is summarized and divided into three equal parts from low to high to obtain two threshold points. The first threshold point is closer to the lake shoreline, and the second threshold point is farther away from the lake shoreline. The lake shrinkage area enclosed by the first threshold points on each sampling point strip is called the near-lake bare area (1). The lake shrinkage area enclosed by the second threshold points on each sampling point strip is called the Suaeda salsa remediation area (2). The lake shrinkage area enclosed by the outermost sampling point on each sampling point strip is called the wetland remediation area (3). S2, Restoration of bare areas near the lake (1): S2-1, Block division: The near-lake bare area (1) is divided into several first sub-blocks according to the sampling point strips; S2-2. Fertility Assessment: If more than half of the sampling points in the first sub-block meet the national soil fertility standard Level 1 of the National Soil Survey, the standards for Level 1 soil fertility of the National Soil Survey are as follows: organic matter > 40 g / kg, total nitrogen > 2 g / kg, total phosphorus > 1 g / kg, available phosphorus > 40 g / kg, and total potassium > 25 g / kg. If any two indicators at a sampling point meet Level 1, the soil fertility of that sampling point is considered to meet the national soil fertility standard Level 1 of the National Soil Survey. In this case, the fertility of the first sub-block is considered to be up to standard, and it can be used as arable land after leveling and weeding. S2-3, Ecological Restoration: If the fertility of the first sub-block does not meet the standard, the vegetation coverage of the first sub-block will be optimized. The vegetation coverage of the first sub-block will be calculated. If the vegetation coverage is >30%, some vegetation will be removed to ensure that the vegetation coverage is ≤30%. If the vegetation coverage is ≤20%, aquatic plants will be planted in the first sub-block to ensure that 20% < vegetation coverage ≤30%. S3, Suaeda salsa restoration area (2) restoration: S3-1, Block division: Divide the sampling point strip of the Suaeda salsa restoration area (2) into several second sub-blocks; S3-2. Fertility Assessment: If more than half of the sampling points in the second sub-block meet the national soil fertility standard Level 2 of the National Soil Survey, the standards for Level 2 of the National Soil Survey are as follows: 30g / kg < organic matter ≤ 40g / kg, 1.5g / kg < total nitrogen ≤ 2g / kg, 0.8g / kg < total phosphorus ≤ 1g / kg, 20g / kg < available phosphorus ≤ 40g / kg, and 20g / kg < total potassium ≤ 25g / kg. If any three indicators at a sampling point meet Level 2, the soil fertility at that sampling point is considered to meet the national soil fertility standard Level 2 of the National Soil Survey. Therefore, the fertility of the second sub-block is considered to be up to standard, and it can be used as arable land after leveling and weeding. S3-3, Ecological Restoration: If the fertility of the second sub-block does not meet the standard, the vegetation coverage of the second sub-block will be optimized. The vegetation coverage of the second sub-block will be calculated. If the vegetation coverage is >50%, the vegetation in the second sub-block will be allowed to grow naturally. If the vegetation coverage is ≤40%, Suaeda salsa will be planted in the second sub-block to ensure that 40% < vegetation coverage. S4, Wetland Restoration Area (3) Restoration: S4-1, Block division: Divide the sampling point strip of the wetland restoration area (3) into several third sub-blocks; S4-2. Fertility Assessment: If more than half of the sampling points in the third sub-block meet the soil fertility standard Level 3 of the National Soil Survey, the standards for Level 3 of the National Soil Survey are as follows: 20g / kg < organic matter ≤ 30g / kg, 1g / kg < total nitrogen ≤ 1.5g / kg, 0.6g / kg < total phosphorus ≤ 0.8g / kg, 10g / kg < available phosphorus ≤ 20g / kg, and 15g / kg < total potassium ≤ 20g / kg. If any four indicators at a sampling point meet Level 3, the soil fertility at that sampling point is considered to meet the soil fertility standard Level 3 of the National Soil Survey. Therefore, the fertility of the third sub-block is considered to be up to standard, and it can be used as arable land after leveling and weeding. S4-3. Ecological Restoration: If the fertility of the third sub-block does not meet the standard, the vegetation coverage of the third sub-block will be optimized. The vegetation coverage of the third sub-block will be calculated. If the vegetation coverage is >70%, the vegetation in the third sub-block will be allowed to grow naturally. If the vegetation coverage is ≤60%, aquatic plants will be planted in the third sub-block to ensure that 60% < vegetation coverage.

2. The method for ecological restoration of vegetation in saline-alkali land in a lake shrinkage area according to claim 1, characterized in that, In S1, there are 5 to 20 sampling point strips, and each sampling point strip has 9 to 30 sampling points. The spacing between sampling point strips is 50 to 5000 m, the spacing between sampling points is 10 to 100 m, and the soil sampling depth is 5 to 20 cm.

3. The method for ecological restoration of vegetation in saline-alkali land in a lake shrinkage area according to claim 1, characterized in that, The aquatic plants in S2-3 and S4-3 are reeds, rushes, cattails, tamarisk, sparganiums, and water onions.

4. The method for ecological restoration of vegetation in saline-alkali land in a lake shrinkage area according to claim 1, characterized in that, In steps S2-2, S3-2, and S4-2, after leveling and weeding, it is necessary to apply tillage enzymes to the soil. The preparation method of the tillage enzymes is as follows: Mix fruits, aquatic plant stems and leaves and water in a weight ratio of 1:2~3:10~15, place them in a sealed container and ferment for 90~100 days, and take the upper liquid to obtain the enzyme for arable land. Among them, the fruits are one or more of the following: sea buckthorn, crabapple, apple pear, blueberry, plum, apricot, crisp jujube, and cantaloupe; the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3. In S2-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the first sub-block at 50-60%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:50 and added to the soil to increase the soil moisture content by 1-3%. This process is repeated every 5-7 days, increasing the soil moisture content by 0.2-0.4% each time, for a total of 5 times. In S3-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the second sub-block at 45-55%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:80 and added to the soil to increase the soil moisture content by 2-4%. This is then applied every 5-7 days, increasing the soil moisture content by 0.5-1% each time, for a total of 5 applications. In S3-2, after leveling and weeding, water is first added to the soil to maintain the soil moisture content in the third sub-block at 40-50%. Then, the tillage enzyme is mixed with animal manure and water in a weight ratio of 1:2:100 and added to the soil to increase the soil moisture content by 3-5%. This process is repeated every 5-7 days, increasing the soil moisture content by 0.6-1.2% each time, for a total of 5 times.

5. The method for ecological restoration of vegetation in saline-alkali land in a lake shrinkage area according to claim 4, characterized in that, In S3-3 and S4-3, a soil conditioner is applied to the soil before planting vegetation. The method for preparing the soil conditioner is as follows: The enzyme residue, aquatic plant stems and leaves, and clay minerals are mixed in a weight ratio of 1:4~6:7~9, crushed, dried, and then passed through a 30-mesh sieve. The enzyme residue is the lower layer residue produced during the preparation of the enzyme for arable land, the aquatic plant stems and leaves are the aquatic plant stems and leaves harvested in S2-3 and S4-3, and the clay minerals are kaolinite, montmorillonite, illite or sepiolite. The application rate of the soil conditioner is 20-25 kg / mu.

6. The method for ecological restoration of vegetation in saline-alkali land in a lake shrinkage area according to claim 1, characterized in that, In S3-3, Suaeda salsa is harvested every 3 to 6 months.

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