An alpine meadow ecological restoration method

Abstract

The application provides a high-cold meadow ecological restoration method, which evaluates the optimal vegetation coverage range of a target area, and the optimal vegetation coverage range is obtained according to soil moisture vegetation bearing capacity; the current vegetation coverage of the target area is obtained, and if the current vegetation coverage is not within the optimal vegetation coverage range, the vegetation coverage is regulated to be within the optimal vegetation coverage range by artificially changing the underlying surface. The application firstly evaluates whether the current coverage of the meadow steppe target area exceeds the optimal vegetation coverage range, and the meadow coverage is reduced to be within the optimal vegetation coverage range by changing the underlying surface. The application reduces the vegetation coverage appropriately under the premise of guaranteeing the ecological function, so as to reduce the excessive consumption of soil moisture by the vegetation; the soil structure and infiltration capacity are improved by artificially changing the underlying surface, the soil water supply amount of the precipitation is improved, the soil water balance of the meadow steppe is improved, so as to improve the soil water storage capacity, and effectively alleviate the drought.

Description

Technical Field

[0001] This application relates to ecological restoration methods, and more particularly to a vegetation ecological restoration method. Background Technology

[0002] Currently, meadow steppes in arid and semi-arid regions are facing severe drought problems. The region receives less than 400 mm of rainfall annually, and the rainfall distribution is extremely uneven throughout the year, with distinct wet and dry seasons, making it difficult for soil moisture conditions to meet the normal growth needs of vegetation. At the same time, excessive consumption of soil moisture by vegetation exacerbates soil aridification.

[0003] In existing technologies, to improve the ecological condition of meadow steppes in semi-arid regions, it is generally believed that meadow cover should be increased as much as possible. This is because increased cover leads to an increase in green area, while a continuous decrease in cover is generally considered to increase drought and exacerbate desertification. Therefore, existing technologies typically involve using tillage machinery to thoroughly plow the target grassland at the beginning of the growing season, supplemented by artificial irrigation and grass seeding. Water infiltrates into the deeper soil layers, increasing soil moisture content, which in turn promotes more vigorous growth of the sown grasses. While this method can replenish soil moisture and increase vegetation biomass to some extent, it suffers from problems such as high labor and material costs and significant disturbance to the native ecological environment.

[0004] Secondly, the alpine meadows located in the semi-arid zone have sensitive and fragile vegetation ecosystems. Therefore, if the ecological restoration work is not precise enough, it may have the opposite effect of damaging the ecosystem. Summary of the Invention

[0005] Purpose of the invention: This application provides a method for ecological restoration of alpine meadows that is simple to operate and requires moderate intervention.

[0006] Technical solution: This application provides a method for ecological restoration of alpine meadows.

[0007] The optimal vegetation cover range for the target area is assessed, and the optimal vegetation cover range is obtained based on soil moisture and vegetation carrying capacity.

[0008] Obtain the current vegetation cover of the target area. If the current vegetation cover is not within the optimal vegetation cover range, adjust the vegetation cover to the optimal range by artificially changing the underlying surface.

[0009] In one implementation, the optimal vegetation cover range is set such that the vegetation cover does not exceed the soil moisture and vegetation carrying capacity.

[0010] In one implementation, the optimal vegetation cover range is set such that the vegetation cover does not exceed 80% of the cover value calculated based on soil moisture and vegetation carrying capacity.

[0011] In one implementation, the optimal vegetation cover range is set such that the vegetation cover does not exceed the level value of the cover in the target area within a set time period.

[0012] One method for calculating soil moisture and vegetation carrying capacity includes the following steps:

[0013] S101. Calculate the effective water storage capacity of the soil:

[0014] Based on the effective soil depth, the soil profile is divided into K layers at intervals of a mm, and θ layers are stratified. k Let W be the volumetric water content of the k-th soil layer, and W be the soil water storage capacity of the k-th layer. k for:

[0015] W k =θ k ×a (1)

[0016] S102. Calculate the average water storage capacity (ASWS) within the effective depth of the soil:

[0017]

[0018] In the formula, the unit of the average water storage capacity of the soil layer ASWS is mm;

[0019] S103. Calculate the minimum value of the average water storage capacity of the soil layer:

[0020] Record the total average soil water storage (ASWS) measured n times during the entire growing season, arranged from morning to night as W1, W2, ..., W n MVASWS is the minimum average water storage capacity of the soil layer.

[0021] MVASWS = min(W1, W2, ..., W n (3)

[0022] S104. Calculate soil moisture and vegetation carrying capacity:

[0023] The optimal fitting model F(x) was obtained by fitting the minimum value of vegetation cover and corresponding average soil water storage in different plots to MVASWS, with the independent variable being soil water storage W. i The dependent variable is vegetation cover C, that is:

[0024] C = F(W) i (4)

[0025] If W m Substituting the soil water storage corresponding to the wilting point into the above fitting model, the soil moisture-vegetation carrying capacity (SWCCV) is:

[0026] SWCCV=F(W m (5).

[0027] One implementation method, which involves artificially altering the underlying surface to adjust the vegetation cover to the optimal range, includes:

[0028] Calculate the difference Δ between the optimal vegetation cover and the current vegetation cover. If the difference Δ is less than 0, human intervention is required; if the difference Δ is not less than 0, no intervention is needed.

[0029] Δ=SC (6)

[0030] In the formula, S is the optimal vegetation cover and C is the current vegetation cover.

[0031] One implementation method, which involves artificially altering the underlying surface to adjust the vegetation cover to the optimal range, includes:

[0032] Calculate the ratio of the difference Δ between the optimal vegetation cover S and the current vegetation cover C to the current vegetation cover C, and then calculate the percentage of underlying surface area that needs to be changed:

[0033] δ=Δ / C (7).

[0034] One implementation method involves artificially altering the underlying surface, including: plowing and turning the soil within the target area, laying gravel on the surface of the furrows to form gravel strips, and calculating the distance L between adjacent gravel strips.

[0035] L=B / δ (8)

[0036] In the formula, B is the width of the gravel zone.

[0037] The gravel belt is plowed along the contour lines of the meadow steppe, and the length of the furrows is consistent with the length of the meadow in the target area.

[0038] One way to achieve this is by using a mini tiller or yaks to plow and turn the soil.

[0039] Beneficial effects: 1. This invention first assesses whether the current vegetation cover of the target meadow steppe area exceeds the optimal vegetation cover range. By changing the underlying surface, the meadow cover is reduced to the optimal vegetation cover range. Unlike existing technologies that blindly increase cover to promote vegetation growth, this invention mainly includes two core measures: First, appropriately reducing vegetation cover while ensuring ecological function, so as to reduce excessive consumption of soil moisture by vegetation; Second, improving soil structure and infiltration capacity by artificially changing the underlying surface, increasing the amount of soil water replenished by precipitation, improving the soil water balance of the meadow steppe, thereby increasing soil water storage and effectively alleviating drought.

[0040] 2. This invention calculates the ratio of the difference between the optimal vegetation cover and the current vegetation cover to the current vegetation cover, thereby obtaining the proportion of the underlying surface area that needs to be changed. Based on this ratio, human intervention to reduce the vegetation cover can be carried out precisely, and the ecological restoration indicators of alpine meadow grasslands can be quantified in a targeted manner to avoid ecological damage caused by blind restoration, so as to overcome the sensitive problems of meadow grasslands.

[0041] 3. This invention changes the underlying surface by plowing and laying a layer of crushed stone, reducing direct evaporation of soil water. It also utilizes the low specific heat capacity of crushed stone to obtain condensate water to replenish soil water. This is a more scientific and adaptable ecological restoration strategy that can ensure the long-term stability and sustainable development of the ecosystem.

[0042] 4. Due to the limited water resources in meadow grasslands in arid and semi-arid areas, this invention improves soil infiltration capacity by plowing, and can naturally replenish vegetation after rainfall. Compared with the time-consuming and labor-intensive artificial water replenishment, this method can improve meadow ecology over a large area through natural water replenishment, coordinate the water use contradiction between soil moisture and vegetation growth, reduce surface water evaporation, increase soil water storage, and promote the sustainable development of soil water and vegetation ecosystems. Attached Figure Description

[0043] Figure 1 A schematic diagram of the ploughed area;

[0044] Figure 2 This is a schematic diagram of the plowing process. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] Traditional meadow-steppe ecological restoration practices generally focus on maximizing vegetation cover and biomass to quickly achieve surface greening and soil and water conservation. These practices mainly include, but are not limited to: thorough tilling and large-scale sowing of grass seeds at the beginning of the growing season, high-density reseeding using aerial seeding, and irrigation to maintain high biomass. However, these practices significantly disturb the native ecological environment, and alpine meadows are located in the semi-arid zone, where vegetation ecology is sensitive and fragile. Therefore, ecological restoration work must be precise to avoid adverse effects and ecological damage.

[0048] Based on this, the present invention provides a method for ecological restoration of alpine meadows:

[0049] S100. Evaluate the optimal vegetation cover range for the target area, wherein the optimal vegetation cover range is obtained based on soil moisture and vegetation carrying capacity.

[0050] The optimal vegetation cover range is set to be no more than the soil moisture carrying capacity, in order to avoid excessive consumption of soil moisture by the vegetation. For example, the optimal vegetation cover range for a meadow is no more than 80% of the soil moisture carrying capacity.

[0051] As a prerequisite for this plan, it is necessary to first calculate the soil moisture and vegetation carrying capacity of the target area. Specifically, the process of calculating the soil moisture and vegetation carrying capacity includes the following steps:

[0052] S101. Calculate the effective water storage capacity of the soil:

[0053] First, the soil is stratified according to its effective soil depth, which refers to the maximum soil depth at which plant roots can access water during normal growth. In one example, to improve calculation accuracy, the soil profile is divided into K layers at intervals of a mm, θ. k Let W be the volumetric water content of the k-th soil layer; therefore, the soil water storage capacity W of the k-th layer is... k For (1≤k≤K, (for the set of integers):

[0054] W k =θ k ×a (1)

[0055] In the formula, the smaller the value of 'a', the more accurate the calculation result of soil water storage. Usually, 'a' is 100 or 200.

[0056] S102. Calculate the average water storage capacity (ASWS) within the effective depth of the soil:

[0057]

[0058] In the formula, the unit of the average water storage capacity of the soil layer ASWS is mm;

[0059] S103. Calculate the minimum value of the average water storage capacity of the soil layer:

[0060] Record the total average soil water storage (ASWS) measured n times during the entire growing season, arranged from morning to night as W1, W2, ..., W n (n≥3, ), MVASWS is the minimum average water storage capacity of the soil layer:

[0061] MVASWS = min(W1, W2, ..., W n (3)

[0062] S104. Calculate soil moisture and vegetation carrying capacity:

[0063] The optimal fitting model F(x) is obtained by fitting the minimum values ​​of vegetation cover and corresponding average soil water storage in different plots to MVASWS. To ensure the uniqueness of the fitting model, F(x) must be a monotonic function. The independent variable of this model is soil water storage W. i The dependent variable is vegetation cover C, that is:

[0064] C = F(W) i (4)

[0065] If W m Let be the soil water storage corresponding to the wilting point. Substituting this into the above fitting model, the soil moisture-vegetation carrying capacity (SWCCV) is:

[0066] SWCCV=F(W m (5)

[0067] Among them, the soil water storage W corresponding to the wilting point m The soil moisture content was measured using a biological method, specifically by planting barley seedlings and determining the soil moisture content when the seedlings had just wilted due to water shortage and could not be restored by watering. If the soil moisture content was consistently at this value across all soil layers, then the soil water storage capacity at that point was W. m .

[0068] In addition, as an alternative to assessing the optimal vegetation cover range for the target area, the optimal vegetation cover range is set as the vegetation cover level within a specified time period in the target area, i.e., the result of ecological succession. The optimal vegetation cover range is determined based on the actual growth of meadows and steppes in different regions and exhibits spatial variability, requiring specific determination according to the specific circumstances. The specified time period here refers to all years from the initial acquisition of observational data to the present, and should be at least 5 years; the longer the time period, the more accurate the average.

[0069] S200. Obtain the current vegetation cover of the target area. If the current vegetation cover is not within the optimal vegetation cover range, adjust the vegetation cover to the optimal vegetation cover range by artificially changing the underlying surface.

[0070] Based on the above-mentioned setting of the optimal vegetation cover range, the present invention does not limit the method for determining whether the current vegetation cover is within the optimal vegetation cover range. As long as the relationship between soil moisture and vegetation carrying capacity and vegetation cover in the current state can be obtained by judgment, it is acceptable to determine whether it is necessary to artificially intervene in the vegetation cover in order to adjust it to the optimal vegetation cover range.

[0071] First, a preliminary assessment of whether ecological restoration is necessary can be made through human judgment. If the meadow does not show yellowing leaves or cessation of growth when the soil moisture content reaches its lowest value during the growing season, the vegetation status is assessed as healthy and no human intervention is required. Conversely, if the meadow shows yellowing leaves or cessation of growth during this period, the vegetation status is set as unhealthy and human intervention is required.

[0072] Secondly, precise calculations can be used to accurately determine whether ecological restoration is needed. One method to determine whether the current vegetation cover is within the optimal range is to calculate the difference between the soil moisture and vegetation carrying capacity and the current vegetation cover. If the difference is less than 0, human intervention is required; if the difference is not less than 0, no human intervention is needed.

[0073] Specifically, the current vegetation cover C of the grassland can be estimated by visual estimation, and then it can be judged whether the current vegetation cover is within the range of the optimal vegetation cover. The difference between the optimal vegetation cover S and the current vegetation cover C, Δ = SC, can be calculated.

[0074] If Δ ≥ 0, it indicates that the current vegetation growth is normal and no human intervention is needed; if Δ < 0, it indicates that the vegetation growth is unhealthy and the vegetation quantity exceeds the soil water carrying capacity, requiring human intervention to control soil drought. The calculated difference can quantitatively serve subsequent ecological restoration work, enabling quantitative and precise ecological restoration.

[0075] For example, by artificially altering the underlying surface, the vegetation cover can be adjusted to the optimal range. Specifically, the ratio of the difference Δ between the optimal vegetation cover S and the current vegetation cover C to the current vegetation cover C is calculated, and the percentage of the underlying surface area that needs to be changed, δ = Δ / C, is then calculated.

[0076] One way to artificially alter the underlying surface is by first plowing and turning the soil in the target area of ​​the grassland, then laying a layer of gravel on the surface of the furrows to change the meadow's underlying surface, creating a gravel strip. The gravel should be laid as soon as possible after plowing to prevent excessive soil moisture evaporation. The size of the gravel must consider both rainfall infiltration and preventing soil moisture evaporation; therefore, the gravel should not be too large or too small, with a particle size of approximately 5–10 cm being preferred. Figure 1 As shown, the gravel strips follow the contour lines of the meadow, with furrow lengths matching the grassland length of the restoration area. The distance L between adjacent gravel strips is determined according to a set ratio δ.

[0077] L=B / δ

[0078] In the formula, B is the width of the gravel band. Since the width of the plowshare is fixed, B can be regarded as a constant value.

[0079] In nature, stones on grasslands can hinder the growth of the meadows beneath them, but meadows around the stones often grow better than normal meadows, and the soil under the stones is more moist with better water conditions. Based on this natural phenomenon, this invention modifies the underlying surface of meadow grasslands by first plowing the land and then laying gravel. The gravel strip formed after the plowing pits are filled with gravel increases soil water replenishment and reduces soil water consumption. In the early stages, plowing reduces cover to prevent soil drought; in the middle stages, furrowing enhances soil infiltration and increases water storage; and in the later stages, vegetation cover increases the economic benefits of the grassland. After modifying the underlying surface using this method, the increased soil water storage can meet the needs of more plant growth. According to the natural cycle of plant growth, the number of plants will also increase accordingly. The increased amount of forage grasses improves the economic benefits of the grassland, alleviating the conflict between grazing and ecological protection.

[0080] In this embodiment, ploughing reduces vegetation cover and turns the soil, resulting in a direct reduction in meadow cover due to ploughing or an indirect reduction due to soil turning. Considering that large agricultural machinery is inconvenient to operate on grasslands with a certain slope and is prone to soil compaction, it is recommended to use micro-tillers or yaks for ploughing. Yaks are common livestock in the area, are docile and strong, and often carry heavy loads during herders' migration of pastures. In cases of limited funds, yaks can be used as the primary means of ploughing.

[0081] In some embodiments, such as Figure 2As shown, plowing takes place at the beginning of the growing season (around May), using a triangular plowshare to turn the soil. Immediately afterward, a layer of gravel is laid on the surface of the furrows, forming a gravel belt. First, after turning the soil, it changes from compacted to loose, increasing soil porosity and significantly increasing the proportion of preferential flow in the soil infiltration pattern, which is conducive to more precipitation replenishing the deeper soil. Furthermore, the gravel belt is parallel to the contour lines, which helps intercept small surface runoffs, which then replenish the deeper soil. Second, the gravel belt replacing the meadow not only reduces the meadow's consumption of soil water but also reduces direct evaporation loss. Third, because the surface gravel has a low specific heat capacity, it facilitates water vapor condensation on clear nights, increasing soil water replenishment. In summary, by changing the underlying surface of the meadow steppe, the amount of soil water replenishment is increased, the amount of soil water consumption is reduced, and the soil water storage capacity is increased.

[0082] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A method for ecological restoration of alpine meadows, characterized in that, The optimal vegetation cover range for the target area is assessed, and the optimal vegetation cover range is obtained based on soil moisture and vegetation carrying capacity. The optimal vegetation cover range is set such that the vegetation cover does not exceed the soil moisture and vegetation carrying capacity. Calculating soil moisture and vegetation carrying capacity includes the following steps: S101. Calculate the effective water storage capacity of the soil: Based on the effective soil depth, the soil profile is divided into K layers at intervals of a mm, and θ layers are stratified. k Let W be the volumetric water content of the k-th soil layer, and W be the soil water storage capacity of the k-th layer. k for: W k =θ k ×a (1) S102. Calculate the average water storage capacity (ASWS) within the effective depth of the soil: ； In the formula, the unit of the average water storage capacity of the soil layer ASWS is mm; S103. Calculate the minimum value of the average water storage capacity of the soil layer: Record the total average soil water storage (ASWS) measured n times during the entire growing season, arranged from morning to night as W1, W2, ..., W n MVASWS is the minimum average water storage capacity of the soil layer. MVASWS=min(W1,W2…,W n ) (3) S104. Calculate soil moisture and vegetation carrying capacity: The optimal fitting model F(x) was obtained by fitting the minimum value of vegetation cover and corresponding average soil water storage in different plots to MVASWS, with the independent variable being soil water storage W. i The dependent variable is vegetation cover C, that is: C= F(W i ) (4) If W m Let be the soil water storage corresponding to the wilting point. Substituting this into the above fitting model, the soil moisture-vegetation carrying capacity (SWCCV) is: SWCCV=F(W m ) (5); Obtain the current vegetation cover of the target area. If the current vegetation cover is not within the optimal range, adjust the vegetation cover to the optimal range by artificially altering the underlying surface, including: Calculate the difference Δ between the optimal vegetation cover and the current vegetation cover. If the difference Δ is less than 0, human intervention is required; if the difference Δ is not less than 0, no intervention is needed. Δ=SC (6) In the formula, S is the optimal vegetation cover and C is the current vegetation cover; Calculate the ratio of the difference Δ between the optimal vegetation cover S and the current vegetation cover C to the current vegetation cover C, and then calculate the percentage of underlying surface area that needs to be changed: δ=Δ / C (7); By plowing and turning the soil within the target area, and spreading gravel on the surface of the furrows to form gravel strips, the distance L between adjacent gravel strips is calculated: L=B / δ (8) In the formula, B is the width of the gravel band; The gravel belt is plowed along the contour lines of the meadow steppe, and the length of the furrows is consistent with the length of the meadow in the target area.

2. The method for ecological restoration of alpine meadows according to claim 1, characterized in that, The optimal vegetation cover range is set to be such that the vegetation cover does not exceed 80% of the cover value calculated based on soil moisture and vegetation carrying capacity.

3. The method for ecological restoration of alpine meadows according to claim 1, characterized in that, The optimal vegetation cover range is set such that the vegetation cover does not exceed the level value of the cover in the target area within a set time period.

4. The method for ecological restoration of alpine meadows according to claim 1, characterized in that, Use a mini tiller or yaks to plow and turn the soil.

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