A reasonable spatial configuration method of row belt shrub shelterbelt in semi-arid steppe region

Abstract

The application provides a reasonable space configuration method of a row type shrub shelter forest in a semi-arid grassland area, and mainly comprises the following steps: (1) determining a potential maximum density of the shrub forest; (2) determining key ecological hydrological function parameters of the shrub forest with different row distances; (3) comprehensively evaluating the ecological hydrological function parameters of the sand-fixing shrub forest with different row distances by using an analytic hierarchy process-entropy weight method, and finally determining the best row distance and plant distance of the forest belt in combination with the potential maximum density of the shrub forest in the step (1) and the key ecological hydrological function parameters of the shrub forest with different row distances in the step (2). The application has a reasonable concept, can not only improve the growth stability of the shelter forest, but also simultaneously enhance the ecological functions such as the windproof effect of the shelter forest, and can provide a theoretical basis for efficient utilization of water resources and ecological restoration in the arid grassland area.

Description

Technical Field

[0001] This invention relates to the field of land desertification control and grassland ecological environment protection technology, specifically to a method for the rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas. Background Technology

[0002] Semi-arid grasslands are located within my country's northern sand-prevention belt, where row-belt shrub shelterbelts are crucial for combating desertification and protecting grassland ecosystems and utilizing resources. These shelterbelts not only effectively reduce wind erosion, but some shrubs (such as *Caragana microphylla*) can also serve as high-quality fodder after coppicing, achieving a dual improvement in ecological and economic value. In arid regions, soil wind erosion can be effectively controlled when the coverage of perennial shrubs, semi-shrubs, and perennial herbs is maintained at 20%–40%. These shelterbelts typically employ drought-resistant and wind-resistant native shrubs (such as *Caragana microphylla*) planted in strips, effectively preventing wind erosion and providing high-quality fodder after coppicing. However, under the combined influence of climate change and human activities (such as overgrazing), coupled with insufficient understanding of water resource and vegetation carrying capacity in afforestation design, some shelterbelts have experienced growth degradation, leading to a decline in their windbreak function and seriously affecting regional production, livelihoods, and ecological security. Therefore, in the future, under the constraints of water resources, it is necessary to explore how to optimize the spatial configuration of forest belts and propose climate-adaptive management measures to promote the stability and positive succession of vegetation communities, reduce surface wind erosion, and balance the relationship between grassland ecological protection and sustainable resource utilization. This has important theoretical value and practical significance for achieving regional ecological security and sustainable social development.

[0003] Currently, theoretical research on row-and-belt shrub shelterbelts in semi-arid grassland areas has focused on individual aspects such as the water physiology, tree growth, soil infiltration and forest water balance, and windbreak effects of major shrub species like Caragana korshinskii and Caragana microphylla. However, systematic comparative studies and comprehensive evaluations of multiple functions are still lacking regarding key ecological functions such as soil hydrology (bulk density, porosity, infiltration capacity, etc.), vegetation growth (leaf area index, etc.), and windbreak under different vegetation configurations (e.g., row spacing).

[0004] At the technological research and development level, although technical measures such as site-specific tree selection, planting methods, and fencing have been proposed, and the principle of "determining afforestation based on water availability" has been strongly advocated in recent years, effective calculation methods and detailed plans are lacking in implementation. Furthermore, in some areas, in an effort to improve afforestation survival rates, the initial planting density of forest belts has been excessively high, leading to problems such as exacerbated water deficit.

[0005] At the same time, there is still a lack of optimization and functional improvement of existing afforestation models for degraded shelterbelts, especially the following key issues that urgently need to be addressed:

[0006] (1) How to determine the potential maximum density of forest belts under water resource constraints;

[0007] (2) The technical parameters are unclear, and there is a lack of dynamic monitoring and comprehensive evaluation of the eco-hydrological functions of forest belts with different row spacing.

[0008] These problems not only affect the long-term stability of sand-fixing vegetation and regional water resource security, but also restrict the realization of the goal of coordinated and sustainable development of ecology, society and economy. Summary of the Invention

[0009] To address the technical problems existing in the background art, this invention proposes a reasonable spatial configuration method for row-type shrub shelterbelts in semi-arid grassland areas. The method is well-conceived, based on systematic observation and comprehensive analysis of key eco-hydrological functions such as soil hydrological processes, vegetation growth dynamics, and windbreak effects. It proposes a reasonable structural configuration of forest belts considering multiple functions under water resource constraints, which can not only improve the growth stability of forest stands but also simultaneously enhance the ecological functions of shelterbelts, such as windbreak effects. This provides a theoretical basis for the efficient utilization of water resources and ecological restoration in arid grassland areas.

[0010] To address the aforementioned technical problems, this invention provides a method for the rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas, which mainly includes the following steps:

[0011] (1) First determine the potential maximum density of the shrubland;

[0012] (2) Further determine the key eco-hydrological function parameters of shrubland belts with different row spacing;

[0013] (3) The analytic hierarchy process (AHP)-entropy weight method was used to comprehensively evaluate the eco-hydrological function parameters of sand-fixing shrub belts with different row spacings. Combining the potential maximum density of the shrub belts in step (1) above and the key eco-hydrological function parameters of the shrub belts with different row spacings in step (2) above, the optimal row spacing and plant spacing of the belts were finally determined.

[0014] The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas, wherein step (1) is specifically as follows:

[0015] Estimate the transpiration of individual shrub clumps and calculate the potential maximum density of shrubland under a certain rainfall condition:

[0016] (1);

[0017] (2);

[0018] (3);

[0019] In equations (1)-(3) above, N represents the potential maximum number of shrubs under a certain amount of precipitation; P e P is the annual effective rainfall; S is the annual rainfall; E is the area of ​​shrubland; and E is the average transpiration of a single shrub clump during the growing season. It is the daily average sap flow rate of the shrub; A si A is the sapwood area of ​​the i-th branch, and n is the total number of branches in the shrub. G D is the projected area of ​​the shrub's canopy; D is the number of days in the growing season.

[0020] The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas, wherein: the eco-hydrological function parameters in step (2) include soil hydrological function parameters, windbreak function parameters and vegetation growth function parameters;

[0021] The soil hydrological function parameters include soil bulk density, total soil porosity, soil capillary porosity, soil non-capillary porosity, soil saturated hydraulic conductivity, and soil water content, which are used to reflect the changes in soil hydrological function in different rows of shrub forests.

[0022] The windbreak function parameters include the wind speed at a height of 0.2m near the ground surface and the wind speed at a height of 3m above the canopy, which are used to characterize the windbreak function of shrub belts with different row spacings.

[0023] The vegetation growth function parameters are expressed using the leaf area index, which includes shrubs and herbaceous plants within the forest belt that reflect the growth status of plants within forest belts with different row spacings.

[0024] The method for the rational spatial configuration of row-type shrub shelterbelts in the semi-arid grassland area, wherein the soil bulk density is obtained by the following formula (4):

[0025] (4);

[0026] In equation (4), d v ρ is the soil bulk density, m is the mass of the dried soil, and v is the volume of the ring cutter.

[0027] The total porosity of the soil is obtained by the following formula (5):

[0028] (5);

[0029] In equation (5), P is the total porosity of the soil; d is the bulk density of the soil; and D is the specific gravity of the soil.

[0030] The soil capillary porosity is obtained by the following formula (6):

[0031] (6);

[0032] In equation (6), P1 is the soil capillary porosity; A is the water content of the soil sample in the ring cutter; and V is the volume of the ring cutter.

[0033] The non-capillary porosity of the soil is equal to the difference between the total porosity and the capillary porosity of the soil, which is obtained by the following formula (7):

[0034] (7);

[0035] In equation (7), P n P is the non-capillary porosity of the soil, and P is the total porosity of the soil; P is the capillary porosity of the soil.

[0036] The soil saturated hydraulic conductivity reflects the surface rainwater infiltration capacity of forest land under different row spacing conditions, and it is measured using a MiniDisk small disc infiltration meter.

[0037] The soil moisture content directly reflects the soil moisture status of the forest land, and it is measured by profile probe positioning or drying method.

[0038] The method for the rational spatial configuration of row-type shrub shelterbelts in the semi-arid grassland area includes the following: the wind speed at a height of 0.2m near the ground surface and the wind speed at a height of 3m above the canopy are both measured using a small meteorological station or anemometer.

[0039] The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas, wherein the LAI of shrubs and herbaceous plants in the shelterbelts are both measured using the AccuPAR plant canopy analyzer.

[0040] The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas, wherein step (3) is specifically as follows:

[0041] Based on the principles of scientific rigor, operability, and hierarchy, and through expert consultation and review of domestic and international literature, a multi-functional comprehensive evaluation tiered structure for sand-fixing forest belts with different row spacings was established. The multi-functional comprehensive evaluation tiered structure includes a target layer, a criterion layer, and a scheme layer.

[0042] Then calculate the analytical weight, entropy weight, and comprehensive weight of the multifunctional comprehensive evaluation hierarchical structure, and calculate the multifunctional comprehensive evaluation results of shrubland belts with different row spacings according to the following formula (8):

[0043] (8);

[0044] In equation (8), M is the comprehensive functional index of forest belts with different row spacings; i is the i-th function; G i F represents the weight of the i-th functional evaluation index; i The score for the i-th function;

[0045] Finally, based on the comprehensive evaluation results of soil hydrological function parameters, windbreak function parameters and vegetation growth function parameters, combined with the potential maximum density of shrubs under a certain rainfall in step (1) and the key eco-hydrological function parameters of shrub belts with different row spacing in step (2), the potential maximum row spacing and plant spacing of shrub belts were finally determined.

[0046] By adopting the above technical solution, the present invention has the following beneficial effects:

[0047] This invention adheres to the core principle of "determining forest and greening based on water availability," and explicitly proposes a method for calculating the potential maximum density of row-type shrub shelterbelts under specific rainfall conditions. Based on systematic observation and comprehensive analysis of key eco-hydrological functions such as soil hydrological processes, vegetation growth dynamics, and windbreak effects, this invention proposes a rational structural configuration of forest belts considering multiple functions under water resource constraints. This invention not only improves the growth stability of forest stands but also simultaneously enhances the ecological functions of shelterbelts, such as windbreak effects, providing a theoretical basis for the efficient utilization of water resources and ecological restoration in arid grassland areas.

[0048] Compared with existing technologies, this invention has made significant breakthroughs in both overall design concept and quantitative methods, specifically in the following aspects: 1) Systemic innovation: It dynamically couples water resource carrying capacity with ecological function (vegetation growth and windbreak, etc.) requirements, breaking through the limitations of traditional single-objective design; 2) Methodological advancement: It proposes a method for calculating the potential maximum density of forest belts; and through multi-process integrated analysis, it establishes a quantifiable forest belt structure configuration decision model.

[0049] This invention first determines the maximum vegetation density that can be carried under specific water resource constraints, providing a theoretical basis for the rational configuration of shrub and grass vegetation under different site conditions. Based on this, the invention further systematically integrates water resource carrying capacity, vegetation growth dynamics, environmental impact, and windbreak function, thereby determining the optimal structure of the shelterbelt (row spacing and plant spacing), ultimately forming a set of techniques for determining the rational density and spatial configuration of row-type shrub belts applicable to areas with soil desertification and wind erosion. This invention not only helps maintain the long-term stability of shelterbelt vegetation but also achieves synergistic optimization of water resources, vegetation structure, and ecological function, providing a scientific basis and typical demonstration for vegetation construction and ecological security in semi-arid regions. Attached Figure Description

[0050] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the multifunctional comprehensive evaluation tiered structure involved in the rational spatial configuration method of row-type shrub shelterbelts in semi-arid grassland areas according to the present invention.

[0052] Figure 2 This is a diagram showing the soil bulk density, total porosity, capillary porosity and non-capillary porosity results for different forest belts and layers involved in the rational spatial configuration method of row-belt shrub shelterbelts in semi-arid grassland areas in Embodiment 1 of the present invention.

[0053] Figure 3 This is a diagram showing the results of saturated hydraulic conductivity and soil moisture content involved in the rational spatial configuration method of row-type shrub shelterbelts in semi-arid grassland areas according to Embodiment 1 of the present invention.

[0054] Figure 4 This diagram illustrates the growth status of individual shrub clusters (LAI) and herbaceous plants within the Caragana microphylla shrub belt, as described in the rational spatial configuration method for row-belt shrub shelterbelts in semi-arid grassland areas according to Embodiment 1 of the present invention.

[0055] Figure 5 This is a diagram showing the windbreak function of shrub belts with different row spacings in the rational spatial configuration method of row-strip shrub shelterbelts in semi-arid grassland areas according to Embodiment 1 of the present invention. Detailed Implementation

[0056] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] The present invention will be further explained below with reference to specific embodiments.

[0058] like Figure 1 As shown in this embodiment, a method for the rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas is provided, and its theoretical basis is as follows:

[0059] ① Determining Greenery Based on Water Supply: In semi-arid regions, natural rainfall is the primary water source for plant survival and growth; however, effective theoretical solutions have been lacking in past vegetation construction efforts. Based on field observations of shrub transpiration water consumption, this invention proposes a method for calculating the potential maximum density of shrub forest belts under certain natural rainfall conditions.

[0060] ② Determination and calculation of key eco-hydrological function parameters: Based on previous results, a quantitative method for determining and calculating key eco-hydrological function parameters of shrubland belts was proposed, providing a basis for understanding and evaluating shrubland belts with different row spacings;

[0061] ③ Taking shrub belts with different row spacings in arid grassland areas as the research object, a multi-functional comprehensive evaluation of the forest belts was conducted using the sampling hierarchical analysis-entropy weight method. Combined with the previous results, the optimal row spacing and tree spacing of the forest belts were determined, providing a basis for the construction and management of shelterbelts in arid grassland areas.

[0062] To achieve the above objectives, the specific process of the method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas according to the present invention is as follows:

[0063] (1) Determine the potential maximum density of the shrubland belt

[0064] Estimate the transpiration of individual shrub clumps and calculate the potential maximum density of shrubland under a certain rainfall condition:

[0065] (1);

[0066] (2);

[0067] (3);

[0068] In equations (1)-(3) above, N represents the maximum potential number of shrubs (trees) under a certain amount of precipitation; P e P is the annual effective rainfall (mm); S is the annual rainfall (mm); S is the area of ​​shrubland (m²). 2 E represents the average transpiration rate of a single shrub clump during the growing season (kg / year). It is the average daily sap flow rate of the shrub (ml·cm) -2 ·d -1 ), A si It is the sapwood area of ​​the i-th branch (cm²) 2 ), n is the total number of branches in a shrub; A G It is the projected area of ​​the shrub's canopy (m²) 2 D represents the number of days in the growing season.

[0069] (2) Further determine the key eco-hydrological function parameters of shrubland belts with different row spacings.

[0070] This invention proposes using parameters such as soil hydrology, windbreak effect, and tree growth to reflect key eco-hydrological functions and effects of forest belts with different row spacings. The eco-hydrological function parameters mainly include soil hydrological function parameters, windbreak function parameters, and vegetation growth function parameters.

[0071] The soil hydrological function parameters mainly include six indicators: soil bulk density, total soil porosity, soil capillary porosity, soil non-capillary porosity, soil saturated hydraulic conductivity, and soil water content. These parameters primarily reflect the changes in soil hydrological function across different rows of shrubland. The methods for determining and calculating soil bulk density, total soil porosity, capillary porosity, and non-capillary porosity are as follows:

[0072] The soil bulk density mentioned above is obtained by the following formula (4):

[0073] (4);

[0074] In equation (4), d v m is the soil bulk density (g / cm³); m is the mass of the dried soil (g); v is the volume of the ring cutter (cm³). 3 ).

[0075] The total porosity of the soil mentioned above is obtained by the following formula (5):

[0076] (5);

[0077] In equation (5), P represents the total porosity of the soil (%); d represents the soil bulk density (g / cm³). 3 D represents the soil specific gravity (g / cm³).

[0078] The above-mentioned soil capillary porosity is obtained by the following formula (6):

[0079] (6);

[0080] In formula (6), P1 is the soil capillary porosity (%); A is the water content of the soil sample in the ring cutter (g); and V is the volume of the ring cutter (cm³).

[0081] The aforementioned non-capillary porosity of soil is equal to the difference between total soil porosity and capillary porosity, that is:

[0082] (7);

[0083] In equation (7), P n P represents the soil non-capillary porosity (%); P represents the soil total porosity (%); P represents the soil capillary porosity (%).

[0084] The saturated hydraulic conductivity mentioned above reflects the surface rainwater infiltration capacity of forest land under different row spacing conditions, and can be measured using a MiniDisk small disc infiltration meter.

[0085] The soil moisture content mentioned above directly reflects the soil moisture status of the forest land, and is measured by profile probe positioning or drying method.

[0086] The windbreak function parameters mainly include two indicators: the wind speed at a height of 0.2m near the ground surface and the wind speed at a height of 3m above the canopy (0.2m represents the wind speed near the ground surface; 3m represents the wind speed at a height above the shrubs). These parameters are used to characterize the windbreak function of shrub belts with different row spacings. The wind speed at a height of 0.2m near the ground surface and the wind speed at a height of 3m above the canopy are both measured using a small weather station or anemometer.

[0087] The vegetation growth function parameter is represented by the leaf area index (LAI), which mainly includes two indicators: shrub LAI and herbaceous plant LAI within the forest belt. It mainly reflects the growth status of plants within forest belts with different row spacings. The shrub LAI and herbaceous plant LAI within the forest belt are both measured using the AccuPAR plant canopy analyzer.

[0088] (3) The analytic hierarchy process (AHP) and entropy weight method were used to comprehensively evaluate the eco-hydrological function parameters of sand-fixing shrub belts with different row spacings. The optimal row spacing and plant spacing of the shrub belts were finally determined by combining the potential maximum density of the shrub belts and the key eco-hydrological function parameters of the shrub belts with different row spacings.

[0089] Based on the principles of scientific rigor, operability, and hierarchy, and through expert consultation and review of domestic and international literature, a multi-functional comprehensive evaluation tiered structure for sand-fixing forest belts with different row spacings was established. This multi-functional comprehensive evaluation tiered structure mainly includes the target layer A, the criterion layer B, and the scheme layer C, as shown below. Figure 1 .

[0090] Next, calculate the analytical weight, entropy weight, and comprehensive weight of the hierarchical structure of the multifunctional comprehensive evaluation. The specific method is based on the master's thesis of the Chinese Academy of Forestry, "Multifunctional Evaluation of Four Typical Plant Communities in the Diediegou Small Watershed of Liupanshan" (Tu Lihui, 2020; Section 2.2.10, see pages 22-25). The multifunctional comprehensive evaluation results of shrubland belts with different row spacings are calculated according to formula (8):

[0091] (8);

[0092] In equation (8), M is the comprehensive functional index of forest belts with different row spacings; i is the i-th function; G i F represents the weight of the i-th functional evaluation index; i Let be the score for the i-th function.

[0093] Finally, based on the comprehensive evaluation results of the multi-functional (soil hydrological function parameters, windbreak function parameters and vegetation growth function parameters), combined with the potential maximum density of shrubs under a certain rainfall in step (1) and the key eco-hydrological function parameters of shrub belts with different row spacing in step (2), the potential maximum row spacing and plant spacing of the shrub belt are finally determined. For example: First, according to formula (1)-(3), the maximum density of shrubs in a certain rainfall area is calculated to be 3359 plants / hectare; then, according to the multi-functional evaluation results, the optimal row spacing of the forest belt is determined to be 2 meters, and the corresponding plant spacing is calculated as: 1 hectare ÷ (2 meters × 3359 plants) = 10000 square meters ÷ (2 meters × 3359 plants) = 1.49 meters / plant; so the optimal row spacing is 2m (row spacing) × 1.49m (plant spacing)).

[0094] Example 1

[0095] The method for rational spatial configuration of row-type shrub shelterbelts in arid and semi-arid grassland areas in Example 1, taking the Caragana microphylla shrub belt as an example, includes the following steps:

[0096] (1.1) Determine the potential maximum density of the shrubland belt

[0097] Based on sap flow observations of Caragana microphylla branches during the growing season, the average daily water consumption of a single Caragana microphylla shrub can be calculated using formula (3) to be 2.14 kg / shrub, and the total water consumption during the growing season (April 1st to October 30th) is 460.1 kg / year. Data shows that the average annual rainfall in Siziwang Banner is 280 mm. Based on formulas (1) and (2), the potential maximum density of Caragana microphylla shrubs can be calculated to be 3359 plants / hectare.

[0098] (1.2) Determination and calculation of key eco-hydrological functional parameters of Caragana microphylla shrub belts with different row spacing:

[0099] This Example 1 involves four row spacings of Caragana microphylla shrubland: 2m, 4m, 6m, and 8m. Eco-hydrological function parameters were measured and calculated, as follows:

[0100] (1.2.1) Bulk density, porosity and non-capillary porosity

[0101] In this example, soil layers 0-40cm, 60-120cm, and 140-200cm were defined as the surface, middle, and deep layers, respectively. Based on field surveys, soil bulk density, total porosity, capillary porosity, and non-capillary porosity were calculated for different forest belts and layers. The results are shown below. Figure 2 .

[0102] (1.2.2) Saturated hydraulic conductivity and soil moisture content (e.g.) Figure 3 ).

[0103] (1.2.3) Leaf Area Index (LAI)

[0104] In Example 1, the LAI (Liquid Aggregate Intake) of individual shrub clumps and herbaceous plants within a *Caragana microphylla* shrub belt was measured to characterize plant growth. The results are shown below. Figure 4 .

[0105] (1.2.4) Wind speed

[0106] In Example 1, two wind speeds were measured at a height of 0.2 m and 3 m in Caragana microphylla shrub belts with different row spacings to characterize the windbreak function of shrub belts with different row spacings. The results are shown below. Figure 5 .

[0107] (1.3) Calculate the multi-functional comprehensive evaluation value of forest belts with different row spacings, so as to determine the optimal row spacing.

[0108] This embodiment 1 establishes a multi-functional comprehensive evaluation hierarchical structure for shrub belts with different row spacings, mainly including a target layer, a criterion layer, and a scheme layer. The criterion layer includes soil hydrological function, windbreak function, and vegetation growth function. Specifically, for soil hydrological function, this case study selects six evaluation indicators: soil bulk density (C1), total porosity (C2), capillary porosity (C3), non-capillary porosity (C4), saturated hydraulic conductivity (C5), and soil moisture content (C6). For windbreak function, two evaluation indicators are selected: wind speed at 0.2 m above the ground (C7) and wind speed at 3 m above the canopy (C8). For vegetation growth function, two evaluation indicators are selected: shrub LAI (C9) and herbaceous plant LAI (C10) within the forest belt. In total, this case study selects 15 indicator factors as the indicator layer. This case study calculates the weights using the analytic hierarchy process (AHP), entropy weight method, and comprehensive weights for shrub belts with four different row spacings; the results are shown in Table 1.

[0109] Table 1. Hierarchical structure and weights of multifunctional evaluation indicators for four types of Caragana microphylla shrubland with different row spacing.

[0110]

[0111] Substituting the weight results and functional scores from Table 1 into formula (8), the comprehensive functional evaluation index of Caragana microphylla forest belts with row spacing of 2m, 4m, 6m, and 8m can be calculated, and the results are shown in Table 2. Table 2 shows that although the soil hydrological function of forest belts with row spacing of 6m and 8m is relatively good, forest belts with row spacing of 4m and 2m have higher multifunctionality indices due to their better windbreak function.

[0112] Table 2. Multifunctional evaluation results of four different row spacing Caragana microphylla shrub belts

[0113]

[0114] Based on the first step of the calculation of the potential maximum density of Caragana microphylla forest belt of 3359 trees / hectare according to formula (1), it can be concluded that the reasonable spacing between trees and rows of Caragana microphylla forest belt is 4m (row spacing) × 0.75m (tree spacing) or 2m (row spacing) × 1.49m (tree spacing).

[0115] Based on systematic observation and comprehensive analysis of key eco-hydrological functions such as soil hydrological processes, vegetation growth dynamics, and windbreak effects, this invention proposes a rational structural configuration of shrub shelterbelts that consider multiple functions under water resource constraints. This configuration can not only improve the growth stability of the forest stand but also simultaneously enhance the ecological functions of the shelterbelt, such as its windbreak effect. It can provide a theoretical basis for the efficient utilization of water resources and ecological restoration in arid grassland areas.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for the rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas, characterized in that... This includes the following steps: (1) First, determine the potential maximum density of the shrubland; the specific process is as follows: Estimate the transpiration of individual shrub clumps and calculate the potential maximum density of shrubland under a certain rainfall condition: （1）； （2）； （3）； In equations (1)-(3) above, N represents the potential maximum number of shrubs under a certain amount of precipitation; P e P is the annual effective rainfall; S is the annual rainfall; E is the area of ​​shrubland; and E is the average transpiration of a single shrub clump during the growing season. It is the daily average sap flow rate of the shrub; A si A is the sapwood area of ​​the i-th branch, and n is the total number of branches in the shrub. G D is the projected area of ​​the shrub's canopy; D is the number of days in the growing season. (2) Further determine the key eco-hydrological function parameters of shrubland belts with different row spacing; (3) The analytic hierarchy process (AHP)-entropy weight method was used to comprehensively evaluate the eco-hydrological function parameters of sand-fixing shrub belts with different row spacings. Combining the potential maximum density of the shrub belts in step (1) above and the key eco-hydrological function parameters of the shrub belts with different row spacings in step (2) above, the optimal row spacing and plant spacing of the belt were finally determined. The eco-hydrological functional parameters in step (2) include soil hydrological functional parameters, windbreak functional parameters, and vegetation growth functional parameters. The soil hydrological function parameters include soil bulk density, total soil porosity, soil capillary porosity, soil non-capillary porosity, soil saturated hydraulic conductivity, and soil water content, which are used to reflect the changes in soil hydrological function in different rows of shrub forests. The windbreak function parameters include the wind speed at a height of 0.2m near the ground surface and the wind speed at a height of 3m above the canopy, which are used to characterize the windbreak function of shrub belts with different row spacings. The vegetation growth function parameters are expressed using the leaf area index, which includes shrubs and herbaceous plants within the forest belt that reflect the growth status of plants within forest belts with different row spacings.

2. The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas as described in claim 1, characterized in that, The soil bulk density is obtained by the following formula (4): （4）； In equation (4), d v ρ is the soil bulk density, m is the mass of the dried soil, and v is the volume of the ring cutter. The total porosity of the soil is obtained by the following formula (5): （5）； In equation (5), P is the total porosity of the soil; d is the bulk density of the soil; and D is the specific gravity of the soil. The soil capillary porosity is obtained by the following formula (6): （6）； In equation (6), P1 is the soil capillary porosity; A is the water content of the soil sample in the ring cutter; and V is the volume of the ring cutter. The non-capillary porosity of the soil is equal to the difference between the total porosity and the capillary porosity of the soil, which is obtained by the following formula (7): （7）； In equation (7), P n P is the non-capillary porosity of the soil, and P is the total porosity of the soil; P is the capillary porosity of the soil. The soil saturated hydraulic conductivity reflects the surface rainwater infiltration capacity of forest land under different row spacing conditions, and it is measured using a MiniDisk small disc infiltration meter. The soil moisture content directly reflects the soil moisture status of the forest land, and it is measured by profile probe positioning or drying method.

3. The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas as described in claim 1, characterized in that: The wind speeds at a height of 0.2m near the ground surface and at a height of 3m above the canopy were both measured using small weather stations or anemometers.

4. The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas as described in claim 1, characterized in that: The LAI of shrubs and herbaceous plants within the forest belt was measured using the AccuPAR plant canopy analyzer.

5. The method for rational spatial configuration of row-type shrub shelterbelts in semi-arid grassland areas as described in claim 1, characterized in that... The specific process of step (3) is as follows: Based on the principles of scientific rigor, operability, and hierarchy, and through expert consultation and review of domestic and international literature, a multi-functional comprehensive evaluation tiered structure for sand-fixing forest belts with different row spacings was established. The multi-functional comprehensive evaluation tiered structure includes a target layer, a criterion layer, and a scheme layer. Then calculate the analytical weight, entropy weight, and comprehensive weight of the multifunctional comprehensive evaluation hierarchical structure, and calculate the multifunctional comprehensive evaluation results of shrubland belts with different row spacings according to the following formula (8): （8）； In equation (8), M is the comprehensive functional index of forest belts with different row spacings; i is the i-th function; G i F represents the weight of the i-th functional evaluation index; i The score for the i-th function; Finally, based on the comprehensive evaluation results of soil hydrological function parameters, windbreak function parameters and vegetation growth function parameters, combined with the potential maximum density of shrubs under a certain rainfall in step (1) and the key eco-hydrological function parameters of shrub belts with different row spacing in step (2), the potential maximum row spacing and plant spacing of shrub belts were finally determined.

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