A method for regulating grazing intensity in alpine meadows to enhance plant diversity

Abstract

This invention relates to the field of alpine meadow ecosystem regulation and restoration technology, specifically a method for regulating grazing intensity in alpine meadows to enhance plant diversity. The method includes the following steps: S1: basic survey and monitoring of the study area; S2: construction of a correlation model; S3: determination of the target grazing intensity; S4: determination of the grazing livestock combination; S5: setting the grazing cycle; S6: implementation of regulation and dynamic adjustment. This invention precisely regulates grazing intensity through seasonal differences and key family and genus litter volume, significantly enhancing alpine meadow plant diversity and achieving synergistic optimization of ecological restoration and livestock production.

Description

Technical Field

[0001] This invention relates to the field of alpine meadow ecosystem regulation and restoration technology, specifically a method for regulating grazing intensity in alpine meadows to enhance plant diversity. Background Technology

[0002] Alpine meadows are one of the most representative ecosystems on the Qinghai-Tibet Plateau, serving as both important ecological barriers and valuable for livestock production. Plant diversity, as a core indicator of its health, directly relates to the system's stability, resilience, and the sustainable supply of ecosystem services. Grazing, as the most significant form of human disturbance, profoundly influences the direction of vegetation succession: overgrazing leads to the decline of high-quality forage and the expansion of weeds, while undergrazing causes excessive accumulation of litter, inhibiting seed germination and seedling regeneration. Both result in decreased plant diversity, homogenized community structure, and soil degradation. Although existing technologies employ measures such as rotational grazing, grazing bans, grazing rest, and livestock carrying capacity assessment for regulation, these largely rely on experience or overall forage yield estimations, lacking a refined consideration of internal ecosystem processes—especially litter dynamics.

[0003] For example, existing methods for determining carrying capacity based on forage yield typically use the annual average carrying capacity or the growing season carrying capacity, neglecting the unique characteristics of vegetation cessation and slow litter decomposition during the winter non-growing season. This can easily lead to excessively high or low grazing intensity in winter, making it impossible to achieve precise year-round control of litter volume. Furthermore, existing methods generally fail to differentiate the ecological functions of litter from different plant families and genera. For instance, leguminous litter decomposes quickly and has a high nitrogen content, which is beneficial for improving soil fertility and promoting the growth of other plants; while some grass litter is tough and decomposes slowly, and excessive accumulation can form a physical barrier. Ignoring these family-specific differences in regulation makes it difficult to achieve targeted cultivation of factors that promote plant diversity.

[0004] It is worth noting that litter plays a crucial role in the material cycle and microenvironment shaping of alpine meadows. Litter from different plant families (such as Poaceae and Leguminosae) exhibits significant differences in cellulose / lignin content, decomposition rate, and nutrient release characteristics, thus having a differentiated impact on plant diversity. However, current grazing control techniques generally overlook this family-specificity and fail to consider the differences in ecological responses between the summer growing season and the winter non-growing season. They still employ a uniform grazing intensity model across the entire area, resulting in extensive, weakly targeted, and unstable control measures, making it difficult to achieve targeted enhancement of plant diversity.

[0005] Therefore, there is an urgent need for a precise grazing control method that integrates seasonal dynamics and the family and genus characteristics of litter, in order to break through the bottlenecks of traditional technology and promote the synergistic optimization of the ecological and production functions of alpine meadows. Summary of the Invention

[0006] The purpose of this invention is to provide a method for regulating the grazing intensity of alpine meadows to enhance plant diversity, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0008] The purpose of this invention is to provide a method for regulating grazing intensity in alpine meadows to enhance plant diversity, comprising the following steps:

[0009] S1: Basic Survey and Monitoring of the Study Area

[0010] Based on the topography, soil type and existing vegetation composition of the alpine meadow, summer grazing area and winter grazing area were divided to ensure that the basic vegetation conditions of the two areas were consistent. Basic surveys were conducted using the quadrat method to record the characteristics of plant communities within the quadrats and calculate the plant diversity index. Litter was collected by family and genus and its physicochemical properties were analyzed. At the same time, the grazing status, soil physicochemical properties and climate factors were monitored.

[0011] S2: Constructing the Relationship Model

[0012] Using litter quantity of each family and genus as independent variable, plant diversity index as dependent variable, and soil and climate factors as covariates, statistical methods were used to analyze correlation and influence weight, screen litter of key families and genera and determine their suitable range.

[0013] S3: Determine the target grazing intensity

[0014] Different grazing intensity gradients were set up and rotational grazing was used to conduct experiments. The target grazing intensity for summer and winter was determined in combination with seasonal characteristics to ensure that the utilization rate of forage and the amount of litter from key genera and species are within an appropriate range.

[0015] S4: Determine the grazing livestock mix

[0016] A mixed grazing model of yaks and Tibetan sheep is adopted in both summer and winter.

[0017] S5: Set grazing period

[0018] Based on seasonal characteristics and the need for litter control, a short-term rotational grazing model is adopted in summer, while a combination of continuous grazing and intermittent rest is adopted in winter.

[0019] S6: Implement regulation and make dynamic adjustments

[0020] Management should be implemented according to the target grazing intensity, key indicators should be monitored regularly, and grazing intensity should be adjusted in a timely manner based on the monitoring results.

[0021] As a further aspect of the present invention: in step S1, at least three replicate plots with an area of ​​1m×1m are set up; the plant diversity indices include the Margalef richness index, the Shannon-Wiener diversity index, the Simpson dominance index, and the Pielou evenness index.

[0022] As a further aspect of the present invention: In step S1, litter collection adopts the harvesting method, selecting 0.5m×0.5m subplots to collect litter within 5cm of the surface and top 5cm of the soil. After collection, the litter is dried, weighed, and the amount of litter is determined. The physicochemical properties include cellulose content and lignin content. The consistency requirement for the basic vegetation conditions of summer grazing areas and winter grazing areas is that the difference in species richness and the proportion of dominant species is ≤10%.

[0023] As a further aspect of the present invention: in step S2, the statistical method is multiple linear regression; the screening criteria for key family and genus litter is: the absolute value of the correlation coefficient with at least one plant diversity index is ≥0.5, and P<0.05.

[0024] As a further aspect of the present invention: In step S3, summer grazing is carried out during the plant growing season from June to September, with a moderate grazing intensity, controlling the livestock carrying capacity at 3.65 sheep units / hm², and maintaining the forage utilization rate at 50%-60%; winter grazing is carried out during the non-plant growing season from November to March of the following year, with a light to moderate grazing intensity, controlling the livestock carrying capacity at 1.825-3.65 sheep units / hm², and maintaining the forage utilization rate at 35%-45%.

[0025] As a further aspect of the present invention: in step S3, the grazing intensity gradient includes no grazing, light grazing, moderate grazing, heavy grazing and optimized grazing, wherein light grazing is 60%-80% of the traditional grazing amount, moderate grazing is 90%-110% of the traditional grazing amount, and heavy grazing is 120%-140% of the traditional grazing amount.

[0026] As a further aspect of the present invention: in step S4, the ratio of yaks to Tibetan sheep is 1:2, and healthy yaks aged 2-3 years and healthy Tibetan sheep aged 1-2 years are selected.

[0027] As a further aspect of the present invention: In step S5, the summer short-term rotational grazing mode is specifically as follows: the summer grazing area is divided into 3-5 rotational grazing areas, each area is grazed for 7-10 days, and the rotational grazing interval is 21-28 days.

[0028] As a further aspect of the present invention: in step S5, the number of rotational grazing areas is 3-5, and the rotational grazing cycle is 90-150 days; the winter continuous grazing and intermittent rest combination mode is specifically: 15 days of continuous grazing followed by 5 days of rest.

[0029] As a further aspect of the present invention: in step S6, the periodic monitoring cycle is every quarter or every six months, and the monitoring indicators include the amount and physicochemical properties of key genera and families of litter, plant diversity index, soil physicochemical properties and microbial community structure; when adjusting grazing intensity, the amount of litter is maintained within a suitable range by fine-tuning the carrying capacity or rotational grazing cycle.

[0030] Compared with the prior art, the beneficial effects of the embodiments of the present invention are:

[0031] This invention integrates seasonal dynamics and family-specific litter regulation, and by constructing a "key family litter-plant diversity" correlation model, it achieves precise, dynamic, and differentiated adaptation of grazing intensity, breaking through the limitations of traditional extensive management. While significantly improving alpine meadow plant diversity, it also takes into account ecological stability and sustainable animal husbandry, and has high scientific value, operability, and promotion value. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0033] This invention provides a method for regulating grazing intensity in alpine meadows to enhance plant diversity, comprising the following steps:

[0034] S1: Basic Survey and Monitoring of the Study Area

[0035] Based on the topography, soil type, and existing vegetation composition of the alpine meadow, summer and winter grazing areas were divided to ensure that the basic vegetation conditions of the two areas were consistent. A basic survey was conducted using the quadrat method, with at least three replicate quadrats, each with an area of ​​1m×1m. The characteristics of plant communities within the quadrats were recorded, and four types of plant diversity indices were calculated. Litter was collected according to family and genus, and its physicochemical properties were analyzed. The grazing status, soil physicochemical properties, and climatic factors were monitored.

[0036] Specifically, based on the topography, soil type, and existing vegetation composition of the alpine meadow, the grazing area was divided into summer grazing and winter grazing areas to ensure that the basic vegetation conditions of the two areas were consistent (species richness and dominant species ratio difference ≤10%). A basic survey was conducted using the quadrat method, dividing the area into several quadrats (herbaceous plant communities were typically divided into 1m × 1m quadrats, with at least three replicates per quadrat). The characteristics of the plant communities within the quadrats were investigated, recording parameters such as family, species, and number of plants. The Margalef richness index, Shannon-Wiener diversity index, Simpson dominance index, and Pielou evenness index were calculated. Litter was collected according to family and genus classification (using the harvesting method, selecting 0.5m × 0.5m sub-quadrats to collect litter from the surface and the top 5cm of soil), dried, weighed, and the amount of litter was determined. Physicochemical properties such as cellulose and lignin were analyzed. The current grazing status (livestock species, carrying capacity, etc.) was investigated, and soil physicochemical properties and climatic factors were monitored.

[0037] S2: Constructing the Relationship Model

[0038] Using statistical methods such as multiple linear regression, the correlation between litter volume and plant diversity index of each family and genus and its influence weight were analyzed, and key families and genera of litter were screened and their suitable ranges were determined.

[0039] Specifically, using litter quantity of each family and genus as independent variable, plant diversity index as dependent variable, and soil and climate factors as covariates, statistical methods such as multiple linear regression were used to analyze correlation and influence weights; key family and genus litter were screened (screening criteria: absolute value of correlation coefficient with at least one diversity index ≥0.5, P<0.05), and their suitable range (with the highest diversity index within this range) was determined.

[0040] The method for determining the suitable range is as follows: Based on the constructed association model, with the goal of maximizing the plant diversity index (preferably the index with the best overall performance, such as the Shannon-Wiener index), the numerical range of litter volume for the corresponding key genera and families is derived through model fitting or interval optimization algorithms. This range is the suitable range. For example, a scatter plot and fitting curve of litter volume for key genera and families versus the target diversity index can be plotted, and the litter volume range corresponding to the diversity index being higher than a preset threshold (such as 90% of the peak value) near the peak value of the curve can be selected as the suitable range.

[0041] S3: Determine the target grazing intensity

[0042] Different grazing intensity gradients were set up, and rotational grazing was used for the experiment. The target grazing intensity for summer and winter was determined in combination with seasonal characteristics to ensure that the utilization rate of forage and the amount of litter from key genera are within an appropriate range.

[0043] Specifically, grazing intensity gradients were established (light grazing 60%-80%, moderate 90%-110%, heavy 120%-140% of traditional grazing and grazing bans, and optimized grazing; optimized grazing refers to grazing management implemented according to the target grazing intensity determined in steps S2-S3), and rotational grazing was used for the experiment (3-5 rotational grazing areas, cycle 90-150 days); changes in litter volume and diversity index of key genera were monitored regularly, and the target grazing intensity was determined in combination with seasonal characteristics: summer grazing (plant growing season, June-September): moderate grazing intensity was adopted, and the livestock carrying capacity was controlled at 3.65 sheep units / hm², ensuring that the forage utilization rate was maintained at 50%-60%, while keeping the litter volume of key genera within an appropriate range; at this intensity, the dominance of grasses could be moderately weakened, the growth of leguminous and miscellaneous grasses could be promoted, the family composition of litter could be optimized, and species diversity could be improved. Winter grazing (non-growing season for plants, November to March of the following year): adopt light to moderate grazing intensity, control the livestock carrying capacity to 1.825-3.65 sheep units / hm², ensure that the forage utilization rate is maintained at 35%-45%, avoid excessive accumulation of litter and ensure its reasonable decomposition; winter grazing disturbance is mild, and the trampling of livestock can promote the breaking down and decomposition of litter and the return of excrement, improve the soil microenvironment, and maintain the stability of litter amount of key genera.

[0044] The optimized grazing intensity is not a fixed carrying capacity percentage, but rather refers to the optimal grazing intensity determined through gradient experiments in step S3, after key genera and families have been screened using the model in step S2, with the goal of maintaining the litter volume of these key genera and families within their respective suitable ranges. This intensity is a dynamic output of the method of this invention, rather than a static input parameter.

[0045] S4: Livestock Grazing Combination

[0046] In both summer and winter, a mixed grazing model of yaks and Tibetan sheep is adopted, with the ratio of the two being controlled at 1:2. Healthy yaks aged 2-3 years and healthy Tibetan sheep aged 1-2 years are preferred. By taking advantage of the selective feeding characteristics of different livestock, the amount of plant and litter generated by different functional groups can be balanced and regulated.

[0047] Specifically, the above combination method can precisely regulate the feeding intensity of different families and genera of plants by taking advantage of the selective feeding characteristics of different livestock, thereby achieving balanced regulation of the production of different functional groups of plants and litter, avoiding overfeeding of specific species by a single livestock; at the same time, it promotes the sexual reproduction of dominant species (such as Kobresia dwarfii), optimizes the plant community structure and litter family and genera composition, and enhances the stability of the ecosystem.

[0048] The 1:2 ratio of yaks to Tibetan sheep is based on the complementary foraging habits of the two species. Yaks prefer taller grasses and graze extensively, which helps control the excessive accumulation of grass litter. Tibetan sheep, on the other hand, prefer shorter grasses and legumes, and their grazing is more refined. This ratio effectively regulates the growth and litter volume of grasses, which are key genera, while also promoting the proliferation of legumes and other grasses through the presence of Tibetan sheep. This achieves a balanced utilization of different functional plant groups at the community level, thus enhancing plant diversity.

[0049] S5: Grazing Period Setting

[0050] Based on seasonal characteristics and the need for litter control, a short-term rotational grazing model is adopted in summer, dividing the grazing area into 3-5 sub-areas, with each sub-area grazing for 7-10 days and an interval of 21-28 days; in winter, a combination of continuous grazing and intermittent rest is adopted, with 15 consecutive days of grazing followed by 5 days of rest.

[0051] Specifically, grazing cycles are set based on seasonal characteristics and litter control needs: Summer grazing: A short-term rotational grazing model is adopted, further dividing the summer grazing area into 3-5 rotational grazing plots. Each plot is grazed for 7-10 days, with a rotational grazing interval of 21-28 days, ensuring sufficient time for vegetation recovery while avoiding excessive or insufficient litter accumulation in local areas. Winter grazing: A combination of continuous grazing and intermittent rest is adopted, with 15 consecutive days of grazing followed by 5 days of rest, to avoid excessive soil compaction, promote the even distribution and decomposition of excrement, and ensure efficient litter decomposition and soil nutrient cycling.

[0052] S6: Implement regulation and make dynamic adjustments

[0053] Management is implemented according to the target grazing intensity, and the amount of litter, diversity index, soil physicochemical properties and microbial community structure of key genera are monitored regularly. The grazing intensity is adjusted in a timely manner based on the monitoring results to ensure the continuous improvement of plant diversity.

[0054] Specifically, management is implemented according to the target grazing intensity, and key genera and species litter volume and physicochemical properties, diversity index, soil physicochemical properties and microbial community structure are monitored every quarter or every six months; if the litter volume exceeds the appropriate range, the grazing intensity is fine-tuned by adjusting parameters such as carrying capacity to ensure continuous improvement in diversity.

[0055] The timely adjustment of grazing intensity specifically includes: when the amount of litter from a key family of plants is consistently below its lower limit of suitability, the proportion or number of livestock with a strong preference for grazing on that family of plants can be appropriately reduced, or the rotational grazing time in that area can be shortened; conversely, when the amount of litter is consistently above the upper limit of suitability, the proportion or number of livestock with a preference for grazing on that family of plants can be increased, or the rotational grazing time can be extended. The adjustment range can be designed in a step-by-step manner according to the degree of deviation. For example, when the deviation is <10%, the carrying capacity can be slightly adjusted by 5%; when the deviation is 10%-20%, the carrying capacity can be adjusted by 10%, and so on.

[0056] Example: Grazing Intensity Regulation Experiment in an Alpine Meadow on the Qinghai-Tibet Plateau

[0057] 1. Sample plot selection and basic setup

[0058] A typical alpine meadow located at an altitude of 3800–4000 m on the Qinghai-Tibet Plateau, with an average annual temperature of −2.5℃ and an annual precipitation of approximately 550 mm, was selected as the experimental plot. The soil type in this area is alpine meadow soil, and the vegetation is dominated by *Elymus nutans*, with associated species including *Poa crymophila*, *Oxytropisochrocephala*, and various miscellaneous grasses. Local yaks and Tibetan sheep are the grazing livestock.

[0059] Ten 10m×10m master quadrats were established within the area, and three 1m×1m plant community subquadrats were set up within each master quadrat for subsequent diversity and litter monitoring. Simultaneously, in accordance with the technical requirements of this invention, the entire experimental area was divided into summer grazing areas and winter grazing areas to ensure that the initial vegetation structure (e.g., species richness, dominant species ratio difference ≤10%) of the two areas was basically consistent.

[0060] 2. Grazing gradient design and rotational grazing arrangement

[0061] Five grazing intensity gradients were set up: no grazing (0% traditional carrying capacity), light grazing (60%–80%), moderate grazing (90%–110%), heavy grazing (120%–140%), and optimized grazing (based on the target intensity determined by the model). Each gradient had three replicate quadrats, for a total of 15 treatment quadrats. Rotation grazing was adopted, dividing each grazing area into three rotational grazing plots with a rotational grazing cycle of 120 days.

[0062] 3. Basic Survey and Model Building

[0063] Before the experiment began, a comprehensive basic survey was conducted: parameters such as plant species, number of plants, and canopy cover in each subplot were recorded, and the Margalef richness index, Shannon-Wiener diversity index, Simpson dominance index, and Pielou evenness index were calculated; simultaneously, litter was collected from the surface and the top 5 cm of soil in 0.5m×0.5m subplots using the harvesting method, dried, weighed, and the cellulose and lignin contents were determined; at the same time, livestock species and historical carrying capacity were recorded, and soil samples were collected to analyze physicochemical indicators such as pH, organic matter, and total nitrogen, and microclimate data were recorded simultaneously.

[0064] Using litter quantity of each family and genus as independent variables, four types of diversity indices as dependent variables, and soil and climate factors as covariates, multiple linear regression analysis was employed to determine correlations. Key family and genus litter quantities (such as Poaceae and Leguminosae) that were significantly correlated with at least one diversity index (|r|≥0.5, P<0.05) were identified, and suitable ranges for their litter quantity were determined (e.g., the diversity index was highest when the litter quantity of Poaceae was maintained at 80–120 g / m²).

[0065] 4. Determination and Implementation of Target Grazing Intensity

[0066] Based on the results of the gradient experiment, it was determined that a moderate grazing intensity should be adopted in summer (June–September), with a carrying capacity of 3.65 sheep units / hm² and a forage utilization rate of 50%–60%; and a light to moderate grazing intensity should be adopted in winter (November–March of the following year), with a carrying capacity of 1.825–3.65 sheep units / hm² and a forage utilization rate of 35%–45%.

[0067] The grazing livestock are uniformly combined with a yak and Tibetan sheep mix, with a ratio of 1:2, using healthy yaks aged 2-3 years and healthy Tibetan sheep aged 1-2 years.

[0068] Summer grazing adopts short-term rotational grazing: each rotational grazing area is grazed for 7–10 days, with an interval recovery period of 21–28 days; in winter, an intermittent pattern of “15 consecutive days of grazing + 5 days of rest” is adopted to promote the even distribution of excrement and the decomposition of litter.

[0069] 5. Dynamic monitoring and regulation adjustment

[0070] After the regulation was implemented, the amount of litter from key genera and families, diversity index, soil physicochemical properties, and microbial community structure were monitored quarterly. If the amount of litter deviated from the appropriate range, the carrying capacity or rotational grazing cycle was adjusted. For example, if the amount of legume litter was found to be low in the sixth month, the proportion of yaks was appropriately reduced to increase the opportunities for Tibetan sheep to graze on legumes, so that the composition of litter would become more balanced.

[0071] 6. Effect Verification

[0072] After one year of implementation, the litter content of key genera and families in each treatment plot tended to stabilize and remained within the suitable range determined by the model. Plant diversity indices (especially the Margalef richness index and the Shannon-Wiener index) were significantly improved compared with before the experiment (P<0.05), the dominance of grasses decreased, the proportion of leguminous and miscellaneous weeds increased, and the community structure became more balanced. Soil organic matter content and microbial activity also improved.

[0073] To compare the results, a control area was set up in an adjacent area of ​​the experimental site, using the local traditional grazing method (a fixed annual carrying capacity of approximately 3.0 sheep units / hm², with no seasonal distinction and arbitrary livestock mixing ratios). After one year, the plant diversity index (Shannon-Wiener) in the control area decreased from an initial 2.1 to 1.9, the amount of grass litter accumulated to over 150 g / m², and the proportion of legumes decreased. In contrast, in the experimental area using the method of this invention, the Shannon-Wiener index significantly increased from 2.1 to 2.5 (P<0.05), the amount of grass litter stabilized within a suitable range of around 100 g / m², and the proportion of legumes increased by approximately 15%. This indicates that the method of this invention is significantly superior to the traditional model in improving diversity.

[0074] The results show that the method of the present invention can precisely regulate the generation and decomposition process of litter in alpine meadows, effectively improve plant diversity, take into account both grassland ecological function and sustainable livestock production, and achieve coordinated development of ecology and production.

[0075] The above embodiments of the present invention provide a method for regulating the grazing intensity of alpine meadows to enhance plant diversity, which has the following significant advantages:

[0076] Breaking away from the traditional extensive management model of uniform grazing intensity across the entire area, this approach combines for the first time the differences in ecological characteristics between the summer growing season and the winter non-growing season with the differentiated impact of litter from key genera and families on plant diversity. By constructing a litter quantity-diversity correlation model, key genera and families with significant regulatory effects on diversity are identified. Based on their suitable litter quantity range, grazing parameters such as carrying capacity, livestock composition, and rotational grazing cycle are precisely matched to achieve targeted linkage of "litter genera and family regulation - grazing intensity optimization - plant diversity enhancement," effectively solving problems such as monotonous community structure and declining diversity caused by excessive or insufficient litter accumulation.

[0077] By regularly monitoring litter volume, diversity index, and soil microenvironment indicators of key genera and species, and by fine-tuning grazing intensity through a dynamic feedback mechanism, we can effectively avoid natural and human disturbances such as climate fluctuations and livestock behavior. This ensures the continuous improvement of plant diversity while taking into account the coordinated development of grassland ecological function maintenance and livestock production, thus forming a long-term and stable meadow management paradigm.

[0078] The technical process is clear, and the survey methods (such as sampling method and harvesting method), analytical models (multiple linear regression) and management parameters (such as carrying capacity, rotational grazing cycle and livestock ratio) used are all based on mature ecological theories and actual production experience in plateau pastoral areas. The indicators are quantifiable, the measures are executable, and it is easy to promote and apply them to the Qinghai-Tibet Plateau and other similar alpine meadow ecosystems.

[0079] By optimizing the family and genus composition and quantity of litter, promoting its rational decomposition and nutrient return, improving soil physicochemical properties and microbial activity, enhancing the meadow's water conservation, carbon sequestration and anti-degradation capabilities, and effectively curbing the ecological degradation trend of alpine meadows.

[0080] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for regulating grazing intensity in alpine meadows to enhance plant diversity, characterized in that, Includes the following steps: S1: Basic Survey and Monitoring of the Study Area Based on the topography, soil type and existing vegetation composition of the alpine meadow, summer grazing area and winter grazing area were divided to ensure that the basic vegetation conditions of the two areas were consistent. Basic surveys were conducted using the quadrat method to record the characteristics of plant communities within the quadrats and calculate the plant diversity index. Litter was collected by family and genus and its physicochemical properties were analyzed. At the same time, the grazing status, soil physicochemical properties and climate factors were monitored. S2: Constructing the Relationship Model Using litter quantity of each family and genus as independent variable, plant diversity index as dependent variable, and soil and climate factors as covariates, statistical methods were used to analyze correlation and influence weight, screen litter of key families and genera and determine their suitable range. S3: Determine the target grazing intensity Different grazing intensity gradients were set up and rotational grazing was used to conduct experiments. The target grazing intensity for summer and winter was determined in combination with seasonal characteristics to ensure that the utilization rate of forage and the amount of litter from key genera and species are within an appropriate range. S4: Determine the grazing livestock mix A mixed grazing model of yaks and Tibetan sheep is adopted in both summer and winter. S5: Set grazing period Based on seasonal characteristics and the need for litter control, a short-term rotational grazing model is adopted in summer, while a combination of continuous grazing and intermittent rest is adopted in winter. S6: Implement regulation and make dynamic adjustments Management should be implemented according to the target grazing intensity, key indicators should be monitored regularly, and grazing intensity should be adjusted in a timely manner based on the monitoring results.

2. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1, characterized in that, In step S1, at least three replicate quadrats with an area of ​​1m × 1m are set up; The plant diversity indices include the Margalef richness index, the Shannon-Wiener diversity index, the Simpson dominance index, and the Pielou evenness index.

3. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1 or 2, characterized in that, In step S1, litter collection adopts the harvesting method. A 0.5m×0.5m subplot is selected to collect litter within 5cm of the surface and top 5cm of the soil. After collection, the litter is dried, weighed and the amount of litter is determined. The physicochemical properties include cellulose content and lignin content. The requirement for consistency in the basic vegetation conditions between summer grazing areas and winter grazing areas is that the difference in species richness and the proportion of dominant species is ≤10%.

4. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1, characterized in that, In step S2, the statistical method is multiple linear regression. The screening criteria for key family and genus litter were: the absolute value of the correlation coefficient with at least one plant diversity index was ≥0.5, and P<0.

05.

5. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1, characterized in that, In step S3, summer grazing is carried out during the plant growing season from June to September, with a moderate grazing intensity, controlling the livestock carrying capacity at 3.65 sheep units / hm², and maintaining the forage utilization rate at 50%-60%. Winter grazing takes place during the non-growing season of plants, from November to March of the following year. Light to moderate grazing intensity is adopted, and the livestock carrying capacity is controlled at 1.825-3.65 sheep units / hm², while the forage utilization rate is maintained at 35%-45%.

6. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1 or 5, characterized in that, In step S3, the grazing intensity gradient includes no grazing, light grazing, moderate grazing, heavy grazing, and optimized grazing, wherein light grazing is 60%-80% of the traditional grazing amount, moderate grazing is 90%-110% of the traditional grazing amount, and heavy grazing is 120%-140% of the traditional grazing amount.

7. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1, characterized in that, In step S4, the ratio of yaks to Tibetan sheep is 1:2, and healthy yaks aged 2-3 years and healthy Tibetan sheep aged 1-2 years are selected.

8. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1, characterized in that, In step S5, the summer short-term rotational grazing pattern is specifically as follows: The summer grazing area is divided into 3-5 rotational grazing areas, with each area grazing for 7-10 days and a rotational grazing interval of 21-28 days.

9. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 8, characterized in that, In step S5, the number of rotational grazing areas is 3-5, and the rotational grazing cycle is 90-150 days; The winter grazing combined with intermittent rest pattern is as follows: grazing for 15 consecutive days followed by 5 days of rest.

10. The method for regulating grazing intensity in alpine meadows to enhance plant diversity according to claim 1, characterized in that, In step S6, the periodic monitoring cycle is every quarter or every six months, and the monitoring indicators include the amount and physicochemical properties of litter from key genera and families, plant diversity index, soil physicochemical properties, and microbial community structure. When adjusting grazing intensity, the amount of litter can be maintained within an appropriate range by fine-tuning the carrying capacity or rotational grazing cycle.