| Gannan Tibetan Autonomous Prefecture(Gannan Prefecture)is located in the eastern margin of Qinghai-Tibet Plateau,with special geographical and geological background and complex topographic and geomorphic features.It is an important activity site for alpine meadow plants and animals in Gannan Prefecture,and also an important hub for soil nutrient transformation.It controls the nutrient material circulation of meadow ecosystem and plays an important role in plant growth,water and nutrient movement.Soil nutrient content in alpine meadow plays an important role in global material cycle and has a direct impact on soil quality and productivity of alpine meadow.Soil organic carbon content,soil total nitrogen content and soil total phosphorus content showed significant spatial heterogeneity under the influence of soil physical and chemical properties and human activities.Therefore,to further understand the coupling relationship between soil organic carbon content,soil total nitrogen content and soil total phosphorus content and environmental factors in the alpine meadow of Gannan Prefecture.It is helpful to improve our understanding of the influence mechanism of soil organic carbon content,soil total nitrogen content and soil total phosphorus content,soil evolution in alpine meadow and the biochemical cycle of soil organic carbon content,soil total nitrogen content and soil total phosphorus content in the process of soil erosion,so as to clarify the law of soil occurrence,development and change in Gannan Prefecture.To provide scientific basis for sustainable development of Gannan Prefecture.This study takes the alpine meadow soil of Gannan Prefecture as the research object,and its basic data are obtained through a series of laboratory analysis after a large area of field sampling and investigation.Then,with the help of basic methods such as classical statistics and geostatistics,To explore the horizontal,spatial variability and spatial distribution characteristics of soil organic carbon content,soil total nitrogen content and soil total phosphorus content in the horizontal and vertical directions in Gannan Tibetan Autonomous Prefecture,and then to explore the effects of different environmental factors on the spatial distribution of soil organic carbon content,soil total nitrogen content and soil total phosphorus content with the help of geographical detector method.In order to understand the spatial distribution patterns of soil organic carbon content,soil total nitrogen content and soil total phosphorus content under the influence of various environmental factors,to prevent the dual degradation of soil and vegetation in the alpine meadow,and to provide a certain scientific basis for the rational management of grassland in Gannan region.The main research results are as follows:(1)The horizontal and vertical distributions of soil temperature,soil water content,soil p H,and soil bulk density in Gannan Tibetan Autonomous Prefecture were significantly heterogeneous.In the vertical direction,with the increase of soil depth,the trend of soil temperature and soil water content in Gannan alpine meadow was decreasing,the trend of soil p H value was increasing,and the trend of soil bulk density was first decreasing and then increasing.In the horizontal direction,the overall spatial distribution characteristics of soil water content in Gannan Prefecture were as follows:higher in the southwest and lower in the northeast,and higher in the west and lower in the east.Specifically,the high values were mainly concentrated in the western Maqu County and Luqu County,and the low values were mainly concentrated in Hezuo City.The overall spatial distribution characteristics of soil temperature,soil p H value and soil bulk density in Gannan Prefecture are as follows: it is high in the northeast and low in the southwest,and high in the east and low in the west.(2)The distribution of soil organic carbon content,soil total nitrogen content and soil total phosphorus content in Gannan Prefecture showed obvious heterogeneity in horizontal and vertical directions.In the vertical direction,with the increase of soil depth,soil organic carbon content,soil total nitrogen content and soil total phosphorus content in the meadow of Gannan showed a downward trend,that is,surface agglomeration phenomenon existed.In the horizontal direction,the overall spatial distribution characteristics of the meadow soil organic carbon content,soil total nitrogen content and soil total phosphorus content in Gannan Prefecture are as follows:high in the southwest and low in the northeast,high in the west and low in the east.Specifically,the high value is mainly concentrated in the west of Maqu County and Luqu County,while the low value is mainly concentrated in Hezuo City.(3)The results showed that soil moisture content,soil p H value and soil bulk density were the key factors for soil organic carbon at 0-20 cm soil depth.In 20-100 cm soil depth,soil moisture content is the key factor.For soil total nitrogen in the 0 to10 cm of soil depth,soil water content and soil bulk density is the key factor;At 10-20 cm soil depth,soil water content,soil p H and soil bulk density were the key factors.At20-40 cm soil depth,soil water content was the key factor.At the soil depth of 40-60 cm,soil water content,soil p H and soil bulk density were the key factors.At 60-80 cm,soil water content is the key factor.At 80-100 cm,soil p H,soil water content and soil bulk density are the key factors.For soil total phosphorus,soil water content,soil bulk density and soil p H were the key factors at 0-20 cm soil depth.At 20-40 cm soil depth,soil water content is the key factor.At the depth of 40-60 cm,soil moisture content,soil p H and soil bulk density were the key factors.At the depth of 60-80 cm,soil water content is the key factor.At a depth of 80-100 cm soil layer,soil p H,soil water content,and soil bulk density are key factors. |
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