| With urban expansion,peri-urban agricultural land gradually convert to urban land be constructed or urban land,soil in Urban-rural ecotone are affected by urban expansion, the internal elements of the distribution of nutrients and the spatial variability have great changed in this place.Distribution and spatial variability of internal Nutrient elements of its are great changed.As a result of the city,urban fringe and rural soils have different functions,so study on the soil nutrient distribution and variation characteristics of Urban-rural ecotone not only reasonable to determine the process of urban expansion in the use of soil resources necessary precondition,but also soil nutrient management and efficient fertilizer precise basis of practice.Wuhan City in recent years to further accelerate the speed of urban expansion,so this paper select Wuhan East Lake New Technology Development Zone as research object, study on the distribution of nutrient elements and spatial variability characteristics of soil organic matter,total N,total P,available K and available P,The main research content and results are as follows:(1) Comprehensive use of GIS technology,landscape ecology and statistical analysis methods,analysis of the landscape characteristics of the study area,by using the "breaking point" method to initial divide urban areas,urban fringe and rural areas of the study area,and put forth a optimization methods,based on in determining the urban areas, urban fringe and rural areas to divide of the different functional areas of the soil.(2) Analysis soil nutrient distribution of elements at different depths of research area. The results show that natural and human factors in the double impact of the increase with depth,total N,total P,available K,organic matter and available P content of the average downward trend has emerged,and gradually increasing reduction.Which increase soil organic matter decrease with the relatively high,and total P and available P content of the drop is relatively small.Soil nutrient content of the study area in a shallow surface enrichment.(3) Comparative analysis of the soil nutrient elements in urban areas,urban fringe, rural areas in three different levels of soil functional distribution of the content.The results show that rural and urban areas of soil organic matter content is generally higher than urban fringe.City total N content is generally higher than other regions.Total P concentration in urban areas have a certain amount of shallow gathered,other soil and a more balanced regional content.K content in the three regions did not change significantly,the overall distribution is balanced.City soil available P content is generally higher than rural and urban fringe.Land use patterns on soil nutrient content will have an appreciable effect,the results of the analysis show that the organic matter in wood land and arable land with a high level,and urban construction sites and construction sites to be relatively low organic matter content,total N content of arable land in general less than other land types.Total P,available K and available P in a variety of land types was rather evenly distributed among the content,the difference was not obvious.(4) Study the spatial variability of soil characteristics of the region,results showed that the different layers of different elements of the spatial variability of nutrients is not the same as the characteristics and distribution,in the role of strong man-made some elements is not subject to the assumption of intrinsic which is the premise of semi-variance Analysis,but overall,0-10cm of soil spatial distribution is relatively homogeneous,mainly due to the first layer of soil exposed at the surface,by the continued and strong role of man-made impact is more prominent,making elements of the original soil spatial variability Characteristics slowing down.10-20cm and 20-40cm of soil by man-made impact is smaller,soil parent material,climate and other structural factors impact are enhanced on spatial variability.
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