艾比湖湿地土壤氮素空间异质性分析

发布时间：2018-06-28 05:12

本文选题：土壤氮素 + 分布特征　；参考：《新疆师范大学》2015年硕士论文

【摘要】：干旱区湿地生态系统及其荒漠生态系统很脆弱,土壤养分(矿质元素)极贫乏,氮素含量较低,土壤氮被认为是仅次于有机质和水分影响植物生长发育的因素,又由于各种地理环境、气象气候条件和人为的影响和控制,氮的分布特殊。因此,干旱区湿地土壤氮的分布的研究,对于揭示干旱区土壤氮素的分布特征、土地荒漠化、土地盐渍化、植被空间分布、生物多样性变少、生态系统演变和氮积累、氮循环过程意义重大。本研究通过对艾比湖湿地土壤氮的测定,分析湿地土壤氮素统计特征、空间分布以及湿地土壤在不同植被类型下的空间分布状况和变异特征,探讨影响和控制湿地土壤氮空间变异的主要因素。主要得出以下结论:(1)研究区土壤全氮、碱解氮、有机碳、速效磷和速效钾含量随土层深度的增加平均含量递减趋势,变化趋势体现了土壤的各指标含量的分布是受明显的生物富集和表聚作用。(2)全氮变异系数也随土层深度的增加而递减趋势。碱解氮变异系数0~20cm40~60cm20~40cm60~80cm80~100cm。(3)通过对土壤全氮、碱解氮及各指标整体含量的原始数据进行对数转化后K-S检验结果显示,双尾渐近概率(PK-S)大于给定的显著性水平0.05,符合正态分布趋势。(4)在研究区选取盐化草甸、小乔木荒漠、灌木荒漠、干涸湖底、荒漠河岸林、盐生灌丛和寒湿性针叶林等自然样地,分析土壤全氮和碱解氮在各样地的分布特征,结果表明:随着土层深度增加,土壤全氮含量整体上呈现降低趋势,但不同植被类型对土壤全氮剖面分布的影响存在明显差异。土壤全氮含量高低顺序为寒湿性针叶林小乔木荒漠灌木荒漠干涸湖底荒漠河岸林盐生灌丛盐化草甸,湿地不同植被类型土壤全氮含量属缺乏型;碱解氮含量整体上也随着土层深度增加,呈现降低趋势,含量高低顺序为寒湿性针叶林盐化草甸灌木荒漠小乔木荒漠荒漠河岸林盐生灌丛干涸湖底。总体上看,土壤全氮,碱解氮含量在不同植被类型均属于缺乏型。(5)使用(0~100cm)各层土壤全氮、碱解氮原始数据对数转换后的数据进行半方差函数的拟合,但总体上拟合效果均较好。全氮0~20cm其空间分布体现为中等空间相关性;20~40cm、40~60cm、60~80cm和80~100cm土层空间变异性主要是随机性因素引起,其空间分布相关性很弱。在0~20cm和40~60cm土层碱解氮其空间分布相关性很弱;在20~40cm、60~80cm和80~100cm土层碱解氮其空间分布体现为中等空间相关性。通过Kriging插值,结果表明:0~100cm各土层全氮和碱解氮含量在研究区西部和西北部区域较高,东部、东北部和中间区域含量较低。其原因可以从以下2方面分析:①从地理位置来看,研究区东部、东南部所辖地区在阿拉山口的东南方(即下风向),同时在上风方向是面积约500km2的湖面,对风的摩擦阻力远较其他下垫面小,从而带走了大量土壤养分②从生物量来看,西部区域平均每个样点覆盖度在25%~35%之间,东部,东北部区域平均每个样点覆盖度在10%~30%之间,西部植物量明显高于东部,说明植物量的多少会导致氮素在两区域分配不均。
[Abstract]:The wetland ecosystem and its desert ecosystem in arid areas are very fragile, soil nutrients (mineral elements) are very poor, nitrogen content is low, soil nitrogen is considered to be the second only to organic matter and water affecting plant growth and development, and the distribution of nitrogen is special because of various geographical environment, weather climate strip and artificial influence and control. The distribution of nitrogen in the wetland soil in arid areas is of great significance to reveal the distribution characteristics of soil nitrogen, land desertification, land salinization, the spatial distribution of vegetation, the less biological diversity, the evolution of ecosystem and nitrogen accumulation, and nitrogen cycling process. This study analyzed the nitrogen of wetland soil in the Ebinur Lake and analyzed the nitrogen nitrogen of the wetland The statistical characteristics, spatial distribution and the spatial distribution and variation characteristics of wetland soil under different vegetation types were used to discuss the main factors affecting and controlling the spatial variability of soil nitrogen in the wetland. The following conclusions were drawn as follows: (1) the content of soil total nitrogen, alkali hydrolysable nitrogen, organic carbon, available phosphorus and available potassium in the study area increased with the depth of soil layer. The trend of decrease in content shows that the distribution of each index of soil is affected by obvious bioaccumulation and aggregation. (2) the variation coefficient of total nitrogen decreases with the increase of soil depth. The variation coefficient of alkali hydrolysable nitrogen 0~20cm40~60cm20~40cm60~80cm80~100cm. (3) passes through the total nitrogen, alkali hydrolysable nitrogen and the overall content of each index. The K-S test results after logarithmic transformation of the original data show that the double tail asymptotic probability (PK-S) is greater than the given significant level 0.05, which is in line with the normal distribution trend. (4) select the salinized meadow, small arbor desert, shrub desert, dry lake bottom, desert riparian forest, salt shrub and cold wet coniferous forest in the study area, and analyze soil total nitrogen The distribution characteristics of alkali hydrolysable nitrogen in various fields showed that the total nitrogen content of soil showed a decreasing trend as the depth of soil increased, but the effect of different vegetation types on the distribution of total nitrogen in the soil was obviously different. The total nitrogen content of different types of wetland vegetation in the coastal salty shrubs is deficient, and the content of alkali hydrolysable nitrogen is also decreasing along with the depth of soil layer. The content of the content is in the order of cold wet coniferous meadow, shrub desert small tree desert desert desert riverside shrubs dry and the bottom of the lake. Nitrogen, alkali hydrolysable nitrogen content in the different vegetation types belong to the lack of type. (5) the use (0~100cm) of all layers of soil total nitrogen, alkali hydrolysable nitrogen data after the logarithmic conversion of data to fit the semi variance function, but the overall fitting effect is better. The spatial distribution of total nitrogen 0~20cm is medium spatial correlation; 20~40cm, 40~60cm, 60~80cm and 80~100cm The spatial variability of soil layer is mainly caused by random factors, and its spatial distribution correlation is very weak. The spatial distribution of alkali hydrolysable nitrogen in 0~20cm and 40~60cm soil is very weak; in 20~40cm, the spatial distribution of alkali hydrolysable nitrogen in 60~80cm and 80~100cm soil is medium spatial correlation. The result of Kriging interpolation shows that all soil layers of 0~100cm are total nitrogen and alkali. The content of nitrogen in the western and northwestern regions of the study area is higher, the East, the northeast and the middle area are low. The reasons can be analyzed from the following 2 aspects: (1) from the geographical position, the east of the study area, the southeast of the Southeast (the lower wind direction) in the ARA mountain pass, and the upper wind direction of the lake with an area of about 500km2, and the wind The friction resistance is much smaller than the other underlying surface, thus taking away a large amount of soil nutrients. From the biomass, the average coverage of each sample in the western region is between 25%~35%, the East, the northeast region, the average coverage of each sample is between 10%~30%, and the Western plant is significantly higher than that in the East, indicating that the amount of plant biomass will lead to nitrogen in the two region. The distribution is uneven.
【学位授予单位】：新疆师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S153

【参考文献】