黄花甸子流域柠条锦鸡儿细根与土壤水分空间分布特征研究

发布时间：2018-09-10 08:13

【摘要】：本文以内蒙古农牧交错带黄花甸子流域典型柠条人工林为研究对象,在全面调查研究区柠条的栽植密度、立地条件、林龄等资料的前提下,分析了不同坡位柠条林地柠条细根质量、总根长、比根长、体积及表面积密度和土壤含水率的空间分布特征,在此基础上分析了柠条细根表面积密度与土壤水分的关系,并进一步研究了柠条细根与土壤干层的关系。对深入揭示内蒙古农牧交错带不同坡位柠条细根与土壤水分的关系具有重要的理论意义,对于干旱区的造林树种选择具有实用价值。研究结果表明:(1)研究区各坡位土壤剖面中柠条细根各项特征值与土壤含水率随距标准丛的距离增加呈逐渐减小的趋势,二者水平和垂直方向最大值始终在标准丛正下方。柠条细根各项特征值与土壤含水率在不同坡位均显著相关,总体表现为坡顶坡底坡中;柠条细根各项特征值与土壤含水率的相关性为:细根表面积密度(0.823)细根体积(0.766)细根质量(0.704)细根总根长(0.672)细根比根长(0.602);柠条细根各项特征值与土壤含水率的分布规律基本一致,且对垂直方向的影响较大。(2)建立柠条细根表面积密度和土壤含水率的关系模型并加入水平距离和垂直距离进行校正,得到模型:(3)坡位对柠条根系生长速率和土壤水分补充速率的比值kth值和iht值出现负值的情况均有显著影响,表现为坡顶(15%)坡中(5%)坡底(几乎没有),说明随坡位降低水分供应情况好转,且垂直方向对水分供应的影响较大。(4)研究区柠条林地各坡位0-200cm各土层含水率低于田间稳定含水率约62%,低于撂荒地含水率低约41%,土壤水分极度亏缺,同时也说明柠条林是导致柠条林地出现土壤干层的主要原因。在整个研究区形成了至少200cm的土壤干层,70cm的钙积层处土壤干化最为严重几乎达到凋萎湿度。
[Abstract]:In this paper, the typical Caragana korshinskii plantation in the Huanghuadian Valley of Inner Mongolia was studied, and the planting density, site conditions and forest age of Caragana korshinskii were investigated. The spatial distribution characteristics of fine root mass, total root length, specific root length, volume and surface area density and soil moisture content of Caragana korshinskii in different slope positions were analyzed. The relationship between the fine roots of Caragana korshinskii and the soil dry layer was further studied. It is of great theoretical significance to reveal the relationship between the fine roots of Caragana korshinskii and soil moisture at different slope positions in the interlaced zone of agriculture and animal husbandry in Inner Mongolia. It is of practical value for the selection of afforestation species in arid areas. The results showed that: (1) the characteristic values and soil moisture content of Caragana korshinskii in each slope soil profile of the study area gradually decreased with the increase of the distance from the standard bundle, and the maximum values of both horizontal and vertical directions were always directly below the standard bundle. Each characteristic value of fine root of Caragana korshinskii was significantly correlated with soil moisture content in different slope positions, and the overall performance was in the slope at the top of the slope. The correlation between each characteristic value of fine root and soil moisture content is: fine root surface area density (0.823), fine root volume (0.766), fine root mass (0.704), fine root total root length (0.672), fine root specific root length (0.602), and each characteristic value of fine root of Caragana korshinskii is basically consistent with the distribution of soil moisture content. The relationship between surface area density and soil moisture content of Caragana korshinskii was established and corrected by adding horizontal and vertical distance. The results showed that: (3) the slope position had significant influence on the ratio of kth value and iht value of root growth rate and soil water supplementation rate of Caragana korshinskii. The top (15%) middle slope (5%) slope bottom (almost none) shows that the water supply is improved with the slope position decreasing. The vertical direction has a great influence on the water supply. (4) the soil moisture content of 0-200cm in each slope of Caragana korshinskii forest is lower than that of stable water content in field about 62and 41% lower than that of abandoned land, and the soil water is extremely deficient. It also shows that Caragana korshinskii forest is the main cause of soil dry layer in Caragana woodland. At least 70 cm of dry layer of 200cm was formed in the whole study area. Soil drying was the most serious and almost reached wilting humidity.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S793.3

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