基于稳定性同位素技术荒漠植物红砂水分来源的研究

发布时间：2018-01-07 16:02

本文关键词：基于稳定性同位素技术荒漠植物红砂水分来源的研究　出处：《内蒙古农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：本研究选择额济纳荒漠区三个典型红砂群落为样地,通过分析样地土壤的理化性质以及红砂的含水率和水势,同时对红砂的茎干水、降水、各土层的土壤水以及地下水的氢氧稳定性同位素(δD和δ18O值)进行测定,运用二源或三源线性混合模型、多元线性混合模型、耦合模型以及吸水深度模型对各样地红砂的水分来源进行分析,得到红砂的主要水分来源。研究结果如下:(1)Ⅰ号样地乌兰图格嘎查,红砂为主要优势种,土壤质地的主要类型为砂土,地下水水位在220cm 土层处。Ⅱ号样地天鹅湖路北,红砂为单一优势种,土壤质地的主要类型为砂土。Ⅲ号样地火车站东北方向,红砂为主要优势种,土壤质地的主要类型为砂壤土和砂土。三个样地土壤类型为灰棕漠土。土壤容重为1.46～1.76g/c m3,红砂生长的土壤环境呈碱性(pH8.02～8.97),土壤电导率为0.06～2.25ms/cm。土壤含水率为0.187%～20.23%,土壤水势为-2.99～-12.09Mpa。(2)红砂叶片含水率为18.032%～38.063%,红砂根、茎、叶水势均值分别为-8.61Mpa、-8.89Mpa、-9.71Mpa。Ⅰ号样地红砂主要的吸水根系分布在90cm～170cm土层,Ⅱ号样地红砂主要的吸水根系分布在70～80cm 土层;Ⅲ号样地红砂主要的吸水根系分布在50～90cm 土层。(3)不同样地红砂的吸水层位不同。Ⅰ号样地红砂主要吸水层位在130～220cm,对应的土壤含水率为8.55%～20.23%。Ⅱ号样地红砂主要吸水层位在70～100cm,对应的土壤含水率为1.28%。Ⅲ号样地红砂主要吸水层位在70～100cm,对应的土壤含水率为2.08%。随着根系不断的生长,红砂的吸水层位逐渐延伸到更深土层。(4)通过模型确定红砂的生长发育依赖于较稳定的土壤水分。在Ⅰ号样地,红砂吸收并且利用最多的是130～160cm处的土壤水,平均吸水深度位于100～130cm土层;在Ⅱ号样地,红砂主要利用70～100cm处的土壤水,平均吸水深度位于50～70cm土层;在Ⅲ号样地,红砂对70～100cm处的土壤水利用较多,平均吸水深度位于70～100cm 土层。
[Abstract]:This study selected three typical Ejina desert area red sand community as the sample, through the analysis of physicochemical properties of soil and red sand water content and water potential, while the red sand stem water, precipitation, soil water and groundwater and oxygen isotope (delta D and delta 18O) were measured using two or three source linear mixed model, multivariate linear mixed model, analyzes the water source coupling model and the model of the water depth of red sand, get the main water source of red sand. The results are as follows: (1) 1 kind of Ulan tug GaZha, red sand as the main dominant species. The main types of soil texture is sandy soil, the groundwater level in the depth of 220cm. 2 kind of Swan Lake North, red sand as the single dominant species, the main types of soil texture sand. III kind of train station northeast, red sand was the dominant species in soil. The main types of soil texture is sandy loam and sandy soil. Three soil types for the grey brown desert soil. Soil bulk density is 1.46 ~ 1.76g/c m3, the growth of red sand soil environment is alkaline (pH8.02 ~ 8.97), 0.06 ~ 0.187% soil conductivity ~ 20.23% 2.25ms/cm. soil water content, soil water potential was -2.99 -12.09Mpa. ~ (2) red sand leaf water content is 18.032% ~ 38.063%, red sand root, stem, leaf water potential values are -8.61Mpa, -8.89Mpa, -9.71Mpa., 1 kind of red sand fine roots were mainly distributed in the 90cm ~ 170cm soil layer, the water absorption of root distribution in 70 ~ 80cm soil layer II plots mainly red sand the third kind of red sand; the fine roots were mainly distributed in 50 ~ 90cm soil layer. (3) the water layer is not as red sand. I like the red sand main water layer in 130 ~ 220cm soil water content corresponding to the rate of 8.55% ~ 20.23%. II kind of red sand main absorption layer In 70 ~ 100cm soil water content corresponding to the rate of 1.28%. III kind of red sand is mainly water layer in 70 ~ 100cm soil water content corresponding to the rate of 2.08%. with root growth continuously, the water layer red sand gradually extended to deeper layers. (4) through the model to determine the red sand growth dependence in the soil water stable. In No.1 plots, red sand absorption and use the most is the 130 ~ 160cm soil water, the average water depth is 100 ~ 130cm soil layer; in No. 2 plots, red sand mainly by 70 ~ 100cm of soil water, the average water depth is 50 ~ 70cm soil; in III plots, the red sand on the 70 ~ 100cm soil water more, the average water depth is 70 ~ 100cm soil layer.

【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】：Q948

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