胶州湾典型河口湿地土壤溶解性有机碳含量及结构特征研究

发布时间：2018-04-16 04:08

本文选题：河口湿地 + 土壤溶解性有机碳　；参考：《青岛大学》2015年硕士论文

【摘要】：本文以胶州湾典型河口湿地为研究对象,在对土壤DOC含量时空分布及结构特征研究的基础上,探究了潮汐作用对土壤DOC的影响,揭示了该区土壤DOC时空变化规律及关键影响因子,为河口湿地及滨海湿地碳循环研究提供了基础参考数据。研究结果如下:(1)土壤DOC含量从海向陆地方向呈递减规律,但垂直方向上不同湿地变化规律差异较大。土壤DOC含量季节变化趋势整体表现为4月7月10月。水文、植被、土壤理化性质等是土壤DOC含量分布差异的重要原因。与土壤DOC不同,夏季土壤水DOC含量在从海向陆地方向上未呈现出递减规律;在垂直方向上,光滩湿地土壤水DOC变异系数低于具有植被覆盖的湿地,且具有植被覆盖的湿地土壤水DOC最大值位于根际层。土壤水DOC分布特征受植被覆盖条件及土壤水含盐量等因子的影响较大。(2)土壤DOC中芳香类化合物组分从海向陆地方向呈较弱的递增趋势,且具有植被覆盖的湿地土壤DOC腐殖化程度高于光滩湿地。垂直方向上,表土DOC中芳香类组分相对较高。不同样地土壤DOC结构特征季节变化不同,光滩湿地土壤DOC腐殖化程度表现为10月7月4月;碱蓬湿地和芦苇湿地则表现出W型变化,整体上7月份最低。地表植被及地下根系分布、土壤理化性质是影响土壤DOC腐殖化程度的重要因子。夏季土壤水DOC在从海向陆地方向上结构特征变化规律不明显。垂直方向上,具有植被覆盖的湿地根际层土壤水DOC结构简单,而光滩湿地变化规律不明显。(3)夏季潮汐过程中土壤水向潮水输出DOC,其含量及腐殖化程度表现为落潮后低于涨潮前。在0~60cm土壤剖面上,光滩样点不同土层土壤水DOC的芳香类化合物组分变化规律较为一致,具有植被覆盖的碱蓬样点不同土层变化趋势各异,说明植被对土壤DOC对潮汐作用的响应具有一定的影响。近海湿地土壤水含盐量对潮汐过程的响应大于上游湿地,但pH和ORP则与之相反。在潮汐过程中土壤水DOC含量的关键影响因子是含盐量而腐殖化程度则主要受pH和ORP控制。
[Abstract]:Taking the typical estuarine wetland of Jiaozhou Bay as the research object, based on the study of the temporal and spatial distribution and structure of soil DOC content, the effect of tidal action on soil DOC was studied.The temporal and spatial variation of soil DOC and the key influencing factors were revealed, which provided the basic reference data for the study of carbon cycle in estuarine wetland and coastal wetland.The results were as follows: (1) the DOC content of soil decreased from sea to land, but the variation law of different wetland was different in vertical direction.The seasonal variation trend of soil DOC content was in April, July and October.Hydrology, vegetation and physical and chemical properties of soil are the important reasons for the difference of soil DOC content.Different from soil DOC, the DOC content of soil water did not decrease from sea to land in summer, and in vertical direction, the coefficient of variation of soil water DOC in Guangtan wetland was lower than that in wetland with vegetation cover.The maximum value of soil water DOC in vegetation covered wetland is in the rhizosphere.The distribution of DOC in soil water was influenced by vegetation coverage and salt content of soil water. (2) the composition of aromatic compounds in soil DOC increased weakly from sea to land.The degree of DOC humification in wetland with vegetation cover was higher than that in Guangtan wetland.In the vertical direction, the aromatic components of DOC in topsoil are relatively high.The seasonal variation of soil DOC structure was different in different areas. The degree of soil DOC humification in Guangtan wetland was October / April, while that in Suaeda salsa wetland and Reed wetland was W-type, and the whole July was the lowest.The distribution of surface vegetation, underground root system and physical and chemical properties of soil are important factors affecting the degree of soil DOC humification.The variation of DOC structure from sea to land was not obvious in summer.In the vertical direction, the DOC structure of rhizosphere soil water in wetland with vegetation cover is simple, but the variation law of Guangtan wetland is not obvious. 3) during summer tidal process, soil water outputs DOC to tidal water, and its content and humification degree are lower than that before high tide after falling tide.On the soil profile of 0~60cm, the variation of aromatic compounds in soil water of different soil layers at Guangtan sampling site was consistent, and the variation trend of different soil layers in Suaeda salsa sampling site with vegetation cover was different.The results show that vegetation has a certain effect on the response of soil DOC to tidal action.The response of soil salinity in offshore wetland to tidal process is greater than that of upstream wetland, but pH and ORP are opposite.The key influencing factor of DOC content in soil water during tidal process was salt content, while the humification degree was mainly controlled by pH and ORP.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S153.62

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