草本泥炭水分特征曲线及影响因素研究

发布时间：2018-05-09 22:02

本文选题：泥炭 + 土壤水分特征曲线　；参考：《东北师范大学》2017年硕士论文

【摘要】：水分特征曲线是研究土壤水力特性的重要参数,是反映土壤持水能力和滞后能力的重要依据。研究泥炭水分特征曲线及影响因素,有助于深入理解水分对泥炭地的碳累积的影响机理。本文通过野外采样、室内实验,初步研究了自然状态泥炭的草本泥炭(金川)和开采泥炭地(辽源)的草本泥炭的水分特征曲线的变化规律,分析了泥炭水分特征曲线的影响因素,建立了水势与泥炭CO2释放速率的函数关系,主要研究结果如下:1.用Gardner公式对金川草本泥炭和辽源草本泥炭水分特征曲线的拟合效果良好,拟合系数在0.90-0.99之间。随含水量的升高,泥炭水势都呈现出快速下降-缓慢下降-基本平稳的变化趋势。金川草本泥炭的水分特征曲线吸湿过程曲线参数在0.2583-0.328之间,脱湿过程曲线参数在0.4291-0.5205之间;辽源泥炭的水分特征曲线吸湿过程曲线参数在0.4134-0.4823之间,脱湿过程曲线参数在0.7175-0.8983之间。泥炭水分特征曲线说明泥炭具有易吸水难失水的特点,辽源草本泥炭的吸水能力和持水能力强于金川草本泥炭。2.金川草本泥炭和辽源草本泥炭均存在水分滞后现象,金川草本泥炭的水分特征曲线滞后参数在0.0326-0.0427之间,辽源草本泥炭的水分特征曲线滞后参数在0.0657-0.0848之间,辽源草本泥炭的水分滞后特征比金川草本泥炭的水分滞后特征更加明显,其中辽源表层泥炭的水分滞后特征比中层和底层的明显。3.泥炭的容重、毛管孔隙度、总孔隙度、纤维含量是影响泥炭水分特征曲线和水分滞后能力的关键因素,纤维素含量、半纤维素含量、木质素含量与泥炭水分特征曲线以及滞后参数没有明显的相关性。4.水势对泥炭CO2释放速率的影响可以用幂函数来表示,系数在0.87-0.99之间,随水势的升高,草本泥炭采样点的CO2释放速率都呈现出快速下降-缓慢下降-基本平稳的变化趋势。
[Abstract]:The water characteristic curve is an important parameter to study the hydraulic characteristics of soil, and it is an important basis for reflecting the water holding capacity and lagging capacity of soil. The study of water characteristic curve and influencing factors of peat is helpful to understand the influence mechanism of moisture on carbon accumulation in peat soil. Based on field sampling and laboratory experiments, the variation law of water characteristic curve of natural peat (Jinchuan) and peat (Liaoyuan) was studied in this paper. The influencing factors of water characteristic curve of peat were analyzed, and the functional relationship between water potential and CO2 release rate of peat was established. The main results were as follows: 1. Gardner formula was used to fit the water characteristic curves of Jinchuan herbaceous peat and Liaoyuan herbaceous peat, and the fitting coefficient was between 0.90-0.99. With the increase of water content, the water potential of peat decreased rapidly, slowly and steadily. The moisture characteristic curve parameters of Jinchuan herbaceous peat were between 0.2583-0.328 and 0.4291-0.5205, and those of Liaoyuan peat and Liaoyuan peat were 0.4134-0.4823 and 0.7175-0.8983 respectively. The water characteristic curve of peat shows that peat is easy to absorb water and lose water, and the water absorption and water holding capacity of peat in Liaoyuan is stronger than that of Jinchuan herbaceous peat. 2. Both Jinchuan herbaceous peat and Liaoyuan herbaceous peat have water lag phenomenon. The hysteresis parameter of water characteristic curve of Jinchuan herbaceous peat is 0.0326-0.0427, and that of Liaoyuan herbaceous peat is 0.0657-0.0848. The moisture hysteresis characteristics of Liaoyuan herbaceous peat were more obvious than that of Jinchuan herbaceous peat, and the water lag characteristics of Liaoyuan surface peat were more obvious than those of middle layer and bottom layer. The bulk density, capillary porosity, total porosity and fiber content of peat are the key factors affecting water characteristic curve and moisture lag ability of peat, cellulose content, hemicellulose content, cellulose content, hemicellulose content, cellulose content, hemicellulose content, cellulose content, hemicellulose content, There was no significant correlation between lignin content and water characteristic curve and hysteresis parameters of peat. 4. The effect of water potential on the CO2 release rate of peat can be expressed by power function. The coefficient is between 0.87-0.99. With the increase of water potential, the CO2 release rate of herbaceous peat sampling points shows a tendency of fast decreasing, slowly decreasing and basically stable.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152.7

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