【作者】 彭世良；

【导师】 吴甫成；

【作者基本信息】 湖南师范大学 ， 自然地理学， 2002， 硕士

【摘要】 酸雨污染是当前全球性的环境问题之一。在酸雨对生态环境的影响中，土壤酸化是中心环节。因为土壤的酸缓冲性能反映了土壤的酸敏感性，而土壤的酸敏感性决定了土壤的酸化趋势，所以研究土壤酸化，预测土壤酸化趋势，应当同时研究土壤的酸缓冲性能和酸敏感性。 湖南省由于特定的地形、气象条件以及以煤炭为主的能源结构而成为全国严重酸雨区之一；同时湖南省土壤类型中，大多数属于酸性较强的富铁土，酸敏感性较高，易于遭受酸害。因此，研究湖南土壤酸缓冲性能和酸敏感性，预测湖南土壤酸化趋势，进行湖南土壤生态系统酸相对敏感性研究，既是土壤科学和环境科学研究的重要课题，又可以为湖南酸雨控制区的合理规划和酸雨污染的针对性治理，为湖南农业的可持续发展和生态环境保护提供科学依据。 本文主体分为三个部分，第一部分是衡山土壤酸化研究。首先选取衡山不同垂直带谱上5个代表性地点不同年代的土壤样品，通过实验分析得出，衡山土壤酸度时空变化明显。从1983年到2001年，衡山土壤酸度变化主要表现在：土壤pH值降低，交换性酸度和活性酸度增加，交换性盐基离子减少，盐基饱和度降低，其中交换性酸增加量同其它各变化量之间存在着一定的相关性。衡山土壤酸度变化表明衡山土壤有明显的酸化趋势。其次，为客观地预测衡山土壤酸化趋势，本文在分析国内应用较多的土壤酸化趋势预测方法的基础上，提出利用酸缓冲曲线定性地分析土壤的酸化趋势，利用土壤酸害容量和土壤酸害容量年降低率定量地预测土壤的酸化年限，第一次提出了土壤酸害容量年降低率这一概念。运用这一方法，通过实验测定，分析衡山土壤酸缓冲能力的时空变化，得出衡山土壤酸化年限和土壤酸化特点： lI①衡山不同土壤以及同一土壤不同层次酸化进程有快有慢;②衡山土壤酸化是一个由表及里的过程。最后，在衡山土壤酸化研究基础上提出土壤酸害容量是一个理想的土壤酸敏感性评价指标，并通过相关分析，得出土壤酸害强度也是一个相对理想的酸敏感性指标，而土壤阳离子交换量、盐基饱和度、酸害偏差等作为我国南方土壤酸敏感性指标并不恰当。 第二部分是湖南土壤酸缓冲性能和酸敏感性研究。首先根据湖南土壤的成土母质、土壤类型、耕作程度、典型分布等采集了湖南代表性土壤样品，并实验测定湖南代表性土壤的酸害容量和酸害强度，绘制土壤酸缓冲曲线。然后分析湖南土壤酸缓冲性能的时间特征(滞后性和阶段性)，分析影响湖南土壤酸缓冲性能的因素，如土壤pH值、成土母质、海拔高度、土壤层次、耕作程度等。最后根据湖南供试土壤酸害容量和酸害强度的测定以及湖南土壤酸缓冲性能的分析，将湖南土壤的酸敏感性划分为最敏感、敏感、中等敏感、不敏感4个等级。 第三部分是湖南土壤生态系统酸相对敏感性研究。这是本文的成果部分，具有一定的实践意义。首先在前两部分研究的基础上，选取适合湖南土壤生态系统的5个酸相对敏感性指标(成土母质、土壤酸碱度、土壤类型、植被类型、湿度类型)，并对每个指标进行酸敏感性等级分类，根据加权评价模型，建立湖南土壤生态系统酸相对敏感性评价指标体系。然后利用GIS中的Maplnf。软件，进行湖南土壤生态系统酸相对敏感性区划，绘制区划图，并分析了这一区划在湖南酸沉降控制中的作用。最后探讨湖南土壤生态系统酸化防治的三条基本途径:①控制致酸物质排放，减少酸沉降;②施加碱性物质，提高土壤酸缓冲性能;③筛选耐酸植物品种，抑制土壤酸害。更多还原

【Abstract】 Acid rain pollution has been a global environment problem and has caused great damage to ecosystem at present. Soil acidification is the central link in the influence of acid rain pollution to ecological environment. Soil acid-buffer ability reflects soil acid-sensitivity, and soil acid-sensitivity determines soil acidification, so soil acidification, soil acid-buffer ability and soil acid-sensitivity are interactive.The peculiar terrain, meteorological condition and energy structure based on coal have caused serious acid rain pollution in Hunan Province, and most soils in Hunan Province belong to Ferralsols with strong acidity , so the study on Hunan’s soil acid-buffer ability, Hunan’s trend of soil acidification and Hunan’s relative sensitivity to acid deposition of the soil ecosystem can provide scientific bases for ecological environment protection and the sustainable development of Hunan’ agriculture.The paper contains three parts. The first part is a study, on Mt. Hengshan’s soil acidification. Firstly, the experiments on Mt. Hengshan’s soil acidity prove that the time and space change of Mt. Hengshan’s soil acidity is obvious. From 1983 to 2001, the change of Mt. Hengshan’s indicates the following: the soil pH values drop down; the soil exchangeable acidity and the soil active acidity increase; the exchange base reduces and the base saturation percentage decreases. Secondly, based onanalyzing the methods of forecasting the trend of soil acidification, the paper puts forward the specific methods to forecast the trend of soil acidification: utilizing soil acid-buffer curves to qualitatively.analyze the trend of soil acidification; utilizing soil acid-damage capacity and the year-decrease-rate of soil acid-damage capacity to quantitatively forecast soil acidification limitation. Thirdly, after analyzing the time and space change of Mt. Hengshan’s soil acid-buffer ability, the paper obtains two characteristics of Mt. Hengshan’s soil acidification. One is that the soil acidification speeds of different soils and the different soil layers of the same soils are different. The other is that the process of soil acidification is from soil surface to soil interior. Finally, on the basis of comparison and analyses of main sensitive indices of soils to acid deposition, soil acid-damage capacity(SADC) and soil acid-damage intensity (SADI) are considered as two ideal- sensitive indices of soils to acid deposition, and the other soil sensitive indices such as cation exchange capacity (CEC) and base saturation percentage (BSP) et al. aren’t quite suitable in South China.The second part is a study on the soil acid-buffer ability and the soil acid-sensitivity in Hunan Province. Firstly, the soil acid-damage capacity and the soil acid-damage intensity of Hunan’s representative soils are determined by the experiments, and some soil acid-buffer curves are drawn. Secondly, the paper analyzes the time characteristics and the influential factors of Hunan’s soil acid-buffer ability. The principal factors which affect soil acid-buffer ability are soil pH value, parent material, elevation, soil layer and cultivation degree. Finally,the representative soils in Hunan are classified into four sensitive groups: the most sensitive, sensitive, less sensitive and not sensitive, with the SADC being 0-10mmol/kg, 10-30 mmol/kg, 30-60.mmol/kg, >60 mmol/kg, and the SADI being 0-8 mmol/kg, 8-18 mmol/kg, 18-28 mmol/kg, >28 mmol/kg.The third part is a study on the relative sensitivity of the soil ecosystem to acid deposition in Hunan Province. Firstly, based on the former parts’ analyses, five ecological factors, that is to say, parent material, soil acidity and alkalinity, soil type, vegetation type and humidity type, which are suitable for Hunan’ soil ecosystem, are selected, and every ecological factor is classified into 2-4 relative sensitivity classes according to their sensitivity to acid deposition. Secondly, in the light of accumulative weighted average assess model, the index system of the relative sensitivity to acid de更多还原