Evaluation and Prediction of Forest Soil Acidification in Japan

通过实验和理论方法对日本森林土壤酸化进行了研究。从生态学的角度，对土壤酸化过程中铝的溶解和离子交换过程进行了特别的论述。研究了铝（Al）和盐基阳离子（Ca、Mg、K、Na）在土壤中的动态行为，评价了用邻苯二酚紫柱后衍生离子色谱法定量测定水溶液中Al的方法。腐殖酸铝和腐殖酸铝复合物的铝溶液的色谱图内的不同的峰进行了鉴定。草酸盐和铝溶液样品的热力学预测值与离子色谱法测定值定量吻合。利用模拟的酸性降水或穿透雨进行了饱和土柱实验。总离子浓度 关于我们 降雨量大于入射降水量。与入射降水相比，模拟穿透雨降低了土壤中阳离子交换的酸中和作用，提高了出水中铝的浓度。在模拟穿透雨中共存的阳离子中，钙离子和钾离子对土壤酸化的影响比钠离子更大。林地土壤阳离子交换量远高于无机土壤（A层）。结果表明，在土壤溶液pH值较高（4.5-5.15）的条件下，森林地被物延缓了无机森林土壤中铝的溶解，并使铝以有机络合物的形式存在，De弗里斯等提出的SMART模型常被认为是估算土壤酸化的通用模型。al.is SMART模型仅考虑铝的溶解和交换反应等物理化学过程。将结构化模型应用于柱实验，通过使用模拟的酸入射沉淀或穿透雨（pH3.3或4.0）进行。结构化模型能较好地解释实验结果，特别是在模拟酸入射降水和穿透雨的情况下。PH3.3。并对各参数取值的有效性进行了讨论。利用该模型对日本森林土壤化学性质的未来变化进行了百年预测。少

Japanese forest soil acidification was investigated by experimental and theoretical approach. From the ecological point of view, Special accounts were taken to the aluminum dissolution and ion exchange process derived from soil acidification. Dynamic behavior of aluminum (Al) and base cation (Ca, Mg, K,Na) in soil systems were evaluated and predicted.An ion chromatographic method in which Al is quantitatively determined via postcolumn derivatization with PCV (pyrocatechol violet) was evaluated for its utility as a method for speciating Al in aqueous solutions. oxalato- and humic aluminum complexes were identified by distinct peaks within chromatograms of Al solutions. Quantitative agreement between predicted species concentrations via thermodynamic data and determined by ion chromatography was obtained for oxalate and aluminum solution samples.Using the simulated acid incident precipitation or throughfall, saturated soil column experiments were carried out. Total ion concentration of t … More hroughfall is higher than that of incident precipitation. As compared with incident precipitaion, Simulated throughfall reduced acid neutralization by cation exchange in soil, and raised Al concentration in effluent. Among co-existing cation in simulated throughfall, the effect of calcium ion and potassium ion on soil acidification were more important than that of sodium ion.Another column experiments, using inorganic forest soil (A-horizon) and forest floor (O-horizon), were carried out. Cation exchage capacity of forest floor was much higher than that of inorganic soil (A-horizon). It was indicated that forest floor retarded the aluminum dissolution in inorganic forest soil and change aluminum species to organic complexes at the condition of relatively high pH (4.5-5.15) in soil solution.SMART Model proposed by De Vries et al.is often referred as a general model for estimate soil acidification. SMART model was simplified only to include the physicochemical processes such as the aluminum dissolution and some exchange reactions. The structured model were applied to column experiments which were carried out by using simulated acid incident precipitation or throughfall (pH3.3 or 4.0). The structured model could explain the experimental results especially at the case of both simulated acid incident precipitation and throughfall. of PH3.3. Also we discussed about the validity of each parameter value. Using this model, future changes of chemical property of forest soil in Japan were predicted for one hundred years. Less