Research for chemical reaction and transportation of chemical elements as a successive reaction system in forest ecosystem

酸性物质的沉积会影响森林生态系统的养分循环。本研究的目的是将养分循环系统视为雨水依次与树叶、树干和土壤接触的流动过程中的一个连续的化学反应系统，并评价酸性物质的影响。在本研究中，利用HINOKI进行了两个实验：第一个是连续野外观测，以确定干沉积对叶表面淋溶过程的影响。结果表明，干沉降影响了阴离子在叶表面的行为，可能会增强阴离子在叶表面的渗透性。第二个实验是在Hinoki林分利用人工雨水进行的大规模降雨实验。雨水的PH值调整为6.8的3.2。研究了穿透雨、树干径流和土壤水中化学元素的浓度变化。结果表明，钾离子从叶和茎中淋失，钙离子被吸收到叶和茎中。钠离子与树体表面的相互作用很小。叶片、茎和土壤中无机阴离子浓度变化不明显。结果表明，有机阴离子的存在在体系中起着重要作用。

Nutrient cycle in forest ecosystem would be affected by deposition of acidic materials. The purpose of this study were to consider the nutrient cycle system as a successive chemical reaction system through a flow process of rain water contacting with leaves, stem and soil, successively, and to evaluate the effect of acid materials. In this study, two experiments were performed by using HINOKI.The first was the continuous field observation to determine the effect of dry deposition on leaching process from leave surface. As the results, it was recognized that the behaviors of anions on leaf surface were affected by dry deposition and their penetration through leaf surface might be enhanced. The second experiment was a large-scale rain fall experiment using artificial rain water in HINOKI forest stand. pH of rain water were adjusted to 3.2 of 6.8. The concentration change of chemical elements in through fall, stem flow and soil water were pursued. As the results, it was found that potassium ion is leached from leaves and stem and calcium ion is uptake into leaves and stem. Sodium ion has little interaction with the surface of tree. On the other hand, the change in concentration of inorganic anions through leaves, stem and soil was not found. It is suggested that the existence of organic anions is important in the system.