Catchment study on micro-constituents derived from combustion of fossil fuels

为了研究化石燃料燃烧产生的微量组分的地球化学行为，在东京郊区、山梨县、栃木县和长野县的小森林集水区收集了水、气溶胶、地表水和土壤样品，并在长野县的湖集水区研究了物质循环。湖的碱度和电导率很低，因此，人们认为梅克湖对酸沉降很敏感。在山梨县的志必雷湖也进行了类似的研究，大气存款中的硫酸盐有一部分来自北方地区，硝酸盐主要来自南方城市地区，多摩山林区湿沉积中硝酸盐与非海盐硫酸盐的比例较高（1.1），高于日本平均值（0.35）.从地表自来水中硝酸盐浓度高判断，可能出现氮饱和，在东京多摩山森林集水区，土壤中硝酸盐的垂直分布和硝酸盐从土壤中的高沥滤率，在那里观察到温室效应气体二氮氧化物的排放量很高，通过对硫酸盐稳定硫同位素比值（^ S）的测定，<34>估算了亚洲大陆排放的二氧化硫在大气中的迁移，多环芳烃（PAHs）在日本上空被氧化成硫酸盐，然后沉积到日本岛上。化石燃料燃烧产生的二氧化碳被捕获到树叶的蜡层和/或沉积在树叶的表面，然后通过降雨提供给森林地面。

In order to study geochemical behavior of micro-constituents derived from combustion of fossil, fuels, samples of atomospheric deposition(wet and dry) ,aerosol, surface water and soil were collected at the small forest catchment areas in the suburb of Tokyo, Yamanashi, Tochigi and Nagano Prefectures.Material cycles were studied at the watershed of Lake Meike, Nagano Pref. Alkalinity and electric conductivity in Lake Meike were very low, and therefore Lake Meike is considered to be sensitive ; to acid deposition. Similar studies were carried out at Lake Shibire, Yamanashi Pref., and it was estimated that a part of sulfate in atmospheric deposit were transported from northern areas and nitrate was mainly from southern urban areas.Proportion of nitrate to non-sea salt sulfate in wet deposition was higher at the forest area in Tama Hill(1.1), than that of average value in Japan(0.35).It was suggested that nitrogen saturation may occur, judging- from high nitrate concentration in surface running water, vertical profile of nitrate in soil and high leaching rate of nitrate from soil, at the forest catchment area in Tama Hill, Tokyo, where emission of dinitrogen oxide, greenhouse effect gas, was observed to be high, compared with other forest areas.It was estimated from the measurement of stable sulfur isotope ratio( ^<34>S)of sulfate, sulfur dioxide emitted at the Asia continent is transported, oxidized to sulfate in the skies of Japan and then deposited to Japan island.It was suggested that a part of polycyclic aromatic hydrocarbons(PAHs)derived from combussion of fossil fuels were trapped to wax layers of the leaf and or deposited on the surface of the leaf, and then supplied to the forest floor by rainfall.