CHEMICAL CHARACTERISTICS OF ACID RAIN AND SNOW AND THE EFFECT ON FORESTS

Acid rain and snow that have fallen in Niigata Prefecture revealed characteristics to measure the pH levels and to analyze the components in the rain and snow. Also, the influence of the acid rain and snow on several kinds of trees, evergreen trees and broadleaf trees in a forest of Sado Island was considered. In addition, in mainly Niigata Prefecture, the influence of such acid rain and snow on the soil was also considered. The conditions of some forests in Czech Republic and former East Germany were reported with respect to social and natural conservation. From the measurement of the pH levels and the analysis of components of the fallen snow in Niigata Prefecture, the characteristics of the snow were almost the same as those observed in the snow along the coast of the Sea of Japan from Shimane Prefecture to Akita Prefecture. Using the multiple regression analysis method, the cause for the lower value of pH in the fresh snow has become evident as a result of mainly the sulfate ions contained in the snow. By the analysis of the components and the measurement of pH levels in each different depth of the piled snow, small amounts of chloride ions and potassium ions as well as lower pH levels were observed near the surface. A general characteristic concerning acid rain and snow in the forest, cedar, a kind of evergreen tree, has the capability to include more amounts of acidic deposits than the broadleaf trees because of the cedar's rougher trunk and evergreen leaves. While, the flowdown water of melted snow along the trunks of broadleaf trees was neutralized or relaxed with the basic substances released from the trees. The influence of acid rain and snow on soil is not such a serious problem at the present time. However, from the results of the pH measurement of soil and the amounts of Ieached-elements from the soil, e.g., phosphor, aluminum, calcium, etc., 43% of the sample soils gathered in mainly Niigata Prefecture was estimated to be already acidified. Various field surveys were performed in forests in September 1996. In spite of the limited area in Czech Republic and former East Germany, as many reporters pointed out, large forests were dead due to the acidic rain fall probably coming from the large consumption of brawn coal. A large amount of spruce, a kind of pine tree, was especially to be found dead in various places