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Fields Surveys in the Forests Affected by Acid Snow and Rain

对受酸雪雨影响的森林进行实地调查

基本信息

批准号：
07680575
负责人：
TAGUCHI Yoji
金额：
$ 1.28万
依托单位：
NIIGATA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07680575/
关键词：
Acid Snow and Rain pH Anions Forest Soil Acidification Dissolved Aluminum and Phosphorous Acid shock 森林(スギ)

项目摘要

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 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.From some field surveys in the forests at Niigata Prefecture, few withered trees due to acid snow and rain have been found, although the possibility such damaged trees should exist. 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 flow-down water of melted snow along the trunks of broadleaf trees was neutralized or relaxd 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 leached-elements from the soil, 35% of 113 soil samples mostly gathered in the Niigata Prefecture was estimated to be already acidified.There is a remarkable tendency for the hydrogen ion concentration in snowmelt water in the early spring to be higher than that in the late spring. The fresh fallen snow on the ground is compressed by repeated dissolution and crystallization and forms icy granular snow. The repetition causes sulfate, nitrate and chloride ions to be concentrated near the surface of the icy granular snow. Some laboratory experiments were performed to examine this concentration phenomenon by the formation of spherical ice.

从新泻县降雪的pH值测量和成分分析来看，降雪的特征与岛根县至秋田县日本海沿岸的降雪几乎相同。利用多元回归分析方法，发现新雪pH值较低的原因主要是雪中含有的硫酸根离子。从新泻县森林的一些实地调查来看，虽然应该存在这种受损树木的可能性，但很少发现因酸雪和酸雨而枯死的树木。雪松是一种常绿树，由于雪松的树干较粗糙，叶子常绿，因此比阔叶树能够含有更多的酸性沉积物。而沿阔叶树树干流下的融雪水则被树木释放出的碱性物质所中和或缓和。酸雨和雪对土壤的影响目前还不是一个严重的问题。然而，从土壤pH测量结果和土壤淋滤元素量来看，在新泻县采集的113个土壤样本中，估计有35%已经酸化。早春融雪水中的氢离子浓度有明显高于晚春的趋势。地面上刚落下的雪，经过反复溶解、结晶而被压缩，形成冰冷的粒状雪。这种重复导致硫酸盐、硝酸盐和氯离子集中在冰粒雪表面附近。进行了一些实验室实验，通过球形冰的形成来检验这种集中现象。