Extensive comparison of purificatory function of environmental pollutants by forest ecosystems

点击翻译按钮获取中文摘要

Extensive comparison studies were carried out to evaluate the function of forest ecosystems to purify the environmental pollutant.1. Water chemicals of rain and runoff stream water from thirteen forested watersheds which are located in the area of Hokkaido, Gifu, Mt.Hiei in Kyoto, and Takamatsu in Japan, Southern China and Northern Thailand were analyzed.According to Warmth Index, those six areas are classified in cool-temperate, warm-temperate or sub-Tropical zones.Both in cool-temperate and sub-tropical areas, major dissolved ions in runoff water were low comparing with those in warm-temperate area.2. In Shimane prefecture, high concentration of Na^+, Cl^-, NO_3^-, SO_4^<2-> ions was detected in snowfall.However, the effects of these chemicals on runoff water were not detected.3. In Yamaguchi Prefecture, wet-and dry-fall to the forest was separately measured.So-called man-made pollutants were contained more in dry-fall.4. On the three kinds of forest soils in Chugoku area, the hydraulic conductivity was compared using heavy water and heavy nitrogen.5. Through the measurements of natural abundance of ^<15>N in rain and soil water, denitrification in the watersheds was confirmed.