The influence of Yellow-sand (KOSA) on the forest, the presumption of the sulfur sources identification and the contribution rate of dry deposition

黄沙(KOSA)对森林的影响、硫源识别推论及干沉降贡献率

基本信息

批准号：
15380114
负责人：
SAKAI Masaharu
金额：
$ 7.23万
依托单位：
Forestry and Forest Products Research Institute
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2006
项目状态：
已结题

项目摘要

In this research, it aims to evaluate the influence of Yellow-sand (KOSA) on the forest, to identify sulfur sources of SO_4^<2-> of rainwater (precipitation, thoughfall, stemflow) by the sulfur isotopic method, and to estimate contribution rate of dry deposition on total deposition.The outline of the result at all periods is as follows.We investigated qualitative change of rainwater in an evergreen broadleaved forest in a southern part of Japan1. KOSA flies from a continental desert to Japan at the early spring. Observation frequency of KOSA is an increasing tendency for the long term. In the spring of 2002 when the especially maximum KOSA in Beijing was observed, the color of aerosol filter presented yellowish. The Ca^<2+> concentration of the aerosol at KOSA event became 20-70nmol/m^3, and was higher than these values (20 nmol/m^3 or less) at normal event. The ion concentrations in precipitation, thoughfall and stemflow at KOSA event were higher than these at normal event. The influe … More nce on the forest by KOSA was admitted.2. The sulfate concentration and sulfur isotopic ratio of the wet deposition at 20 precipitation events and the dry deposition at 9 precipitation events were determined. The SO_4^<2-> concentrations increased in the order of precipitation, throughfall and stemflow, whereas their sulfur isotopic ratio( δ^<34>S) decreased in the order of precipitation, throughfall and stemflow. These results suggest that δ^<34>S-depleted light sulfur is added to throughfall and stemflow. On the other hand, δ^<34>S values of aerosol and gas were +2.7〜+5.3‰ and-2.1〜2.0‰, respectively. The latter is light enough to reduce the δ^<34>S values of throughfall and stemflow. Therefore we concluded that 1) SO_2 in dry deposition is the main substance causing low pH of stemflow and throughfall, 2) a lot of SO_4^<2-> with light δ^<34>S value are loaded to precipitation flowing down as stemflow and throughfall.3. About 60 percent of total deposition (wet deposition and dry deposition) was loaded to the forest by a dry deposition, using the mass balance model. Less

在这项研究中，它的目的是通过硫同位素方法对黄色鲜菜（KOSA）对森林浮动的影响，尽管降落了，但要估计沉积的贡献率。所有时期的结果atline atline atline astlins aster.we.we we we。在春季的一个春季，在春季观察到了春季的质量变化+>在KOSA事件中的气溶胶浓度变为20-70nmol/m^3，在正常事件时，这些值（20 nmol/m^3或更少）比正常事件时的GHFARF和Stemflow。事件的爆发...最早的kosa被接受。降水，贯穿和干液的顺序，而它们的硫同位素比（Δ<34> ation，贯穿和茎流。这些结果表明δ^^^<34> s depleded的光硫添加到贯穿和茎流中。另一方面，另一方面， δ^<34> s的光足以减少to throfly和stemflow的δ^<34> s so_2在干沉积中的so_2是引起l的主要物质，2）很多so_4^<2-> with光Δ^<34>使用质量弹出模型，约为总沉积的60％