Effect of sulphur dioxide on precipitation and on the sulphur content and acidity of soils in Alberta,Canada |
| |
Authors: | M. Nyborg J. C. Repin D. Hocking J. Baker |
| |
Affiliation: | 1. Department of Soil Science, University of Alberta, Edmonton, Canada 2. Canadian Forestry Service, Northern Forest Research Centre, Edmonton, Canada
|
| |
Abstract: | Rain and snow in Alberta are seldom acid. The S content of snow is so low that the snow pack gives a deposition of less than 1 kg S ha?1, even downwind from large SO2 emission sources. Rainfall contributes at the most 4 kg S ha?1 yearly near SO2 sources, and only about 1 kg S ha?1 in clean areas. However, rain intercepted by forest trees exposed to SO2 emission becomes acid (pH 3.5 to 4.5) and has a S content of 3 to 4 times greater than rain. Soils absorb large amounts of S from emissions (up to 50 kg S ha ?1 annually) but much of the S is found in non-sulphate form. Soils are slowly acidified by the SO2 at a rate estimated at 1 pH unit in 10 to 20 yr. Water surfaces will absorb SO2 emissions at a rate of about 4 to 15 kg S ha?1 annually. Particulates deposit 3 to 4 times as much S as is deposited by rainfall. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|