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Volume 32 (1990)
- Issue 2 Pages 43-
- Issue 1 Pages 1-
Volume 32, Issue 2
Displaying 1-6 of 6 articles from this issue
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T. SASSA, K. GOTO, K. HASEGAWA, S. IKEDAArticle type: Article
1990 Volume 32 Issue 2 Pages 43-58
Published: December 30, 1990
Released on J-STAGE: October 20, 2017
JOURNAL FREE ACCESSThey say, forests are being damaged in many parts of Europe, North America and Scandinavia by acid rain. In Japan also, the decline of adult Sugi tree (Cryptomeria japonica D. Don.) is going in urban areas, which is supposed by acid rain or acid materials from exhaust gases. The authors have an opinion that the influences of acid water will appear firstly on increase of soil acidity. Because, many kind of metals in soil will be exchanged to poisonous ions for tree fine roots or mycorrhizae, under such an acid soil condition. But, as it is extremely rare that rain water reaches forest floor directly without any touches on leaves, twigs, branches and stems, the water supplied to soil will certainly contain much amount of soluble nutrient elements derived from tree body, other than the amount in rain water. The other words, "the rain fall dropped on soil" means the throughfall or the stem flow changed in quality by such nutrient elements. The authors schement out a new method for collecting the stem flow and studied about the differences of acidity among rain fall, through fall and stem flow in relation to those nutrients' concentration. As the results of their study, they listed the following topics. 1) The acidity of stem flow always seems to converge to characteristic pH value in every species, independently of that of rain fall, as followings; Cryptomeria japonica: pH3.5〜pH4.1 Larix leptolepis: pH4.2〜pH4.8 Pinus densiflora: pH4.5〜pH5.2 Thujopsis dolabrata: pH5.0〜pH6.0 Fagus crenata: pH5.9〜pH6.5 2) The pH value of throughfall is always between that of rain fall and that of stem flow. 3) The pH value of stem flow is determined by multiple ionic action, not by single element. 4) The larger istheratio of(Ca+Mg+K+Na)/ organic-C in stem flow, the lower is the acidity. 5) The succeeding stem flow is different from the beginning one in the proportion between alkaline earth metals and alkali metals.View full abstractDownload PDF (1771K) -
Hiroshi YASUDA, Kunihiro FUJII, Reiko OKAMOTOArticle type: Article
1990 Volume 32 Issue 2 Pages 59-64
Published: December 30, 1990
Released on J-STAGE: October 20, 2017
JOURNAL FREE ACCESSChemical compositions of precipitation were measured at six sampling points in Toyama prefecter in the Hokuriku district during the piriod from April 1987 to March 1988. And pH, EC and concentrations of eight dissolved ions were measured and the property of the precipitation was investigated. The pH and EC of precipitations were in the range of 4.51 to 4.75 and 9.77 to 40.13μs/cm, respectively. The maximam frequencies of pH in the precipitation of the six sampling points concentrated at 4.4 to 5.0. On the assumption that the acid deposition was defined by the precipitation with a pH of less than 5.6, 70-90% of the precipitation were found to be the acid deposition. The dissolved ions in precipitation were consisted of six cations and three anions. The concentration of six cations and three anions in the precipitation were 43.5-280. 1 and 43.3-263. 3μeq/l, respectively. Ratios of equivalent composition of Cl^-/Na^+ in the precipitation was resemble to that of sea water. Contribution of sea salt to the dessolved ions in precipitation at coastal, urban and inland region. Annual amount of dopositions of SO_4^<2->, Cl^-, Mg^+ and Na^+ components were remarkablly revealed in regional difference. The amount of depositions of those decreased according to inland mountainous region from urban region.View full abstractDownload PDF (646K) -
Yojiro MATSUURA, Isao HOTTA, Makoto ARAKIArticle type: Article
1990 Volume 32 Issue 2 Pages 65-69
Published: December 30, 1990
Released on J-STAGE: October 20, 2017
JOURNAL FREE ACCESSDownload PDF (538K) -
Makoto NASHIMOTO, Keiji TAKAHASHIArticle type: Article
1990 Volume 32 Issue 2 Pages 70-78
Published: December 30, 1990
Released on J-STAGE: October 20, 2017
JOURNAL FREE ACCESSThe relationships between probable causal factors of damage and actual health and damage to Japanese cedar (Cryptomeria japonica D. Don) trees in the Kanto-Koshin and Kansai-Setouchi Districts were studied. The causal factors included the combination of secondary air pollutants with levels of precipitation, and soil condition. Large trees, especially large healthy trees, were fewest in damaged zones coinciding with regions having high concentrations of secondary air pollutants and low levels of precipitation. On the other hand, many large healthy trees were found in zones having low concentrations of secondary air pollutants and either high or low levels of precipitaion. Therefore, we can infer that the low number of large healthy trees in damaged zones is a result of exposure to damaging secondary air pollutants. It was found that the number of damaged trees was not related to the condition of soil surface, represented by the percentage of bare ground compared to the percentage of litter or plant-covered ground under the tree crown. It is generally believed that higher percentages of bare ground causes deterioration of soil conditions (i.e. hardness and soil acidificaton) due to a shortage of nutrient baring compost. However, we found that changes in the percentage of bare ground did not correlated to cedar damage as of the date of this study.View full abstractDownload PDF (1017K) -
Yasuyuki OKIMORI, Paulus MATIUSArticle type: Report
1990 Volume 32 Issue 2 Pages 79-87
Published: December 30, 1990
Released on J-STAGE: October 20, 2017
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Kiyoshi MIYAKAWAArticle type: Translation
1990 Volume 32 Issue 2 Pages 88-94
Published: December 30, 1990
Released on J-STAGE: October 20, 2017
JOURNAL FREE ACCESSDownload PDF (1109K)
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