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 (366Kb)
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40,861,000 Yen (FY1995 13,739,000 Yen)
Sugi(Cryptomeria japonica) seedlings cultivated in low mineral soils revealed that potassium concentration in shoot clearly corresponded with soil exchangeable potassium concentration. Sugi seedlings cultivated in sufficient or low potassium soil revealed that their photosynthetic rate and stomatal conductance both decreased along with drought, but some delay occurred on seedlings grown in low potassium soil. In shrine or temple garden located in Kantoh area, potassium concentration of old Sugi needles or exchangeable potassium concentration of the soils were somewhat low in declined stands. Soil pH were very low in narrow area near stems in Sugi and Hinoki(Chamaecyparis obtusa) stands in southern Japan, because of low pH of the stemflow. Sugi seedlings were cultivated in two types of brown forest soil: acidic soil and neutral soil. For one and half years, total amount of additional H2SO4(pH=2) was 18750ml each pot. There were little influences of H2SO4 solution on root development, root biomass and root activity. For the estimation of critical load by acid deposition in Japanese forests, the forest site database is formed and analyzed. Japanese forest soils are strongly acidic and have already contained plenty exchangeable aluminum. Exchangeable cation concentrations are useful information for estimation of acid buffering capacities. Exchangeable acidity is more useful and practical data than exchangeable cation, because of information size. The effects of volcanic ash erupted in quaternary period are clear in surface soil pH.
Acid Deposition, Critical Load, Mineral Deficiency, Stemflow Zone, Buffering Capacity