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Volume 19, Issue 2
Displaying 1-5 of 5 articles from this issue
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Toshiharu WATANABE1957 Volume 19 Issue 2 Pages 45-50
Published: November 30, 1957
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESS1. A study of algal ecology was made in a waterfall “Ryuo-daki” at Tsukigasemura, Nara Prefecture, in August, 1956.
2. The waterfall is regarded as a mosaic of some different environmental complexes and some different biotic communities.
3. Five points which differ in conditions from each other were selected on the rock wall of the waterfall (Fig. 1), and their algal communities were studied (Table 1). The main factor controlling the difference between the communities selected is probably the rate of flow of water which supports the algal communities.
4. Achnanthes crenulata GRUNOW which is a rare species in Japan was found in this waterfall, and was a dominant component of the algal communities at some parts. Besides a short note of its ecology, its morphology is also given.View full abstractDownload PDF (1424K) -
Mikio NAGASAWA1957 Volume 19 Issue 2 Pages 51-58
Published: November 30, 1957
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSThe first examination of the water of a newly drilled well was made just after the sinking was finished.
The strainers were then set up at four layers, the first 10-13 m, the second 16-20 m, the third 27-31 m, and the fourth 42-45 m respectively. The well has been covered up tightly for 3 months after the first investigation was made. Then the water pumped out and was examined. The analyses showed that the water contained the ferrous iron, ferric iron, chloride, bicarbonate, and free carbon dioxide in two or three times as much the amounts as before the investigation began. After then, however, the findings have proved that the quality of water becomes to be the same as that at the time of the first examination was made.
A method of eliminating large quantities of iron from water was discussed.View full abstractDownload PDF (670K) -
Shoji HORIE1957 Volume 19 Issue 2 Pages 59-67
Published: November 30, 1957
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (1227K) -
Ken-ichiro NEGORO1957 Volume 19 Issue 2 Pages 68-71
Published: November 30, 1957
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSIbanai-ko, or Nakanoumi, is a small lake which lies on the east coast of Lake Biwa-ko. Ten years ago, one fourth of its flat shallow basin (2-3 m in depth) was reclaimed for the construction of paddy-fields, leaving the water surface of 14.5 km2.
The composition of the plankton of this lake was studied in the late summer of 1953 so as to use as trophic indicators of that lake.Pediast Aum BiwaeNEGORO is the dominant species in the warm season, making up 90 % in composition of the plankton. The remaining 10 % of the community is constituted by Ceratium hirundiella, Eudorin Eelegansand several species of zooplankters.
Differing from the oligotrophic nature of the main basin of Lake Biwa-ko, Ibanai-ko was appreciated by the late Dr. S. YOSHIMURA (1937) as the eutrophic type, but the author recognizes this water-mass merely as a mesotrophic type, because its summer plankon lacks entirely the blue-green algae (Cyanophyceae), by which the water-bloom is ordinary caused in summer as in many eutrophic lakes.View full abstractDownload PDF (442K) -
The Plankton and the environmental conditions of the freshwater ponds on the coast of the Inland SeaToshihiko MIZUNO1957 Volume 19 Issue 2 Pages 72-74
Published: November 30, 1957
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (286K)
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