The Natural Environmental Science Research

Diatoms from Akan-ko (Lake Akan) in Hokkaido, Japan. 11. Raphid diatoms: Campylodiscus, Cymatopleura, Surirella and additional 10 taxa

Ayako KAWASHIMA, Shigeki MAYAMA

2004 Volume 17 Pages 1-21
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_1

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In this paper, a continuation of ten previous papers, 14 taxa belonging to the genera Campylodiscus, Cymatopleura, Surirella and 10 taxa belonging to the formerly reported genera are reported with light and scanning electron microscope photographs. Some comments are made mostly on the taxonomy and morphology of each taxon.

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Dissolved inorganic and organic nitrogen in throughfall and stemflow of coniferous trees in a nitrogen saturated forest

Akihiko NAEMURA, Tetsuo YOSHIKAWA, Muneoki YOH, Norio OGURA, Yukiko DO ...

2004 Volume 17 Pages 23-27
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_23

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Research survey was conducted in Tama Hills and Kamakura, suburban areas, where nitrogen saturation has been reported, and in Oku-Chichibu, a mountain range, to determine the quantitative effect of dissolve inorganic nitrogen (DIN; [NO₃ -N]+[NH₄ -N]) and dissolved organic nitrogen (DON) on Japanese cedar (Cryptomeria japonica) forest canopies. The total nitrogen value in through fall was 32.2 and 47.2 in the Tama Hills and Kamakura areas, respectively (unit: kg N ha^-1 yr^-1). DIN values were significantly higher in the suburban areas than in the mountain range. In the suburban areas, the DIN increased due to dry deposition. Similar DON values were obtained in all the research areas, including slightly larger DON values in older trees.

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Causes of long-term changes in organic pollution of a river system with increasing population: a case study in the Kurosegawa River, Higashi-Hiroshima, Hiroshima.

Asami OGURA, Takayuki NAKATSUBO

2004 Volume 17 Pages 29-36
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_29

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The Kurosegawa River, a polluted small river, flows through Higashi-Hiroshima, Hiroshima, where the population has increased steadily within the last decade. In order to clarify the impact of urbanization on the quality of the river water, changes in the state of organic pollution were studied in relation to population, construction of sewers and septic tanks in a recent 13-year period (1989-2001). Improvement in water quality (as indicated by BOD) was observed in the central area of the city, possibly as a result of the construction of sewers and septic tanks. In contrast, the BOD tended to increase in the lower reaches of the river. The pollutant flow analysis indicated that inflow of pollutant from a sewage treatment plant contributed to a significant proportion of the load. A simulation suggested that, with increasing population and sewage water, the BOD in the lower reaches of the river would be higher in the future because of the increase in the load from the plant. Based on the pollutant flow analysis, some solutions for reducing organic pollution are suggested.

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Eucladium verticillatum (Brid.) Bruch & Schimp. and Gymnostomiella longinervis Broth., newly found in Yokohama and Kamakura, Kanagawa

Shigeko SASAKI, Teruyo HIRAOKA

2004 Volume 17 Pages 37-41
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_37

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Eucladium verticillatum (Brid.) Bruch & Schimp. and Gymnostomiella longinervis Broth., designated as critically endangered or endangered species. were found in Sakae, Yokohama, Kanagawa. Eucladium verticiltatum had been found in the marine caves at the Miura Peninsula, Kanagawa, where Zushi stratum of Miura stratum group lies. This time, E. verticillatum was found on a wet cliff of Nozima stratum of Kazusa stratum group. Gymnostomiella longinervis was found on a separate dry cliff of the same stratum, which was the first report from Kanagawa.

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Fossil pollen assemblages of the Late Pleistocene Maebashi Peat Bed and palaeoclimatic oscillation at Takasaki, Gunma, centeral Japan

Takashi NIREI, Masakazu HAYASHI

2004 Volume 17 Pages 43-49
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_43

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Pollen analysis was conducted at the Maebashi peat bed, late Pleistocene, Takasaki, Gunma. Paleovegetation of approximately 13 to 21 Ka was reproduced and local pollen zones were determined. The paleo vegetation of this age was primarily comprised of conifer trees of the subarctic to temperature zone mixed with deciduous broard-leaved trees. The combined occurrence of Fagus and Quercus, which are major deciduous broad-leaved trees of the cool temperature zone, was subject to changes consistent with the paleoclimate change curve.

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Ecological status of naturalized plants in early stages of plant succession on different soils

Yuuya ISHII, Toshihiko NAKAMURA

2004 Volume 17 Pages 51-57
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_51

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Structural and compositional succession patterns of plant communities from bare ground were studied on three soil types, i.e. sandy, loamy, and Ando soils. In addition, the ecological status of naturalized plants was examined in relation to both succession and soil conditions. Differences in structure and composition of plant communities among soil types were small in the earliest (1st year) stage. However, they became larger with advancing succession. Naturalized plants mostly dominated in the succession stages on sandy soil. In the following (2-4th year) stages of succession, naturalized plants were dominant on all soil types; however, they were replaced by native plants in the later stages. The results suggested that naturalized plants were overwhelming in the stages where indigenous plants were still vulnerable, particularly on open and sandy soil that resembles their hometown habitats. Therefore, the establishment of native plants seems to be delayed in the succession.

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Diel activity periodicity of Exechesops leucopis (Coleoptera: Anthribidae) monitored by actography using infrared beams

Yoh MATSUO

2004 Volume 17 Pages 59-61
Published: 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_59

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In the beetle Exechesops leucopis, the male eyestalk is extremely elongated compared with the female's, and thought to be used in male-male combat for mates. In this study, in order to know the importance of visual cues in their activities, locomotion of 2 males and 2 females was monitored for 4 days using actography which records interruptions of a fine infrared beam by insects as pulses on the chart. As a result, locomotory activity was restricted to in the light period and, thus, development of the visual sense may be correlated with their diurnal activity.

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Campylopus gemmiparus newly found in Kanagawa

Hiroshi KIGUCHI, HIRAOKA Teruyo, Eiko KAWAASUMI, Shigeko SASAKI Shige ...

2004 Volume 17 Pages 63-66
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_63

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Campylopus gemmiparus Z. lwats. et al. (newly described in Japan in 2002) was found in Kanagawa. Illustrations and full descriptions including newly found perichaetial leaves of 10 samples found from four localities are presented.

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Bryophytes of Mt. Shoutousan and adjacent area, Kanagawa, Japan

Teruyo HIRAOKA, Sumiko ISONO, Showzaburoh HIRAOKA

2004 Volume 17 Pages 67-84
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_67

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146 species of moss, 56 species of liverwort, and one species of hornwort were recorded from approximately 850 specimens collected from Mt. Shoutousan and adjacent area, lying north of Lake Sagami, Kanagawa Prefecture. Taxa of phytogeographic interest included Fissidens geppii, Campylopus gemmiparus, Orthotrichum erubescens, O. exiguum, and Plagiochila yokogurensis.

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Naturalized plants of Suzaki, Shimoda, in Izu Peninsula, Shizuoka, Japan

Fumihiro KONTA, Sadamu MATSUMOTO, Teruo KATSUYAMA, Hideaki NOGUCHI, Iw ...

2004 Volume 17 Pages 85-93
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_85

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Suzaki, Shimoda is a small coastal area, approximately 3 km X 2.5 km, which is located in the southeastern part of Izu Peninsula, Shizuoka. The natural environment of this area is preserved in good conditions; the vegetation is characterized by dense natural forests of evergreen broad-leaved trees and coastal plant communities along a rocky sea shore, which is a part of the national park. Naturalized plants of Suzaki are compared from two viewpoints. One is a chronological viewpoint; the present distribution of naturalized plants is compared with that in 1980. The other is a geographical one; the naturalized plants of Suzaki are compared with those in Tama, which is a highly urbanized city in the metropolitan Tokyo area.
Based on our field work, 104 naturalized species belonging to 33 families are recorded. This number is double of that in 1980 and approximately one third of Tama.

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Distribution of opal phytoliths in shore zone of several region in Japan

Sei-ichi EGUCHI

2004 Volume 17 Pages 95-100
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_95

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Phytoliths originating from major Japanese coastal plants were investigated at six survey areas. Correlation between the phytolith's concentration or density in surface sediments was studied. In addition, relationships among the numbers of phytoliths, their grain size, and sediment grain size were studied at the Obitsu River estuary, Tokyo Bay. It was suggested that most of the phytoliths were transported by winds, and were deposited in lower areas or sites along with silt and very fine sand particles, such as salt ponds. Correlation between the density and the coverage and distance from the source suggested that the transportation efficiency or transportability of phytoliths decreased in the following order: “Phragmites australis type,” “Carex pumila type ・ Ischaemum anthephoroides type ・ Calamagrostis epigeios type,” “Leymus mollis type,” “Imperata cylindrica var. koenigii type”.

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Notes on Japanese Lycoperdaceae.

2. The genera Bovista and Lycoperdon in the herbarium of Hiratsuka City Museum

Taiga KASUYA

2004 Volume 17 Pages 101-106
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_101

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Six species of the genera Bovista and Lycoperdon (Lycoperdaceae) deposited in the herbarium of Hiratsuka City Museum, Japan are reported: Bovista aspera, B. dermoxantha, Lycoperdon caudatum, L. lividum, L. perlatum, and L. umbrinoides. Among these species, B. aspera is newly recorded from Japan.

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Nectar-source plants and their usage patterns by an adult butterfly community in a riparian biotope

Yoshitaka KAMIMURA

2004 Volume 17 Pages 107-115
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_107

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Flower visiting by butterflies for nectar feeding was studied quantitatively using the transect-counts method at a newly created riparian biotope located in Sakado, Saitama, central Japan. During the study period (May-November, 2003), 590 flower visits by 20 butterfly species were recorded. Although only 12 (34.3 %) of 35 nectar source plants were exotic plants, they received 74.2 % of the total flower visits. Dependency on exotics (the proportion of exotics to the total number of flower visits) varied seasonally and correlated negatively with the diversity of nectar sources which was determined by the Shannon-Weaner function. This trend implies that a few exotics are seasonally dominant (Erigeron annuus and E. philadelphicus in May-July, and Bidens pilosa and Solidago allissima in October-November). The comparison of the results of this study with those of a similar study conducted at Mt. Fuji, Japan, I suggest the possible use of the transect-counts of butterflies feeding nectar as a convenient method to quantify the prevalence of exotic plants.

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Common scops owl (Otus scops)

Morio URANO, Susumu OSAWA

2004 Volume 17 Pages 117-118
Published: December 11, 2004
Released on J-STAGE: December 25, 2024

DOIhttps://doi.org/10.32280/nesr.17.0_117

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A photographic report is presented on the morphologic and behavioral characteristics of the Common scops owl (Otus scops).

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