Japanese Journal of Forest Environment
Online ISSN : 2189-6275
Print ISSN : 0388-8673
ISSN-L : 0388-8673
Volume 34, Issue 2
Displaying 1-8 of 8 articles from this issue
  • Yoshiaki GOTO, Osamu MAGARISAWA, Takeshi MORISAWA
    Article type: Article
    1992 Volume 34 Issue 2 Pages 73-79
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
    Vegetation recovery in a 19-year-old sugi (Cryptomeria japonica D. Don) forest was investigated for the first three after fire in Kiryu city, Gunma prefecture, northern Kanto district. Stephanandra incisa, Lespedeza bicolor yar. japonica, Oplismenus undulatifolius, Macleaya cordata, Miscanthus sinensis or Rubus microphyllus were the dominant species through the three years. Increase ratios of SDR_3 of R. microphyllus or S. incisa also declined in the thrid year, while some species such as M. sinensis, M. cordata and Pueraria lobata had high rate of increase in SDR_3 also in the thrid year, and the former two dominated next to L. bicolor var. japonica in the thrid year. The aboveground biomass of the study site had been increasing rapidly year by year, and that of the thrid year was seven times more than that of the first year. The species originating from the buried seeds such as L. bicolor var. japonica, M. cordata or Mallotus japonicus were the most important species contributed to the increase of the biomass. Numbers of species decreased in the second year while vegetation cover amounted to 100% in the year. MORISITA'S Cλ(ρ) between the study site and adjacent unburnt forests had been decreasing year by year. Many species migrated in the study site and made a high diversity community in the first year. While a few species increased in SDR_3 repidly and the degree of succession also increased in the second year, some species disappeared and the number of species decreased. Accordingly the diversity of the community changed into lower in the year. Though the number of species in the thrid year was about hte same as in the second year, it became a greater difference of SDR_3 among species, and consequently, the diversity of the community decreased further. The community will be expected to continue for the present in the condition that many dominant species will change one after another.
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  • Ryota ENDO, Tetsuo KODAIRA
    Article type: Article
    1992 Volume 34 Issue 2 Pages 80-84
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
    After researching on single storied stand of Sanbu-sugi standing on flat ground in Hokuso region, Chiba prefecture, it was attempted to find a relating between a relative illuminance and factors of stand structure, that is, tree height, crown length, breast height diameter, stand density. The result was as follows: RI=-(G×Hk)/(0.210H-0.738)+100 whereRI=Relative illuminance (%) H=Mean tree height (m) Hk=Mean crown length(m) G=Basal area (m^2/ha) Next, this equation and the volume increment shown in the yield tables of Sanbu-sugi stands were used to evaluatee the decrease of relative illuminance. From these results, the stand density tables for making multiple storied stand of Sanbu-sugi was made out. And it can be used for the judgement of propriety on making single storied stand of Sanbu-sugi into multiple storied ones and the decision of stand density of multiple storied ones after setting up.
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  • Yoosuke MATSUMOTO, Yutaka MARUYAMA, Yasushi MORIKAWA, Takao INOUE
    Article type: Article
    1992 Volume 34 Issue 2 Pages 85-97
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
    On experiment 1, simulated acid rain of sulfuric acid at pH 2.0, 3.0, 4.0, and 7.5 were sprinkled to two-year-old potted Cryptomeria japonica D. Don seedlings during four months. On experiment 2, simulated acid mist of sulfuric, hydrochloric, and nitric acids at pH 2.5, 3.5, and 7.5 were sprayed to two-year-old potted clone seedlings for three to five times a week during six weeks. On experiment 3, same mixed acids in experiment 2 at pH 2.5, 3.5, 4.5, and 7.5 were sprayed for three times a week with 0.1ppm O_3 exposure for five hours a day to two-year-old potted seedlings during 12 weeks. On experiment 4, high concentration of O_3 (0.5, 1/0, 2.0, and 3.2ppm) exposed to one-year-old potted clone seedlings for three hours after treatment of same simulated mixed acids mist in experiment 2 during five weeks. Visible injuries did not occer on pH 3.5 and 4.5 mist treatments, and on conbination of pH 2.0 mist and ozone treatments in experiment 2, 3, and 4. Dry matter production and fine root growth were decreased with decreasing pH of simulated acid rain and the effect of pH was markedly in pH 2.0 in experiment 1. Net photosynthesis and stomatal conductance were slightly increased in pH 3.5 and 4.5 mist treatments and these increases were accelerated markedly by the conbination of pH 2.5 mist and ozone treatments. Annual reports from air pollution obervatories in Japan suggests that NO_2 was almost constant leval (0.020-0.028ppm) from 1970 to 1990, and SO_2 was decreasing gradually from 0.057ppm to 0.010ppm for the period of 25 years before 1990 around Tokyo bay, one of the highly polluted area in Japan. The highest concentration of O_3 in a year was 0.39ppm in 1975, however, less than 0.23ppm in 1990 in Japan. These tendencies in decreasing air pollutions were allmost the same in the Kanto plains. Annual mean pH of wet deposition was 4.3-5.6 in Japan, and the mean values of pH were constant in resent year. From our experiments and the status of air pollution and wet deposition on the Kanto plains in Japan, we can not elucidate the causes of C. japonica tree decline in wet deposition and air pollution.
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  • Nobuyoshi ISAMOTO, Tatumi TAKAMIYA
    Article type: Comment
    1992 Volume 34 Issue 2 Pages 98-105
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
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  • Masayuki ARAKI, Kohji UCHIDA
    Article type: Comment
    1992 Volume 34 Issue 2 Pages 106-114
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
    Yearly observations of temperature and maximum depth of snow-cover were carried in 1989-'91 at six points setlled in beech forests respectively. On the record of temperature observed at five points where the maximum depth of snow-cover reached to over the sensor's height of thermometer as 150cm above ground, many specific tendencies were shown in winter season. It was thought that the reason for appearance of these tendencies is sensor, which is set inside a ventilation pipe, being buried under snow layer. Therefore, next analyses were carried to confirm the reason; cross comparison with three records as seasonal change of temperature (air or snow), estimated air temperature on the snow and depth of snow-cover which is observed nearest weather station; comparison of temperature (air or snow) with depth of snow they were observed simultaneously at a moutainous temporary observation site; experimental observation carried in Tsukuba. By these analyses some facts are established as follows; each specific tendencies are caused by the effect of snow-cover on the ventilation pipe, the beggining day when ventilation pipe had been buried in snow can be estimated from temperature record less than range two days, the appearance day of the ventilation pipe up to snow surface with snow melting can be estimated less range six days in this case.
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  • Koichi YAMAYA
    Article type: Comment
    1992 Volume 34 Issue 2 Pages 115-125
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
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  • Masahiro SAITO
    Article type: Document
    1992 Volume 34 Issue 2 Pages 126-131
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
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  • Keizo HIRAI
    Article type: Record
    1992 Volume 34 Issue 2 Pages 133-135
    Published: December 30, 1992
    Released on J-STAGE: October 20, 2017
    JOURNAL FREE ACCESS
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