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Volume 48, Issue 2
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Masahisa NISHIZAWA1966 Volume 48 Issue 2 Pages 45-47
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSBy the note of Lars Strand (Forest Science 10 (1), 1964 p. 51), a relascope consisting of a fixed opening, mounted on a rod of variable length, may be used directly to estimate the volume of a stand
on the field. If we use a relascope with wide scale, we can estimate directly the volume per hectare
of a stand, too.
When vi is the volume per ha (m8), (fh)i is the form height and the stem number counted by the basal area factor ki is ni,
vi=ki(fh)i ni (1)
If we put ki
(fh)i=Ci (2)
we get vi=Ci ni (3)
In this equation, Ci is called the volume factor in contrast to the basal area factor.
There are next two cases for the estimation of the volume per hectare by use of the, volume factor.
(1) Constant volume factor and variable relascope units (RE)i.
From equation (2), we get
ki=Ci/(fh)i
If we know (fh)i of a stand, we can calculate ki according to constant Ci (for example, 10, 20, 30, 40, 50 etc.). As (RE)i=√ki, we can get the neccesary number of relascope unit(RE)i.
Stem number counted by (RE)i multiplied by the constant volume factor is the volume per hectare. In this case, we had better use a small volume factor for a young stand and a large one for an old stand.
(2) Constant relascope unit and variable volume factor.
If we use a constant relascope unit, i.e. √1, √4, √9 etc., we can
calculate variable volume factor Ci according to (fh)i from equation (2).
In this case, the stem number counted by the constant relascope unit multiplied by the volume factor is the volume per hectare.View full abstractDownload PDF (205K) -
On Development Road DensityMinoru KAMIIZAKA1966 Volume 48 Issue 2 Pages 48-54
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSIn forest development area, forest roads are also useful as public roads and it plays a role in regional development.
In this paper, the relationship of the density of forest roads to that of public roads, which changes with the distance from the timber market, is studied on a trial basis, in several famous forestry areas.
The following results were obtained:
(1) The minimum value of the development road density in the forestry industrial area is assumed to 300 m/km2.
(2) The combination of road network for the lowest total cost of the vehicle running cost and the cost of road construction and maintenance is assumed to that consisting of the forest roads occupying some 40% in the total length of all roads.
(3) In respect of the road structure, almost all roads are of the middle-class gravelled roads, and the Road Ability Density value which has been adjusted taking into consideration the width and the road surface conditions is found to be less than 400m/km2.View full abstractDownload PDF (474K) -
Primary Productivity of a Young Cryptomeria Plantation with Excessively High Stand DensityYoshiya TADAKI, Yoshinori KAWASAKI1966 Volume 48 Issue 2 Pages 55-61
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSA dense Cryptomeria japonica stand, composed of many different clones grafted on two-year-old seedling stocks in 1959, was investigated in the fall of 1964 near Kumamoto City. Total standing crop was estimated at 97. 3 t/ha in dry weight, of which 26.5 t/ha was the biomass of foliage and leaf-bearing green twigs. The latter value was the largest among all Cryptomeria stands hitherto known, showing that the stand had already reached the pole stage due to the very high density (29, 500 trees/ha) and favorable site conditions. Relative light intensity under the canopy averaged 1. 1 percent, and the coefficient of light extinction was 0.26/LAT. Net production, or the sum of the annual wood increment (22.5 t/ha/yr) and the amount of yearling leaves (6. 6 t/ha), was 29. 1 t/ha/yr. Tentative estimation of the annual respiration loss in leaves (51. 5 t/ha/yr) and woods (3.5 t/ha/yr) led to a very high gross productivity, 84. 1 t/ha/yr in dry matter equivalent to an efficiency in the solar energy conversion of 2.8 percent for the whole year. The advantage of dense stands in the dry matter production is discussed.View full abstractDownload PDF (516K) -
Effect of Chronic Gamma Irradiation on the Growth and Foliar Cell Division of Japanese Larch, Larix leptolepsis in a Gamma FieldMasafumi MURAI, Kihachiro OHBA1966 Volume 48 Issue 2 Pages 62-68
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSThe effects of chronic gamma irradiation on the growth of Japanese larch, Larix leptolepsis, in a gamma field were studied with cytological observation. Hundred percent lethal dose rate of the sapling was 13r/day in the first year and no cumulative effect of the radiation on the lethality was noted during 1962 to 1965. Annual height increment was inhibited at about 2r/day, and 50% reduction dose rates were estimated for the height increment 2.5-4.5r/day and for the breast height diameter, the leaf length, and the leaf number per leaf fascicle 7-9r/day, respectively. Internal morphological changes in leaves such as the missing of lateral resin canals or irregularity of the cell size in endodermal sclerenchyma cells significantly rose with the increasing dose rate. Moreover, in newly sprouted leaves, abnormal cell division represented by the percentages of the cells with chromosomal bridge for all dividing cells had also a plus correlation with the dose rate, but showed no cumulative effect in successive years. In a similar meaning as in the above stated growth traits, 50% reduction dose rate of the frequency of cells with the bridge was estimated as 10r/day and it had a high consistency with those of the growth traits except the annual height increment. Though there was detected no somatic mutation in the saplings in this experiment, it is clear that genic and chromosomal aberration in the cells of the growing points might result induction of somatic mutations, and there should be an optimum dose rate range in which higher aberration but lesser damage of cell division were expected for the induction of somatic mutations under chronic gamma irradiation.View full abstractDownload PDF (1539K) -
Takanobu Furukoshi1966 Volume 48 Issue 2 Pages 69-71
Published: 1966
Released on J-STAGE: December 18, 2008
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1966 Volume 48 Issue 2 Pages 71
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSDownload PDF (69K) -
Kazuhiko TAKATA1966 Volume 48 Issue 2 Pages 72
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSDownload PDF (81K) -
Saizo KUMAGAI1966 Volume 48 Issue 2 Pages 73-74
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSDownload PDF (122K) -
Yukio MOMOSE1966 Volume 48 Issue 2 Pages 75-77
Published: 1966
Released on J-STAGE: December 18, 2008
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Tadashi FURUKAWA1966 Volume 48 Issue 2 Pages 78-83
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSDownload PDF (426K) -
Sumihiko ASAKAWA, Akinori NAGAO1966 Volume 48 Issue 2 Pages 84-87
Published: 1966
Released on J-STAGE: December 18, 2008
JOURNAL FREE ACCESSDownload PDF (333K)
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