択伐方式によるシカラシ薪炭林の生産機構に関する研究(第3報) : シラカシ皆伐薪炭林の林分構造および林分収穫予想表の作成

For the purpose of establishing an empirical yield table of "Shirakashi" coppice forest in the Takae-Sunji village (Hakuta choo, Noki district, Shimane prefecture), 39 sample plots were measured during 8 days, in Aug. 1963, by fully density stand that "Shirakashi" mingle with over half. Results of sample plots are shown in Table 1.
First of all, the stand structure of the Shirakashi coppice forest were studies 39 sample plot data. The calculation of the factors (Mean diameter breast high, mean height of dominant trees, tree number, basal area and volume) were made on the basis that all factors were a function of years. The result of calculation were as follows.
1) Diameter distribution of the coppice stand were applied Meyer's formula. The relation of the formula's coefficient and years, κ and α were as follows.
log κ = 4.8814-1.4273 logA
log α = 0.4511-0.6993 logA
log α = 2.17697＋0.4604 logκ
And the results of calculation are shown schemally in Fig 1～4.
2) The relation of every factors and years were as follows.
<tt>
mean diameter(Fig.5) D = 0.8327・A^<0.4518296>
mean height(Fig.8) H = A / (0.04974・A＋1.37150)
number of tree(Fig.9) N = 90734・A^<-0.44765>
basal area (Fig.10) G = A / (0.01538・A＋0.35879)
volume (Fig.11) V = A / 0.001843・A＋0.106499
</tt>
Regression coefficient of each formulas is highly significant. And 68 % confidence band are shown in every figures. But the volume value revised by free hand as rationally growth curve.
Results of the empirical yield table by estimate of the previous calculation is shown in Table 12. The annual mean volume increment per ha of the Shirakashi cppoice forest in this district estimated amounts to 7.8 m^3 at 20 years, and this increment is about three times larger than the growth of the deciduous wood in this region.