DIGITALNA ARHIVA ŠUMARSKOG LISTA
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|ŠUMARSKI LIST 1-2/1960 str. 36 <-- 36 --> PDF|
THE SHARE OF ASSORTMENTS AND THE AMOUNT OF WASTES IN THE
FELLING AND ROUGH CONVERSION OF FIR STEMS IN THE PLANT
COMMUNITY OF ABIETETO-BLECHNETUM
Discussed are the respective shares of assortments and wastes in the felling
and primary conversion of Fir stems in the plant community of Blencho-Abietum,
site class II, in the area of the Zalesina forest district in Gorski Kotar. Produced
were: sawlogs, pitprops, pulpwood and fuelwood. At the cutting into assortments
the decisive role was played by the dimensions and to a lesser extent by the
quality. Wastes were not treated in a cumulative manner but according to the component
parts (bark, excess measure for »nosing« logs for skidding, and the error
of Huber´s formula). The waste for the notch in felling trees was neglected owing
to its small size. From the losses due to the rounding off when measuring the diameters
of sawlogs and mining timber presented were their upper and lower limits
as well as the average value only in percentages.
As to the measuring data in table 1 one can notice a correlation between the
diameter b. h. on the one hand and the obtained assortments and wastes on the
other. On the basis of this interrelationship the data were smoothed numerically
by means of the correlation equations as follows:
a) sawlogs, bark and waste for »nosing« the logs by means of a standard
straight line equation: y = ax + b;
b) pitprops, fuelwood and pulpwood, and the error of Huber´s formula by
means of the equation: y = axb.
In these equations x represents the diameter b. h. over the bark, y the smoothed
volume of assortments and wastes; a and b are the parameters of the equation.
The share of some assortments and wastes is directly proportional and of some
of them inversely proportional with respect to the increase of d. b. h.
When using table 3 in practice in order to determine the percentage of assortments
and wastes it is to be mentioned that the volume of the stands — to which
the data are intended for application — ought to be established separately according
to the diameter gradations. The data from table 3 are applicable only to the
area from which the measuring data are derived, i. e. for the plant community of
Blechno-Abietum, site class II.
(Primljeno u štampu 19. VI. 1959.)