DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu



ŠUMARSKI LIST 1-2/2009 str. 39     <-- 39 -->        PDF

Ž. Zečić, I. Stankić, D. Vusić, A. Bosner, D. Jakšić: ISKORIŠTENJE OBUJMAI VRIJEDNOST DRVNIH ...Šumarski list br. 1–2, CXXXIII (2009), 27-37


The utilization percentage of wood volume is determined as the ratio of the
produced wood volume and the volume of large wood over bark according to
Schumacher-Hall (Table 2). In the sample, the utilization percentage ranged
from 35.79 % to 87.10 % with an average of 71.97 %, or 73.54 % (Median).
Wood waste amounted to 28.03 % (26.46 %) on average. In the “3b” damage
class the average breast diameter was 53 cm and height was 31 metre.
Overall marked volume was 157.31 m3, the volume of processed wood over
bark was 137.07 m3, and that under bark was 120.42 m3. The average percentage
participation of bark was 12.69% and was lower by 0.6 % than that in
the “4” damage class. With regard to the net structure of 116.54 m3 of roundwood,
technical roundwood accounted for 77.13 m3 (66.18 %), and pulpwood
for 39.41 m3 (33.82 %). Within overall utilization, 49.03 % related to
technical roundwood and 25.05 % to pulpwood. With regard to the quality of
felled trees, only logs in class I, II and III were produced, while the remaining
volume related to pulpwood. In the structure of produced wood assortments,
class I accounted for 19.85 %, class II for 43.78 %, and class III for 36.37 %.
Of the total number in the sample, 156 trees were in the crown damage class
“4”. These trees had an average breast diameter of 46 cm and a height of
29 m. The total volume of marked trees was 413.64 m3. The volume of processed
wood over bark was 356.60 m3 and volume under bark was 312.56 m3,
which shows that bark participates with 13.31% in the total wood volume. A
quantity of 302.51 m3 of wood assortments was produced, of which technical
roundwood accounted for 114.01 m3 and pulpwood for 188.51 m3. The percentage
share of wood waste was 26.86 %. Overall utilization was lower than
in class “3b” and amounted to 73.14 %. Within total utilization, 27.56 %
related to technical roundwood and 45.57 to stacked wood. In terms of structure,
technical roundwood accounted for only 37.69 % and pulpwood for


62.31 % of the net volume. Only logs in class I, II and III were produced. In
the structure of produced wood assortments, only 5.02 % related to class I,
30.39% to class II and as much as 64.59 % to class III.
Monetary value of trees is determined on the basis of volume of a particular
diameter class and the price of principal forest products. The price of
forest assortments made from standing trees (“stump price”) was used to calculate
monetary value of wood volume. According to the pricelist, monetary
value of assortments was divided into three price classes based on the mean
saw log diameter. The largest number of assortments was in the price class of
pulpwood, for which an index of 1.00 was determined. Value indices given in
Table 3 were established on the basis of the price ratio of other price classes
and the mentioned one. Multiplying the price class index with assortment
volume resulted in the assortment value index. The sum of all assortment
value indices of individual trees is the relative value of the produced wood
volume, i.e. relative tree value. Stem value rises with an increase in breast
diameter. The value of damaged trees (Figure 7) in crown damage class “3b”
is lower by more than 20 %, and the value of trees in class “4” is lower by
more than 35 % in relation to the value of undamaged trees from regular
selection cuts. Value increases per wood volume unit (Figure 8) in accordance
with an increase in tree breast diameter. The reason is the absence of certain
quality classes in the thinnest trees and division of monetary value
according to the prescribed assortment diameter. The relative value of wood
volume unit in crown damage class “3b” is lower by 10 % to 30 % than the
value unit of undamaged trees. In crown damage class “4”, the values of
volume unit are lower by 30 % to 45 % in relation to undamaged trees.
Key words:silver fir; dead tree; utilization; roundwood; timber value