DIGITALNA ARHIVA ŠUMARSKOG LISTA
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|ŠUMARSKI LIST 7-8/2003 str. 72 <-- 72 --> PDF|
.1. Zelić, B. Puača: PRILOG ODREĐIVANJU NORMALA ZA MJEŠOVITE PREBORNE SASTOJINE ... Šumarski list br. 7-8. CXXVII (2003). 389-402
The geometric progression coefficient (q) of the number of trees from
lower to higher diameter degrees is higher than 1 (q > I) and is called
Liocourt´s progression coefficient. In the given mixed stand of beech and fir
the geometric progression coefficient for beech was 1.4693 according to
Collet and that for fir was 1.3651 according to Susmel.
The normal tree number (N), the normal basal area (G) and the normal
volume (V) per hectare were calculated using the stated geometric progression
coefficients (q) for beech and fir (Table 2).
The dominant height (hdom)for beech is 29.60 m and for fir 31.12 m.
Normal tree number series for beech and fir in Compartment 56a were
calculated using Mayer s function of tree number density per hectare:
N = 385,2748 e °-76,5i,for beech ... 460 trees
N = 334,4691 e °-6244d, for silverfir ... 546 trees
The tariff volume series were constructed according to Spiranec s functions
for beech and fir volume and Mihajlov s height curves:
v = 0,00003468 d2024425 h u,i22,2,for beech
v = 0,00005015 d IS77477 h umm\ for silver fir
Local tariffs are given in Tables 3, 3a and Graph 3.
The normal model for beech was determined at 285.72 m3/ha and for fir at
380.33 m3/ha. The normal model for a mixed stand of beech (53 %) and fir
(47 %) was determined at 330.18 m3/ha (Table 3, 3a, Graph 4).
The transition time for a mixed stand of beech and fir was determined on
the basis of breast diameter, which decreases with an increase in breast diameter.
The transition time for the stand in Compartment 56a was equalised with
T = 2,3789 d °-82´8, for beech
T = 2,4922 d ,mm,for silver fit-
Equalised transition times for beech and fir in Compartment 56a, MU
"Zapadni Papuk II", are given in Graph 5.
The percentage of current annual volume increment for beech and fir was
equalised with functions:
Pi = 7,525 - 2,996 log A, for beech,
p, = 5,955 - 2,235 log d, for silver fir
Equalised percentage of current annual fir increment is given in Graph 6.
A cutting cycle (10 years) of 90.00 m3/ha can be calculated on the basis of
the normal model for a mixed stand of beech and fir of 330.18 m3/ha, current
volume transition of 91.10 m3/ha and current volume stand increment (10
years) of 89.90 m3/ha. (Table 4)
The difference between the normal volume per hectare before cutting (M)
and after cutting (m) is determined on the basis of a 10-year increment or volume
transition and is equal to the felling cycle (E = M - m).
Key words: Mean breast diameter, dominant height, Swedish method,
normal model, Liocourt´s distribution, tariffs, transition time, annual volume
transition, 10-year volume increment, normal stand volume before and after
cutting per hectare.