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 exponential functions: 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. 402 |