broj: 1-2/2003
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| IZVORNI ZNANSTVENI ČLANCI | ||
| Trinajstić, I., Franjić, J., Škvorc, Ž. | UDK 630* 188 (001) | |
| Syntaxonomic Analysis of the Beech Forests of Međimurje (Croatia) pdf HR EN | 3 | |
| Zelić, J. | UDK 630* 226 (001) | |
| The Problems of Management with Beech and Silver Fir Selection Forest (Abieti-Fagetum pannonicum Rauš 1969) in the Mountain Papuk pdf HR EN | 11 | |
| Summary: Mixed stands of silver fir and beech on Papuk (Abieti - Fagetum panonnicum Rauš 1969) recently were management as regular forests, and regeneration was made in way of shelter wood cutting. Biological and ecological means of silver fir and beech point to possibility of doing management in selection forest way, wich will increase ecological stability and better use of soil and climate characteristics. Important participants of selection management are biological characteristics in forest associations of silver fir regenerates in smaller or bigger groups, very often under the beech trees and opposite, beeches are regenerated in groups under thin treetops of silver fir. Silver fir can tolerate shade very good and photosynthesis is being made under high-frequecy of lower light waves. By humification of organic substance in stand, the layer of carbon dioxide is being made in height of forty centimeters which has good influence on growth of silver fir seedlings and young plants because reinforcement of assimilation and photosynthesis. Vertical structure of selection stand makes better use of assimilative tree surfaces for photosynthesis possible, and root zone is also optimally developted for better use of prodicing capability of soil. Results of higher ecological stability and biological sign of selection stands of silver fir and beech are optimal products of stem wood and equalized balance of menagement. As manage example of selection stand of silver fir and beech on Papuk we took forest compartment 56a in menagement unit "Zapadni Papuk II", on the surface of 15,10 hectares and with 60 % silver fir and 40 % of beech. According to Mayer "balanced selection forest" is the one were the course increase can be used over a period of time (for example rotation period of 10 years) so that there is always the same distribution of volume in stand. Liocourt discovered in 1898 that number of trees in selection forest redused from lower to higher diameter class by the law of geometrical line. Multiplication (q) of numbers of trees lower and higher diameter class is number higher than one (q > 1) and it, s called Liocourts multiplication. For dominant high of trees of 33 meters and site class III by Šurić and with Susmels coeficient for silver fir (q = 1,3408) and Collets for beech (q = 1,4154) normal number of trees and normal stand basal area for diameter classes have been calculated. According to Mayers function of thickness are calculated the functions for normal numbers of trees for silver fir and beech for forest compartment 56a, this way: N = 288,64476 · e - 0,05865 · d … silver fir … 524 trees N = 322,01947 · e - 0,06948 · d … beech … 450 trees N = 297,34888 · e - 0,06225 · d … silver fir (0,6) + beech (0,4) … 495 trees Tariff line of site class III for silver fir and beech can bee made through this functions: v = 0,38 - 0,015852 d + 0,0012362 d2 … silver fir v = 0,185 - 0,031711 d + 0,0016608 d2 … beech With help of Mayer function of thickness and function for tariff line for site class III by Šurić, the normal stem wood is calculted 317 m3/ha for silver fir, 258 m3/ha for beech and 294 m3/ha for mixed population of silver fir (0,6) and beech (0,4). Transition time for mixed forest silver fir and beech is given for diameter classes and decrease in higher classes. The average are 9 years for beech and 11 years for silver fir. For the forest compartment 56a it is equalized by exponential function: T = 177,47288 · d - 0,81033. From distribution of diameter classes for silver fir and beech arithmetic middle is calculated this way: da = 32,21 cm, and arithmetic middle volume 1,00 m3. Standard deviation of diameter classes is: sa = 13,70 According to earlier type of management as regular stands, curve of distribution of diametar classes have a shape of bell. Correction of distribution for diameter classes is made with Beta - distribution: f (d) = 0,017109 1 · S (( d - 10,0 ) 0,433 · (75,0 - d )1,679)) Number of trees per hectare is shown in table number 5. Curve of equaling is asymmetric on the left side (positively) because of the exponent a < g, (a = 0,433, and exponent g = 1,679). Normal distribution of diameter classes is asymmetrically bell shaped and it stands for 95-year-regular stand. Management of stand in past was made acording to nature laws of regular stand. Number of trees per hectare is 294. Mentioned distribution of diameter classes for silver fir ond beech in stand shows characteristic structure of regular stand. We can get that conclusion from equal distribution by Liocourt: N = 135,851 · e - 0,05261 · d , which devates a lot from normal and mentioned distribution (graph 1). According to projected normal volume of 293,57 m3/ha and increase over 10 years we can cut (as much as) 123,30 m3/ha. It is possible to mark a whole volume over diameter of 60 cm (28,40 m3/ha) and other 94,90 m3/ha on account 10 years growth (table 5). Volume of trees cutting is necessary to make for each forest compartment, and wholw volume for cutting which can be calculated by formula: E = M · ((1 - (1/1,0 · p l )) · f , for all forest compartments and can be used for checking and correcting volume for cutting in each compartment. It is recommended that after classifying stands according to site class, volume proportion and previous age structure we have determine relevant structural biometric parameters which can be comparated to placed models of normal structure in selection system by number of trees and volume per hectare. It is necessary to determine the details of forest compartments selection. Mixed forest associatons of silver fir and beech, which are by measurements and biometrical parameters under model of normal selection stands, need to be managed so that we can cut only 50 % of increment until we reach normal volume per hectare. Cutting should be done in 10 years rotation in diameter classes over 60 cm (technicllay maturity) and we must remove dead trees too. We must form group structure in areas of 2/3 to 3/4 height of dominant trees, comparing, for example, concrete distribution with Beta - distribution of numbers of trees and volume with normal model. In stands which volume is over the average we must do cutting more intensively which is higher then growth, until we reach normal volume. Cutting must be done in groups in the year when there is good crop of seed and must be done during 10 years. Groups must be formed in the areas of diameter 1 to 1,5 height of dominant trees. We should mark and cut silver fir and beech trees which have diameter over 60 cm and diameter classes (technically maturity) where there are more trees and volume than in Beta - distribution or normal model, and also we must do sanitary cutting, as it shown in the graph 3 and table 6. In stands which have normal volume per hectare we can cut about 50 to 100 % of increment, but we must take care of stability, vitality and ecolocical condition. In these stands it is desirable that middle diameter class is about 32,5 cm and basal area about 32 m2. Example for definition of permissible cut is mentioned forest compartment 56a, which structure and biometrical parameters shows that that permissible cut can be almost the same as increment (104,10 m3/ha by Menagement plan) in the time before cut. If we determined permissible cut in compartment 56a by the formula E = V/3T, where permissible cut is equal volume per hectare divided with a transiton time multipled with 3. I this way permission cut would be determined in amount 107 m3/ha (322/10 · 3). In whole permissible cut we must always to add dead and sick trees. Key words: regular forest association; shelterwood cutting; selection structure and selection menangement; biometrical parameters; middle breast diameter; middle volume of trees; Beta distribution; Liocourt´s distribution; tariffs; transition time; ten - year increment; normal wood volume before felling and after felling per hectare | ||
| PRETHODNO PRIOPĆENJE | ||
| Vodolšak, M., Križaj, D. | UDK 630* 156 | |
| Game Loss and Damages from the Game in the Krapinsko-Zagorska County District pdf HR EN | 27 | |
| Prka, M. | UDK 630* 325 + 851 | |
| Value Characteristics of Common Beech Trees with Regard to the Type of Felling in the Cutting Areas of Bjelovar Bilogora pdf HR EN | 35 | |
| PREGLEDNI ČLANCI | ||
| Franjić, J., Pandža, M., Škvorc, Ž. | UDK 630* 181.1 (Anthyllis barba-jovis L.) | |
| Distribution of Anthyllis barba-jovis L. (Fabaceae) in Croatia pdf HR EN | 45 | |
| STRUČNI ČLANCI | ||
| Farkaš-Topolnik, N., Krauthacker, H., Trenc, N. | UDK 630* 907.1 | |
| International Conference "Protected Areas of European Mountains - Place of Life Recreation and Exchange", Chambery, France pdf HR EN | 51 | |