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Znanstveno-stručno i staleško glasilo
Hrvatskoga šumarskoga društva
Journal of Forestry Society of Croatia
      Prvi puta izašao 1877. godine i neprekidno izlazi do današnjeg dana
   ISSN No.: 0373-1332              UDC 630* https://doi.org/10.31298/sl
upute autorima
WEB EDITION
ARHIVA ČASOPISA


HRČAK


 
ORIGINAL SCIENTIFIC PAPERS
     
Božić, M., J. Čavlović, M. Vedriš, M. Jazbec UDK 630* 523 (001)
Modeling Bark Thickness of Silver Fir Trees (Abies alba Mill.)     pdf     HR     EN 3
Summary: Basic aim of research was to make correlation models that explain bark thickness of silver fir in dinaric beech – fir forests as a function of ecological and stand factors. Modeling was made by using spatial variables (altitude, terrain slope and orientation) and individual tree characteristics (diameter at breast height, tree height and age). Sample was taken by measuring given parameters of 531 fir trees in dinaric region of Republic of Croatia (Forest Administrations: Delnice, Gospić, Ogulin i Senj). Bark thickness was measured on increment cores taken at breast height by using Pressler’s increment bore. Calculating was made by MS Excel application, and modeling bark thickness by Statistica 7.1 software. Diameter at breast height (DBH), tree height, tree age and altitude were variables with highest correlation coefficients to bark thickness that proved to be statistically significant, and were therefore used in model building. Models were made using partial linear correlation method, with variables calculated both in original and logarithmic form, considering p = 0,05 as a limit of statistical significance. Determination coefficients of 8 models ranged from 62,5 % to 70,4 %, with logarithmic form variables showing on average 4 % higher values. Diameter at breast height proved to be basic variable for models, with determination coefficient of 63 %, while additional variables increased it at most to 70 %. Therefore it is suggested to use simple model for predicting bark thickness, with DBH in logarithmic form as the only independent variable. Impact of site quality on bark thickness was also studied, emphasizing that trees in lower quality stands have thicker bark. Models obtained by this research give lower values of bark thickness compared to former studies of Bojanin (1966a, 1966b) and Klepac (1972). Calculating percentage in tree dimensions, according to our model 1.2, bark make 4,1 % (diameter class 97,5 cm) to 8,1 % (diameter class 12,5 cm) of tree diameter, which is about 2,3 % lower to 1,7 % higher compared to their research. According to this study silviculture and management proved to influence bark thickness: trees in intensively managed stands have thinner bark. However this may be the result of difference in site quality of intensively managed and non-managed stands. Bark increment can also be predicted based on obtained models. According to model 1.2, bark contributes from 2,8 % (diameter class 92,5 cm). to 5,6 % (diameter class 12,5 cm) in tree diameter increment.
Key words: bark thickness; linear correlation; modeling; silver fir
Ballian, D., F. Bogunić, M. Konnert, H. Kraigher, M. Pučko, G. Božič UDK 630* 165 (001)
The Analysis of Genetic Variability of Norway Spruce (Picea abies (L.) Karst.) Subpopulation at the Igman Mountain     pdf     HR     EN 13
Majnarić. D. UDK 630* 156 (001)
Harvest and Mortality of the Brown Bear in Gorski Kotar     pdf     HR     EN 25
 
PRELIMINARY COMMUNICATION
     
Bezak, K., D. Kuric, M. Vrebčević UDK 630* 612
The Dissipative Structure of High Forests of Pedunculate Oak (Quercus robur L.) in the Management Unit “Slavir”     pdf     HR     EN 35
 
REVIEWS
     
Trinajstić, I. UDK 630* 164
About the Problem of Differentiation Between the Oaks Quercus pubescens Willd. and Quercus virgiliana. (Ten.) Ten.     pdf     HR     EN 57
Sabadi, R. UDK 630* 721 + 722
Promotion of Forest and Forest Industry’s Products in Fair Trading     pdf     HR     EN 61

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