Journal of Forest Science, 2008 (vol. 54), issue 4
Current use of European beech (Fagus sylvatica L.) for artificial regeneration of forests in the air-polluted areas
P. Hobza, O. Mauer, M. Pop
J. For. Sci., 2008, 54(4):139-149 | DOI: 10.17221/788-JFS 
The paper deals with the use of European beech in the reconstruction of substitute species stands and in the regeneration of existing spruce stands in the air-polluted region of the north-eastern Krušné hory Mts. (air-pollution damage zones A, B, forest altitudinal vegetation zones 6 and 7, acidophilic sites). Twenty stand situations were analyzed during the study. The study objective was to compare the growth of European beech plantations in the Krušné hory Mts. with the growth of plantations of the same age in similar sites in the unpolluted region of the Bohemian-Moravian Upland (air-pollution damage zones C, D, forest altitudinal vegetation zone...
Comparison of the root system architecture between windthrown and undamaged spruces growing in poorly drained sites
P. Štofko, M. Kodrík
J. For. Sci., 2008, 54(4):150-160 | DOI: 10.17221/3101-JFS
In the locality Hnilé Blatá (High Tatras Mts.) the parameters of root plates and the number, length and diameter of the individual root branches in windthrows and standing Norway spruces (Picea abies [L.] Karst.) were measured. Individual root branches were classified to 12 diameter classes according to their diameter measured in the middle of the root branch length. Using random sampling, 21 windthrows were selected. In their neighbourhood, another 21 undamaged trees were selected on the basis of their similarity in aboveground parameters and they were uprooted by a tractor winch. We found out significantly higher mean values of the vertical...
Structure of coarse woody debris in Lange-Leitn Natural Forest Reserve, Austria
M. M. Rahman, G. Frank, H. Ruprecht, H. Vacik
J. For. Sci., 2008, 54(4):161-169 | DOI: 10.17221/3102-JFS
The amount, variability and quality of coarse woody debris (CWD) in an oak-dominated natural forest reserve in Austria were studied in 2006. The average volume of CWD (snags and logs) was 107.3 m3/ha, which accounted for 39% of the total living volume. Among the CWD, on average, 23.4 m3/ha (22%) were snags and 83.9 m3/ha (78%) were logs. According to quality aspects the CWD displayed a wide range of variation in tree species, tree size, stage of decay, and structural characteristics, creating a high diversity of CWD habitats for microorganisms. Among the three forest associations, the highest amount of CWD was found...
The relation between the microscopic structure and the wood density of European beech (Fagus sylvatica L.)
V. Gryc, H. Vavrčík, M. Rybníček, E. Přemyslovská
J. For. Sci., 2008, 54(4):170-175 | DOI: 10.17221/1/2008-JFS
The aim of this study was to compare the structure of beech juvenile and mature wood in relation to wood density. The comparative analysis between juvenile and mature wood examined the diameter of vessels, the width and height of pith rays, and the number of vessels and pith rays per 1 mm2. The results show that the average vessel diameter as well as the width and height of pith rays reach statistically lower values in juvenile wood than in mature wood. On the other hand, no significant difference between the two types of wood has been found in terms of the frequency of vessels per 1 mm2. Having said that, the difference in the...
Estimating the sample size for fitting taper equations
K. Kitikidou, G. Chatzilazarou
J. For. Sci., 2008, 54(4):176-182 | DOI: 10.17221/789-JFS
Much work has been done fitting taper equations to describe tree bole shapes, but few researchers have investigated how large the sample size should be. In this paper, a method that requires two variables that are linearly correlated was applied to determine the sample size for fitting taper equations. Two cases of sample size estimation were tested, based on the method mentioned above. In the first case, the sample size required is referred to the total number of diameters estimated in the sampled trees. In the second case, the sample size required is referred to the number of sampled trees. The analysis showed that both methods are efficient from...
Time study and skidding capacity of the wheeled skidder Timberjack 450C in Caspian forests
F. K. Behjou, B. Majnounian, M. Namiranian, J. Dvořák
J. For. Sci., 2008, 54(4):183-188 | DOI: 10.17221/5/2008-JFS
This study was carried out in a steep and difficult terrain. Trees were logged downhill to the landing by a wheeled skidder Timberjack 450C. Selection cutting was performed on a 66-hectare tract with an average slope of 30%. The elemental time study method was applied to develop the skidding time predicting model. In this study 43 working cycles were included. The skidding cycle time was mainly affected by skidding distance, winching distance and interaction between skidding distance and slope. The gross and net production rate was 20.51 and 22.93 m3/h, respectively. The unit cost considering the gross and net production rate was 6.31 and...
Can clearcuts increase bird species richness in managed forests?
M. Żmihorski
J. For. Sci., 2008, 54(4):189-193 | DOI: 10.17221/787-JFS
Clearcuts are one of the results of forest management. The aim of this study was to assess the effect of clearcuts on bird communities in a managed forest in Western Poland. I applied the method of point transect counts. 20 points were located near clearcuts (less than 100 m from the nearest clearcut) and 25 points in the forest interior. In total, 36 bird species were recorded. On average, I found 9.20 bird species at points located near clearcuts and 6.72 species at points situated in the forest interior, and the difference was significant. The cumulative number of bird species for a given number of sampling points in the vicinity of clearcuts was...