Journal of Forest Science, 2010 (vol. 56), issue 4
Comparison of output results from two programmes for hemispherical image analysis: Gap Light Analyser and WinScanopy
B. Jarčuška, S. Kucbel, P. Jaloviar
J. For. Sci., 2010, 56(4):147-153 | DOI: 10.17221/76/2009-JFS 
We compare the results of the analysis of hemispherical images (of a broadleaved and a coniferous forest) obtained using the Gap Light Analyser (GLA) software and the results obtained by analyzing the same images with the aid of WinScanopy. The two packages were used to calculate relative total, relative diffuse and relative direct transmittance, canopy openness, and leaf area index. Our aim was to find out whether it is possible to compare the studies using different software packages for determining light conditions. The binary pixel classification of images of canopy and sky was performed automatically (in the case of Gap Light Analyser, using the...
Variability of Norway spruce (Picea abies [L.] Karst.) cone entomofauna in the Tatra National Park in association with the development of cones
M. Kozioł
J. For. Sci., 2010, 56(4):154-164 | DOI: 10.17221/119/2008-JFS
In the years 1987-1993 research aimed at the qualitative and quantitative composition of insects inhabiting the cones of Norway spruce (Picea abies [L.] Karst.) was carried out in the area of the Tatra National Park (Poland) for the first time. Approximately 72 thousand specimens of insects were obtained, representing 50 species from 8 orders. Kaltenbachiola strobi (Winn.), Plemeliella abietina Seitn. and Cydia strobilella L. were among the most frequently occurring species. The entomofauna of ripening, ripe and old, already lignified cones was determined, and among the insects found trophic groups were distinguished...
Diameter structure of the stands of poplar clones
R. Petráš, J. Mecko, V. Nociar
J. For. Sci., 2010, 56(4):165-170 | DOI: 10.17221/65/2009-JFS
The construction of a continuous mathematical model of frequency distributions of the diameters of trees of poplar clones Robusta and I-214 in dependence on tree diameter and mean diameter of stand is presented. Empirical material consists of diameter measurements on research plots from poplar regions in Slovakia. There were 90 plots for I-214 clone and 142 plots for Robusta clone. There were about 10-250 trees with mean diameter 2-70 cm on the research plots. The model was derived according to the three-parameter Weibull function. Its parameters were estimated by maximum likelihood method of the logarithm of the probability density function. Smoothed...
Different approaches to the classification of vertical structure in homogeneous and heterogeneous forests
V. Šebeň, M. Bošeľa
J. For. Sci., 2010, 56(4):171-176 | DOI: 10.17221/49/2009-JFS
The paper shows difficulties in the evaluation of the forest status when considering forests with different height structure (uneven-aged forests). It is the main problem in categorizing such forests. Concerning the actual forest management conception in Slovakia, it is assumed that the area of forests with close-to-nature management system will increase. It leads to more structured forests, as for the tree species, age, height, as well as the spatial structure. The typical vertically homogeneous forests account for only 50% of all Slovak forests, according to results from the National Forest Inventory in Slovakia (NFI SR). During the processing of...
Visible foliar injury as a tool for the assessment of surface ozone impact on native vegetation: a case study from the Jizerské hory Mts
L. Matoušková, R. Novotný, I. Hůnová, V. Buriánek
J. For. Sci., 2010, 56(4):177-182 | DOI: 10.17221/61/2009-JFS
Surface ozone is considered to be a very phytotoxic gaseous air pollutant. Its negative impacts at both the cell and the organ level have been shown, mainly as a result of experiments. However, the demonstration of ozone negative impacts on native plants is not explicit. An assessment of ozone impact on vegetation and ecosystems using indicators based on ambient ozone concentrations is insufficient and assessment techniques based on internal ozone dose and on real plant damage are more appropriate. Such a possible technique is the mapping of ozone visible symptoms due to ozone influence. The ICP-Forest method concerning ozone visible symptoms and the...
Soil preparation by ploughing in the floodplain forest and its influence on vegetation and primary soil characteristics
J. Libus, O. Mauer, D. Vavříček
J. For. Sci., 2010, 56(4):183-196 | DOI: 10.17221/46/2009-JFS
The paper analyzes the effect of whole-area site preparation by ploughing and of alternate field and forest crops on the understorey, soil biological activity and physical and chemical characteristics in the commercial forest. Another factor of the study was to assess the effect of the clearcut size on forest stands. Analyzed were 20-years-old stands of pedunculate oak (Quercus robur [L.]) on alluvial sites 1L9 (Fraxino pannonicae-Ulmetum). It can be deduced from the conducted analyses that after twenty years neither different site preparation nor clearcut size affected the understorey and soil biological activity. Field crops and...