Journal of Forest Science, 2007 (vol. 53), issue 8
Assessment of some forest characteristics employing IKONOS satellite data
Ľ. Scheer, R. Sitko
J. For. Sci., 2007, 53(8):345-351 | DOI: 10.17221/2181-JFS 
In recent years, satellite remote sensing has become a new tool for estimation of forest condition. The paper deals with spruce timber growing stock and vegetation cover assessment employing IKONOS satellite data from a mountain forest area of Central Slovakia. Original digital data as well as enhanced digital images were used to estimate some forest variables. Image enhancement approaches employing topographic normalization, PCA analysis and different vegetation indices are a very important part of data processing. Apart from spectral characteristics, texture as an additional variable was utilized. In order to improve classification accuracy the knowledge...
Derivation of target stocking for forests of Norway spruce vegetation zone in Slovakia
M. Moravčík
J. For. Sci., 2007, 53(8):352-358 | DOI: 10.17221/2183-JFS
The present paper deals with derivation of target stocking in forests of Norway spruce vegetation zone. Target stocking in forests with prevailing ecological and social functions is the stocking when the forest fulfils demanded functions in the best way. For forests in the Norway spruce vegetation zone target stocking was derived by original procedures as an optimum stocking in harmonization of demands on the fulfilment of ecological functions (especially erosion control, hydrological and water protection ones), securing static stability and preconditions for the formation and growth of natural regeneration. We investigated the relations between stocking...
Risk factors influencing the probability of browsing by hoofed game on forest trees
V. Malík, J. Stuchlý
J. For. Sci., 2007, 53(8):359-363 | DOI: 10.17221/2179-JFS
In this paper we analyze how selected risk factors determine the probability of browsing by hoofed game on forest trees. Risk factors covered by the model are: tree species (Norway spruce or Scotch pine), time period (season: spring + summer or autumn + winter) and chemical structure of bark (content of selected nutrients and chemical elements). We use a logit model for these purposes. We formulate the model and perform linear transformation by the natural log. Since the disturbance term in the logit model is heteroscedastic, we cannot use the ordinary least-squares method to estimate the parameters of the model. In this case the maximum likelihood...
Occurrence, biology and harmfulness of Galerucella lineola (F.) (Coleoptera, Chrysomelidae) - Part 1. Last year's (parent) beetles
J. Urban
J. For. Sci., 2007, 53(8):364-380 | DOI: 10.17221/2182-JFS
In Moravia in 1995 to 2006, the abundant occurrence of Galerucella lineola (F.) was used to study its occurrence, biology and harmfulness. An "alder" biological form was studied in Alnus glutinosa and A. incana mainly in Polnička Forest District (Žďár region) and a "willow" form in Salix viminalis, S. triandra and S. caprea in riparian and accompanying stands of the Svitava river near Bílovice nad Svitavou (Brno region). Imagoes leave their sites usually in the 1st half of May. In the course of 2.5 to 3 months, they damage on average 22.6 cm2 leaves of A. glutinosa and S. caprea (of...
Parasitic Hymenoptera associated with Thecodiplosis brachyntera (Diptera: Cecidomyiidae) on the genus Pinus (Pinaceae) in the Czech Republic
V. Skuhravý, C. Thuróczy
J. For. Sci., 2007, 53(8):381-389 | DOI: 10.17221/2180-JFS
Aprostocetus micantulus (Thomson, 1878) (Chalcidoidea: Eulophidae), Torymus heyeri Wachtl, 1833 (Chalcidoidea: Torymidae), Pseudencyrtus idmon (Walker, 1848) (Chalcidoidea: Encyrtidae) and Platy-gaster compressicornis (Thomson, 1859) (Platygasteroidea: Platygasteridae) are four main parasitoids reared from galls of Thecodiplosis brachyntera (Schwägrichen, 1835) (Diptera: Cecidomyiidae) developing on Pinus mugo L., P. rotundata Link, P. sylvestris L. and P. × pseudopumilio (Willk.) G. Beck (Pinaceae) in the Czech Republic during outbreak 1967-1972. Of total 4,279 parasitoid specimens,...