Journal of Forest Science, 2003 (vol. 49), issue 9
Effects of overstory structure and fire regime upon diversity and abundance of selected understory species in longleaf pine (Pinus palustris Mill.) forests in southeastern Georgia
W. Keith Moser, Chui Kwan Yu
J. For. Sci., 2003, 49(9):395-402 | DOI: 10.17221/4787-JFS 
We examined the impacts of variation in overstory structure and burning regime on understory vegetation in the longleaf pine (Pinus palustris Mill.) forest of the Okefenokee National Wildlife Refuge in southeastern Georgia, U.S.A. On sandy upland sites surrounding the Okefenokee Swamp and on islands, we established five randomly-located 0.04-ha plots within each of six study areas. The plots varied in overstory density, past management and fire regime. We measured overstory tree size of longleaf pines in the 0.04-ha plots and percent cover of ground cover species in five 1-m2 subplots nested within each 0.04-ha plot. We also calculated diversity...
Induced wound response of Norway spruce Picea abies P. Karst. after artificial inoculation by imagoes of Ips typographus
L. Jankovský, D. Novotný, R. Mrkva
J. For. Sci., 2003, 49(9):403-411 | DOI: 10.17221/4713-JFS
Inoculation experiments were carried out on a set of trees with imagoes of Ips typographus L. which origin from the Šumava Mts. and the Křtiny Training Enterprise. The objective of back inoculations was to determine whether species found on the surface of Ips typographus imagoes spread after the inoculation also through host tissues. It the vicinity of inoculation by Ips typographus imagoes, marked necrotic zones are evident including symptoms of the penetration of vascular pathogens through phloem and sapwood. The most marked reactions were observed in case of inoculation...
Analysis of cambial activity and formation of wood in Quercus robur L. under conditions of a floodplain forest
P. Horáček, J. Šlezingerová, L. Gandelová
J. For. Sci., 2003, 49(9):412-418 | DOI: 10.17221/4714-JFS
The analyses of the activity of cambium and the study of the increment of wood during one growing season of pedunculate oak (Quercus robur L.) under conditions of a floodplain forest is provided. The following parameters were studied: the beginning and end of the cambial activity, differentiation of wood fibres (libriform) and vessels and analysis of the total increment of wood during vegetation in dominant (D), co-dominant (CD) and subdominant (SD) trees in relation to ecological factors of the environment. The course of wood formation corresponds to typical growth curves which are modified by factors of the environment...
Virtual forest stand as a component of sophisticated forestry educational systems
M. Fabrika
J. For. Sci., 2003, 49(9):419-428 | DOI: 10.17221/4715-JFS
The paper presents the methodology of virtual stand generation. Virtual stand serves for forestry e-learning as a tool for training of forest tending and demonstration of stand structure and some forest mensuration practices. The model can be connected with growth simulator and geographical information system, or integrated into the Internet environment. In the first part of the paper, the methodology of individual tree visualisation, total stand visualisation, terrain and stand environment visualisation and the principle of user's interaction with virtual forest are proposed. The Virtual Reality Model Language (VRML 97) was used for these goals. In...
Remote monitoring of forest response to changed soil moisture regime due to river regulation
S. Tewari, J. Kulhavý, B.N. Rock, P. Hadaš
J. For. Sci., 2003, 49(9):429-438 | DOI: 10.17221/4716-JFS
Floodplain forest response to changed soil moisture regime and nutrient availability due to river regulation was studied using remote sensing (ETM) data. Images of May and October 2001 were used to prepare NDVI, SAVI, 5/4-ratio images and ETM band 7. Comparisons of the LAI, NDVI, 5/4-ratios and ETM band 7 mean values were done to find out the differences between the flooded and non-flooded sites. Unsupervised clustering of images was done using single transformed channels, i.e. NDVI, SAVI, 5/4-ratio and ETM band 7 to find seasonal variations in the values of these indices. The results were found to be in agreement with ground research.
Optimisation of forest road network under principles of functionally integrated forest management
P. Hrůza
J. For. Sci., 2003, 49(9):439-443 | DOI: 10.17221/4717-JFS
A traditional approach to problems of the opening-up of forests has been based primarily on technical and economic aspects. It results particularly from the ground configuration and calculations of minimum costs for logging and transport operations. Optimum density of main forest roads is determined by a minimum value of the summary curve of costs of forest road construction and timber skidding. A new conception from the aspect of integrated forest management taking into account forest functions is based on a standard approach when technical and economic aspects are complemented by the particular functions of the forest. Thus, the technical and economic...