Template-Type: ReDIF-Article 1.0 Author-Name: D. Gaffrey Author-Workplace-Name: University of Göttingen, Faculty of Forest Sciences and Forest Ecology, Institute of Forest Biometry and Informatics, Göttingen, Germany Author-Name: O. Kniemeyer Author-Workplace-Name: University of Göttingen, Faculty of Forest Sciences and Forest Ecology, Institute of Forest Biometry and Informatics, Göttingen, Germany Title: The elasto-mechanical behaviour of Douglas fir, its sensitivity to tree-specific properties, wind and snow loads, and implications for stability - a simulation study Abstract: A full 3-D model was developed to simulate the elasto-mechanical behaviour of trees subjected to wind and gravitational forces with the aim of estimating the stress and strain distribution at the surface of the stem. The model was adapted to geometry and material properties of a 64-year old Douglas fir tree. The results are comparable, on the whole, with those of a finite element model of this tree. Original stem and crown data, as well as the applied forces, were modified manifold in order to study their importance on the change in fibre stress and thus, on the safety reserve against stem breakage. Keywords: Douglas fir, elasto-mechanical model, stress, strain, safety reserve, stem breakage Journal: Journal of Forest Science Pages: 49-69 Volume: 48 Issue: 2 Year: 2002 DOI: 10.17221/11856-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/11856-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200202-0001.txt Handle: RePEc:caa:jnljfs:v:48:y:2002:i:2:id:11856-JFS Template-Type: ReDIF-Article 1.0 Author-Name: L. Janovský Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Author-Name: A. Vágner Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Author-Name: J. Apltauer Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Title: The decomposition of wood mass under conditions of climax spruce stands and related mycoflora in the Krkonoše Mountains Abstract: The mycoflora was investigated under the conditions of climax spruce stands in the Krkonoše Mountains in relation to wood decomposition. The areas under observation have been affected more or less by air pollution since the eighties. The average mass of deadwood found on the plots is 124 m3 per ha - the mass of fallen trunks is about 32 m3 per ha, mean value from total average. About 128 species of macrofungi were identified that besides others included 43 species of wood-decaying fungi. Also 54 mycorrhizal species were identified. Among the mycorrhizal fungi about 10 species were dominant, such as Laccaria laccata (Scop.: Fr.) Cooke, Lactarius helvus Fr., Lactarius mitissimus Fr., Lactarius rufus (Scop.) Fr., Russula emetica (Schaeff.: Fr.) Pers. and Russula ochroleuca Pers. etc. Concerning the volume of decomposed wood on monitored plots in climax spruce stands, the prevalent wood-decaying fungi are brown rot fungi. The proportion of brown rot fungi in wood decomposition is 60-95% of deadwood mass on the plots of climax spruce stands. A dominant species is Fomitopsis pinicola (Sw.: Fr.) P. Karst. causing the brown rot. Concerning the group of white rot fungi, the most important is Stereum sanguinolentum (Alb. & Schw.: Fr.) Fr., participating by 17% in wood decomposition on plots damaged by deer. Keywords: deadwood, wood decomposition, mycoflora, decay, brown rot, white rot, Krkonoše Mountains Journal: Journal of Forest Science Pages: 70-79 Volume: 48 Issue: 2 Year: 2002 DOI: 10.17221/11857-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/11857-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200202-0002.txt Handle: RePEc:caa:jnljfs:v:48:y:2002:i:2:id:11857-JFS Template-Type: ReDIF-Article 1.0 Author-Name: R. Petráš Author-Workplace-Name: Forest Research Institute, Zvolen, Slovak Republic Title: Reduction of timber value from damaged spruce stands after their dieback Abstract: The paper presents a method for the derivation of total timber production and of increments in value units, particularly in net financial yield for spruce stands damaged by crown defoliation after their dieback. The value production was derived by means of value growth models of undamaged stands and models for the adjustment of volume and qualitative production of damaged and died stands. Changes in timber quality after tree drying and changes in the production of damaged stands compared with undamaged ones are illustrated in tables and graphs. The changes are expressed by means of the indexes of total mean increment and total current increment. They depend mainly on the degree of stand damage expressed by crown defoliation, age and yield class of stand, the age of stand when the damage started and duration of damage. The value of damaged stands after their dieback is lover minimally by 50% than before their dieback. It is caused mainly by deteriorated quality of timber from dead trees in stand. Keywords: spruce, total value production of timber, increments Journal: Journal of Forest Science Pages: 80-87 Volume: 48 Issue: 2 Year: 2002 DOI: 10.17221/11858-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/11858-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200202-0003.txt Handle: RePEc:caa:jnljfs:v:48:y:2002:i:2:id:11858-JFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Viewegh Author-Workplace-Name: J. VIEWEGH University of Agriculture, Faculty of Forestry, Prague, Czech Republic Title: South-Moravian floodplain forest herb vegetation in the period 1978-1997 Abstract: The results document changes in the herb vegetation of a South-Moravian floodplain forest in the period of 1978-1997. It is shown that hydrological measures strongly changed the floodplain forest in the area of the Dyje river near Lednice na Moravě. The herb vegetation in the area of the confluence of the Morava and the Dyje rivers was conserved nearly unchanged after artificial floods. Keywords: herb vegetation, floodplain forest, changes Journal: Journal of Forest Science Pages: 88-92 Volume: 48 Issue: 2 Year: 2002 DOI: 10.17221/11859-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/11859-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200202-0004.txt Handle: RePEc:caa:jnljfs:v:48:y:2002:i:2:id:11859-JFS