Template-Type: ReDIF-Article 1.0 Author-Name: Maame Esi Hammond Author-Name: Radek Pokorný Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Title: Preliminary assessment of effect of disturbance on natural regeneration in gaps of different sizes Abstract: The study focused on natural regeneration of European beech (Fagus sylvatica), Norway spruce (Picea abies) and European larch (Larix decidua) within very small and four times bigger size gaps following a disturbance at a mixed temperate forest in the Czech Republic. In spring 2013, experimental gap design starts, when 1 m2 circular sampling plots along transects were delineated within four selected naturally occurring canopy openings with size below 20 m2. In December 2013, these initial canopy openings were artificially enlarged by felling to 226 m2 for small and 904 m2 for big gaps. Regeneration was monitored in the next two consecutive growing seasons after disturbance. Light conditions were measured before and after disturbance. Results indicated that four times larger gaps increased twice levels of light conditions, and that diffuse light starts to equilibrate to direct light there. Large gaps were favouring larch regeneration. Beech regeneration was predominant, independently on gap size as the study area belongs naturally to Beech Forest Vegetation Zone, however, the decline of spruce regeneration was presumably linked to drought. Gap size explained variation of larch regeneration in gaps. Contrarily, gap size could not be associated with the prolific regeneration of beech and abysmal regeneration performances of spruce in gaps. Keywords: European beech, European larch, growing season, light conditions, Norway spruce, regeneration Journal: Journal of Forest Science Pages: 185-196 Volume: 66 Issue: 5 Year: 2020 DOI: 10.17221/25/2020-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/25/2020-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202005-0001.txt Handle: RePEc:caa:jnljfs:v:66:y:2020:i:5:id:25-2020-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Vilém Podrázský Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Zdeněk Vacek Author-Name: Stanislav Vacek Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Jan Vítámvás Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Josef Gallo Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Anna Prokůpková Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Giuseppe D'Andrea Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Production potential and structural variability of pine stands in the Czech Republic: Scots pine (Pinus sylvestris L.) vs. introduced pines - case study and problem review Abstract: Scots pine (Pinus sylvestris L.) is one of the most important tree species in Eurasia. During the past centuries, it has been extensively introduced into artificial monocultures, but is currently experiencing a number of problems related to climate change and extreme droughts. There is a large-scale disintegration of its stands and, in addition to its replacement by other native trees, it is possible to use a wide range of introduced species of the same genus. The aim of the investigation was to compare production parameters, structure and diversity of pine stands at the age of 35 years in school Arboretum of Faculty of Forestry and Wood Science in Central Bohemia (320 m a.s.l., medium rich habitats, water deficit site). Seven species of pine were compared: ponderosa pine (Pinus ponderosa Douglas ex C. Hawson), Jeffrey pine (Pinus jeffreyi Balf.), black pine (Pinus nigra J.F.Arnold), eastern white pine (Pinus strobus L.), Lodgepole pine (Pinus contorta Douglas), Macedonian pine (Pinus peuce Griseb.) and the only native Scots pine. The results showed that significantly (P < 0.001) highest height, diameter at breast height and mean stem volume were achieved in Pinus ponderosa and P. strobus stands, while these parameters were lowest in P. peuce and P. nigra. In contrast, the lowest stand volume was calculated for P. strobus (112 m3.ha-1) due to the lower stand density, while the highest production was again in P. ponderosa (430 m3.ha-1). In terms of structural variability, the highest diversity was found in P. jeffreyi and P. peuce. The introduced pine species, especially P. ponderosa, could therefore play an important role in terms of production and economic potential and even replace native P. sylvestris on suitable sites. Keywords: introduction, forest structure, biodiversity, timber production, Central Europe Journal: Journal of Forest Science Pages: 197-207 Volume: 66 Issue: 5 Year: 2020 DOI: 10.17221/42/2020-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/42/2020-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202005-0002.txt Handle: RePEc:caa:jnljfs:v:66:y:2020:i:5:id:42-2020-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Sanjeet Kumar Hom Author-Workplace-Name: Forest Research Institute, Dehradun, India Author-Name: Sauradipta Ganguly Author-Name: Yasir Ullah Bhoru Author-Workplace-Name: Forest Research Institute, Dehradun, India Author-Name: Ajmal Samani Author-Workplace-Name: Forest Research Institute, Dehradun, India Title: Effect of chemical modification on dimensional stability of Pinus radiata D. Don using acetic anhydride Abstract: Chemical modification is used to efficiently improve some properties of wood to make it suitable for specific end uses. Modification using acetic anhydride (AA) is found suitable to make the wood more stable dimensionally. Pinus radiata wood samples treated with pyridine catalyzed AA were exposed to four different treatment methods comprising vacuum dipping and full cell method (cured with and without chemical). Physical properties like weight percentage gain (WPG), bulking coefficient, swelling coefficient (S) due to the chemical, water absorption and anti-swelling efficiency (ASE) were assessed for a comparative analysis. Results indicated a significant reduction in water absorption of acetylated wood. The swelling coefficients of all the treatments were found in the range of 3.86-4.96, which was twice to three times less than in the control (11.72) attributing 55-64% improvement in dimensional stability. Samples treated with full cell method and cured in the chemical mixture showed minimum swelling coefficient and best anti-swelling efficiency. All the four treatment methods chosen for the study returned significantly better dimensional stability as compared to untreated wood. Keywords: Anti-swelling efficiency (ASE), dimensional stability, swelling coefficient, water absorption, weight percentage gain (WPG) Journal: Journal of Forest Science Pages: 208-217 Volume: 66 Issue: 5 Year: 2020 DOI: 10.17221/13/2020-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/13/2020-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202005-0003.txt Handle: RePEc:caa:jnljfs:v:66:y:2020:i:5:id:13-2020-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Aidin Parsakhoo Author-Workplace-Name: Department of Forestry, Faculty of Forest Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran Author-Name: Seyed Ataollah Hosseini Author-Workplace-Name: Forestry and Forest Economics Department, University of Tehran, Karadj, Iran Author-Name: Majid Lotfalian Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran Author-Name: Jahangir Mohammadi Author-Workplace-Name: Department of Forestry, Faculty of Forest Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran Author-Name: Meysam Salarijazi Author-Workplace-Name: Department of Water Engineering, Water and Soil Engineering Faculty, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran Title: Effects of molasses, polyacrylamide and bentonite on dust control in forest roads Abstract: In this study, some environmentally friendly anti-dust agents including sugar cane molasses, polyacrylamide and bentonite were used to control dust emission from the forest road surface within the 3, 9, 27 and 81-day timeframe. A rear-mounted spray system and dust collector devices were used for implementation of treatments and dust emission recording, respectively. The results showed that emitted dust tended to decrease with the increase of anti-dust agent concentrations. Moreover, the emitted dust started to decrease with time, with minimum reduction efficiency at the end of the 81st day. More than half of road surface aggregates had the size smaller than 10 µm that were aggregated by the application of molasses and polyacrylamide. The size of 70% of the road surface fines increased to more than 50 µm. Bentonite affected negatively road surface materials and caused fine aggregates to increase. It is concluded that the amount of fine aggregates in surfacing materials, rainfall occurrence, and type and dosage of anti-dust agents play an important role in the effectiveness and longevity of treatment Keywords: anti-dust agent, rear-mounted spray system, road surface material, fine aggregates, dust collector Journal: Journal of Forest Science Pages: 218-225 Volume: 66 Issue: 5 Year: 2020 DOI: 10.17221/41/2020-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/41/2020-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202005-0004.txt Handle: RePEc:caa:jnljfs:v:66:y:2020:i:5:id:41-2020-JFS