Template-Type: ReDIF-Article 1.0 Author-Name: Nikita Debkov Author-Workplace-Name: Institute of Monitoring of Climatic and Ecological Systems, Russian Academy of Sciences, Tomsk, Russia Author-Workplace-Name: All-Russian Research Institute for Silviculture and Mechanization of Forestry, Pushkino, Moscow region, Russia Title: Accelerated formation of Siberian pine (Pinus sibirica Du Tour) stands: a case study from Siberia Abstract: Under natural conditions, Siberian pine Pinus sibirica begins to produce commercial cone yields of nuts relatively late (after more than 100 years). The aim of this study was to summarise the experience of the directed formation of Siberian pine forests in Siberia. Experimental objects included plots with traditional thinning of varying intensity and frequency as well as chemical treatment. We assessed the parameters of the stand and its seed production dynamics. Only stands with a minimum density (395-435 trees.ha-1) had a normal seed production energy (1.5 or more cones per shoot). Over-dense stands (830-930 trees.ha-1) were characterised by a low seed production energy (two times or more below the threshold value). In all plots, there were Siberian pine trees with absent or unacceptable seed production energy, which should be removed (DBH up to 28 cm). Seed production energy positively correlated with most tree parameters (age, height, diameter, volume, length and width of crown). Keywords: thinning, seed orchards, radial growth, seed production energy, middle taiga Journal: Journal of Forest Science Pages: 291-300 Volume: 65 Issue: 8 Year: 2019 DOI: 10.17221/48/2019-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/48/2019-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201908-0001.txt Handle: RePEc:caa:jnljfs:v:65:y:2019:i:8:id:48-2019-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Mehrdad Nikooy Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources, University of Guilan, Iran Author-Name: Alireza Ghomi Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources, University of Guilan, Iran Author-Name: Farzam Tavankar Author-Workplace-Name: Department of Forestry, Khalkhal Branch, Islamic Azad University, Khalkhal, Iran Title: The effect of forest management on the frequency of dangerous trees in the Northern forests of Iran Abstract: A study of work accidents in forests has shown that dangerous trees play an important role in forest accidents. Despite the importance of safe working environments for forestry operations, the definition of these areas in natural forests is still unclear. Dangerous trees are considered those snagged with broken branches and a canopy or ones with dead trunks and stumps that have a hazard potential to the forest workers. This study investigates the frequency of these trees in the managed and unmanaged forests in the Caspian forests of Iran. In order to do the study, 15 circular plots with a total area of 1,000 square metres in two studied parcels were selected and the trees, according to their dangerous characteristics, were evaluated. The final results indicated that 66 and 50 trees per hectare had signs of being dangerous trees in the managed and unmanaged stand, respectively. A comparison of the average number of dangerous trees in the two studied parcels using the Mann-Whitney test indicated a significant difference so that the average number of dangerous trees in the managed parcel was more than the ummanaged parcel. Trees with broken branches had the highest frequency in the managed stand, while trees with a dead trunk or stump, a broken branch and canopy in the unmanaged forest were more than the other classes. Considering the relative frequency of the dangerous trees in the two study areas, identifying them could be one of the main attempts in logging safety. The existence of hazardous trees with different risk classes in each of the forest stands requires the development of specific safety instructions to deal with the risks of each tree. Keywords: forest harvesting, managed forests, unmanaged forests, work accident Journal: Journal of Forest Science Pages: 301-308 Volume: 65 Issue: 8 Year: 2019 DOI: 10.17221/51/2019-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/51/2019-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201908-0002.txt Handle: RePEc:caa:jnljfs:v:65:y:2019:i:8:id:51-2019-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Şeyma Yigit Author-Workplace-Name: Department of Plant Protection, Ondokuz Mayis University, Samsun, Turkey Author-Name: Islam Saruhan Author-Workplace-Name: Department of Plant Protection, Ondokuz Mayis University, Samsun, Turkey Author-Name: Izzet Akça Author-Workplace-Name: Department of Plant Protection, Ondokuz Mayis University, Samsun, Turkey Author-Workplace-Name: Agrobigen, Samsun Technopark, Ondokuz Mayis University, Samsun, Turkey Title: The effect of some commercial plant oils on the pine processionary moth Thaumetopoea pityocampa (Lepidoptera: Notodontidae) Abstract: Thaumetopoea pityocampa (Lepidoptera: Notodontidae) is one of the major forest pests and causes serious damage especially to pine trees. Mechanical and chemical methods are used in the control of this pest in Turkey's forests. In recent years, a chemical control has been the most preferred method against this pest. Due to the chemical control's harmful effects on the environment and the human health, alternative methods of control are being emphasised today. There are many studies on the use of plant oils against pests in agricultural areas. However, studies on the effect of plant oils against the pine processionary larvae are very limited. In this study, commercial oils containing 8 different essential oil types (thyme oil, peppermint oil, poppy oil, garlic oil, rosemary oil, pine oil, sage oil, lavender oil) were applied in 3 different doses (0.1%, 0.5%, 1%) and 4 repetitions against the pine processionary larvae. The experiments were conducted at 65% humidity and 25°C in laboratory conditions. The study was monitored for five days and the results were evaluated through the mortality rates. On the 5th day of the study, 1% dose of thyme oil was found to be most effective with 100% mortality followed by the poppy oil (95%), the sage oil (95%), the garlic oil (90%), the rosemary oil (70%), and the pine oil (45%). The peppermint (40%) and lavender oil used in the study were found to be ineffective. As a result of the study, it was determined that thyme oil, poppy oil, sage oil, and garlic oil were effective against the pine processionary larvae and that they had the potential to be used in the control of this pest. Keywords: essential oil, toxic effect, control, pine moth Journal: Journal of Forest Science Pages: 309-312 Volume: 65 Issue: 8 Year: 2019 DOI: 10.17221/63/2019-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/63/2019-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201908-0003.txt Handle: RePEc:caa:jnljfs:v:65:y:2019:i:8:id:63-2019-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Olga N. Tyukavina Author-Workplace-Name: Department of Biology, Ecology and Biotechnology, Faculty of Natural Sciences and Technology, North (Arctic) Federal University named after M.V. Lomonosov, Arkhangelsk, Russian Federation Author-Name: Nikolay A. Neverov Author-Workplace-Name: Federal Center for Integrated Arctic Research named after N.P. Laverov, Russian Academy of Sciences, Arkhangelsk, Russian Federation Author-Name: Alexander L. Mineev Author-Workplace-Name: Federal Center for Integrated Arctic Research named after N.P. Laverov, Russian Academy of Sciences, Arkhangelsk, Russian Federation Title: Variations in the length of Scots pine (Pinus sylvestris L.) needles under the influence of climatic factors and solar activity in different conditions of northern taiga Abstract: The aim of the study was to assess the influence of climatic factors on the growth of pine needles in different conditions of the water regime of soil. Studies were conducted in lichen pine forests, cowberry pine forests, blueberry pine forests, shrub-sphagnum pine forest and pine on swamp in the Arkhangelsk forestry regions (northern taiga). The needle length is influenced by solar activity (the Wolf number). The effect of solar activity on increasing the needle length is greatest in optimal growing conditions. In northern taiga conditions, air temperature is the main climatic factor affecting the growth of needles. In the blueberry, cowberry and lichen pine forests, an inverse high correlation of the needle length with the night air temperature of August of the current year was revealed. The pine on swamp revealed a high correlation between the needle length and the air temperature at the end of July of the current year of needle development. In the year preceding the needle development, a high inverse correlation was found between the needle length and the temperature of mid-September in the cowberry and blueberry pine forests. In the current year, high correlations of the lengths of needles and precipitation were observed in extreme growing conditions. Keywords: needle length, air temperature, precipitation, Wolf number Journal: Journal of Forest Science Pages: 313-320 Volume: 65 Issue: 8 Year: 2019 DOI: 10.17221/47/2019-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/47/2019-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201908-0004.txt Handle: RePEc:caa:jnljfs:v:65:y:2019:i:8:id:47-2019-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Haitao Wang Author-Name: Yanli Chen Author-Workplace-Name: School of Electrical and Information Engineering, Hunan International Economics University, Changsha, China Title: A smoke image segmentation algorithm based on rough set and region growing Abstract: Because the image fire smoke segmentation algorithm can not extract white, gray and black smoke at the same time, a smoke image segmentation algorithm is proposed by combining rough set and region growth method. The R component of the image is extracted in the RGB colour space, the roughness histogram is constructed according to the statistical histogram of the R component, and the appropriate valley value in the roughness histogram is selected as the segmentation threshold, the image is roughly segmented. Relative to the background image, the smoke belongs to the motion information, and the motion region is extracted by the interframe difference method to eliminate static interference. Smoke has a unique colour feature, a smoke colour model is created in the RGB colour space, the motion disturbances of similar colour are removed and the suspected smoke areas are obtained. The seed point is selected in the region, and the region is grown on the result of rough segmentation, the smoke region is extracted. The experimental results show that the algorithm can segment white, gray and black smoke at the same time, and the irregular information of smoke edges is relatively complete. Compared with the existing algorithms, the average segmentation accuracy, recall rate and F-value are increased by 19%, 21.5% and 20%, respectively. Keywords: forest fire prevention, roughness histogram Journal: Journal of Forest Science Pages: 321-329 Volume: 65 Issue: 8 Year: 2019 DOI: 10.17221/34/2019-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/34/2019-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201908-0005.txt Handle: RePEc:caa:jnljfs:v:65:y:2019:i:8:id:34-2019-JFS