Template-Type: ReDIF-Article 1.0 Author-Name: Sima Lotfi Asl Author-Workplace-Name: Department of Forestry, University Campus, University of Guilan, Rasht, Iran Author-Name: Iraj Hassanzad Navroodi Author-Workplace-Name: Department of Forestry, Faculty of Natural Resources, University of Guilan, Sowmehsara, Iran Author-Name: Aman Mohammad Kalteh Author-Workplace-Name: Department of Rang and Watershed Management, Faculty of Natural Resources, University of Guilan, Sowmehsara, Iran Title: Sensitivity analysis and performance evaluation of neural networks for predicting forest stand volume - A case study: District 2, Kacha, Guilan province, Iran Abstract: Tree volume is a characteristic used in many cases, such as determining fertility, habitat quality, growth size, allowable harvesting, and the principles of forest trade. It is imperative to develop methods that predict forest stand volume to obtain this extensive information quickly and cost-effectively. This study used supervised self-organising map (SSOM), multi-layer perceptron (MLP), and radial basis function (RBF) neural networks to predict forest stand volume based on physiography, topography, soil, and human factors. A sensitivity analysis method called the importance of prediction was used to determine how input variables influenced network output. First, the map of homogeneous units was prepared with ArcMap (Version 10.3.1, 2015) by combining digital layers to measure the tree's volume per hectare. Then, separate tree species in different diameter classes were measured in a circular grid of 200 m × 150 m, 0.1 ha of coverage, 3.3% sampling intensity, and a diameter at breast height (DBH) greater than 7.5 cm using systematic sampling on a homogeneous unit map in a regular random method. The neural network modelling results showed that SSOM, MLP, and RBF predicted forest stand volume most accurately according to physiography, topography, soil, and human factors. Furthermore, the sensitivity analysis results found that altitude above sea level, soil depth, and slope are the most influential input variables. In contrast, soil texture variables are the least effective at predicting forest stand volume. Keywords: best matching unit, error back-propagation, importance of prediction neighbour function, spread, supervised learning Journal: Journal of Forest Science Pages: 209-222 Volume: 70 Issue: 5 Year: 2024 DOI: 10.17221/111/2023-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/111/2023-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202405-0001.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:5:id:111-2023-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Naimah Alanazi Author-Workplace-Name: Department of Biology, Faculty of Science, University of Ha'il, Ha'il, Saudi Arabia Title: Tree resources decline in Saudi Arabia: Climate change or pest attack causes? Abstract: In Saudi Arabia, tree mortality has abnormally increased over the past ten years, exceeding regulatory standards without clear interpretation. The present study aimed to investigate three attacked tree populations in different biogeographic regions of Saudi Arabia. For this purpose, climatic data from the last thirty years, forest densities, soil cover, pest search, and insect damage to trees have been reported. The results of this study show a distinct climate change manifested by an increase of 2 °C in temperature accompanied by a decrease in precipitation and the extension of drought periods during the last 30 years. Analysis of satellite images and the computation by quadrat methods revealed a decline in forest density and soil tree cover caused by dieback associated with an increase in the rate of tree pest attacks. Furthermore, tree investigations show attacks of the xylophagous beetles Steraspis speciosa and Paropta paradoxus on Acacia population in the north and centre of the country. In addition, many strains of termites are attacking the Dobera glabra population in the south of the Kingdom. This study shows that tree dieback, as a response to long periods of drought, when associated with pest attacks, provokes a dramatic decline in forest tree heritage. Climate change is the principal precursor to forest decline and pest invasion in Saudi Arabia. Keywords: climate analysis, forest decline, tree death, xylophagous insects Journal: Journal of Forest Science Pages: 223-234 Volume: 70 Issue: 5 Year: 2024 DOI: 10.17221/9/2024-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/9/2024-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202405-0002.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:5:id:9-2024-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Zdeněk Odvárka Author-Workplace-Name: Department of Forest and Wood Product Economics and Policy, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Author-Name: Jitka Meňházová Author-Workplace-Name: Department of Forest and Wood Product Economics and Policy, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Title: Innovations in the methodological approach to quantifying and evaluating the supported effects of forests for recreational and educational ecosystem services Abstract: The paper deals with a new method of innovative assessment of the supported effects and ecosystem services of forests using the actual amount of their increased costs. Among the most important research findings and significance of the new method is that it contributes to the body of knowledge on valuation and payment for ecosystem services. The focus of the research task is to help address the current difficult economic situation of forest owners resulting from the impacts of climate change. The study aims to determine what work quantifies the amount of compensation for the provision of supported ecosystem services that is sufficient for owners by using hypothesis testing. The evaluation of the supported effects was carried out in a case study in the area of the Chrudim-Podhůra Recreational Forests in the Czech Republic. The results of the evaluation were quantified in two experimental spreadsheets of the results, a comparative analysis of the evaluation results was performed, and hypothesis testing was conducted. The innovative methodological approach to the assessment of supported effects can be easily modified and used to assess the actual amount of increased costs of other ecosystem services of the forest. Keywords: comparative analysis, compensation for increased costs, forest valuation methods, payments, special-purpose forests, subsidies Journal: Journal of Forest Science Pages: 235-248 Volume: 70 Issue: 5 Year: 2024 DOI: 10.17221/13/2024-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/13/2024-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202405-0003.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:5:id:13-2024-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Salem Hamdiah Author-Workplace-Name: Department of Forest Botany, Dendrology and Geobiocoenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Author-Workplace-Name: Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia Author-Name: Klemen Eler Author-Workplace-Name: Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia Author-Name: Kay Van Damme Author-Workplace-Name: Department of Forest Botany, Dendrology and Geobiocoenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Author-Name: Fabio Attorre Author-Workplace-Name: Department of Environmental Biology, Sapienza - University of Rome, Rome, Italy Author-Name: Dario La Montagna Author-Workplace-Name: Department of Environmental Biology, Sapienza - University of Rome, Rome, Italy Author-Name: Michele De Sanctis Author-Workplace-Name: Department of Environmental Biology, Sapienza - University of Rome, Rome, Italy Author-Name: Mohammed Shaneyehen Author-Workplace-Name: Department of Forest Botany, Dendrology and Geobiocoenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Author-Name: Mohammed Amar Author-Workplace-Name: Department of Forest Botany, Dendrology and Geobiocoenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Author-Name: Theodore Danso Marfo Author-Workplace-Name: Department of Environmental Management and Technology, Cape Coast Technical University, Cape Coast, Ghana Author-Name: Petr Maděra Author-Workplace-Name: Department of Forest Botany, Dendrology and Geobiocoenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Title: Overgrazing strongly impedes the natural regeneration of the endemic Boswellia species on Socotra Island Abstract: Frankincense trees (Boswellia spp.) worldwide are affected by a number of threats, including global warming and changing land management practices. On the Socotra Archipelago (Yemen), which harbours eleven endemic Boswellia species, grazing is generally assumed to be one of the main threats preventing natural regeneration. To test the impact of overgrazing on natural regeneration, we established an in situ experiment on four different Boswellia taxa in different areas of Socotra Island. Mortality and the height increment of seedlings were measured for a period of two/three years in five plots excluded from grazing (fenced) and in five paired control (unfenced) plots. Each plot was 50 m × 50 m in size and contained several adult trees as a source of viable seeds. Our results show that seedling mortality was significantly higher, and seedling height increment generally (4 out of 5 sites) lower in open compared to fenced plots. In the fenced plots, the number of seedlings for all species reached up to 772, with 560 surviving seedlings. In comparison, the control plots reached up to 296 seedlings, with 176 seedlings surviving after 2-3 years. The results of our experimental study indicate that grazing directly threatens the natural regeneration of the endemic Boswellia on Socotra Island. However, seedling mortality remained relatively high inside the exclosures as well, which indicates that even without the pressure of livestock grazing, other impacts remain a challenge for the future conservation of the archipelago's unique frankincense trees. Keywords: dryland flora, exclosure experiments, frankincense trees, land management, seedling survival and mortality Journal: Journal of Forest Science Pages: 249-263 Volume: 70 Issue: 5 Year: 2024 DOI: 10.17221/3/2024-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/3/2024-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202405-0004.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:5:id:3-2024-JFS