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Ključne besede: varstvo gozdov, morfološke analize, Dothistroma, rjavenje borovih iglic, Lecanosticta acicola, rdeča pegavost borovih iglic, bori, Pinus
Objavljeno v DiRROS: 16.08.2023; Ogledov: 244; Prenosov: 0

Ključne besede: smrekovi sestoji, Jelovica
Objavljeno v DiRROS: 04.08.2023; Ogledov: 254; Prenosov: 67
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Povzetek: The research presented in this study addressed the distribution of volume across different log grades in three hardwood species: European beech (Fagus sylvatica L.), sycamore maple (Acer pseudoplatanus L.) and English oak (Quercus robur L.). Standing trees were selected, marked, and measured. Afterwards the trees were felled and bucked into assortments according to national legislation regarding assortment grades and requirements for each assortment grade. Each individual assortment was measured and classified into one of the national log quality grades. Proportions of log volume with different grades within individual tree volumes were calculated and presented in this study. Differences were found in log grade volume distribution between different species and diameter classes. By following the national grading system for assortments, between 40% and 50% of total volume will be usable assortments in hardwoods
Ključne besede: logs, hardwoods, volume, quality, log grading
Objavljeno v DiRROS: 03.08.2023; Ogledov: 308; Prenosov: 164
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Povzetek: Gozdarstvo in lesnopredelovalna industrija sta za Slovenijo strateško pomembni gospodarski panogi, ki v zadnjih letih krepita svojo vlogo v biogospodarstvu. Raziskava se osredotoča na problematiko rabe lesa listavcev v Sloveniji. Za akterje, ki se ukvarjajo z rabo lesa listavcev, je pomembno vedenje o razpoložljivi količini domačega lesa, ki se lahko ponudi na trgu. V raziskavi je bila nadgrajena leta 2014 razvita metodologija za oceno količin in potencialov lesa listavcev. Za prihodnje odločanje o razvoju gozdarskega in lesnopredelovalnega sektorja je potrebno tudi raziskovanje tokov lesa, zato je bila v raziskavi opravljena anketa med večjimi predelovalci okroglega lesa listavcev. Ocenjeni teoretični tržni potencial hlodovine listavcev v slovenskih gozdovih je v letu 2021 znašal 0,777 mio m³ in 2,372 mio m³ ocenjeni teoretični tržni potencial lesa slabše kakovosti. Ocenjeni dejanski tržni potencial hlodovine listavcev je v letu 2022 znašal 0,528 mio m³, lesa slabše kakovosti pa 0,741 mio m³. Projekcije potencialov hlodovine listavcev kažejo, da bodo v letu 2025 na trgu podobne količine lesa kot leta 2022. Poraba okroglega lesa listavcev je v letu 2021 znašala 1,433 mio m³, od tega je bilo 0,906 mio m³ lesa predelanega za energetske namene, ostalih 0,527 mio m³ pa v industriji. Rezultati raziskave potrjujejo problematiko rabe lesa listavcev v Sloveniji in nakazujejo priložnosti slovenskega gozdno-lesnega sektorja za prihodnji razvoj.Forestry and wood processing are strategically important industries for Slovenia and have been strengthening their role in the bioeconomy. The study addresses the use of hardwood timber in Slovenia. For actors involved in the use of hardwood timber, it is important to know the available volume of domestic timber that affects the market. For this reason, the survey presented in this work builds on the methodology for estimating the volumes and potentials of hardwood timber developed in 2014. For future decision-making on the development of the forestry and wood-processing sector, it is also essential to analyse wood flows carried out among the major wood processors of round hardwood timber. The estimated theoretical market potential for lower-quality hardwood in Slovenian forests in 2021 was 2.372 million m³, and the estimated theoretical market potential for logs was 0.777 million m³. The estimated real market potential for lower-quality hardwood in 2022 was 0.741 million m³, and for hardwood logs 0.528 million m³. Projections of hardwood potential show that similar volumes of wood will be on the market in 2025 as in 2022. The consumption of round hardwood in 2021 was 1.433 million m³, of which 0.906 million m³ was processed for energy purposes, and the remaining 0.527 million m³ was used in industry. The survey results confirm the concerns about hardwood wood use in Slovenia and indicate opportunities for the future development of the Slovenian forest and wood sector.
Ključne besede: hardwood, roundwood flows, sawmills, market, potentials
Objavljeno v DiRROS: 03.08.2023; Ogledov: 265; Prenosov: 166
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Povzetek: Brown spot needle blight (BSNB), caused by Lecanosticta acicola (Thüm.) Syd., is an emerging forest disease of Pinus species originating from North America and introduced to Europe and Asia. Severity and spread of the disease has increased in the last two decades in North America and Europe as a response to climate change. No modeling work on spread, severity, climatic suitability, or potential distribution has been done for this important emerging pathogen. This study utilizes a global dataset of 2,970 independent observations of L. acicola presence and absence from the geodatabase, together with Pinus spp. distribution data and 44 independent climatic and environmental variables. The objectives were to (1) identify which bioclimatic and environmental variables are most influential in the distribution of L. acicola; (2) compare four modeling approaches to determine which modeling method best fits the data; (3) examine the realized distribution of the pathogen under climatic conditions in the reference period (1971–2000); and (4) predict the potential future global distribution of the pathogen under various climate change scenarios. These objectives were achieved using a species distribution modeling. Four modeling approaches were tested: regression-based model, individual classification trees, bagging with three different base learners, and random forest. Altogether, eight models were developed. An ensemble of the three best models was used to make predictions for the potential distribution of L. acicola: bagging with random tree, bagging with logistic model trees, and random forest. Performance of the model ensemble was very good, with high precision (0.87) and very high AUC (0.94). The potential distribution of L. acicola was computed for five global climate models (GCM) and three combined pathways of Shared Socioeconomic Pathway (SSP) and Representative Concentration Pathway (SSP-RCP): SSP1-RCP2.6, SSP2-RCP4.5, and SSP5-RCP8.5. The results of the five GCMs were averaged on combined SSP-RCP (median) per 30-year period. Eight of 44 studied factors determined as most important in explaining L. acicola distribution were included in the models: mean diurnal temperature range, mean temperature of wettest quarter, precipitation of warmest quarter, precipitation seasonality, moisture in upper portion of soil column of wettest quarter, surface downwelling longwave radiation of driest quarter, surface downwelling shortwave radiation of warmest quarter and elevation. The actual distribution of L. acicola in the reference period 1971–2000 covered 5.9% of Pinus spp. area globally. However, the model ensemble predicted potential distribution of L. acicola to cover an average of 58.2% of Pinus species global cover in the reference period. Different climate change scenarios (five GCMs, three SSP-RCPs) showed a positive trend in possible range expansion of L. acicola for the period 1971–2100. The average model predictions toward the end of the century showed the potential distribution of L. acicola rising to 62.2, 61.9, 60.3% of Pinus spp. area for SSP1-RCP2.6, SSP2-RCP4.5, SSP5-RCP8.5, respectively. However, the 95% confidence interval encompassed 35.7–82.3% of global Pinus spp. area in the period 1971–2000 and 33.6–85.8% in the period 2071–2100. It was found that SSP-RCPs had a little effect on variability of BSNB potential distribution (60.3–62.2% in the period 2071–2100 for medium prediction). In contrast, GCMs had vast impact on the potential distribution of L. acicola (33.6–85.8% of global pines area). The maps of potential distribution of BSNB will assist forest managers in considering the risk of BSNB. The results will allow practitioners and policymakers to focus surveillance methods and implement appropriate management plans.
Ključne besede: brown spot needle blight, BSNB, pines, species distribution model, climate change, biosecurity
Objavljeno v DiRROS: 02.08.2023; Ogledov: 345; Prenosov: 213
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