51. A comparison of radial increment and wood density from beech provenance trials in Slovenia and HungaryLuka Krajnc, Peter Prislan, Gregor Božič, Marjana Westergren, Domen Arnič, Csaba Mátyás, Jožica Gričar, Hojka Kraigher, 2022, izvirni znanstveni članek Povzetek: Provenance trials are a valuable source of information, especially in species such as European beech (Fagus sylvatica L.), which will likely increase its distribution due to global warming. The current study compares radial increment and wood density of beech provenances in the juvenile development stage from contrasting environments in Europe (Belgium, Slovenia, Czech Republic, Italy) planted at a mesic to wet site in Slovenia and a xeric site in Hungary. Existing data (past measurements of diameters and height) were combined with new measurements of tree height, diameter, dendrochronological and resistance drilling density measurements to assess differences in provenance radial growth. The wood density data were evaluated using a Bayesian general linear model. In order to study the differences in radial increment in more detail, two weather-wise contrasting years (2014 and 2017) were selected from the last decade, based on calculations of the 12-month Standardized Precipitation-Evapotranspiration Index. The differences in average tree-ring width among provenances at each sampled site appeared to be relatively small when averaged over a whole decade of data. However, according to year-to-year data, some provenances grew faster than others, especially in favorable weather conditions. In unfavorable conditions, the differences in tree-ring widths among provenances were smaller. For most provenances, variation in tree-ring widths within the same provenance increased in unfavorable conditions. The difference between the provenances with the highest and lowest wood densities at both locations did not exceed 5%. The model results indicate that the Idrija (Slovenia) provenance probably has a higher median wood density than other studied provenances at both sites. Although the current study confirmed some differences in wood density between provenances and trial locations, the differences are negligible in practice due to their low magnitude and the fact that the analyzed trees were still juvenile. As beech has a diffuse-porous wood, negligible differences in wood density would also be expected in adult trees. Beech provenances for planting in relation to changing weather should probably be chosen for their ability to survive more extreme weather events rather than to improve radial increment or wood density, especially as the differences in wood density of juvenile trees are relatively small.
Ključne besede: Fagus sylvatica, tree-ring width, common garden, resistance drilling
Objavljeno v DiRROS: 15.04.2022; Ogledov: 631; Prenosov: 472
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52. Relationships between wood-anatomical features and resistance drilling density in Norway spruce and European beechDomen Arnič, Luka Krajnc, Jožica Gričar, Peter Prislan, 2022, izvirni znanstveni članek Povzetek: Environmental conditions affect tree-ring width (TRW), wood structure, and, consequently, wood density, which is one of the main wood quality indicators. Although studies on inter- and intra-annual variability in tree-ring features or density exist, studies demonstrating a clear link between wood structure on a cellular level and its effect on wood density on a macroscopic level are rare. Norway spruce with its simple coniferous structure and European beech, a diffuse-porous angiosperm species were selected to analyze these relationships. Increment cores were collected from both species at four sites in Slovenia. In total, 24 European beech and 17 Norway spruce trees were sampled. In addition, resistance drilling measurements were performed just a few centimeters above the increment core sampling. TRW and quantitative wood anatomy measurements were performed on the collected cores. Resistance drilling density values, tree-ring (TRW, earlywood width–EWW, transition-TWW, and latewood width–LWW) and wood-anatomical features (vessel/tracheid area and diameter, cell density, relative conductive area, and cell wall thickness) were then averaged for the first 7 cm of measurements. We observed significant relationships between tree-ring and wood-anatomical features in both spruce and beech. In spruce, the highest correlation values were found between TRW and LWW. In beech, the highest correlations were observed between TRW and cell density. There were no significant relationships between wood-anatomical features and resistance drilling density in beech. However, in spruce, a significant negative correlation was found between resistance drilling density and tangential tracheid diameter, and a positive correlation between resistance drilling density and both TWW + LWW and LWW. Our findings suggest that resistance drilling measurements can be used to evaluate differences in density within and between species, but they should be improved in resolution to be able to detect changes in wood anatomy.
Ključne besede: wood structure, Fagus sylvatica, Picea abies, quantitative wood anatomy, xylem anatomy, wood density, increment borer
Objavljeno v DiRROS: 08.04.2022; Ogledov: 597; Prenosov: 437
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54. Napredki v primarni predelavi lesa listavcevPeter Prislan, 2022, strokovni članek Ključne besede: gozdarstvo, gozdovi, predelava lesa, listavci, topol, razžagovanje, žagarstvo, avtomatiziran proizvodni sistem
Objavljeno v DiRROS: 22.02.2022; Ogledov: 759; Prenosov: 371
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55. Energetska storitev : energetsko pogodbeništvo : toplota namesto energentaNike Krajnc, Thomas Loibnegger, Peter Prislan, Marjan Dolenšek, Christian Metschina, 2014, strokovna monografija Ključne besede: energetika, učinkovita raba energije, varčevanje z energijo, lesna biomasa, ekonomika
Objavljeno v DiRROS: 05.01.2022; Ogledov: 884; Prenosov: 285
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56. Kakovostna lesna goriva za vsakogar : koristne informacije za vse, ki se ogrevajo z lesomNike Krajnc, Mitja Piškur, Peter Prislan, Matevž Triplat, 2014, strokovna monografija Ključne besede: energetski viri, ogrevanje, drva, lesni sekanci, lesni peleti
Objavljeno v DiRROS: 05.01.2022; Ogledov: 1042; Prenosov: 332
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57. Stanje žagarske panoge v Sloveniji v letu 2019Špela Ščap, Nike Krajnc, Peter Prislan, 2021, izvirni znanstveni članek Povzetek: Z raziskavo, opravljeno v letu 2020, smo želeli ugotoviti stanje žagarske panoge v Sloveniji v letu 2019 (t.j. ocena števila obratov, ocena razžagane količine lesa, uporaba ostankov in vpliv pandemije covid-19 na poslovanje). Pred izvedbo raziskave smo iz različnih podatkovnih baz zbrali seznam 1.128 poslovnih subjektov, ki imajo kot C16 (Obdelava in predelava lesa) registrirano primarno ali sekundarno dejavnost. Izpolnjene vprašalnike nam je posredovalo 588 podjetij, od katerih se jih 328 ukvarja z razžagovanjem hlodovine. V letu 2019 je skupna evidentirana količina razžagane hlodovine znašala 1,71 milijona m3, od tega so z 84 % prevladovali iglavci. Žagarski obrati, ki so sodelovali v anketi, so v letu 2019 proizvedli 633.894 m3 žaganega lesa. Proizvodnja žagovine in lesnega prahu je znašala 237.389 ton, kosovnih ostankov pa 252.655 m3. Epidemija nalezljive bolezni covid-19 in ukrepi za njeno zajezitev so v obdobju od marca do maja 2020 (prvi val) vplivali na poslovanje podjetij v primarni lesnopredelovalni industriji; 63 % sodelujočih podjetij v tem sklopu vprašanj je občutilo posledice epidemije.
Ključne besede: žagarstvo, žagan les, žagarski obrat, predelava okroglega lesa, iglavci, listavci
Objavljeno v DiRROS: 18.12.2021; Ogledov: 1119; Prenosov: 339
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60. Climatic regulation of leaf and cambial phenology in Quercus pubescens : their interlinkage and impact on xylem and phloem conduitsJožica Gričar, Jernej Jevšenak, Polona Hafner, Peter Prislan, Mitja Ferlan, Martina Lavrič, Dominik Vodnik, Klemen Eler, 2022, izvirni znanstveni članek Povzetek: Increased frequency and severity of stressful events affects the growth patterns and functioning of trees which adjust their phenology to given conditions. Here, we analysed environmental effects (temperature, precipitation, VPD and SWC) on the timing of leaf phenology, seasonal stem radial growth patterns, and xylem and phloem anatomy of Quercus pubescens in the sub-Mediterranean in the period 2014%2019, when various adverse weather events occurred, i.e. spring drought in 2015, summer fire in 2016 and summer drought in 2017. Results showed that the timings of leaf and cambium phenology do not occur simultaneously in Q. pubescens, reflecting different environmental and internal constraints. Although year-to-year variability in the timings of leaf and cambial phenology exists, their chronological sequence is fairly fixed. Different effects of weather conditions on different stages of leaf development in spring were observed. Common climatic drivers (i.e., negative effect of hot and dry summers and a positive effect of increasing moisture availability in winter and summer) were found to affect the widths of xylem and phloem increments with more pronounced effect on late formed parts. A legacy effect of the timing of leaf and cambial phenology of the previous growing season on the timing of phenology of the following spring was confirmed. Rarely available phloem data permitted a comprehensive insight into the interlinkage of the timing of cambium and leaf phenology and adjustment strategies of vascular tissues in Mediterranean pubescent oak to various environmental constraints, including frequent extreme events (drought, fire). Our results suggest that predicted changes in autumn/winter and spring climatic conditions for this area could affect the timings of leaf and stem cambial phenology of Q. pubescens in the coming years, which would affect stem xylem and phloem structure and hydraulic properties, and ultimately its performance.
Ključne besede: pubescent oak, leaf development, radial growth, initial earlywood vessel, sieve tube, anatomy, cambial cell production, extreme weather events
Objavljeno v DiRROS: 06.09.2021; Ogledov: 956; Prenosov: 280
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