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Raziskali smo vpliv podnebnih sprememb na debelinsko rast in lastnosti lesa smreke in bukve ter na razpoložljivost lesa in razvoj gozdno-lesnega biogospodarstva. Na različnih rastiščih po Sloveniji smo s prirastnim svedrom odvzeli vzorce bukve in smreke za dendrokronološke in lesno-anatomske raziskave ter z meritvami z rezistografom ocenili variabilnost gostote. Rezultati kažejo značilno zvezo med širino branike, lesno-anatomskimi posebnostmi in vremenskimi spremenljivkami. Potrdili smo značilno zvezo med zgradbo lesa in gostoto pri smreki, medtem ko pri bukvi teh zvez nismo ugotovili. Za oceno vpliva podnebnih sprememb ter gospodarjenja z gozdom smo simulirali različne načine gospodarjenja z gozdom in scenarije podnebnih sprememb na razpoložljivost lesa na trgu. Ugotovili smo, da načini gospodarjenja z gozdom ter ekstremni vremenski dogodki značilno vplivajo na razpoložljivost okroglega lesa na trgu. Razvili smo nacionalni input-output model za ovrednotenje možnih scenarijev prihodnjega razvoja gozdno-lesnega biogospodarstva. Iz rezultatov scenarijske analize input-output modela je razvidno, da lahko Slovensko gozdno-lesno biogospodarstvo preko prestrukturiranja gospodarskih aktivnosti v prihodnosti doseže do 20 % višjo vrednost proizvodnje, povečanje števila zaposlenih za 24 % ter povečanje dohodka gospodinjstev za 19 %. Podnebne spremembe bodo dolgoročno vplivale na drevesno sestavo in produktivnost slovenskih gozdov in s tem zahtevale tudi prilagoditev gozdno-lesnega biogospodarstva. V Sloveniji obstaja velik potencial multiplikativnih učinkov razvoja gozdno-lesne verige. Za izkoriščanje teh potencialov pa je treba razvoj gozdno-lesnega biogospodarstva načrtovati dolgoročno z jasno definiranimi cilji. In this thesis we examined the impact of climate change on the radial growth and wood properties of spruce and beech, as well as on wood availability and the development of the wood-based bioeconomy. Samples of beech and spruce were taken with an increment borer at different sites around Slovenia for dendrochronological and wood anatomical studies. Additionally, wood density variability was assessed using resistograph measurements. The results show a significant relationship between tree ring width, wood anatomical features and weather variables. We confirmed a significant relationship between wood structure and density in spruce, while no such relationship was found in beech. To assess the impact of climate change and forest management, we simulated different forest management practices and climate change scenarios on the availability of roundwood and found that forest management practices and extreme weather events have a significant impact on the availability of roundwood on the market. We developed a national input-output model to evaluate possible scenarios for the future development of the wood-based bioeconomy. The results of scenario analysis of the input-output model shows that the Slovenian wood-based bioeconomy can achieve up to 20% higher production value, 24% increase in employment and 19% increase in household income in the future through restructuring of economic activities. Climate change will cause a long-term change in the tree composition and productivity of Slovenian forests, and consequently require technological changes and adaptations of the wood-based bioeconomy. The wood value chain in Slovenia has a high potential for multiplier effects, while its development needs to be planned in the long term with clearly defined goals in order to exploit these potentials.

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. Nasl. z nasl. zaslona. Opis vira z dne 8. 4. 2022. Bibliografija: str. 11-13.

V Evropi so razširjeni različni načini redčenj, ki so delno odgovor na različne cilje gospodarjenja delno so posledica tradicije in različnih kulturnih okolij. S spremembami v okolju in zaostrovanjem družbeno-ekonomskih razmer ter splošnim nazadovanjem nege gozdov postajajo odločitve o najprimernejšim načinu in intenzivnosti redčenj vse pomembnejše. V prispevku primerjamo situacijsko redčenje, redčenje šopov in skupin, redčenje spremenljive gostote in pri nas ustaljeno izbiralno redčenje. Navajamo usmeritve, kako redčenja kombinirati ter kako izbrati primeren način in program redčenj. Na temelju sinteze dosedanjih raziskav izpostavljamo, da so za utemeljeno izboljšanje načinov redčenj pomembni poskusi v naravi. Various methods of thinning forest stands are common in Europe. These are partly a response to diverse management objectives, partly due to tradition and cultural context. With environmental changes, rapidly transforming socio-economic conditions, and a general decline in forest management, decisions about the optimal method and intensity of thinnings are becoming increasingly important. In this paper, we compare situational thinning, thinning of clusters and groups, thinning of variable density and selective thinning, traditional in Slovenia. We propose guidelines for combining various thinnings and choosing a suitable model and program of thinning. Based on the synthesis of previous research, we point out that field experiments are important for the evidence-based improvement of thinning methods.

Preveliki stroški izvedbe in upad zanimanja za izvajanje nege mlajših razvojnih faz so privedli do stanja, ko je treba razmisliti o možnostih za racionalizacijo stroškov in spremembah glede načinov nege. V sklopu diplomske naloge so bile v bukovih letvenjakih izvedene raziskave z namenom primerjave med klasično nego in novim načinom % tako imenovano minimalno nego. Na območju Menine je bilo postavljenih 8 raziskovalnih ploskev, 4 ploskve za vsak način nege. Izvedeni so bili popisi gostote in plastovitosti, odkazilo, popisi izbrancev, časovna študija in ocena težavnosti dela s pomočjo merilnika srčnega utripa. Izdelana je bila tudi kalkulacija stroškov. Ugotovljeno je bilo, da v rasti in globini krošenj druge drevesne vrste za bukvijo zaostajajo. Pri minimalni negi je bilo nižja poraba časa za posek ter nižja poraba goriva in maziva. Poraba časa na konkurenta je bila med načinoma primerljiva. Niso pa bile ugotovljene razlike v težavnosti med načinoma nege. Due to high costs and lack of interest in tending of young forest consideration is needed how to reduce the tending costs and alternate the tending approach. This research was performed in beech thicket stage stands where we compared the standard thinning approach with minimal tending approach. On the slopes of Menina Mountain in total 8 research plots were established, 4 for each tending approach. All trees inside the plots were counted and estimated for tree species and stand layer. The tree marking and harvesting were done and a time study including assessment of work load with heart rate monitor was performed. Results show that the growth rates and crown depths of crop trees of other tree species are lower compared to European (Fagus sylvatica L.) beech. According to this study, minimal tending approach reduces the number of crop trees, total time required to mark and cut competitors and consumption of fuel and lubricant. Time required per competitor and work load were similar between the two tending approaches.

Vsebnost vode (vlažnost) je med pomembnejšimi kazalniki kakovosti drv. Za čim učinkovitejše in okolju prijazno delovanje Uredba o emisiji snovi v zrak iz malih kurilnih naprav navaja, da mora biti vsebnost vode v drveh manj kot 20 %. Za hitro preverjanje vsebnosti vode v drveh bi bila smiselna uporaba električnih uporovnih merilnikov. V pričujočem prispevku primerjamo meritve, opravljene z elektrouporovnimi merilniki različnih izvedb ter referenčno gravimetrično metodo. Rezultati kažejo, da gravimetrični metodi najbolj primerljive rezultate kažejo uporovni merilniki, ki omogočajo kompenzacijo gostote lesne vrste in temperature. V prispevku razpravljamo o uporabi različne terminologije in definicije lesne vlažnosti (t.j. relativna in absolutna vlažnost lesa, vsebnost vode) ter predlagamo postopek za čim boljšo oceno vlažnosti z enostavnimi elektro-uporovnimi merilniki. Wood moisture is one of the most important quality indicators for firewood. For the most efficient and environmentally friendly operation, the Decree on the emission of substances into the atmosphere from small combustion plants declares that firewood moisture content should be below 20 %. For fast assessment of the firewood moisture content, electric resistance meter could be used. In this paper, we compare different commercially available electrical-resistance meters with reference gravimetric method. The results show that electrical-resistance meters (which enable the compensation of wood species density and temperature) and gravimetric method provide comparable results. The paper discusses the use of different terminology and definitions of moisture content (i.e. moisture content on the dry and wet basis). Furthermore, we propose a procedure for the most reliable assessment of moisture content using simple electrical-resistance meters.

Krčenje zalog fosilnih goriv, netrajnostno izkoriščanje naravnih virov in podnebne spremembe so dejavniki, ki pospešujejo prehod v biogospodarstvo. Tovrsten prehod omogočajo tehnologije in novo znanje pretvorbe biomase v različne produkte, med seboj povezane v kaskadnih in (energetsko in snovno) krožnih proizvodnih ciklih. Eno ključnih področij biogospodarstva je področje rabe lesa, ki trenutno prispeva eno tretjino k skupni dodani vrednosti slovenskega biogospodarstva. Glede na stanje v državah s primerljivimi naravnimi in strukturnimi danostmi Slovenija v razvoju biogospodarstva zaostaja. V pričujočem delu smo predstavili generične dejavnike, ki vplivajo na razvoj biogospodarstva ter pripravili pregled stanja slovenskega biogospodarstva na področju rabe lesa. Stanje slovenskega biogospodarstva uvrščamo v širši evropski okvir ter ocenjujemo nadaljnje možnosti razvoja rabe lesa. Decreasing stocks of fossil fuels, unsustainable exploitation of natural resources and climate change are factors that accelerate the transition to bio-economy. This transition is enabled by the new knowledge and technologies for converting biomass into different products, interconnected in cascade and circular (in terms of energy and material) production cycles. One of the key areas of the bioeconomy is the use of wood and wood biomass, which currently accounts to one-third of the total added value in the Slovenian bioeconomy. Compared to the countries with similar natural and structural endowments, Slovenia is lagging behind in the development of the bioeconomy. This paper identifies generic factors affecting the development of the bioeconomy and provides an overview of the current state of the Slovenian bioeconomy in the forestry and wood-based sector. The current Slovenian wood-based bioeconomy is placed in a broader European context and the possibilities for further use of wood and wood biomass are evaluated.

Gozdarstvo se v svojem razvoju čedalje bolj ukvarja z racionalizacijo in optimizacijo dela. V okviru magistrske naloge je bilo na podlagi prejšnjih raziskav s pomočjo modeliranja v programskem jeziku Visual Basic razvito orodje za modeliranje treh načinov redčenja bukovega letvenjaka: izbiralnega in dveh načinov situacijskega redčenja. Raziskali smo vpliv števila izbrancev oz. ciljnih dreves ter jakosti redčenja na produktivni in pomožni produktivni čas. Ugotovljeno je bilo, da so situacijska redčenja v primerjavi z izbiralnim redčenjem stroškovno značilno racionalnejša, da jakost redčenja pomembno vpliva na porabo časa, da število izbrancev oz. ciljnih dreves pomembno vpliva na porabo časa kot tudi na odnose med glavnim produktivnim in pomožnim produktivnim časom. Modeliranje je pokazalo, da situacijska nega predstavlja alternativo klasičnemu ukrepanju (izbiralnem redčenju) v gozdu in ob upadanju razpoložljivih sredstvih za nego gozda ponuja za Slovenijo novo in racionalnejšo možnost ukrepanja. Rationalization and optimization of work is becoming increasingly important in the European forestry sector. In this master's thesis, using modeling in the Visual Basic programming language, a tool for modeling three different thinning approaches in younger beech stands was developed namely, selective and two regimes of crop tree situational thinnings. We studied the impact of the number of candidates or crop trees and the impact of harvesting intensity on productive time. We found out that in terms of costs crop tree situational thinning is more rational compared to selective thinning, that harvesting intensity has a significant impact on time consumption and that number of candidates or crop trees has a significant impact on time consumption as well as on the relationships between main productive and auxiliary productive time. Modeling has shown that situational tending represents an alternative to classical tending (selective thinning) and since there is a decline in available subsidies for forest tending in Slovenia, it offers a new and more rational option of forest tending for Slovenian forest managing system.

Nazadovanje opravljanja nege ob večanju stroškov dela je privedlo do razmer, ko je treba proučiti možnosti izboljševanja ustaljenih načinov nege. S tem namenom smo v bukovih letvenjakih na območju Menine naredili primerjalno raziskavo med izbiralnim redčenjem in situacijskim. Postavili smo osem raziskovalnih ploskev, po štiri za vsak način redčenja. Naredili smo analize mešanosti, gostot in plastovitosti sestojev, odkazil, popisov izbrancev ter ciljnih dreves, časovno študijo in oceno težavnosti dela s pomočjo merilnika srčnega utripa. Ugotovili smo, da v rasti in globini krošenj svetloljubne drevesne vrste zaostajajo za bukvijo. Pri situacijskem redčenju sta bili značilno manjši poraba časa za posek ter poraba goriva in maziva. Poraba časa na konkurenta je bila med načinoma primerljiva. Težavnost dela se med načinoma redčenj ni razlikovala. The lack of interest for tending with the increase of labour costs leads to a situation where it is necessary to analyse possibilities for improving conventional tending methods. For this purpose, a comparative study of selective and situational thinning was carried out in beech pole stands in the Menina Mountains area. Eight research plots were established four for each thinning method. Analysis of stand mixture, densities and structure, crop trees and competitors were carried out. Subsequently tree marking, time study and assessment of the work load with the help of a heart rate gauge were performed. It was found out that light-demanding tree species lag behind beech in the growth and crown depth. We recorded significantly lower time use for cutting and lower fuel and lubricant consumption for situational thinning. The time spent on felling the competitor trees as well as work load were comparable between the treatments.