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51.
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Tree rings, wood density and climate–growth relationships of four Douglas-fir provenances in sub-Mediterranean Slovenia
Luka Krajnc, Jožica Gričar, Jernej Jevšenak, Polona Hafner, Robert Brus, 2022, izvirni znanstveni članek

Povzetek: Tree rings, wood density and the climate–growth relationship of four Douglas-fir provenances were analysed separately for the juvenile and adult phases. Four provenances were selected from an existing IUFRO provenance trial planted in 1971 based on their diameter at breast height and vitality. Increment cores were extracted from individual trees, on which we measured tree-ring widths (RW), earlywood widths (EWW) and latewood widths (LWW). Wood density was assessed in standing trees using resistance drilling. The climate–growth correlations were calculated between provenance chronologies of RW, EWW, LWW and latewood share, and the day-wise aggregated Standardised Precipitation-Evapotranspiration Index (SPEI). The analysis was done separately for the juvenile and mature phases of growth. Provenances 1064 (Jefferson) and 1080 (Yelm) exhibited larger annual radial increments than provenances 1028 (Merrit) and 1089 (Cathlamet). The two provenances with the highest annual radial increment in the juvenile phase did not exhibit the same trend in the adult phase. In all provenances, RW, and consequently EWW and LWW, were wider in the juvenile than in adult phase. The share of latewood was in all cases higher in juvenile wood than in mature wood. All four provenances had similar wood densities in both analyzed growth phases. Our analysis showed that when selecting the most promising provenance for planting, possible changes in relative growth rate from the juvenile to adult phase need to be considered.
Ključne besede: Pseudotsuga menziesii, SPEI, juvenile phase, adult phase, latewood share, resistance drilling
Objavljeno v DiRROS: 21.11.2022; Ogledov: 451; Prenosov: 140
.pdf Celotno besedilo (3,07 MB)
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Prva licitacija vrednejše hlodovine iz gozdov v lasti RS
Peter Prislan, Luka Krajnc, Božidar Lovro Birkić, 2021, strokovni članek

Ključne besede: Slovenija, cene lesa, hlodovina, licitacija, dražba
Objavljeno v DiRROS: 12.11.2022; Ogledov: 426; Prenosov: 137
.pdf Celotno besedilo (3,92 MB)

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Ocenjevanje kakovosti stoječih dreves
Luka Krajnc, 2022, strokovni članek

Povzetek: Spremljanje kakovosti lesa se začne v gozdu, saj je poznavanje trenutnega stanja eden izmed ključnih dejavnikov pri usmerjanju nadaljnjega razvoja gozda v smer večje kakovosti lesne surovine. Usmerjanje razvoja gozdov v smer večje kakovosti in s tem večje dodane vrednosti lesu pa za začetek terja merljivost kakovosti. Brez tega je presoja morebitnih ukrepov v sestoju skoraj nemogoča ali vsaj zelo otežena. Trenutno uporabljena metodologija za ocenjevanje kakovosti stoječih dreves na stalnih vzorčnih ploskvah Zavoda za gozdove Slovenije temelji na neveljavnih žagarskih standardih in bi jo bilo treba posodobiti za splošno uporabo v gozdarstvu. V prispevku je na kratko opisana obstoječa metodologija, predstavljen je pregled obstoječih metodologij ocenjevanja kakovosti stoječih dreves različnih držav in predlagana nova metodologija za ocenjevanje kakovosti dreves. Osnovni cilj opisanega dela je bil razvoj metodologije, s katero bi lahko objektivno primerjali kakovost debel med različnimi sestoji in bi omogočala sortiranje prostornine dreves v potencialne gozdnolesne sortimente (t.i. »sortimentacija«). Uporaba predlagane lestvice kakovosti za opis kakovosti stoječih dreves je lahko eden izmed pripomočkov pri odločanju kam, koliko časa ali sredstev vložiti v gozdnogojitveno ukrepanje v posameznem sestoju.
Ključne besede: kakovost stoječih dreves, kvaliteta debla, gozdnolesni sortimenti, sortimentacija stoječega drevesa
Objavljeno v DiRROS: 17.10.2022; Ogledov: 555; Prenosov: 145
.pdf Celotno besedilo (734,44 KB)

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Estimating quantitative physiological and morphological tissue parameters of murine tumor models using hyperspectral imaging and optical profilometry
Tadej Tomanič, Luka Rogelj, Jošt Stergar, Boštjan Markelc, Tim Božič, Simona Kranjc Brezar, Gregor Serša, Matija Milanič, 2022, izvirni znanstveni članek

Povzetek: Understanding tumors and their micro-environment are essential for successfuland accurate disease diagnosis. Tissuephysiology and morphology are altered intumors compared to healthy tissues, andthere is a need to monitor tumors and their surrounding tissues, includingblood vessels, non-invasively. This preliminary study utilizes a multimodaloptical imaging system combining hyperspectral imaging (HSI) and three-dimensional (3D) optical profilometry (OP) to capture hyperspectral imagesand surface shapes of subcutaneously grown murine tumor models. Hyper-spectral images are corrected with 3D OP data and analyzed using the inverse-adding doubling (IAD) method to extract tissue properties such as melaninvolume fraction and oxygenation. Blood vessels are segmented using theB-COSFIRE algorithm from oxygenation maps. From 3D OP data, tumor vol-umes are calculated and compared to manual measurements using a verniercaliper. Results show that tumors can be distinguished from healthy tissuebased on most extracted tissue parameters (p<0:05). Furthermore, blood oxy-genation is 50% higher within the blood vessels than in the surrounding tissue,and tumor volumes calculated using 3D OP agree within 26% with manualmeasurements using a vernier caliper. Results suggest that combining HSI andOP could provide relevant quantitative information about tumors and improvethe disease diagnosis.
Ključne besede: medical physics, hyperspectral imaging, diffuse reflectance spectroscopy, blood vessels, tumors
Objavljeno v DiRROS: 08.09.2022; Ogledov: 530; Prenosov: 180
.pdf Celotno besedilo (3,79 MB)

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Mid-Cretaceous calcarenite in stone products from the Roman colony of Emona, Regio X (modern Ljubljana, Slovenia)
Rok Brajkovič, Bojan Djurić, David Gerčar, Blanka Cvetko Tešović, Boštjan Rožič, Luka Gale, 2022, izvirni znanstveni članek

Povzetek: Over the course of studying stone products from theRoman colony of Emona (Regio X), stratigraphicallyundefined calcarenite that was used to make simplesepulchral and architectural stone products wasdetected. The calcarenite used is late Aptian to earlyCenomanian in age. The corresponding facies werefound in the Lower Flyschoid Formation outcroppingnear the town of Medvode, within the local radius ofEmona. The Roman quarry was likely located in thisarea near the Sava River. According to the collecteddata, the quarry was in operation mainly in the 1stcentury.
Ključne besede: Cretaceous, microfacies, quarry production, Regio X, Roman time, stone products
Objavljeno v DiRROS: 17.08.2022; Ogledov: 630; Prenosov: 429
.pdf Celotno besedilo (25,02 MB)
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