1. Prevedba ocen kakovosti stoječih dreves na izbranih objektih v sortimentno strukturoLuka Krajnc, Janez Zafran, 2025, izvirni znanstveni članek Povzetek: V raziskavi je bila predstavljena in preračunana ocena kakovosti stoječih dreves v sortimentno strukturo. Na 123 drevesih štirih drevesnih vrst je bila opravljena primerjava med dejansko sortimentacijo po poseku in računsko sortimentacijo na osnovi predhodno ocenjene kakovosti. Izmerili smo 869 gozdno-lesnih sortimentov ter primerjali rezultate računske in dejanske sortimentacije. Rezultati so pokazali dobro ujemanje pri smreki, nekoliko manj pa pri listavcih, kjer je bil večji vpliv notranjih napak na sortimentno sestavo. Metoda je praktično uporabna in daje uporabne rezultate za napoved sortimentne sestave. Izboljšati je treba še modele napovedi velikosti grč, s čimer bi natančnost napovedi še dodatno povečali.
Ključne besede: sortimentacija, ocena kakovosti, stoječa drevesa, gozdni lesni sortimenti, iglavci, listavci, grče, računsko krojenje, notranje napake lesa, prostorninska struktura
Objavljeno v DiRROS: 17.12.2025; Ogledov: 182; Prenosov: 59
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2. Raznolikost avtohtonih in neavtohtonih drevesnih in grmovnih vrst na ploskvah Nacionalne gozdne inventure v SlovenijiAnže Martin Pintar, Andreja Ferreira, Luka Krajnc, Gal Kušar, Mitja Skudnik, 2025, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: Nacionalna gozdna inventura, NGI, gozdne inventure, drevesne vrste, grmovne vrste
Objavljeno v DiRROS: 27.11.2025; Ogledov: 117; Prenosov: 35
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3. High-resolution Pan-European forest structure maps : an integration of earth observation and national forest inventory dataJukka Miettinen, Johannes Breidenbach, Patricia Adame, Radim Adolt, Iciar Alberdi, Oleg Antropov, Ólafur Arnarsson, Rasmus Astrup, Ambros Berger, Jón Bogason, Luka Krajnc, Mitja Skudnik, 2024, zaključena znanstvena zbirka raziskovalnih podatkov Povzetek: We developed Pan-European maps of timber volume (V), above-ground biomass (AGB), and deciduous-coniferous proportion (DCP) with a pixel size of 10 x 10 m2 for the reference year 2020 using a combination of a Sentinel 2 mosaic, Copernicus layers, and National Forest Inventory (NFI) data. For mapping, we used the k-Nearest Neighbor (kNN, k=7) approach with a harmonized database of species-specific V and AGB from 14 NFIs across Europe. This database encompasses approximately 151,000 sample plots, which were intersected with the above-mentioned Earth observation data. The maps cover 40 European countries, forming a continuous coverage of the western part of the European continent. A sample of 1/3 of NFI plots was left out for validation, whereas 2/3 of the plots were used for mapping. Maps were created independently for 13 multi-country processing areas. Root-mean-squared-errors (RMSEs) for AGB ranged from 53 % in the Nordic processing area to 73 % the South-Eastern area. The created maps are the first of their kind as they are utilizing a huge amount of harmonized NFI observations and consistent remote sensing data for high-resolution forest attribute mapping. While the published maps can be useful for visualization and other purposes, they are primarily meant as auxiliary information in model-assisted estimation where model-related biases can be mitigated, and field-based estimates improved. Therefore, additional calibration procedures were not applied, and especially high V and AGB values tend to be underestimated. Summarizing map values (pixel counting) over large regions such as countries or whole Europe will consequently result in biased estimates that need to be interpreted with care.
Ključne besede: European forest monitoring system, remote sensing, in-situ data, forest attribute maps
Objavljeno v DiRROS: 17.06.2025; Ogledov: 502; Prenosov: 152
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4. Pan-European forest maps produced with a combination of earth observation data and national forest inventory plotsJukka Miettinen, Johannes Breidenbach, Patricia Adame, Radim Adolt, Iciar Alberdi, Oleg Antropov, Ólafur Arnarsson, Rasmus Astrup, Ambros Berger, Jón Bogason, Luka Krajnc, Mitja Skudnik, 2025, drugi znanstveni članki Povzetek: The dataset includes Pan-European maps of timber volume (Vol), above-ground biomass (AGB), and deciduous-coniferous proportion (DCP) with a pixel size of 10×10 m for the reference year 2020. In addition, a measure of prediction uncertainty is provided for each pixel. The maps have been created using a combination of a Sentinel-2 mosaic, Copernicus layers, and National Forest Inventory (NFI) data. The mapping was done with the k-Nearest Neighbour (kNN, k=7) approach with harmonized data of species-specific Vol and AGB from 14 NFIs consisting of approximately 151 000 field plots across Europe. The maps cover 40 European countries, forming a continuous coverage of the western part of the European continent. A sample of 1/3 of NFI plots was left out for validation, whereas 2/3 of the plots were used for mapping. Maps were created independently for 13 multi-country processing areas. Root-mean-squared-errors (RMSEs) for AGB ranged from 53 % in the Nordic processing area to 73 % in the South-Eastern area. The maps are on average nearly unbiased on European level (1.0 % of the mean AGB), but show significant overestimation for small biomass values (53 % bias for forests with AGB less than 150 t/ha) and underestimation for high biomass values (-55 % bias for forests with AGB higher than 500 t/ha). The created maps are the first of their kind as they are utilizing a large number of harmonized NFI plot observations and consistent remote sensing data for high-resolution forest attribute mapping. While the published maps can be useful for visualization and other purposes, they are primarily meant as auxiliary information in model-assisted estimation where model-related biases can be mitigated, and field-based estimates improved. Therefore, additional calibration procedures were not applied, and especially high Vol and AGB values tend to be underestimated. We therefore discourage from summarizing map values (pixel counting) over areas in interest, as this may inadvertently result in biased estimates.
Ključne besede: European forest monitoring system, remote sensing, in-situ data, forest attribute maps
Objavljeno v DiRROS: 17.06.2025; Ogledov: 585; Prenosov: 366
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10. Different patterns of inter-annual variability in mean vessel area and tree-ring widths of beech from provenance trials in Slovenia and HungaryJožica Gričar, Domen Arnič, Luka Krajnc, Peter Prislan, Gregor Božič, Marjana Westergren, Mátyás Csaba, Hojka Kraigher, 2024, izvirni znanstveni članek Povzetek: International provenance trials of ecologically and economically important tree species are crucial to deciphering the influence of environmental factors and intraspecific variability on tree growth and performance under climate change to guide assisted gene flow and assisted migration of tree provenances and species. In this context, we compared inter-annual trends in tree-ring widths (carbon sequestration potential) and vessel characteristics (conductivity optimisation) of four beech provenances in two international provenance trials, one in Slovenia (Kamenski hrib, a core beech growing site) and one in Hungary (Bucsuta, a marginal beech site) in 2009–2019. We found different patterns of inter-annual variability in mean vessel area and tree-ring widths among provenances and sites, pointing to diverse genetic background and environmental influence on these two wood-anatomical traits. The average values of the vessel area varied less between provenances at Kamenski hrib than at Bucsuta. Weather conditions differently affected tree-ring width and mean vessel area. Furthermore, the length of the period of response of vessel area to the analysed weather conditions differed in summer and winter periods. The differences in the mean vessel area within the tree ring were more pronounced in the weather-wise extreme years, regardless of the provenance. Consistent with previous studies, we confirmed that site conditions affect the climate sensitivity of trees, which is more pronounced at marginal sites or in extreme years. The findings on how different environmental conditions affect the radial growth of young beech trees of different origin are very important for future forest management.
Ključne besede: Fagus sylvatica, quantitative wood anatomy, common gardens, intraspecific variation, juvenile period, weather conditions
Objavljeno v DiRROS: 03.12.2024; Ogledov: 734; Prenosov: 1087
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