Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2026
Sammendrag
Introduction Leaf area index (LAI) estimation is sensitive to sensor field of view (FOV), within-plot spatial heterogeneity, and sampling layout. Because LAI influences canopy radiation transmission, microclimate and vegetation–atmosphere exchange, robust field estimation is important for biometeorological and ecosystem research. Methods We evaluated these effects in mature Norway spruce [ Picea abies (L.) H. Karst] stands in the Czech Republic across 15 sites at elevations of 407–1,019 m a.s.l., using a combined gap-fraction approach based on LAI-2200 PCA measurements and digital hemispherical photography. At each site, a measured 9 × 9 grid of 81 below-canopy measurement points with 2-m spacing was used as an operational within-plot benchmark for mean optically derived LAI and spatial structure. Monte Carlo subsampling was then used to compare how reduced layouts, including random, row-wise, column-wise, block-wise, and spatially balanced block–row–column layouts, reproduced the full-grid benchmark mean. Results Narrower FOVs produced higher stand-level optically derived LAI estimates and greater within-plot variability. The full grids also showed directional spatial structure, with stronger autocorrelation along the north–south column direction than along the west–east row direction, although this contrast weakened under the narrowest FOV. Reduced layouts with more even spatial coverage outperformed random sampling. The spatially balanced block–row–column layout performed most consistently, whereas the row-wise layout provided little improvement. Approximately 25–36 well-distributed below-canopy measurements were sufficient to keep reduced-layout LAI deviations within 0.15 m 2 m −2 of the full-grid benchmark, whereas 7–9 measurements were enough to remain within 5% of this benchmark in most stands. Discussion Spatially balanced sampling can therefore improve the robustness and efficiency of stand-level optically derived LAI estimation, with relevance to forest biometeorology, ecosystem monitoring, and the validation of satellite-derived LAI products.
Forfattere
Simone Bianchi Cornelia Roberge Johannes Schumacher Johannes Breidenbach Kari T. Korhonen Harri MäkinenSammendrag
Sustainable forest management needs growth models. Few studies have explored regional models in Fennoscandia despite similar conditions and challenges. We examined the feasibility of regional models for basal area increment of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and birch (Betula pendula Roth. and Betula pubescens Ehrh.). We compiled over 880,000 growth observations and estimated competition indices, climate variables, and site fertility classes by integrating data from recent National Forest Inventories (2004–2023) in Finland, Norway, and Sweden. Using Random Forest models, we identified the main growth drivers across countries (tree size, accumulated temperature sum, latitude, competition, and site fertility), with minor differences in their responses across countries. However, periodic NFI measurements could not capture the effect of additional climate variables. Using species-specific nonlinear mixed models, we demonstrated that predictive regional models can be fitted using those main drivers. Although we achieved only moderate predictive performance (Weighted Absolute Percentage Error of 45–71%, depending on the species and country), there were no residual geographical biases. The results confirm the potential of Fennoscandian growth models to address shared challenges. Future work should better account for site fertility, integrate process-based approaches for climate responses, and carry out independent validation.
Forfattere
Geir Wæhler Gustavsen Philip Bester Van Niekerk Jonas Niklewski Christian Brischke Gry AlfredsenSammendrag
This cross-country study examineed perceptions of maintenance for coated wooden cladding in residential buildings across Norway, Sweden, and Germany. As timber cladding gains popularity in European homes, understanding expectations around cleaning, recoating, and replacement intervals becomes increasingly important. An online survey gathered responses from over 3,000 participants aged 18–89, randomly selected from representative regional panels in each country. The survey focused on the perception of maintenance practices and intervals, while also collecting data on personality traits, risk aversion, and socioeconomic background. Perceived maintenance practices for coated timber cladding differed across countries, but individual characteristics were generally more influential than national context. Most respondents accepted longer cleaning intervals than recommended, while their preferences more closely aligned with guidelines for recoating. Acceptance of replacement intervals varied markedly by country. Longer acceptable maintenance intervals were associated with a higher preference for uncoated cladding, particularly in Germany and Sweden. Younger age, urban residence, limited experience, and selected demographic and personality traits were linked to more intensive maintenance preferences.
Forfattere
Binbin Xiang Maciej Wielgosz Stefano Puliti Kamil Král Martin Krůček Azim Missarov Rasmus AstrupSammendrag
The segmentation of forest LiDAR 3D point clouds, including both individual tree and semantic segmentation, is fundamental for advancing forest management and ecological research. However, current approaches often struggle with the complexity and variability of natural forest environments. We present ForestFormer3D, a new unified and end-to-end framework designed for precise individual tree and semantic segmentation. ForestFormer3D incorporates ISA-guided query point selection, a score-based block merging strategy during inference, and a one-to-many association mechanism for effective training. By combining these new components, our model achieves state-of-the-art performance for individual tree segmentation on the newly introduced FOR-instanceV2 dataset, which spans diverse forest types and regions. Additionally, ForestFormer3D generalizes well to unseen test sets (Wytham woods and LAUTx), showcasing its robustness across different forest conditions and sensor modalities. The FOR-instanceV2 dataset and the ForestFormer3D code are publicly available at https://bxiang233.github.io/FF3D/.
Forfattere
Jo Jorem AarsethSammendrag
Prosjektet tester ut en automatisert laser som skal holde jordene fri for beitende grågås (og annen gås) som påfører jordene beiteskader.
Forfattere
Stephan HoffmannSammendrag
Det er ikke registrert sammendrag
Sammendrag
Abstract This study assesses the economic feasibility and environmental profile of producing Irvingia-based wood adhesives on a small scale (30 ton/year) in South Africa. A detailed techno-economic analysis was conducted including operating cost estimation and sensitivity analysis of key input variables. The estimated production costs for three adhesive formulations ranged from R157.1/kg – R318.14/kg. The average production cost was R214.62/kg and was below the typical market price of R379/kg for synthetic wood adhesives. Raw materials especially kernels and modifiers were identified as the dominant cost drivers, whereas labour and electricity had minimal impact on unit cost. A carbon footprint assessment (CFA) was performed with cradle-to-gate boundaries to estimate greenhouse gas (GHG) emissions. Two raw material sourcing scenarios were considered. They included adhesive production from kernels and adhesive production directly from whole fruits (including on-site fruit dehulling). The cradle-to-gate CFA indicates that both scenarios have similar GHG emission profiles given equivalent process conditions, with most emissions arising from energy use and chemical additives rather than feedstock transport. A review of mechanical performance from prior studies showed that these bio-based adhesives met industry standard requirements. The results demonstrate that small-scale production of Irvingia adhesives is economically viable and environmentally sustainable, making it a promising alternative to synthetic adhesives for wood composite manufacturing in South Africa.
Forfattere
Jan-Peter George Colin Kelleher Aurore Desgroux Eléonore Scholzen Luis Muheim Irena Fundova Gregor Božič Michele Bozzano Anna-Maria FarsakoglouSammendrag
This report on dynamic and static ex situ conservation of forest genetic resources is a product of the EUFORGEN Programme. The report serves as a reference document that provides the framework for implementing and monitoring ex situ conservation approaches across Europe, complementing existing in situ conservation efforts. It has been developed through the collective expertise of the EUFORGEN network, establishing minimum requirements and data standards for ex situ conservation, proposing indicators for monitoring, and introducing terminology for genetic conservation units at risk. The actions and strategies addressed in this report are dependent on the commitment of all involved actors, including policymakers, forest managers, researchers, and technical staff responsible for gene banks and genetic conservation units, who will guide the application of dynamic and static ex situ conservation, whenever needed, and provide the financial, human and institutional resources required to effectively conserve forest genetic resources across Europe.
Sammendrag
This study (1) determined the differences between the dynamic vapor sorption (DVS) behavior of wood subjected to light (H2O) and heavy water (D2O) vapors at matching equivalent relative humidities (RHs) and (2) developed an in-situ method for studying the transmission-mode Fourier-transform infrared (FTIR) spectra of wood subjected to increasing RHs. The D2O-subjected wood was pre-deuterated so that the hydrogen bonding of the native wood with H2O was compared with the deuterium bonding that occurs with D2O for the DVS and FTIR studies. Fibrous Scots pine sapwood particles were used for the DVS experiments, whereas FTIR spectroscopy involved Scots pine sapwood earlywood microscopic sections placed inside a small RH chamber. The sorption isotherms and hysteresis plots of H2O and D2O showed statistically non-significant differences between the solvent vapors. However, larger practical differences were observed at higher RHs, with the H2O sorption isotherms having higher “equilibrium” moisture contents. The Gibbs free energies of sorption and desorption at equilibrium, as determined from the DVS data, showed statistically significant differences, suggesting that deuterium bonding is more thermodynamically favorable. The sorption and desorption rates obtained from the DVS samples generally indicate that H2O vapor subjection progresses initially at faster rates per RH level, without significantly affecting the total experimental time. The accessibility of the hydroxy groups increased somewhat with D2O between the before- and after-isotherm scenarios. In the FTIR spectra, H2O addition led to higher peak intensities and broader hydroxy band widths due to increased RH. The FTIR spectra for the D2O case had a decrease in the hydroxy band area, particularly in the width parameter, while the intensity and width of the formed deuteroxy peak grew as RH increased. The FTIR spectra also provided evidence of a successful hydrogen-versus-deuterium bonding comparison for the DVS study, as the intensities and band widths reverted to their original states after drying using a water-vapor-subjection method like that used in the DVS. Finally, it is hypothesized that deuterated wood is less hygroscopic than native wood, despite the thermodynamic favorability of deuterium bonding.
Forfattere
Aksel Granhus Christian Kuehne Terje Hoel Haakon Jamtli Kristiansen Erling Bergsaker Even BergsengSammendrag
Denne rapporten sammenstiller resultater fra prosjektet «Tilvekstreaksjon etter selektiv hogst i gran-skog», som er gjennomført i samarbeid mellom NIBIO og Norskog. Prosjektet bygger på feltmålinger som ble gjennomført i 34 bestand i to tidligere prosjekter fra 2017-2019, samt fra ytterligere ni bestand som ble oppmålt i 2024. Det samlede datamaterialet har blitt benyttet til å analysere i hvilken grad ulike bestandskarakteristika bidrar til å forklare variasjonen i produksjon (årlig tilvekst) og foryngelse etter hogst. I de utvalgte bestandene hadde det siste hogstinngrepet blitt utført 6-30 år tidligere med en estimert gjennomsnittlig uttaksstyrke på 49 prosent av grunnflaten (variasjon: 20-79 %). H40-bo-nitet basert på skogbruksplan varierte mellom G8 og G23, og høyde over havet fra 90-820 m. Fem temporære prøveflater (r = 10 m) ble etablert i hvert bestand, med totalklaving av alle trær med diameter i brysthøyde på minst 5 cm. I tillegg ble høyder målt på prøvetrær, og borprøver fra prøve-trærne ble benyttet som grunnlag for å rekonstruere grunnflatesum og stående volum før og etter hogst. Foryngelse (trær med høyde minst 10 cm og diameter i brysthøyde < 5 cm) ble registrert på fem «telleflater» med radius 2,26 m (16 m2) innen hver prøveflate. Rekonstruksjon av diameterfordelingen i de undersøkte bestandene viser at hogstene i et flertall av de undersøkte bestandene best kan karakteriseres som skjermstillingshogst, med uttaket orientert mot de lavere diameterklassene. Langt færre (7-8) hadde en omvendt-j-formet diameterfordeling og hvor uttaket samtidig har vært orientert mot de grøvste trærne, dvs. en bledningslignende hogstføring. Sammenhengen mellom ulike bestands- og voksestedsegenskaper og årlig volumtilvekst i perioden etter hogst ble analysert med en blandet ikke-lineær regresjonsmodell. Modellen forklarte seksti pro-sent av variasjonen i datamaterialet (R2=0.60) og vi fikk som resultat at tilveksten var positivt korre-lert med bonitet fra skogbruksplan og gjenstående grunnflate etter hogst. Modellen angir et produk-sjonsnivå på nivå med produksjonsevnen for ensaldret skog dersom grunnflaten ikke senkes under 20-25 m2 ha-1. Mens gjenstående grunnflate ofte var lavere, har de hogstene hvor det ble satt igjen en tilstrekkelig høy grunnflate hevdet seg godt ut fra et produksjonsperspektiv. Mange av bestandene hadde en høy tetthet av foryngelse, men nullruteandelen var ofte forholdsvis høy, noe som viser at foryngelsen var ujevnt fordelt. Antallet ha-1 av utviklingsdyktig foryngelse av bartrær (planter høyere enn 10 cm og inntil 5 cm diameter i brysthøyde) var høyest i prøveflater der vegetasjonstypen er småbregneskog eller fuktig utforming av blåbærskog, intermediært i normale og tørre utforminger av blåbærskog, og lavest i bærlyngskog. Antallet var negativt korrelert med gjenstå-ende grunnflate eller hogst. Den årlige innvoksingsraten, det vil si antall trær som hadde vokst seg større enn diameter 5 cm i brysthøyde i tidsrommet etter hogst, var i gjennomsnitt på 6,8 trær ha-1 år-1 og negativt korrelert med grunnflatesum etter hogst. Boniteten hadde imidlertid ikke signifikant effekt på innvoksingen av nye trær i prøveflatene. Datamaterialet ble også benyttet for å beregne lønnsomheten av lukket hogst opp mot et scenario med flatehogst og etterfølgende planting. De økonomiske analysene viser at lukket hogst kommer gjen-nomgående best ut der god og jevn foryngelse faller sammen med god vekst på gjenstående skog (skjermtrær). I denne studien var dette tilfelle i ni av de 43 bestandene. Den forutsatte gevinsten ved bruk av foredlede planter etter flatehogst var den av følsomhetsanalysene som hadde størst betydning for lønnsomheten.