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.
2013
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Jonathan Lenoir Bente Jessen Graae Per Arild Aarrestad Inger Greve Alsos William Scott Armbruster Gunnar Austrheim Claes Bergendorff Harry John Betteley Birks Kari Anne Bråthen Jörg Brunet Hans Henrik Bruun Carl Johan Dahlberg Guillaume Decocq Martin Diekmann Mats Dynesius Rasmus Ejrnæs John-Arvid Grytnes Kristoffer Hylander Kari Klanderud Miska Luoto Ann Milbau Mari Moora Bettina Nygaard Arvid Odland Virve Ravolainen Stefanie Reinhardt Sylvi Marlen Sandvik Fride Høistad Schei James David Mervyn Speed Unn Tveraabak Vigdis Vandvik Liv Guri Velle Risto Virtanen Martin Zobel Jens-Christian SvenningSammendrag
Recent studies from mountainous areas of small spatial extent (<2,500 km2) suggest that fine-grained thermal variability over tens or hundreds of metres exceeds much of the climate warming expected for the coming decades. Such variability in temperature provides buffering to mitigate climate-change impacts. Is this local spatial buffering restricted to topographically complex terrains? To answer this, we here study fine-grained thermal variability across a 2,500-km wide latitudinal gradient in Northern Europe encompassing a large array of topographic complexities. We first combined plant community data, Ellenberg temperature indicator values, locally measured temperatures (LmT), and globally interpolated temperatures (GiT) in a modelling framework to infer biologically relevant temperature conditions from plant assemblages within <1,000-m2 units (community-inferred temperatures: CiT). We then assessed: (1) CiT range (thermal variability) within 1-km2 units; (2) the relationship between CiT range and topographically- and geographically-derived predictors at 1-km resolution; and (3) whether spatial turnover in CiT is greater than spatial turnover in GiT within 100-km2 units. Ellenberg temperature indicator values in combination with plant assemblages explained 46-72% of variation in LmT and 92-96% of variation in GiT during the growing season (June, July, August). Growing-season CiT range within 1-km2 units peaked at 60-65°N and increased with terrain roughness, averaging 1.97°C (SD = 0.84°C) and 2.68°C (SD = 1.26°C) within the flattest and roughest units, respectively. Complex interactions between topography-related variables and latitude explained 35% of variation in growing-season CiT range when accounting for sampling effort and residual spatial autocorrelation. Spatial turnover in growing-season CiT within 100-km2 units was, on average, 1.8 times greater (0.32°C km-1) than spatial turnover in growing-season GiT (0.18°C km-1). We conclude that thermal variability within 1-km2 units strongly increases local spatial buffering of future climate warming across Northern Europe, even in the flattest terrains.
Forfattere
Fride Høistad Schei Hans Blom Ivar Gjerde John Arvid Grytnes Einar Heegaard Magne SætersdalSammendrag
Retention of selected trees in clear-felling areas has become an important conservation measure in managed forests. Trees with large size or high age are usually preferred as retention trees. In this paper we investigated whether a single large or several small trees should be left in clear-felling areas to serve as life boats and future habitat for epiphytic species. The focal species were 25 Lobarion epiphytic lichens hosted by aspen (Populus tremula). We analyzed the relationships between: (1) proportion of trees colonized and tree size, (2) number of lichen thalli (lichen bodies) and aspen area, and (3) number of lichen species and aspen area, for 38 forest sites. Mixed effect models and rarefaction analyzes showed that large and small host trees had the same proportion of trees colonized, the same number of thalli, and the same species richness for the same area of aspen bark. This indicates that larger aspens do not have qualities, beyond size, that make them more suitable for Lobarion lichens than smaller sized aspen trees. None of the species, not even the red-listed, showed any tendencies of being dependent on larger aspens, and our results therefore did not support a strategy of retaining only large and old trees for conservation of epiphytic Lobarion lichens. Additionally, young aspens have a longer expected persistence than old aspens. However, old retention trees might be important for other species groups. We therefore recommend a conservational strategy of retaining a mixed selection of small/young and large/old aspens.
Redaktører
Helmer BelboSammendrag
Skilled, motivated and well-informed contractors today form the backbone of a professional, cost-effective, and environmentally friendly forest sector in the Nordic countries. This understanding forms the playground for policy makers, forestry certification bodies, forestry education, business standards and research in forest operations. The aim of this workshop is to provide a special forum for researchers, practitioners and other interested parties to get together in exchanging information, experiences and outlooks in the field of contractor forestry. The fundamental goal and our prime hope is that events like this will bring the Nordic-Baltic forest sector further in improving local and global competitiveness. These proceedings are a collection of abstracts that represent a range of issues being faced, and the status of research within the field of contractor forestry in participating countries. Contractor forestry is a term that includes both operating skills and business management acumen of forestry contractors, but also the formulation of the special environment in which they operate, not least the conditions set and information passed on by landowners, forest management companies, other supply chain actors, and the markets themselves. As such, it represents the whole spectrum of ‘service provision’ in the forestry sector – both the process of placing the work tasks on the market, successfully winning the contract, and carrying out the work in both an economically and environmentally sustainable way that promotes the long-term existence of professional contracting outfits. Not only is the Nordic forestry sector fully dependent on contractor forestry, but the region plays an important role in determining international trends in forest operations and the world closely watches developments and emulates many of them, as the CTL method continues to expand into new markets. This places special impetus on the importance of the research work being done in this field. We wish to thank the OSCAR coordinating committee for their constructive input, as well as all those who participated or contributed to making the seminar a success. We also would like to thank the Nordic Forest Research Cooperation Committee (SNS) for the financial support of the OSCAR2 network, and the Forestry Extension Institute at Honne who provided an exceptionally suitable environment and hosting for the workshop participants.
Forfattere
Jutta Kapfer Harry John Betteley Birks Vivian Astrup Felde Kari Klanderud Tone Constance Martinessen Louise C. Ross Fride Høistad Schei Risto Virtanen John Arvid GrytnesSammendrag
Background: Studies quantifying and comparing the variation and degree of compositional stability of vegetation and what determines this stability are needed to better understand the effects of the projected climate change. Aims: We quantified long-term vegetation changes in different habitats in northern Europe by exploring changes in species co-occurrences and their links to diversity and productivity gradients. Methods: We re-sampled vegetation in 16 arctic, mountain, and mire sites 20 to 90 years after first inventories. A site-specific change in species assemblages (stability) was quantified using species co-occurrences. We tested if the observed changes were significantly greater than would be expected by chance using a randomisation test. Relationships between patterns in vegetation stability and time between surveys, numbers of plots, or species diversity and proxies for productivity were tested using regression analysis. Results: At most sites, changes in species co-occurrences of vascular plants and bryophytes were greater than expected by chance. Observed changes were not found to be related to gradients in productivity or diversity. Conclusions: Changes in species co-occurrences are not strongly linked to diversity or productivity gradients in vegetation, suggesting that other gradients or site-specific factors (e.g. land-use, species interactions) might be more important in controlling recent compositional shifts in vegetation in northern Europe.
Sammendrag
Grot fra taubanedrifter er et potensielt energisortiment. Mengden grot fra taubanedrifter er undersøkt i denne rapporten. Mermassen eller mengden grot fra to taubanedrifter på Vestlandet var i størrelsesorden 25–28 % av avvirket tømmerkvantum. Med en biomassefunksjon ble mengden grot fra en taubanedrift i Ørsta beregnet til 2,7 tonn tørrstoff per dekar. Uttak av grot fra taubanedrift er interessant fordi grener og topp følger treet til bilvei eller opparbeidingsplass. Det kreves dermed ikke noen form for ekstra transport for å få grot til bilvei. En utfordring ved uttak av grot fra taubanedrifter er at arealet for å samle opp og lagre grot på standplass ofte er begrenset. Normalt vil grot bli ryddet unna bilveien og deponert i umiddelbar nærhet til standplass. På denne måten blir ikke grot tatt vare på som en ressurs. Undersøkelsen viste at det var en forskjell på vanlig rydding av grot og stabling av grot i hauger ved skogsbilveien. Vanlig rydding av grot tok 15 sekunder per tre, mens stabling av grot tok 23 sekunder. Dette påvirket imidlertid ikke produksjonen negativt, ettersom man på standplass hadde en del ledig tid hvor man ventet på at nye trær ble vinsjet inn fra bestandet. Grot kan transporteres ut samtidig med utkjøringen av rundtømmer. I denne studien ble grot transport med en vanlig tømmerbil med karmer. Fire lass ble studert og gjennomsnittslasset veide 6,4 tonn. Det kostet om lag 389 kr per tonn tørrstoff, eller 88 kr per MWh for å få transportert grot 50 km. De små lassene gjør at kostnadene blir svært følsomme for transportdistansen. Hvis groten kan lagres et sted langs skogsvegen, slik at transporten blir redusert til eksempelvis 10 km, blir transportkostnaden redusert med ca. 70 %. Bedre tilpasset utstyr, spesielt grot-grip i kranen, vil antageligvis også øke både lessetempo og lass-størrelsen og dermed senke kostnadene for grot-flytting.
2012
Sammendrag
Hovedutfordringen ved transport av heltre og hogstavfall er lav utnyttelse av lastekapasiteten til lassbærere, tømmerbiler eller andre transportmidler. Per i dag blir to metoder nyttet for å øke utnyttelsesgraden til transportutstyret ved transport av slikt virke. Et alternativ er å flishogge virke og transportere videre med fliskontainer eller egne flis-biler. Det andre alternativet er å bunte virke til sigarformede bunter med lengde 2 - 6 meter og diameter på 60-90 cm. Flis-metoden er klart mest utbredt, mens buntemetoden tross mange positive sider så langt ikke har vunnet store markedsandeler....
Sammendrag
Bruken av bioenergi er i stadig utvikling, og både internasjonal og nasjonal politikk tilsier at denne utviklingen vil fortsette i tiden som kommer. I Nord Trøndelag er det per i dag 80 flisfyringsanlegg utenom skogsindustrien med en samlet installert effekt på 13 MW, og flere er i emning. Denne brukerundersøkelsen har kartlagt utnyttelsesgrad, varmeproduksjon og økonomi for et utvalg små- til mellomskala flisfyringsanlegg i Nord Trøndelag. Videre har en kartlagt hvilke brenselressurser som blir benyttet, og drøftet utviklingen i markedet for energivirke i tiden som kommer....