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
This report deals with results of a survey to 60 farming households in the three villages Magoda, Kichiwa and Ibumila in the Njombe region of Tanzania, about 700 km from Dar es Salaam. The farmers were selected among those that came forward at village meetings and the survey is not representative for farming households in the region. However, it may represent farmers interested in developing their farms and looking for better ways to do farming in the area.
Redaktører
Rainer Matyssek Nicholas Clarke Pavel Cudlin Teis Nørgaard Mikkelsen Juha-Pekka Tuovinen Gerhard Wieser Elena PaolettiSammendrag
Det er ikke registrert sammendrag
Forfattere
Rainer Matyssek Nicholas Clarke Pavel Cudlin Teis Nørgaard Mikkelsen Juha-Pekka Tuovinen Gerhard Wieser Elena PaolettiSammendrag
Det er ikke registrert sammendrag
Forfattere
Ryan Bright Rasmus Astrup Anders Hammer Strømman Clara Antón Fernández Maria Malene Kvalevåg Francesco CherubiniSammendrag
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Forfattere
Heleen de Wit Anders Bryn Annika Hofgaard Jonas Karstensen Maria Malene Kvalevåg Glen Philip PetersSammendrag
Expanding high elevation and high latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically-based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase of summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land use history. In the future scenarios, forest cover increased from 12 to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high latitude and high elevation expanding mountain forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts.
Sammendrag
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Forfattere
Sekhar Udaya NagothuRedaktører
Kathrine Torday GuldenSammendrag
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Sammendrag
Use of genetic materials with a more “southern growth rhythm” has been suggested as one of the measures for adapting our forests to climate change. However, studies on Norway spruce (Picea abies (L.) Karst) provenances and families have shown a possible relationship between phenology (apical growth rhythm) and cambial growth rhythm that might have negative effects on latewood proportion and wood density. We made a detailed study of the xylem formation of four clones during one growth season. The clones were known to express contrasting phenology in terms of timing of bud flush equivalent to two weeks when assessed in 1997. Micro cores from four 20 year old ramets of the four clones, 16 trees in total, were sampled once a week from May to October in 2010. When bud flush were assessed in 2010 there were about one week difference between the most contrasting clones. Temperatures during the spring 2010 were low and flushing started in general late. No relationship was found between the clonal values for timing of bud flush and initiation of xylem formation. Large differences between clones in numbers of formed tracheids were found in later phases of the growing season. Both the rate of cell division and number of formed tracheids varied significantly between clones. Only small differences in latewood percentage were found between the clones. Genetic variation in xylem formation was found, but from this study the genetic variation in xylem formation seems to be independent from the genetic variation in phenology.
Forfattere
Grete Lene Serikstad Anne de BoerSammendrag
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Sammendrag
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