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.
2011
Sammendrag
De siste 30 årene har halvparten av gammelskogen på Varaldskogen blitt snauhogd. Likevel har storfuglen klart seg ganske bra, mens orrfuglen har gått litt ned.
Sammendrag
Along the succession gradient of the boreal forest ecosystem, black grouse Tetrao tetrix inhabits the early and capercaillie Tetrao urogallus the latest stages. When converting old forest to clearcuts and plantations, commercial forestry has therefore been assumed to affect capercaillie negatively and to be favourable to black grouse. During a 30-year period (1979–2008) we monitored sympatric populations of the two species in a forest in southeast Norway based on annual spring and autumn censuses and radio-marked birds. During this period, the proportion of old, semi-natural forest was halved and clearcuts and young plantations increased accordingly. The grouse populations did not change as predicted. While the trend in August numbers of adult black grouse declined, males more than females, abundance of adult capercaillie remained unchanged. Number of males at leks showed similar patterns. Equally surprising, breeding success (number of chicks per female in August) of both species increased, thus indicating that the populations were regulated more by variation in adult survivorship than by recruitment of young birds. No correlations were found with changing climatic factors (precipitation and temperatures in winter and spring, snow depth and time of snow melt), except that year-to-year breeding success was positively correlated with minimum temperatures during 2 weeks posthatch. The results are explained by a combination of more flexible habitat selection than previously assumed and a changing predator regime: In the early period, nearly all capercaillie leks were located in old, semi-natural forest, but as plantations grew older (>30 years), new leks were established there. Similarly, while young capercaillie broods used old semi-natural forest almost exclusively when the study started, they frequently used middle-aged plantations, especially those with a ground cover of bilberry Vaccinium myrtillus, when these became common in later years. The increasing breeding success could largely be explained by more females rearing chicks successfully, presumably due to a marked decline in the main nest predator, the red fox Vulpes vulpes. A practice of thinning of the old, semi-natural forest some years prior to final harvesting probably facilitated predation of black grouse by goshawks Accipiter gentilis. Contrary to many beliefs, our results indicate that both capercaillie and black grouse are quite tolerant to changes in forest management regimes. In our study, numerical and functional responses of predators (mainly red fox and goshawk) apparently played a more important role in regulating grouse numbers than habitat factors per se.
Sammendrag
The redlisted epiphytic lichen Evernia divaricata has only rarely been found with fruiting or sorediate thalli, and never so in Norway. August 2009, we reinvented a previously known locality within the Trillemarka-Rollagsfjell nature reserve and found, for the first time in Norway, fertile thalli abundantly along a 1.2 km part of a small brook. Closer examination of samples taken from the same locality in 2003 revealed that immature fruiting-bodies (apothecia) were present on a few thalli at that time. Today the site is characterized by old mixed conifer forest and small bogs. Two additional Norwegian localities have been found to harbor fertile E. divaricata. At yet another locality we found one thallus with abundant large soralia, also recorded for the first time in Norway. Lack of small sprouting thalli with basal holdfasts suggests that dispersal, up till now, mainly have occurred by means of thallus fragmentation, thereby hampering efficient long-distance dispersal.
Sammendrag
Skogsfuglforskningen på Varaldskogen startet opp i 1979 etter en periode med svært lave bestander over hele landet. Etter 25 år med intensivt bestandsskogbruk mente mange at flatehogsten var hovedårsaken til bestandsnedgangen. På Varaldskogen var allerede halvparten av den gamle plukkhogde skogen avvirket, spesielt hadde det gått hardt utover de frodige granliene før staten tok over eiendommen etter Billerud i 1968. Mye av terrenget bestod av grasrike flater og tett ungskog i h.kl. 2. Tiurleikene og skogsfuglkullene befant seg i den gamle skogen. Reven hadde gode tider med mye markmus på hogstflatene, og den livnærte seg av egg og kyllinger når det ikke var museår...
Sammendrag
Biodiversity is assumed to have high value for many people, but the necessary preservation also incurs a cost for the forest owner. Typically, studies of this cost are at the stand level, and hence, not very accurate as the cost may vary even within the stand. In this work, we use a 1m×1m grid, generated from LIDAR data, to estimate the cost for harvesting and forwarding. The method could be utilized to calculate compensation, and to select between key woodland habitats to minimise the cost. In three of four test cases, the main cost was reduced harvested volume, but in one case the key woodland habitat also made the harvesting operations more expensive.
Sammendrag
Det er ikke registrert sammendrag
2010
Sammendrag
Vårens vakreste eventyr er igang - storfugl og orrfugl samles på leikene for å imponere ”damene”. Mange lurer på hvor de kan finne leikene, og skogbruket prøver å ta hensyn til de som allerede er kjent. Men hva er det som bestemmer leikenes størrelse og fordeling i terrenget?
Forfattere
Per Gundersen Ari Laurén Lena Finér Eva Ring Harri Koivusalo Magne Sætersdal Jan-Olov Weslien Bjarni D. Sigurdsson Lars Högbom Jukka Laine Karin HansenSammendrag
Riparian forests (RF) growing along streams, rivers and lakes comprise more than 2% of the forest area in the Nordic countries (considering a 10 m wide zone from the water body). They have special ecological functions in the landscape. They receive water and nutrients from the upslope areas, are important habitats for biodiversity, have large soil carbon stores, but may emit more greenhouse gases (GHG) than the uplands. In this article, we present a review of the environmental services related to water protection, terrestrial biodiversity, carbon storage and greenhouse gas dynamics provided by RF in the Nordic countries. We discuss the benefits and trade-offs when leaving the RF as a buffer against the impacts from upland forest management, in particular the impacts of clear cutting. Forest buffers are effective in protecting water quality and aquatic life, and have positive effects on terrestrial biodiversity, particularly when broader than 40 m, whereas the effect on the greenhouse gas exchange is unclear.
Forfattere
Signe Nybø Gregoire Certain Olav Skarpaas Jarle W. Bjerke Erik Framstad Markus Lindholm Jan-Erik Nilsen Ann Norderhaug Eivind Oug Hans Christian Pedersen Ann Kristin Schartau Ken Olaf Storaunet Gro Ingleid van der Meeren Iulie Aslaksen Steinar Engen Per Arild GarnåsjordetSammendrag
Det er ikke registrert sammendrag
Sammendrag
Degelia cyanoloma (Schaer.) H. H. Blom & L. Lindblom is resurrected from synonymy and elevated from varietal rank to species. The taxon was earlier referred to D. plumbea (Lightf.) P. M. Jørg. & P. James, however, several discontinuous character states distinguish the two species. Degelia cyanoloma is characterized morphologically by having a large thallus that is pale greyish when dry, lobes that are composed of consecutive trough-shaped segments with an upper surface without squamules, no isidia or soredia, and apothecia discs that are dark reddish brown to blackish. Degelia cyanoloma has a euoceanic distribution and is known from western Europe (Norway, France, Great Britain, Ireland, Portugal, Spain). Based on results from studies of morphology, we hypothesize that D. atlantica (Degel.) P. M. Jørg. & P. James is the closest relative of D. cyanoloma among the European species of the genus whereas D. plumbea is closely related to D. ligulata P. M. Jørg. & P. James.