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
1. Surrogate species measures of biodiversity (SSB) are used worldwide in conservation prioritisations. We address the important question whether the ideas behind SSB are consistent with current knowledge on distribution patterns of species, as reflected in theories of community assembly. 2. We investigated whether assumptions necessary for successful functioning of SSB (nested species assemblages, cross-taxon congruence, spatio-temporal consistency) were supported by predictions from either niche or neutral community models. 3. We found a general mismatch between ideas behind SSB and ecological community theory, except that SSB based on complementarity may be consistent with niche-based theory when gradients in species composition are strong. 4. Synthesis and applications. The lack of a necessary scientific foundation may explain the disappointing results of empirical tests of SSB. We argue that site selection should be based on costs and opportunities within complementary environmental/land units, rather than expensive inventories of unfounded surrogate species.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Two new species of Schistidium Bruch & Schimp., S. riparium H.H.Blom, Shevock, D.G.Long & Ochyra, and S. mucronatum H.H.Blom, Shevock, D.G.Long & Ochyra, are described and illustrated. They occur in rheophytic habitats in China, S. riparium in the southern Hengduan Mountains in Yunnan Province (Lancang Jiang and Nu Jiang catchments) and S. mucronatum from further north, on the Qinghai‐Tibet Plateau of Sichuan and Qinghai Provinces (Jinsha Jiang and Huang He catchments). The affinities of the new species are discussed and on the basis of their concave and broadly canaliculate leaves with plane and erect margins, S. riparium is tentatively placed in Schistidium Bruch & Schimp. subgen. Canalicularia Ochyra, whereas S. mucronatum on account of its keeled, ovate-lanceolate leaves and the strongly curved and twisted peristome teeth resembles very much species of sect. Apocarpiformia (Kindb.) Ochyra within subgen. Apocarpa Vilh.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
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.