Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
1997
Abstract
We compared diversity of birds in 35 study plots of equal size (58 ha) and productivity in western Norway, ranging from pure native pine Pinus sylvestris forests (n = 7), through different mosaics of native pine forests and spruce Picea spp. plantations (n = 21), to pure spruce plantations (n = 7). Diversity was evaluated by means of species richness, diversity indices, relative abundance curves and rarefaction. The diversity indices appeared to be less suitable for our purpose. Species richness was higher in pine forest than in spruce forest. However, a peak in species richness was found in mosaic forest. For pooled samples (408 ha), 11 bird species recorded in pine forest were not found in spruce forest, seven species were found in spruce forest but not in pine forest, and seven species were confined to the medium mosaics of pine and spruce forest (on average 56% pine and 44% spruce). We argue that, when mixing two habitat types A and B, the ratio of these habitats that maximize avian diversity depends on the ratio of species confined to habitat A and B, as well as the number of species favoured by the mixture of A and B. Existing spruce plantations (13% of the area) in native pine forests of western Norway have reduced the diversity of birds locally, but increased the diversity of birds on the landscape and regional scale.
Authors
Inger Aandahl Raastad Gunnar OgnerAbstract
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Authors
Rune Halvorsen Økland Eiliv Steinnes Tonje ØklandAbstract
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Ann Merete Furuberg GjedtjernetAbstract
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Tore SkrøppaAbstract
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Abstract
The subfamily ground midges (Lestremiinae) has been poorly studied in Fennoscandia. Until quite recently (1986) only eight species of this group was known from this area. However, the number of species recorded has increased considerably the few last years. This article surveys new and old records of ground midge from Fennoscandia. The survey is based on a new material collected in 49 localities in various parts of Fennoscandia, and on records in previous publications. A list of altogether 73 species of ground midge is presented, including 25 species which are new to Finland, Norway or Sweden.
Abstract
No abstract has been registered
Authors
Birger SolbergAbstract
All countries in Scandinavia have introduced a carbon fee on fossil fuel to reduce the emission of the climate gas CO2. In Norway the fee is 0.82 NOK (or about 0.12 US$) per liter of gasoline, equivalent to 343 NOK (or 49 US$) per ton CO2. The fee is an emission cost which gives a corresponding benefit for absorbing atmospheric CO2 in forest biomass.This article shows that this benefit corresponds to a net economic value of carbon sequestration in forest biomass 2-30 times higher than the net value of timber as raw material for the forest industry in Norway, which has one of the highest timber prices in the world.If a fee high enough to stabilize the CO2 emission in Norway were to be introduced, the value of carbon sequestration will be at least twice as high as the above estimates. It is argued that this will imply substantial changes in forest management and policy, both in rich and poor countries.Projects to restore and maintain sustainable forest ecosystems will be very profitable, and could simultaneously provide considerable other environmental benefits like increased biodiversity, soil stability, and improved watershed structures.