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.
1999
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Heleen A de Wit Sheila KvindeslandSammendrag
The Kyoto Protocol has set targets to reduce the emissions of greenhouse gasses to the atmosphere. One method to stabilise atmospheric CO2 concentrations is to sequester carbon in terrestrial ecosystems. Forest management will possibly be included in the Protocol as an accountable measure for sequestration of C in forests. Soils in boreal forest are presently understood to be a large potential sink for atmospheric CO2. This report presents estimated C-stocks in Norwegian forest soils based on forest monitoring databases which cover forests from all counties except Finnmark. Uncertainty in the estimate of C stocks is ca 30 %, mainly due to missing soil bulk density data and inaccurate estimates of soil stoniness. The estimated C-stocks are higher than published C-stocks in boreal forest soils from Sweden and Finland, but in the same order as Canadian and Scottish estimates. Largest C-stocks are found in organic soils. Considering only mineral soils, pure spruce forest has lowest C-stocks whereas mixed forest and pure pine forest have highest C-stocks in the forest floor. This is in agreement with other studies and implies that planting mixed forest is a measure for increasing C-sequestration in forest soils. The C-stocks in the forest floor of pure pine and spruce forest were larger in higher cutting classes. This may be related to stand age and suggests that an increase in rotation length will increase C-accumulation in the forest floor. Forest management measures that increase C-sequestration in soils are planting or regenerating forest on cultivated, drained soils; N-fertilisation; and increasing rotation length. Measures that may affect soil C-stocks negatively are strongly mechanised site preparation, draining and planting of peatlands, and clearcutting. Organic soils and very sandy soils appear more sensitive to site preparation and harvesting practices, losing more C than other soils after these events.
Sammendrag
Contamination of atmosphere and soils was found to be accompanied by the active participation of S, Ni, Cu and Fe in the biological cycle in the area adjacent to \"Petchenganickel\" group of smelting works. The content of Ni, Cu and S in pine needles near the works is as high as 0,7-1; 0,4-0,5 and 40-60 mmol/kg respectively, these values for metals being by an order of magnitude higher than those in unpolluted areas. With increase in the age of trees the content of N, P, K, Mg and S in pine needles decreases and the content of Ca, Al, Fe and Mn increases; accumulation of Ni and Cu in pine needles is usually observed near the smelting works.
Forfattere
jihong liu clarke Anne Marie Chevre Maria Landgren Kristine GlimeliusSammendrag
Abstract Cytogenetic studies were performed on four male-sterile progenies derived from four different cybrids produced between Brassica napus and B. tournefortii using the donor-recipient protoplast fusion method. The objective of these studies was to characterize the nuclear constitution of the plants. Mitotic investigation revealed that three of the four male-sterile lines had 38 chromosomes, which is equal to that of B. napus. The fourth line, C6, had variable chromosome numbers, ranging from 39 to 42 in different plants. The meiotic behavior in each progeny varied distinctly. Of the plants having 38 chromosomes, fairly high chromosome pairing, on average 18.08 bivalents per cell, was detected at metaphase-I. However, univalents with an average of 1.39 per cell, and very low frequencies of trivalents and/or tetravalents, were also observed in the lines. These results revealed that male-sterile cybrid lines were obtained with 38 chromosomes and a relatively high level of chromosome-pairing ability, indicating their potential for establishing a stable male-sterile rapeseed line.
Forfattere
Vladimir StolbovoiSammendrag
Det er ikke registrert sammendrag
Forfattere
J. Pomeroy R. Granger A. Pietroniro J. Elliott B. Toth N. HedstromSammendrag
Det er ikke registrert sammendrag
Forfattere
Jan Mulder J.F. Gallardo E. Matzner Edward Tipping Charlotte Bryant Nicholas Clarke S. Lofts B. Michalzik M.A. VicenteSammendrag
Det er ikke registrert sammendrag
Redaktører
Tore SkrøppaSammendrag
Det er ikke registrert sammendrag
Forfattere
Oddvar Skre M. NæssSammendrag
Det er ikke registrert sammendrag
Forfattere
Oddvar SkreSammendrag
Seedlings of white birch seem to tolerate high winter temperatures to a higher degree than spruce seedlings, and were also more able to take advantage of elevated CO2 levels. Large differences were observed between provenances in response patterns. The southern provenance of birch was more tolerant against raised winter temperatures than the northern ecotype, and the southern spruce provenance seemed to differ from the two northern provenances in the same way. The Icelandic birch population seemed to have developed a low-growth strategy with strong CO2 acclimation and no significant CO2 responses in photosynthetic rates and growth parameters. This differing response may be explained by long-term selection pressure due to heavy grazing. One of the spruce provenences showed a similar pattern.