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
Potential response of forest soils to sulphur deposition in the Norwegian-Russian border area in the surroundings of the Pechenganikel smelters, the major sulphur emitters in the northern Europe, has been assessed with the PROFILE model. The release rate of base cations due to weathering range from 0.05 to 0.28 kmol(c)/ha/yr in the 0 - 50 cm soil layer, thus demonstrating the high sensitivity of the coarse and thin podzols studied. Calculated steady-state BC/Al values are significantly lower than the presumed critical value of 1, which indicate possible negative effect on vegetation through soil acidification. According to the model calculations future sulphur deposition have to be very low in order to stop the ongoing acidification and prevent vegetation damage. However, model assumptions, uncertainty in input data and critical chemical values applied implies that modelling results must be interpreted carefully
Sammendrag
A field experiment was carried out to test the hypothesis that treatment of Norway spruce trees with the Ips typographus-transmitted blue-stain fungus Ceratocystis polonica enhances tree resistance to later mass attack by this bark beetle. Twenty-five mature trees were pre-treated by inoculating a non-lethal dose of the fungus into the bark, while 18 trees served as untreated controls. Three and a half weeks after treatment a bark beetle attack was initiated by attaching dispensers with I. typographus pheromone to the tree trunks. A significantly larger proportion (67%) of the control trees than of the pre-treated trees (36%) were killed by the beetle attack. The result is discussed in relation to recent results regarding defence mechanisms in Norway spruce trees.
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
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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