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.
2010
Forfattere
Emmanuel Lapied Claire Coutris Elara Moudilou Jean-Marie Exbrayat Deborah H. Oughton Erik JonerSammendrag
Det er ikke registrert sammendrag
Forfattere
E Lapied Deborah H. Oughton Erik JonerSammendrag
In terrestrial ecotoxicology there is a serious lack of data for potential hazards posed by engineered nanoparticles (ENPs). This is partly due to complex interactions between ENPs and the soil matrix, but also to the lack of suitable toxicological endpoints in organisms that are exposed to ENPs in a relevant manner. Earthworms are recognized as key organisms in terrestrial ecosystems, but so far only physiological endpoints of low sensitivity have been used in ecotoxicity studies with ENPs. We exposed the earthworm Lumbricus terrestris to different concentrations (1-100 ppm) silver nanoparticles of two contrasting sizes under three different conditions; in water, in food and in soil. After exposure, we measured the impact on apoptosis in different tissues using two staining techniques to determine apoptosis; TUNEL and Apostain. A dose-dependent response was detected with respect to apoptotic activity in a range of tissues both at acute and sub-lethal concentrations (down to 4 mg kg soil-1). Comparing exposure in water and soil showed that reduced bioavailability in soil is reflected in the apoptotic response. Apoptosis thus seems to be a sensitive endpoint for detection of adverse effects of silver nanoparticles, and potentially a powerful tool for quantifying environmental hazards posed by ENPs.
Sammendrag
The model FROSTOL simulates course of frost tolerance in winter wheat on a daily basis from sowing on as affected by soil temperature (2 cm), snow cover, phenological development, and a genotypic maximum level of frost tolerance (LT 50). A series of cultivar trials in Finland was used to evaluate the model's ability to estimate plant survival in natural field environments during winters with differing weather conditions. Recorded survival was compared with number of intersections between the curves of simulated LT50 and the soil temperature curve for each field. A cumulative stress level (CSL) was calculated based both on number of intersections and FROSTOL simulated stress levels. The correlation between CSL and field recordings was quite low. While the field trials characterize a general ability to stand various types of winter stress, FROSTOL estimates damage caused by the soil temperature regime only. However, FROSTOL simulations seemed to correspond reasonably well to field observations when low temperature was the eventual cause of damage.
Sammendrag
The Skuterud catchment is a small artificially drained agricultural catchment, located in south eastern Norway. The total area of the catchment is 4.5 km2 of which agriculture covers 2.7 km2, forest 1.3 km2 while the rest is occupied by urban area. The main agricultural crops are wheat, barley and oat. The climate is cold temperate continental or subarctic with a winter season, lasting from November -March and characterized by periods with below-zero temperatures and a varying degree of snow cover, interchanged with thaw periods combined with precipitation and runoff. In Norway, melt water, causing surface runoff, is one of the most serious reasons for erosion, in addition to near-saturated soil moisture conditions after longer periods with rainfall during the autumn. Climate change can potentially lead to an increase in the number of freeze/thaw cycles which in addition to the predicted increase in precipitation during the period after the growing season from September - April, might lead to an increase in both the amount of runoff and its intensity, with subsequent adverse effects on erosion and nutrient loss. Models are indispensable tools in the prediction of climate change effects on runoff generation. In this respect, the Drainmod model has been tested on the Skuterud catchment concerning its ability to predict runoff from an artificially drained agricultural catchment under prevailing winter conditions. The results are presented in this paper. If proven successful, the model can be used to predict the long term hydrologic impacts of climate change for the Norwegian conditions
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Erling MeisingsetSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Kari BergjordSammendrag
Høsthveteplantenes evne til å tåle lav temperatur varierer gjennom høst og vinter. Med utgangspunkt i en kanadisk modell, ble modellen FROSTOL utviklet for å simulere daglig utvikling av frosttoleranse fra såing om høsten, og gjennom vinteren. Modellen kan brukes til å estimere faren for overvintringsskader forårsaket av lav temperatur ved å sammenholde simulert utvikling av frosttoleranse med registrert temperatur i det øverste jordlaget (0-5 cm). Ved å bruke klimascenarier i stedet for registrert temperatur, vil en også kunne bruke modellen til å si noe om risiko for denne type vinterskader i et fremtidig klima. En evaluering av FROSTOL basert på registrert overvintring i finske sortsforsøk fra 1989/90-1991/92, indikerte at modellen fungerte relativt bra under forhold der lav temperatur var den avgjørende årsaken til skade.
Forfattere
Anne Kari BergjordSammendrag
Foredraget presenterte resultater fra forsøk der høsthveteplanter fra tre ulike steder med ulikt vinterklima ble testet for frosttoleranse regelmessig gjennom to vintre. Resultatene fra disse forsøkene ble brukt til å utvikle modellen FROSTOL som simulerer utvikling og endring av frosttoleranse fra såing av og gjennom vinteren. Modellens evne til å predikere grad av overvintring gjennom vintre med ulike værforhold ble testet ved bruk av et finsk datasett. Overvintringsskader kan forårsakes av mange ulike biotiske og abiotiske faktorer, men resultatene indikerte at FROSTOL fungerer relativt bra for vintre der frostskader er den avgjørende årsaken til utgang av planter. Den kan således være et viktig første skritt på veien mot en mer helhetlig overvintringsmodell for høsthvete.
Sammendrag
Timothy (Phleum pratense L) is the most important forage grass in Scandinavia and it is therefore highly interesting to study how it will perform in a changing climate. In order to model winter survival, the dynamics of hardening and dehardening must be simulated with satisfactory precision. We investigated an early timothy frost tolerance model (LT50 model), and an LT50 model for winter wheat. Based on the assumption that timothy has no vernalization requirement, unlike winter wheat, but does have the ability to adapt to cold temperatures in a process linked to stage of development, two alternative versions of the winter wheat model were also constructed. In total, these four candidate models were calibrated by a Bayesian approach for the timothy cultivar Engmo. The candidate models were validated using independent observations on LT50 in timothy at different locations reflecting differences in climate. A sensitivity analysis, using the Morris method, to identify important model parameters suggested that there is a connection between frost tolerance and stage of plant development, even if there is no vernalization requirement. The simplified winter wheat model was selected as the best candidate model for LT50 in timothy based on model selection criteria and its ability to capture the hardening and dehardening processes. The results from the Bayesian calibration suggest that there are no major regional differences in Norway calling for regional calibration. However, cultivar-specific calibration is probably required, since there are hardy and less hardy cultivars within the same species. A functional LT50 model would allow risk assessments to be made of future winter survival using specifically tailored and downscaled climate scenarios. (C) 2010 Elsevier B.V. All rights reserved.
Forfattere
Geir-Harald StrandSammendrag
The change from one landscape to another is gradual. Landscape classes can therefore be considered as theoretical concepts and a particular location or area can be affiliated with a number of different landscape classes. Landscape classification thus becomes a statistical and probabilistic exercise. Such a probabilistic approach to landscape regions can be made operational using a grid model combined with binary logistic regression. This approach was tested on a landscape region in Norway.