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.
2004
Abstract
No abstract has been registered
Authors
Lars Sandved Dalen Øystein JohnsenAbstract
Plant growth and adaptation to cold and freezing temperatures in a CO2-enriched atmosphere have received little attention despite the predicted effects of elevated CO2 on plant distribution and productivity. Norway spruce (Picea abies (L.) Karst.) seedlings from latitudinally distinct seed sources (66N and 60N) were grown for one simulated growth season under controlled conditions in an atmosphere enriched in CO2 (70Pa) and at ambient CO2 (40Pa), combined factorially with low (3.6mM) or high (15.7mM) concentrations of nitrogen fertilization.There was a clear difference between the two provenances in height growth, in the timing of bud set, and in freezing tolerance. Nitrogen fertilization increased height growth in both provenances, while CO2-enrichment stimulated height growth only in the southern provenance. We found no significant effects of elevated CO2 or nitrogen fertilization on the timing of bud set.During cold acclimation, freezing tolerance increased from -10C to -35C, and there was a marked increase in all soluble sugars except inositol. Elevated CO2 in combination with high nitrogen led to a slight increased freezing tolerance in both provenances during the early stages of cold acclimation. However, towards the end of cold acclimation, elevated CO2 and high nitrogen led to reduced freezing tolerance in the southern provenance, while elevated CO2 and low nitrogen reduced freezing tolerance in the northern provenance. These results suggest that CO2-enrichment influences the development of freezing tolerance, and that these responses differ with available nitrogen and between provenances.
Abstract
No abstract has been registered
Abstract
This study was conducted to explore organic and conventional dairy farmers perceptions of risk and risk management, and to examine relationships between farm and farmer characteristics, risk perceptions, and strategies. The data originate from a survey of conventional (n = 363) and organic (n = 162) dairy farmers in Norway. Organic farmers had the least risk averse perceptions. Institutional and production risks were perceived as primary sources of risk, with farm support payments at the top. Compared to their conventional colleagues, organic farmers gave more weight to institutional factors related to their production systems. Conventional farmers were more concerned about costs of purchased inputs and animal welfare policy. Organic and conventional farmers management responses were more similar than their risk perceptions. Financial measures such as liquidity and costs of production, disease prevention, and insurance were perceived as important ways to handle risk. Even though perceptions were highly farmer-specific, a number of socio-economic variables were found to be related to risk and risk management. The primary role of institutional risks implies that policy makers should be cautious about changing policy capriciously and they should consider the scope for strategic policy initiatives that give farmers some greater confidence about the longer term. Further, researchers should pay more attention to institutional risks.
Authors
Geir ØstrengAbstract
Artikkelen er basert på resultater fra et nordisk kurs i kalibrering av apparater for måling av CO2-frigivelse fra jord. Geir Østreng deltok på kurset med det apparatet som er brukt bl.a. i SIP Karbondynamikk i skogsjord 2000-2005, og han er medforfatter.
Abstract
No abstract has been registered
Abstract
Conventional extreme value statistics and the calculation of return periods implicitly assume stationarity of distributions and statistical independence at least asymptotically (most extreme events).We demonstrate, using a collection of river runoff time series from Southern Germany, that these assumptions are invalid, and that temporal as well as spatial correlations prevail instead: temporal differences of distributions are nearly synchronized within a region, and there are systematic trends of percentiles especially at low flow conditions within the 20th century.As a consequence, the estimated return periods of a given threshold flow are fluctuating, in some cases even in a dramatic fashion. On the other hand, a general trend towards an increase in flood frequencies cannot be stated on basis of our investigations, in accordance with other recent findings (Mudelsee et al. 2003), but contrary to general expectations drawn from climate change studies.
Authors
Ingrid OlesenAbstract
In spring 2003, the Nordic Gene Bank Farm Animals (NGH) proposed a follow up of the “Strategy for the conservation of genetic resources in the Nordic countries 2001-2004”. It was proposed to formulate criteria for sustainable animal breeding and guidelines for breeding organizations. Thus, the Norwegian Gene Resource Council decided to initiate the development of criteria for sustainable animal breeding and guidelines for breeding organizations in Norway.
Authors
Audun Øvrum Terje BirkelandAbstract
No abstract has been registered
Authors
Nina Elisabeth Nagy Lars Sandved Dalen D. L. Jones B. Swensen Carl Gunnar Fossdal Toril EldhusetAbstract
No abstract has been registered