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
Sammendrag
The leaf blotch complex is one of the most important yield limiting disease on wheat in Norway. It is caused by three pathogens, Septoria tritici ( Mycosphaerella graminicola), Stagonospora nodorum ( Phaeosphaeria nodorum), and Drechslera tritici-repentis (Pyrenophora tritici-repentis). The symptoms of each of the pathogens are similar and easily confused with leaf senescence, making it difficult to assess the true disease severity and thus hampering breeding for leaf blotch resistance. To reduce unnecessary pesticide use and the risk of pesticide resistance developing in the fungal populations, timing of disease control measures are based on forecasting models. The degree of a leaf blotch epidemic is determined by initial inoculums, precipitation, temperature, time, availability of susceptible hosts and the degree of susceptibility. During the last 20 years, the start of the growing season as marked by a soil temperature of 5C, has advanced by 1-1.5 days per year (Rafoss, 2009), indicating an increase in the length of growing seasons. The trend for warmer and wetter growing seasons is predicted to continue in the future. It is of high relevance to the wheat industry to understand the impact of these changes on leaf blotch diseases in the field to optimize disease forecasting and management. We have collected data on leaf blotch severity in the field and weather conditions at different wheat growing areas in Norway over the last 10 years. Based on this data, we do not see a general increase in disease severity over the last decade. However, the data shows that there are local shifts in maximum disease severity; areas that support high disease severity and areas that support very little. Given the amount of initial inoculum and availability of susceptible hosts are comparable between the different wheat growing areas, the local climate per site becomes the determining factor for the epidemic. We studied the effect of relatively small, local differences in precipitation, temperature, and start of growing season on leaf blotch development in the field. The analysis of local shifts in climatic conditions and their relation to disease development allows us to estimate the effect of the changing climate on leaf blotch disease in the future.
Forfattere
Arnstein Staverløkk May-Guri Saethre Trond HofsvangSammendrag
The history of Harmonia axyridis and a summary of surveillance and research in Norway till June 2009 are given. H. axyridis was assessed as a potential bio-control agent for use in Norwegian greenhouses in 2001. The risk of establishment outdoors was assessed too high and no permission was given. The first record in Norway was in 2006 when one adult was found on Thuja sp. imported from the Netherlands. In late 2007 and throughout 2008 adults were found indoors/outdoors at several locations in the Oslo-area. Establishment outdoors became evident. Observations in Aust-Agder, Vestfold and Trondheim revealed further spread/introduction to new areas. The bioclimatic potential of H. axyridis was assessed in 2007 by the aid of CLIMEX using national agrometeorological data, showing that suboptimal microclimates for the species can be found in the coastal areas of the south. In late 2008 a web-site was launched aiming to engage the public to submit observations on-line and has contributed to monitor development of the species across the country. Competition experiments with H. axyridis and Coccinella septempunctata in 2008/2009 showed that only H. axyridis eggs and larvae survived when the two species were mixed.
Sammendrag
In European forests, standing stocks are currently higher than ever during the last decades, in part due to reduced logging or the abandonment of agricultural land. However, data from intensive monitoring plots reveal an increased growth even without direct human intervention.We used a set of 363 plots from 16 European countries to investigate the influence of environmental factors on forest growth: nitrogen, sulphur and acid deposition, temperature, precipitation and drought, for Norway spruce, Scots pine, common beech and European as well as sessile oak.We used existing information on site productivity, stand age and stand density to estimate expected growth. Relative tree growth, i.e., the ratio between actual growth within a five-year period and expected growth, was then related to environmental factors in a stepwise multiple regression.The results consistently indicate a fertilizing effect from nitrogen deposition, with roughly one percent increase in site productivity per kg of nitrogen deposition per ha and year, or 20 kg C fixation per kg N deposition. This was most pronounced for plots having soil C/N ratios above 25. We also found a positive albeit less clear relationship between relative growth and summer temperatures.From the study, we cannot conclude on any detrimental effects on growth from sulphur and acid deposition or from drought periods. A very recent study from the U.S., comprising 4800 plots and 24 tree species, confirms our results. However, we also show that the magnitude of N deposition effects on global forest C balance is currently a highly controversial matter, and comment on this debate. http://www.cef-cfr.ca/uploads/Colloque/Programme10_5.pdf
Forfattere
Adam ParuchSammendrag
Det er ikke registrert sammendrag
Forfattere
Lampros LamprinakisSammendrag
Det er ikke registrert sammendrag
Forfattere
Tao Zhao Paal Krokene Niklas Björklund Bo Långström Halvor Solheim Erik Christiansen Anna-Karin Borg-KarlsonSammendrag
Constitutive and inducible terpene production is involved in conifer resistance against bark beetles and their associated fungi. In this study 72 Norway spruce (Picea abies) were randomly assigned to methyl jasmonate (MJ) application, inoculation with the bluestain fungus Ceratocystis polonica, or no-treatment control. We investigated terpene levels in the stem bark of the trees before treatment, 30 days and one year after treatment using GC–MS and two-dimensional GC (2D-GC) with a chiral column, and monitored landing and attack rates of the spruce bark beetle, Ips typographus, on the trees by sticky traps and visual inspection. Thirty days after fungal inoculation the absolute amount and relative proportion of (+)-3-carene, sabinene, and terpinolene increased and (+)-α-pinene decreased. Spraying the stems with MJ tended to generally increase the concentration of most major terpenes with minor alteration to their relative proportions, but significant increases were only observed for (−)-β-pinene and (−)-limonene. Fungal inoculation significantly increased the enantiomeric ratio of (−)-α-pinene and (−)-limonene 1 month after treatment, whereas MJ only increased that of (−)-limonene. One year after treatment, both MJ and fungal inoculation increased the concentration of most terpenes relative to undisturbed control trees, with significant changes in (−)-β-pinene, (−)-β-phellandrene and some other compounds. Terpene levels did not change in untreated stem sections after treatment, and chemical induction by MJ and C. polonica thus seemed to be restricted to the treated stem section. The enantiomeric ratio of (−)-α-pinene was significantly higher and the relative proportions of (−)-limonene were significantly lower in trees that were attractive to bark beetles compared to unattractive trees. One month after fungal inoculation, the total amount of diterpenes was significantly higher in putative resistant trees with shorter lesion lengths than in putative susceptible trees with longer lesions. Thus, terpene composition in the stem bark may be related to resistance of Norway spruce against I. typographus and C. polonica.
Forfattere
Anne-Kristin LøesSammendrag
The schooldays of European children and youth tend to get longer, and their eating patterns, especially during school hours, are often unsatisfactory. Healthy school food is a logic response to this situation. Organic food contributes to sustainable nutrition, and hence is an interesting starting point for healthier menus and food education. The research project “innovative PublicOrganic food Procurement for Youth” (iPOPY) studies efficient ways to implement organic food in public serving outlets for young people. Out of the four iPOPY funding countries, Finland and Italy serve a warm school meal daily for all pupils, whereas Denmark and Norway rely on packed lunch from home. Italy and Denmark have ambitious goals for organic food in schools, whereasFinland and Norway have not (yet). In Germany, different states have very different school meal systems, but the interest for organic food is generally high. We argue that school food served in “captive catering” such as found in Finland, financed by the public and made by organic or otherwise sustainable products, has the largest potential to support a sustainable nutrition and - development.
Sammendrag
The Lange Bramke catchment has been investigated as a monitored catchment for 60 years. However, its utilization history even dates back to medieval times, and is well documented in part. The intense interplay between ore mining, forestry, and water resources exploitation left remains such as scoriae piles and modified forest growth, e.g. due to local pollution at smelter locations. It is demonstrated that considering local land use history is important for a proper understanding and interpretation of modern monitoring data. A theoretical framework is proposed for the integration of the two data sources. This requires a joint approach combining two modelling paradigms, the functional one dominating in current ecosystem research, and an interactive one which best characterizes the human–environment relationship in historic times.
Forfattere
Arne Grønlund Sissel HansenSammendrag
The agricultural sector contributes about 9 % of the officially reported GHG emissions in Norway, and about 13 % when the estimated CO2 losses from peat and arable soils are included. N2O, CH4 and CO2 make up comparable amounts of the emissions. N2O emissions are estimated at 2.1 million tonnes (Mt) CO2 equivalents, originating in fertilizers in soil, livestock manure, runoff, N fixation, residual crops, NH3 in precipitation, and mineralisation of organic soils. CH4 emissions are calculated at 2.2 Mt CO2 equivalents, of which 85 % originates in enteric fermentation of ruminants and 15 % in farmyard manure. CO2 emissions are estimated at 2.7 Mt CO2 equivalents, and include degradation of organic soils (1.8 Mt), C loss from mineral arable soils (0.5 Mt) and fossil fuel combustion (0.4 Mt). The estimates for N2O and CO2 from soils are very uncertain.
Forfattere
Signe Nybø Gregoire Certain Olav Skarpaas Jarle W. Bjerke Erik Framstad Markus Lindholm Jan-Erik Nilsen Ann Norderhaug Eivind Oug Hans Christian Pedersen Ann Kristin Schartau Ken Olaf Storaunet Gro Ingleid van der Meeren Iulie Aslaksen Steinar Engen Per Arild GarnåsjordetSammendrag
Det er ikke registrert sammendrag