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.
2007
Forfattere
Arnstein StaverløkkSammendrag
Innholdet bygger på undersøkelser gjort under arbeidet med masteroppgaven og resultatene som ble funnet der. Generelt om fremmede arter og konsekvenser, lovverk som berøres ifm import av planter, funn av 16 nye arter for Norge.
Forfattere
Ricardo Holgado Christer MagnussonSammendrag
Cereal cyst nematodes, Heterodera spp., are known world wide as parasites of cereals and grasses. Surveys in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country. The cereal cyst nematode species so far recorded in Norway are H. avenae, H. filipjevi, H. pratensis, H. bifenestra and H. hordecalis. Within H. avenae the pathotypes, Ha 11 and Ha 12, "Ha- Knislinge", "Ha- Ringsåsen" and "Ha- Våxtorp" have been encountered. H. filipjevi is represented by the pathotype "West" HfW (Holgado et al., 2007). In cereals, peaks in cyst nematode populations and damage occur every 20-30 years, and seem to occur simultaneously throughout the Scandinavian Peninsula. We do not have reliable information on the mechanisms behind these wide spread fluctuations. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes, but require detailed information on the occurrence and density of species and pathotypes in the fields (Holgado & Andersson 2005, Holgado et al. 2005, 2006ab). In field soils Ha 11,/12, "Ha-Våxtorp" is often found together with HfW. Resistant cultivars are normally resistant to only one of two species or pathotypes in mixed field populations. Consequently the use of resistant cultivars will lead to an increase of the nematode species or pathotype capable of reproduction, which results in peaks of damage distributed in time. Failure in recognizing the time span of this dynamic may leave the farmer without access to appropriate cultivars when damage occurs. Different species and pathotypes of cyst nematodes may occur simultaneously on the same plant root (Holgado & Magnusson, 2007). This would be an unlikely event without mechanisms reducing competition. Differences in temporal, spatial and physiological niche dimensions between species would support diversity. A better knowledge of key-differences in niche parameters of cereal cyst nematode species would allow for an active management of specific populations, and stabilize their population densities at levels below the threshold of economic damage. Management of niches is management of diversity, and this would allow for an optimal selection of cultivars. In this way the unexpected peaks in cereal damage can be avoided to the benefit of a more stable and sustainable production. The dynamics and principles of coexistence of species in mixed populations need a stronger emphasis in management systems for cereal cyst nematodes.
Forfattere
Ricardo Holgado Christer MagnussonSammendrag
Cereal cyst nematodes, Heterodera spp., are known world wide as parasites of cereals and grasses. Surveys in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country. The cereal cyst nematode species so far recorded in Norway are H. avenae, H. filipjevi, H. pratensis, H. bifenestra and H. hordecalis. Within H. avenae the pathotypes, Ha 11 and Ha 12, "Ha- Knislinge", "Ha- Ringsåsen" and "Ha- Våxtorp" have been encountered. H. filipjevi is represented by the pathotype "West" HfW (Holgado et al., 2007). In cereals, peaks in cyst nematode populations and damage occur every 20-30 years, and seem to occur simultaneously throughout the Scandinavian Peninsula. We do not have reliable information on the mechanisms behind these wide spread fluctuations. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes, but require detailed information on the occurrence and density of species and pathotypes in the fields (Holgado & Andersson 2005, Holgado et al. 2005, 2006ab). In field soils Ha 11,/12, "Ha-Våxtorp" is often found together with HfW. Resistant cultivars are normally resistant to only one of two species or pathotypes in mixed field populations. Consequently the use of resistant cultivars will lead to an increase of the nematode species or pathotype capable of reproduction, which results in peaks of damage distributed in time. Failure in recognizing the time span of this dynamic may leave the farmer without access to appropriate cultivars when damage occurs. Different species and pathotypes of cyst nematodes may occur simultaneously on the same plant root (Holgado & Magnusson, 2007). This would be an unlikely event without mechanisms reducing competition. Differences in temporal, spatial and physiological niche dimensions between species would support diversity. A better knowledge of key-differences in niche parameters of cereal cyst nematode species would allow for an active management of specific populations, and stabilize their population densities at levels below the threshold of economic damage. Management of niches is management of diversity, and this would allow for an optimal selection of cultivars. In this way the unexpected peaks in cereal damage can be avoided to the benefit of a more stable and sustainable production. The dynamics and principles of coexistence of species in mixed populations need a stronger emphasis in management systems for cereal cyst nematodes.
Forfattere
Richard MeadowSammendrag
Foredraget er et framlegg av resultater fra et brukerstyrt prosjekt. Utprøving av alternative midler for bekjempelse i direktesådd kålrot og forsøk med dekke ble omtalt.
Forfattere
I.A. Rasmussen D.L. Benoit A. Davies F. Forcella J.L. Gonzalez-Andujar F. Graziani A.C. Grundy L. Karlsson A. Mead P. Milberg A. Murdoch P. Neve J. Salonen B. Sera E. Sousa F. Tei Kirsten Tørresen J.M. UrbanoSammendrag
Samspill mellom oppspiringsforhold, opphavssted til frø og jordarbeiding på oppspiring av meldestokk på 11 ulike steder i Europa og Nord-Amerika ble presentert.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Kirsten TørresenSammendrag
Virkning av klima om høsten på tilvekst av etablerte planter, gjenvekst fra rotbiter og frosttoleranse til rotbiter av kveke, åkertistel og åkerdylle fra prosjektet WINSUR ble presentert.
Sammendrag
available, especially in Norway. The objective of the present research was to estimate C losses from cultivated peatlands in West Norway by three independent methods: 1) long-term monitoring of subsidence rates, 2) changes in ash contents, and 3) soil CO2 flux measurements. Subsidence of cultivated peat soils averaged about 2.5 cm y-1. We estimated that peat loss and compaction were respectively responsible for 38% and 62% of the total subsidence during a 25-year period after drainage. Based on this estimate the corresponding C loss equals 0.80 kg C m-2 yr-1. The observed increase in mineral concentration of the topsoil of cultivated peat is proportional to their C loss, providing no mineral particles other than lime and fertilizers are added to the soil. Using this novel approach across 11 sites, we estimated a mean C loss of 0.86 kg C m-2 y-1. Soil CO2 flux measurements, corrected for autotrophic respiration, yielded a C loss estimate from cultivated peat soils of 0.60 kg C m-2 yr-1. The three methods yielded fairly similar estimates of C losses from Norwegian cultivated peatlands. Cultivated peatlands in Norway cover an estimated 63 000 ha. Total annual C losses from peat degradation were estimated to range between 1.8 and 2 million tons CO2 y-1, which equals about 3-4 % of total anthropogenic greenhouse gas emissions from Norway.
Forfattere
Marie-France Dignac Cornelia Rumpel Daniel Rasse Mercedes Mendez-Millan Haithem Bahri André MariottiSammendrag
Little is known on the relationship between the chemical composition and the dynamics of plant biomolecules in soils at the long-term scale. Chemical recalcitrance of specific molecules such as lignins has been proposed as a possible factor governing organic matter stabilization in soils. Other stabilization mechanisms, involving soil mineral constituents, may act differently on above- and belowground tissues of plants, leading to contrasting contributions of these tissues to soil organic matter (SOM). Cutins and suberins are present respectively in the aboveground and the belowground tissues of higher plants and can be used as biomarkers of the inputs of these plant tissues to soils. Using compound specific isotopic tracer techniques applied to agricultural lands converted from C3 plant to C4 plant cropping, we followed the molecular turnover of lignins, cutins and suberins in soils, in order to assess their specific residence times, and infer the contributions of above- and belowground tissues to SOM. We showed that lignin turnover in soil is faster than that of total organic carbon. We evidenced contrasting behaviour of lignin as well as cutin/suberin monomers on a molecular basis which may be related to their chemical nature, their position into the polymeric structure and to the plant tissue in which they are present. Therefore, we suggest that compound specific isotope measurements in combination with longterm field trials could lead is understanding of soil carbon stocks and fluxes on a molecular level.
Forfattere
Unni Abrahamsen Guro Brodal Oleif Elen Arne Hermansen Ragnhild Nærstad Arne Stensvand Venche Talgø Brita ToppeSammendrag
Det er ikke registrert sammendrag