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.
2008
Sammendrag
Artikkelen omhandlar rotstokkrote og lerrote i jordbær som begge er årsaka av Phytophthora cactorum.
Forfattere
Arne Stensvand Maria Herrero Håvard Eikemo Andrew Dobson David M. Gadoury Robert C. Seem Catherine Heidenreich Mary Jean WelserSammendrag
Artikkelen gir ein kort omtale av resultat frå eit forskingsprosjekt om mjøldogg i jordbær.
Forfattere
Arne StensvandSammendrag
Artikkelen er ein omtale av Signum (aktive stoff: pyraklostrobin og boskalid) og inkluderer resultat frå utprøvingar av preparatet i Noreg.
Sammendrag
Incomplete combustion during vegetation fire can lead to the conversion of plant and soil organic matter (OM) into charcoal. The thermally altered OM is considered to contribute to the stable pool of soil C. Most of the data on thermal alteration of plant material were obtained in the laboratory, whereas fire consequences on ecosystem C storage calls for data collected in natural-fire conditions. The objective of this study was to relate the quality of visually-identified litter charcoal and the temperature recorded during a scrubland prescribed fire. Litter was sampled before and after the fire along a transect in the 30 ha experimental site. Litter-size fractions were analyzed for chemical composition and properties by elementary and isotopic analysis, solid-state 13C nuclear magnetic resonance spectroscopy, differential scanning calorimetry and quantification of oxidation-resistant pyrogenic C. The maximum temperature reached within the litter layer during fire was assessed with thermo-sensitive paints. Our results showed that fire had little effect on bulk litter composition because the fire event induced a large litter fall of both charred and non-charred material, resulting in the impossibility to distinguish new-litter-input and charring processes. As a consequence, the visual identification and separation of burned and unburned material constituted an essential preliminary step for chemical characterization of thermally altered organic matter. Fire temperatures ranged from 370 to 650°C. Charring signifi- cantly increased the litter C concentration by 115 to 142 mg g"1 under the effects of dehydration and aromatization processes occurring above 370°C. A significant correlation appeared between the production of aromatic structures, the decrease of O-alkyl C contribution and the temperature. The relationship between the maximum temperatures reached during the natural fire and the chemical transformation of the litter organic matter appeared highly consistent with previous results obtained under controlled conditions. Heating also led to a significant decrease of the 13C that we interpret as a higher thermal sensitivity of 13C-rich molecules. The elemental composition, NMR and thermal spectra are consistent with the low oxidation-resistant C concentration of this natural charcoal (16±5 % OC), reflecting a low condensation degree compared to graphitic-like model. These findings suggest that leaf-derived charcoal produced during natural vegetation fire may have a lower C storage potential than previously assumed.
Forfattere
Marie-France Dignac C Rumpel Daniel Rasse M Mendez-Millan H Bahri S Derenne G Bardoux A MariottiSammendrag
How the chemical composition of plant biomolecules controls their dynamics in soils at the long-term scale remains largely unknown. Stabilisation mechanisms in soils might depend upon the chemical nature of organic matter. These mechanisms either involve soil mineral constituents or are related to chemical recalcitrance of specific molecules such as lignins. Physical and physico-chemical protection mechanisms 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 specific for above and the belowground tissues of higher plants, respectively. Their molecular constituents can be used as biomarkers of the inputs of these plant tissues to soils. In this study, the molecular turnover of specifically plant-derived constituents in soils were estimated using compound specific isotopic tracer techniques applied to agricultural lands converted from C3 plant to C4 plant cropping. We assessed the specific residence times of lignins, cutins and suberins in soils, in order to compare the contributions of above- and belowground tissues to SOM. Lignin turnover in soil was faster than that of total organic carbon. Contrasting dynamics in soils were observed among lignin monomers as well as among cutin/suberin markers, which might be related to their chemical nature, their position into the polymeric structure and/or to the plant tissue in which they are present. This study, combining compound specific isotope measurements with a long term field trial helped understanding soil carbon turnover on a molecular level.
Forfattere
Per StålnackeSammendrag
Det er ikke registrert sammendrag
Forfattere
Per StålnackeSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Per StålnackeSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Falk ØgaardSammendrag
Det er ikke registrert sammendrag