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.
2006
Forfattere
Ann NorderhaugSammendrag
Det er ikke registrert sammendrag
Forfattere
Ann NorderhaugSammendrag
Det er ikke registrert sammendrag
Forfattere
Ann NorderhaugSammendrag
Det er ikke registrert sammendrag
Forfattere
V. Asheim J. Brendalsmo Ann NorderhaugSammendrag
Det er ikke registrert sammendrag
Forfattere
N.H. Sæther H. Sickel Ann Norderhaug O. VangenSammendrag
Det er ikke registrert sammendrag
Forfattere
Ian Toth L Moleleki L Pritchard H Liu S Humphris L Hyman Gunnhild Wærsted Takle May Bente Brurberg M Ravensdale E Gilroy PRJ BirchSammendrag
Det er ikke registrert sammendrag
Forfattere
Daniel Rasse Marie-france Dignac Haithem Bahri Cornelia Rumpel André Mariotti Claire ChenuSammendrag
Lignin has long been suspected a major source of stable carbon in soils notably because of the recalcitrant nature of its polyphenolic structure relative to other families of plant molecules. However, lignin turnover studies have produced conflicting results, most of them suggesting that large proportions of plant-residue lignin decompose within a year of incorporation into soils. Here, we propose a two-reservoir model where lignin in undecomposed plant residue (Lp) can either reach soil fractions where it is somewhat protected from further decomposition (Ls) or is transformed to non-lignin products. Model calibration data were obtained through compound-specific 13C isotopic analyses conducted in a zero- to nine-year chronosequence of maize monoculture after wheat in a temperate loam soil of the Paris basin. Lignin was quantified by CuO oxidation as VSC-lignin, i.e., the sum of vanillil- (V), syringyl- (S) and coumaryl-type (C) phenols. Model calibrations indicate that Lp has a turnover rate faster than one year and that 92% is mineralized as CO2 or transformed into other non-lignin products, while only 8% reaches the Ls fraction. Estimated turnover rate of the Ls fraction was 0.05 yr-1. The model also suggested that about half of Lp was not measured because it had been excluded from the samples in the process of sieving at 5 mm. In conclusion, the model indicates that chemical recalcitrance alone is not sufficient to explain VSC-lignin turnover in soils, and that, functionally, the most relevant mechanism appears to be the transfer of VSC-lignin molecules and fragments from decomposing plant tissues to soil-protected fractions.
Forfattere
Marie Alexis Cornelia Rumpel Patrick Louchouarn Nicolas Péchot Daniel Rasse André MariottiSammendrag
Fire is the main disturbance for terrestrial ecosystems, with a strong effect on biogeochemical cycles. Especially, part of the ecosystem organic matter (OM) is chemically modified by temperature elevation. Depending on fire severity, a big variety of chemical structures is produced ranging from slightly altered OM to strongly condensated structures. The fate of these pyrogenic OM when added to soil is unclear. Highly aromatic black carbon (BC) may be the most stable part of the continuum. At molecular level, levoglucosan is the main fire product of cellulose alteration. These two compounds have been separately used as tracers of plant biomass burning in aerosols, soils and sediments. Their combined use may provide closer insight into conditions and OM transformations that occurred during the fire. We aimed at quantifying BC and levoglucosan in plant residues after fire. Their production rates were compared to improve the understanding of their relative contribution to soil OM. Litter leaves were collected after a prescribed burning. The >2mm fraction was visually separated into charred (black, shiny) and unburned (brown) particles. BC was quantified by chemical oxidation (K2Cr2O7/H2SO4) and elemental analyses. Levoglucosan was identified and quantified by GC/MS analysis of the total lipid extract. Unburned post-fire leaves contain more levoglucosan than charred leaves, showing that a chemical alteration occurred despite no visual evidence. Moreover BC and levoglucosan concentrations are negatively correlated. This is consistent with their expected production temperatures: levoglucosan may be destroyed at temperature BC is produced. Relative quantity of theses compounds may then provide information about fire severity. However while BC is expected to be stable in soil, levoglucosan may suffer from degradation processes. Consequently, for historical reconstitution their respective fates in soil degrading conditions have to be considered.
Sammendrag
Fire av instituttene innen Miljøalliansen har gjennomført et felles strategisk instituttprogram (SIP) med fokus på flerfaglig og helhetlig forskning om vassdrag. Programmet er gjenomført i perioden 2002-2006. Programmet fokuserte på fire hovedtemaer i fire hovedkapitler: Elvesletter, Reguleringsdammer, Diffuse kilder og Romlig skalering av data.
Forfattere
Lorenxo Borselli Torri Dino Lillian Øygarden De Alba Saturnio Josè A. Martinez-Casasnovas Paolo Bazzoffi Gergely JakabSammendrag
Boken Soil Erosion in Europe gir en omfattende oversikt over erosjonsprosesser, omfang og fordeling av erosjon i Europa. Den er delt inn i to deler: " Nasjonale oversikter over erosjon og relaterte problemer " Erosjonsprosesser, erosjonsrisiko og konsekvenser av erosjon og tiltak Soil Erosion in Europe er skrevet som en avslutning og oppsummering på et femårig samarbeid i regi av EU sin COST-aksjon 623: Soil erosion and global change der 20 land og 114 forfattere har bidratt. Boka er svært verdifull for alle som er opptatt av jord- og miljøspørsmål, spesielt forskere og studenter som ønsker å få en oversikt over dette fagområdet.