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
Forfattere
Johannes Deelstra Csilla Farkas Alexander Engebretsen Sigrun Kværnø Stein Beldring Alicja Olszewska Lars NesheimSammendrag
A good understanding of the hydrology and its implementation in models is a prerequisite to facilitate decision making relative to the implementation of water management - and farming practices. This paper presents the results of the application of 5 hydrological models in the Skuterud catchment.
Forfattere
Johannes Deelstra Csilla Farkas Alexander Engebretsen Sigrun Kværnø Stein Beldring Alicja Olszewska Lars NesheimSammendrag
Presnetasjon model resultater Skuterud
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Peatland drainage results in several environmental impacts such as release of greenhouse gas to the atmosphere and leaching of nutrients to watercourses. These hazardous environmental effects can partly be controlled with soil management, and different drainage and remediation practices. Grading is a new method developed for soils with low conductivity suffering from poor drainage, water logging and ice. The soil surface is graded towards the ditch to increase surface runoff and drainage. The present study compares environmental effects of peatland grading compared to traditional intense pipe drainage. Detailed measurements of hydrology, climate, leaching and gas emissions were carried out at adjacent drainage areas with grass cultivation. Additional measurements were made at plots that were abandoned, cultivated with perennial crops, and remained as pristine peatlands. The results show that the leaching of nutrients is highest from pipe drainage. Climate gas emission was considerably higher at all managed sites than from the reference pristine site. Drainage, soil hydrology and soil nutrient status seemed to control gas emissions. The gas emissions were higher than assumed for Norwegian cold conditions. The results confirm observations made on peat soils in other climatic regions. The highest emissions of CO2 was observed when the soil temperature was high and groundwater table low. The N2O emission showed a large variation with no clear pattern. However, at some locations it peaked after a dry period when NO3-N was leached. More CH4 was emitted from the intensively drained site than the graded site, but more CO2 was emitted from the graded site. The difference in leaching and emission properties is partly due to differences in near surface hydrology. At grade sites, a faster runoff response to rainfall occur probably due to shallow throughfall or overland flow which provides better drainage. Also, the graded site was prepared recently, and this can have exposed fresh peat for decay. Therefore the drainage history must be well known in peatland studies as peat change in time due to drainage and cultivation. Abandoned peat field continue to leach greenhouse gases in a same way as cultivated sites.
Forfattere
Gunnhild Riise Tore Krogstad Inggard Blakar Elin L. Gjengedal Ståle Haaland Johnny Kristiansen Kristine Naas Torgeir Reierstad Aleksandra Trnic Romarheim Johnson Rutsinda Sara ZambonSammendrag
Det er ikke registrert sammendrag
Sammendrag
Transport and turnover of dissolved organic carbon (DOC) is important in the C cycle of organic soils. The concentration of DOC in soil water is buffered by adsorption to the soil matrix, and has been hypothesized to depend on the pool size of adsorbed DOC. We have studied the effect of frequent artificial excessive leaching events on concentration and flux of DOC in shallow, organic rich mountain soils. Assuming a constant Kd value for DOC adsorption to the soil matrix, we used these data to assess the change in the pool of adsorbed (or potential) DOC in the soil. The study involved manipulation of precipitation amount and frequency in summer and autumn in small, heathland catchments at Storgama, southern Norway. The shallow soils (16-34 cm deep on average) limit the possibility for changes in water flow paths during events. The mini-catchments range in size from 75 to 98 m(2). Our data show that after leaching of about 1.2 g DOC m(-2) the DOC concentration in runoff declines by approximately 50%. From this we conclude that the pool size of adsorbed potential DOC in the shallow soils at any time is of the order 2-3 g m(-2). Frequent episodes suggest that the replenishment rate, which depends on the decomposition rate of soil organic matter, is fast and the potential DOC pool could be fully restored probably within days during summer, but with some more time required in autumn, due to lower temperatures. Both pool size of potential DOC and replenishment rate are seasonally dependent. The pool of potential DOC, and thus the DOC concentration in discharge, is at their maximum in the growing season. However, under non-leaching conditions, the concentration of DOC in soil water and thus the pool size of potential DOC seems to level off, possibly due to conversion of DOC to less reversibly bound forms, or to further decomposition to CO2.
Forfattere
Ståle HaalandSammendrag
Det er ikke registrert sammendrag
Sammendrag
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Sammendrag
Rapporten gir en fremstilling av biologiske og vannkjemiske data innsamlet i 2009 i vassdragene Leira og Nitelva på Romerike. Dataene utgjør andre året av en treårig overvåkning, igangsatt i henhold til avtale med Interkommunal Innkjøpsordning Nedre Romerike (IINR). Dataene er vurdert i forhold til tilstandskriterier gitt i EUs Rammedirektiv for vann (Vanndirektivet). Data for flere andre mindre vassdrag i regionen er også presentert. 30 stasjoner er gitt en foreløpig klassifisering av økologisk tilstand etter både biologiske og kjemiske støtteparametre, ytterligere 26 er gitt en foreløpig klassifisering etter kjemiske støtteparametre, og 3 stasjoner er gitt en foreløpig klassifisering kun etter biologiske parametere. Årets data indikerer at bare de øverste stasjonene i Leira og Nitelva befinner seg over grensen mellom god/moderat økologisk tilstand. De nedre delene av vassdragene er utsatt for eutrofiering. Metodiske vanskeligheter med klassifisering av leirvassdrag drøftes.
Sammendrag
Det er ikke registrert sammendrag