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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.

2009

Sammendrag

The CO2 uptake of the terrestrial biosphere (Gross Primary Productivity, GPP) plays a key role in the global carbon balance. This carbon flux cannot be determined directly on a global scale. Yet, the remotely sensed Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) is a valuable proxy for GPP. This study aims at characterizing global FAPAR dynamics on different temporal scales and extracting corresponding spatial structures. The time series were analyzed to uncover the presence and extent of trends, and to identify quasi-oscillatory patterns from intra- to interannual time scales....

Sammendrag

A catchment provides ecosystem data along with (relatively) simple, operationally defined boundaries. In addition runoff is an integrated measure of the hydrochemical ecosystem response, which can be represented by fluxes at the weir. Integration at the weir occurs first of all with respect to spatial scales. Almost all fluid output leaves a (tight) catchment at this point. Evaluation of the runoff dynamics (quantity and quality) is primarily concerned with temporal scales. The Lange Bramke catchment study with its four runoff series from forested catchments (spring and weir at Lange Bramke, weirs at Dicke Bramke and Steile Bramke) provides an exceptionally comprehensive data set. The following scales and processes can be considered, when interpreting temporal variations in runoff data: above the time scale of forest rotation (species composition, biomass accumulation, timber export, soil nutrient pools) at decadal time scales up to a full forest rotation of about 100-120 years (changes in forest growth rate, changes in deposition, climate change, insect outbreaks) at annual time scales (uptake, transpiration) at hourly to weekly time scales of hydrological events (precipitation, runoff, dilution effects of solvents).

Sammendrag

In high-latitude areas, landscapes with flat or moderate relief areas usually contain lakes and mires. The identification of flowpaths in such areas is a difficult issue. The increasing availability of high resolution topography from airborne Lidar measurements offers new opportunities for automatic or semi-automatic channel extraction from DEMs in small watersheds, substantially outperforming the hydrographic network in conventional digital maps....

Sammendrag

Long-term monitoring meteorological, hydrological and hydrochemical data from small catchments are irreplaceable witnesses of past environmental conditions. This insight shaped the formation of the Long-Term Ecological Research Network (LTER) in the US, but European as well as German siblings are under preparation. Among the European forested monitoring sites, the Bramke catchments in the Harz mountains present a particularly well-documented case, with daily runoff measurements starting after World War II-related reparation cuts in 1948, and surface water chemistry being observed since the 1970ies. Originally powered by research on erosion, then by acid rain research and the then-prominent “forest decline”, a large set of hydrochemical variables (major ions) is available now with basically weekly resolution. Previously tightly connected to academic research at the University of Göttingen, routine measurements are by now performed by local forest authorities, ensuring forthcoming continuity even when public attention should shift away again from climate change research.

Sammendrag

Stream flow observations from a geographical region are known to often exhibit strong common behavior. In order to assess the temporal evolution of the complexity of stream flow time series from all over Europe, we employ the recently developed Linear Variance Decay dimension density (δLV D). It is estimated as the parameter of an exponential decay function fitted to the remaining variances of the eigenvalues of a covariance matrix. Scaling between zero and one, δLV D can be interpreted as a measure of the proportion of linear independent components in a multivariate record.....

Sammendrag

General questions that arise while investigating hydrological extremes are whether these have distinct spatial and temporal variations and how these variations are linked to mean flow conditions. We analyze a large set of European stream flow series. Based on daily observations we derive annual series of stream flow deciles ranging from the minimum to the maximum, resulting in a set of eleven series for each station representing the year to year variability of the flow regimes....

Sammendrag

Lukket hogst vil alltid medføre risiko for vindfellinger. Men den kan reduseres ved valg av bestand, tilpassing av hogstinngrepet og skogskjøtsel i og rundt bestandet. Norskog og Institutt for skog og landskap har gjennomført prosjektet «Vindfellingsfrekvens og trestabilitet ved lukkede hogster». Her har vi analysert 44 lukkede hogster på Østlandet med formål å finne sammenhenger mellom omfang av vindfall og ulike parmetre for inngrepet og bestandet.