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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.

2012

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The ingrowth core method is widely used to assess fine root (diameter < 2 mm) production but has many inherent deficiencies. In this study, we modified this method by adopting mini ingrowth cores (diameter 1.2 cm), extending sample intervals to a growing season, and developing new models to quantify the concurrent production, mortality and decomposition, and applied them to a secondary Mongolian oak (Quercus mongolica Fischer ex Ledebour) forest. Annual fine root production, mortality and decomposition estimated by our method were 2.10 ± 0.23, 1.78 ± 0.20 and 0.85 ± 0.13 t ha−1, respectively, and 33.3% of the production was decomposed in the growing season. The production estimate using our method was significantly higher than those using two long-term ingrowth core (sample interval >2 months) methods. However, it was significantly lower than that using the short-term ingrowth core (sample interval <2 months) method, presumably due to the lower root competition and less decomposition occurring in the short-term cores. The fine root estimates using our method in the growing season were generally higher than those using the forward and continuous inflow methods but lower than those using the backward method. Our method reduces the disturbances in roots and soil, minimizes the sampling frequency and improves the quantification of fine root decomposition during the sample intervals. These modifications overcome the limitations associated with the previous ingrowth core methods. Our method provides an improved alternative for estimating fine root production, mortality and decomposition.

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We exploit two recently developed informationtheoretic quantities (or measures) designed to quantify information content and complexity of ordered data (time series), respectively. Both are based on order statistics of given data sets, and probe into the shortterm structure of the data only due to finite length restrictions. Their usage requires fixing one parameter, word length or order depth D. The information measure is the orderbased Shannon entropy HS, and the complexity measures is the JensenShannon divergence CJS. The latter requires a chosen reference distribution, i.e. CJS represents a class of measures. Entropy HS and complexity CJS of data series may be represented against each other in a twodimensional diagram which we will refer to as ComplexityEntropy Causality Plane, or CECP. Very long realizations of classic stochastic processes and chaotic deterministic maps each obey one location in the CECP, specific for the process. This can be used to differentiate chaos from correlated noise (Rosso et al. 2007), which is notoriously difficult otherwise. For observed data, a mixture of deterministic (signal) and stochastic (noise) parts is to be expected. We use an ensemble of longterm river runoff time series as example, which are known to exhibit powerlaw decaying longrange correlations. We compare these data with a longrange correlated candidate process, the k noise, from the perspective of order statistics and the CECP. Although these processes resemble runoff series in their correlation behavior and may be even tuned to any runoff series by changing the value of k, the CECP locations and in particular the order pattern statistics reveals qualitative differences between them. We give a detailed account of these differences, and use them to conclude on the deterministic nature of the (shortterm) dynamics of the runoff time series. The proposed methodology also represents a stringent test bed for hydrological or other environmental models. http://dames.pik-potsdam.de/Abstracts.pdf

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Rapporten presenterer resultater fra forprosjektet VRI Matopplevelser på Helgeland, 2011. Prosjektet har som mål å bidra til at turister og andre spisegjester får bedre tilgang til «smaken av Helgeland» gjennom å motivere lokale serveringssteder til økt fokus på nord-norske råvarer og matretter med lokal historie. Rapporten presenterer resultater fra en kartlegging av åtte bedrifter i nettverket Et himmelsk sidesprang på Helgeland (EHS), med hensikt å avdekke muligheter og begrensninger for servering av nord-norsk mat, samt bidra til videreutvikling og styrking av nettverket. Resultatene viser at hver bedrift har sine unike fordeler i forhold til historie, kompetanse, beliggenhet og andre ressurser. Dette er fordeler som hver og en bør pleie og videreutvikle for å dyrke sitt særpreg slik at besøkende får tilbud om en unik matopplevelse med utgangspunkt i lokale råvarer, lokal historie og lokale kjennetegn. Prosjektet har også avdekket utfordringer knyttet til tilgang til lokale råvarer, bærekraftig bruk av entreprenøren, samarbeidsformer/nettverksledelse m.m.