Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
1999
Authors
A. Sigurgeirsson Thröstur EysteinssonAbstract
No abstract has been registered
Authors
J. Peter HallAbstract
No abstract has been registered
Authors
Harald Bratli Astrid MyhreAbstract
The vegetation of traditionally managed species-rich hay meadows at Sverveli, Telemark, S Norway was studied applying an indirect gradient approach. The vegetation in 93 randomly placed sample plots was analysed in order to detect the main vegetational gradients. Ecological measurements were recorded from each plot. The relationships between vegetation and environment were studied by DCA and LNMDS ordinations and non-parametric correlation analysis. Both ordinations revealed the same two ecologically interpretable vegetation gradients. Soil moisture was identified as the most important environmental factor in determining the species composition, followed by soil nutrient content. The contents of P, K and Mg in the soil were more strongly correlated with the main vegetational gradients than was soil N.Differences in management history may explain some of the observed variation in species composition that was not accounted for by the recorded environmental variables.
Abstract
No abstract has been registered
Authors
Oddvar Skre M. NæssAbstract
No abstract has been registered
Authors
Birger VenneslandAbstract
No abstract has been registered
Authors
E. Velthorst N. NakkenBrameijer Jan MulderAbstract
The International Humic Substances Society (I.H.S.S.) has published a general procedure for the fractionation and isolation of FA, but crucial information is lacking. Here we give an account of a modified procedure to fractionate and isolate FA from soil using XAD-8 resin. We also present results with respect to the yield of FA and its ash content for a number of soil horizons. Our results indicate that more NaOH than previously assumed was needed to remove all adsorbed FA from the XAD-8 resin. By contrast to the IHSS procedure we combine several FA fractions prior to purification. To purify FA, two HCl/HF treatments were necessary to reduce the ash content to an acceptable level. In the four soil horizons investigated in this study, the relative importance of FA in total humic compounds increases in the order peat podzol O podzol Bhs podzol Bs
Authors
Erik Christiansen Bohumil KuceraAbstract
Kvaelommer fins i mange bartreslekter; de skaper problemer for treforedlingsindustrien, og man vet ikke hvordan de oppstår. De er vanlige i Sørøst-Norge hvor skogen ofte angripes av granbarkbillen, men ikke på Vestlandet hvor billen ikke finnes. Det kunne derfor tenkes at de oppstår som følge av billeangrep. Dette ble undersøkt i et materiale fra Ås i Akershus.Våren 1987 ble et dusin grantrær angrepet av granbarkbillen etter at det var satt feromondispensere på dem, men billene var for få til å erobre trærne. Angrepspunktene på stammen ble merket av, og flere år senere ble trærne felt og undersøkt. Resultatet viste at billeangrepet etterlater tydelige spor i veden hos trær som overlever, men disse er helt forskjellige fra kvaelommene, som derfor må ha en annen årsak.
Abstract
No abstract has been registered
Abstract
No abstract has been registered