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.
2001
Authors
David L. Jones Toril Drabløs Eldhuset Helen Agnes de Wit Berit SwensenAbstract
No abstract has been registered
Authors
David L. Jones Toril Drabløs Eldhuset Heleen A. de Wit Berit SwensenAbstract
While the release of organic acids from plants may offer a protection against rhizotoxic Al, the efficiency of this mechanism will be reduced by the rhizosphere microbial community
Authors
Toril Drabløs Eldhuset Berit Swensen Heleen A. de Wit Nina Davidsen Gro WollebækAbstract
No abstract has been registered
Authors
Heleen A. de Wit Jan Mulder Per Holm Nygaard Dan Aamlid Magne Huse Egil Kortnes Gro Wollebæk Roald BreanAbstract
Aluminium (Al) is a key element in critical load calculations for forest. Here, we argue for re-evaluating the importance of Al. Effects of two levels of enhanced Al concentrations and lowered Ca:Al ratios in the soil solution in a field manipulation experiment in a mature spruce stand (1996-1999) on tree vitality parameters were tested. In addition, Al solubility controls were tested. Various loads of Al were added to forest plots by means of an irrigation system. Potentially toxic Al concentrations and critical ratios of Ca to inorganic Al were established.The ratio of Ca to total Al was not a suitable indicator for unfavourable conditions for plant growth. No significant effects on crown condition, tree growth and fine root production were observed after three years of treatment. In 1999, foliar Mg content in the highest Al addition treatment had declined significantly. This agreed with the known response to Al stress of seedlings in nutrient solution experiments. No support was found for using the chemical criterion Ca:Al ratio in soil solution, foliar and root tissue as an indicator for forest damage due to acidification. Al solubility was considerably lower than implied by the assumption of equilibrium with gibbsite, particularly in the root zone.The gibbsite equilibrium is commonly used in critical load models. Substitution of the gibbsite equilibrium with an Al-organic matter complexation model to describe Al solubility in soil water may have large consequences for calculation of critical loads. The results indicate that critical load maps for forests should be reconsidered.
Authors
Petter NilsenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Halvor TorgersenAbstract
No abstract has been registered
Abstract
This manual contains description of field instrumemntation and the proceedures for field sampling of water and hadling of data at the Cai Jia Tang monitoring site in the Hunan province of China
Authors
E. Mäenpää Oddvar Skre E. Malila R. Partanen Frans-Emil Wielgolaski Kari M. LaineAbstract
Gjennom tre sesongar (1983-85) blei det hausta prøver av bjørk (Betula pubescens) og ulike planteslag i feltskiktet på på seks lokalitetar i bjørkeskog langs ein kyst-innlandsgradient i bjørkeskog i Nord-Skandinavia. Prøvene blei skilt i grupper etter vevstype og analysert for stivelse og løyselege sukker. Analysene viste ein kraftig nedgang i karbohydratinnhaldet gjennom vekstfasen om våren, etterfølgt av ei gradvis oppbygging frå fotosyntesen i nye blad. Deretter var det ein gradvis nedgang, først på grunn av frukt- og frøutvikling, deretter sekundærvekst, og endeleg respirasjonstap gjennom mørkeperioden om vinteren. Denne nedgangen var størt på lågtliggande lokalitetar med lite nedbør.
Authors
Nina Syversen Brit SalbuAbstract
The purpose of the study is to use soil particles labeled with the radioactive tracer cesium-134 as a method for studying soil erosion and sedimentation pattern within a small catchment with buffer zones. Cesium is adsorbed to soil particles, and by mea suring changes in the Cs-134 activity on the soil surface, erosion, sedimentation, and pathways for particles can be traced.