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.
1995
Authors
Anders Göransson Toril Drabløs EldhusetAbstract
No abstract has been registered
Authors
Anders Göransson Toril Drabløs EldhusetAbstract
The effects of aluminium on plant nutrition in small birch plants (Betula pendula Roth) were investigated. By using relative addition rate (r A, g g-1 d-1) of nutrients as the growth-controlling variable, it was possible to grow the plants at very low external nutrient concentrations and to simulate plant requirements at two different fertility levels.Before aluminium addition the plants were at steady-state relative growth rate, (R G, g g-1 d-1). The two addition rates were free access of nutrients with RG 0.215 d-1, or nutrient-limited, RA and R G= 0.10 d-1.Internal concentrations of calcium and magnesium decreased with increasing Al3 conncentration in the nutrient solution while nitrogen concentrations in the plants remained unchanged or increased. It was demonstrated in both nutrition treatments that calcium and magnesium decrease per se does not reduce plant growth and that uptake has to be considered in relation to plant requirement at different growth rates. The interpretation of the effects of aluminium on Ca and Mg uptake and plant biomass development suggested that processes other than disturbances in Ca and Mg uptake are the cause of the decrease in growth.
Authors
Richard A. WernerAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
D.L. Six T.D. PaineAbstract
No abstract has been registered
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No abstract has been registered
Authors
Richard HorntvedtAbstract
No abstract has been registered
Authors
Wenche E. Dramstad Gary L.A. FryAbstract
Increasing interest in combining agricultural and nature conservation goals has focused on the potential beneficial role of remnant biotopes on farmland. This study examines the role of field boundaries and a small habitat island within cereal fields in providing a source of forage for bumblebees (Bombus Latr.), throughout one season. Transect techniques were used to assess bumblebee use of common types of boundary vegetation between crops and semi-natural habitats, and along a footpath within a small woodlot, in southeastern Norway. There were seven species of bumblebee in these habitats, which used only a small fraction of the total number of flowering plant species available to any extent; only nine out of a total of 78 flowering plant species received more than five visits. All bumblebee species had a preference for perennial herbs as forage resources. The quantity of floral resources, their spatial pattern and temporal constancy varied among sites with the least disturbed and open habitats being of greatest value to bumblebees. Length of field boundary and single date surveys are poor indices of the value of field boundaries to bumblebees.
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Gudmund Vollbrecht Pelle Gemmel Björn ElfvingAbstract
No abstract has been registered