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
Abstract
No abstract has been registered
Authors
Arne Olav Stuanes O. Janne Kjønaas Helga van MiegroetAbstract
Nitrogen has been added to a forested 0.52 ha headwater catchment at Gårdsjön on the southwest coast of Sweden to study the ecosystem response to elevated nitrogen deposition. The catchment is dominated by naturally generated, mixed-age conifers, mainly Norway spruce, with Scots pine in dry areas. After a pre-treatment period of about 1 year, nitrogen was added to the whole catchment as ammonium nitrate by means of sprinklers at an intensity of 3 mm h-1 (average concentration 230 mmol N1-1). Total nitrogen input as throughfall to the catchment increased from the ambient 12.5 kg N ha-1 year-1 in the pre-treatment year to a total of 47.3 kg N ha-1 year-1 in the treatment years. Soil solutions were collected using tension lysimeters at four locations covering a moisture gradient from the dry upper to the wet lower parts of the watershed. Results from these locations were compared with soil solution composition at two locations in a nearby control catchment. After 2 years of nitrogen addition, the volume-weighted average nitrate concentrations in the treated catchment were higher than the pretreatment values, especially in the upper soil. Concentrations showed a progressive increase over time. The lack of the same increasing trend in the control catchment precludes natural variations in climatic conditions as the main cause for this increase. Relative to inputs, nitrate concentrations in soil solution were low and showed large variations between the drier and wetter locations. Differences in nitrate concentrations between pre-treatment and treatment periods declined with soil depth, indicating that most of the added nitrogen was consumed in the upper soil. The results from soil solution do not indicate increased nitrogen leaching below the rooting zone in the treated catchment and thus based on these results alone there is as yet no indication of nitrogen saturation.
Authors
Vincent R. Franceschi Trygve Krekling Alan A. Berryman Erik ChristiansenAbstract
No abstract has been registered
Authors
Sverre SkoklefaldAbstract
No abstract has been registered
Authors
Erik Christiansen Alan A. BerrymanAbstract
No abstract has been registered
Authors
Kari Korhonen Katriina LipponenAbstract
No abstract has been registered
Authors
Natali V. Pashenova Valentina P. Vetrova Rida M. Matrenina E.N. AphanasovaAbstract
No abstract has been registered
Authors
David B. Collinge C.H. Andersen T. Bryngelsson A.B. Christensen P.L. Gregersen K. Madriz-Ordeñana V. Smedegaard-Petersen Z. Zhang H. Thordal-ChristensenAbstract
No abstract has been registered
Authors
Guro BrodalAbstract
No abstract has been registered
Authors
Martti Vuorinen Märt Hanso Timo Kurkela J.K. Holopainen P. KainulainenAbstract
No abstract has been registered