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.
2024
Authors
Erik J. JonerAbstract
No abstract has been registered
Authors
Rolf David Vogt Øyvind Aaberg Garmo Kari Austnes Øyvind Kaste Ståle Haaland James Edward Sample Jan-Erik Thrane Liv Bente Skancke Cathrine Brecke Gundersen Heleen de WitAbstract
Rising organic charge in northern freshwaters is attributed to increasing levels of dissolved natural organic matter (DNOM) and changes in water chemistry. Organic charge concentration may be determined through charge balance calculations (Org.−) or modelled (OAN−) using the Oliver and Hruška conceptual models, which are based on the density of weak acid functional sites (SD) present in DNOM. The charge density (CD) is governed by SD as well as protonation and complexation reactions on the functional groups. These models use SD as a key parameter to empirically fit the model to Org.−. Utilizing extensive water chemistry datasets, this study shows that spatial and temporal differences in SD and CD are influenced by variations in the humic-to-fulvic ratio of DNOM, organic aluminum (Al) complexation, and the mole fraction of CD to SD, which is governed by acidity. The median SD values obtained for 44 long-term monitored acid-sensitive lakes were 11.1 and 13.9 µEq/mg C for the Oliver and Hruška models, respectively. Over 34 years of monitoring, the CD increased by 70%, likely due to rising pH and declining Al complexation with DNOM. Present-day median SD values for the Oliver and Hruška models in 16 low-order streams are 13.8 and 15.8 µEq/mg C, respectively, and 10.8 and 12.5 µEq/mg C, respectively, in 10 high-order rivers.
Authors
Mette ThomsenAbstract
No abstract has been registered
Authors
Mette Thomsen Randi Seljåsen Reidun Pommeresche Till Seehusen Belachew Asalf Tadesse Tatiana Francischinelli Rittl Anne-Kristin LøesAbstract
No abstract has been registered
Authors
Randi Berland FrøsethAbstract
No abstract has been registered
Authors
Linn Borgen NilsenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Milica Fotirić Akšić Sezai Ercisli Mekjell Meland Géza BujdosóAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Martha Irene Grøseth Linda Karlsson Håvard Steinshamn Marianne Johansen Alemayehu Kidane Sagaye Egil PrestløkkenAbstract
No abstract has been registered