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.
2013
Authors
Aksel Bernhoft Gunnar Sundstøl Eriksen Leif Sundheim Marc Berntssen Anne Lise Brantsæter Guro Brodal Christiane Kruse Fæste Ingerd Skow Hofgaard Trond Rafoss Tore Sivertsen Anne Marte Tronsmo Heidi Amlund Augustine Arukwe Marit Aursand Margaretha Haugen Gro Ingunn Hemre Trond Hofsvang Helle Katrine Knutsen Åshild Krogdahl Jørgen Fredrik Lassen Christer Magnusson Audun Helge Nerland Live Lingaas Nesse Bjørn Næss Einar Ringø Anders Ruus Janneche Utne Skåre Halvor Solheim Arild Sletten Inger-Lise Steffensen Line Charlotte Sverdrup Birger Svihus Ole Torrissen Bente Elisabeth Torstensen Cathrine Thomsen Robin Ørnsrud Bjørn Økland Olav Østerås Jan AlexanderAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Line Emilie Sverdrup Christine Bjørge Ole Martin Eklo Merete Grung Torsten Källqvist Ingeborg Klingen Marit Låg Erik Ropstad Steinar ØvrebøAbstract
No abstract has been registered
Authors
Line Emilie Sverdrup Christine Bjørge Ole Martin Eklo Merete Grung Torsten Källqvist Ingeborg Klingen Marit Låg Erik Ropstad Steinar ØvrebøAbstract
No abstract has been registered
Authors
Line Emilie Sverdrup Christine Bjørge Ole Martin Eklo Merete Grung Torsten Källqvist Ingeborg Klingen Marit Låg Erik Ropstad Steinar ØvrebøAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Top-dieback of Norway spruce (Picea abies) trees has been observed in SE Norway. Trees usually die within 1-4 years after the first symptoms become visible and the dieback cause is unknown. The aim of our study was to establish when the irreversible spiral to tree death occurs. We assumed that hydraulic dysfunction, exemplified here by the sap flow reduction, was the final trigger of tree decline. We used the non-destructive heat field deformation method (HFD) to monitor the sap flow density (SFD) in non-symptomatic trees. After felling the trees we used the modified differential translucence method (MDT) to evaluate the sapwood translucence as an additional indicator of its functionality. In this study we show three examples of non-symptomatic trees with widely different sap flow densities detected by the HFD; tree A with unchanged sap flow throughout the monitoring period, tree B with decreasing sap flow in the last formed annual rings and minimal sap flow detected in tree C, which also started to show the first visible signs of dieback. In contrast, the MDT method detected in all cases functional (translucent) sapwood. In conclusion, we show that the sap flow reduction may occur during a relatively short period, prior to occurrence of any visual symptoms. Also, dysfunctions in sap flow could not be detected by the MDT method, as the sapwood still looked translucent and thus functional, although minimal sap flow was detected in that area by HFD method. Here we demonstrate the sensitivity of the HFD method in detecting the quantity of sap flow and thus a suitable diagnostic tool to evaluate the vitality in Norway spruce trees before the onset of visible disease symptoms.
Abstract
No abstract has been registered
Authors
Marte MelandAbstract
No abstract has been registered
Authors
Marte MelandAbstract
No abstract has been registered