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.
1998
Authors
Olavi Junttila Jorunn Elisabeth Olsen Jarle Halvard Nilsen Inger Martinussen Thomas Moritz Maria Eriksson Olle Olsson Göran SandbergAbstract
Photoperiodic effects on woody plants were reported already by Gardner and Allard in 1923 and comprehensive studies during the ’50s confirmed the role of photoperiod as an important environmental regulator of growth and growth cessation in many northern tree species (Nitsch, 1957; Wareing, 1956). In woody plants cessation of apical growth is a prerequisite for cold acclimation (Weiser, 1970) and photoperiod, as a factor controlling growth cessation, is therefore an important environmental signal for initiation of cold acclimation. In many cases a proper timing of acclimation and deacclimation, in respect to annual variation of temperature conditions, is more critical for winter survival than the maximum level of frost hardiness. Also in such coniferous species where cessation of apical growth is not controlled by photoperiod, short photoperiod is necessary for good cold acclimation, low temperature causes no or only a limited level of hardiness if combined with long day conditions (Schwarz, 1970; Aronsson, 1975; Christersson, 1978; Jonsson et al., 1981). Thus, photoperiod may have both an indirect, through induction of growth cessation, and a more direct influence on cold acclimation in woody plants.
Abstract
Concentrations of pigments in needles of yellowish Norway spruce (Picea abies (L.) Karst.) trees suffering from either N, Mg or K deficiency in field sites in southeast Norway are reported. The yellowish trees had a considerably lower (roughly 50%) pigment concentration, as well as a lower chlorophyll/carotenoid ratio, compared to the green trees within the same sites. Yellowing was interpreted as a general bleaching of colour, as well as a slight turn from the green (chlorophylls) towards yellow (lutein). Concentrations of pigments were highly intercorrelated. N deficiency was especially associated with low a-carotene concentrations. This was interpreted as a-carotene being the most sensitive pigment to stress. However, this pigment might be specifically sensitive to N deficiency. Carbohydrate concentrations were slightly higher in yellowish trees.
Authors
Espen Lydersen Valter Angell Odd Eilertsen Thorbjørn Larssen Jan Mulder I.P. Muniz Hans Martin SeipAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Knut Rydgren Rune Halvorsen Økland Tonje ØklandAbstract
No abstract has been registered
Authors
Bent BraskerudEditors
L. Øygarden P. BotterwegAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Bridget Emmett D Boxman Michael Bredemeier Per Gundersen O. Janne Kjønaas Filip Moldan Patrick Schleppi Albert Tietema Richard F. WrightAbstract
No abstract has been registered
Authors
Bridget A. Emmett D. Boxman M. Bredemeier Per Gundersen O. Janne Kjønaas Filip Moldan Patrick Schleppi Albert Tietema Richard Frederic WrightAbstract
No abstract has been registered