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.
2012
Authors
May SæthreAbstract
No abstract has been registered
Abstract
In 2008, an epidemic caused by a new Neonectria sp. was discovered on white fir (Abies concolor) in several counties in southern Norway [1]. Later the pathogen was also found on other fir species in Norway and Denmark [2]. Typical symptoms and signs were dead shoots, flagging (dead branches), canker wounds, heavy resin flow, and occasionally red fruiting bodies (perithecia). Pathogenicity tests on several Abies spp. proved the fungus to be very aggressive, which corresponds well with observations of mortality of white fir and subalpine fir (A. lasiocarpa) from different age classes under field conditions. Sequencing of the internal transcribed regions (ITS) of the ribosomal DNA showed that this Neonectria sp. was most similar to N. ditissima (only 5 bp different from isolates in the GenBank), a common pathogen worldwide on broad leaf trees. The ITS sequences were very different (> 20 bp) from N. fuckeliana, a well-known fungus on Norway spruce in Scandinavia and other parts of the world, especially in the northern hemisphere. In 2011, the new Neonectria species was found on diseased trees in a Danish nordmann fir (Abies nordmanniana) seed orchard. Resin flow was seen from mature cones, and tests revealed that the seeds were infected by the Neonectria sp.
Abstract
Sewage sludge application on soils represents an important potential source of silver nanoparticles (Ag NPs) to terrestrial ecosystems, and it is thus important to understand the fate of Ag NPs once in contact with soil components. Our aim was to compare the behavior of three different forms of silver, namely silver nitrate, citrate stabilized Ag NPs (5 nm) and uncoated Ag NPs (19 nm), in two soils with contrasting organic matter content, and to follow changes in binding strength over time. Soil samples were spiked with silver and left to age for 2 h, 2 days, 5 weeks or 10 weeks before they were submitted to sequential extraction. The ionic silver solution and the two Ag NP types were radiolabeled so that silver could be quantified by gamma spectrometry by measuring the 110mAg tracer in the different sequential extraction fractions. Different patterns of partitioning of silver were observed for the three forms of silver. All types of silver were more mobile in the mineral soil than in the soil rich in organic matter, although the fractionation patterns were very different for the three silver forms in both cases. Over 20% of citrate stabilized Ag NPs was extractible with water in both soils the first two days after spiking (compared to 1–3% for AgNO3 and uncoated Ag NPs), but the fraction decreased to trace levels thereafter. Regarding the 19 nm uncoated Ag NPs, 80% was not extractible at all, but contrary to AgNO3 and citrate stabilized Ag NPs, the bioaccessible fraction increased over time, and by day 70 was between 8 and 9 times greater than that seen in the other two treatments. This new and unexpected finding demonstrates that some Ag NPs can act as a continuous source of bioaccessible Ag, while AgNO3 is rapidly immobilized in soil.
Authors
Grete K. Hovelsrud Ingrid Kvalvik Halvor Dannevig Inger Hanssen-Bauer Sigridur Dalmannsdottir Lars Rønning Eivind Uleberg Bob van OortAbstract
An interdisciplinary study, based on downscaled climate change scenarios and interviews with local farmers in Northern Norway, has assessed biological and agronomic effects of climate change, and interaction with political, economic and social factors. The study confirms that farmers are facing complex challenges. Negative effects from climate change combine with other challenges.
Authors
Inger MartinussenAbstract
No abstract has been registered
Authors
Ashraful Islam Sissel Haugslien Dag-Ragnar Blystad Sissel Torre Jorunn Elisabeth Olsen Henrik Lütken Jihong Liu ClarkeAbstract
No abstract has been registered
Authors
Ashraful Islam Sissel Haugslien Dag-Ragnar Blystad Sissel Torre Jorunn Elisabeth Olsen Henrik Lütken Jihong Liu ClarkeAbstract
Poinsettia is one of the most important potted ornamentals for Christmas. Appropriate plant height is an important trait in poinsettia production. Concern about the negative effects of chemical growth retardants has limited their availability and use. Generation of compact poinsettia plants by genetic transformation has become a promising approach.
Abstract
The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them ensuring a sustainable environment. Weak economies, weak institutions and lack of environmental sciences expertise were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. TEMP-activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. In 2008, as a spin-off of TEMP-CA, the Ahangaran Forest Damage Project was initiated realizing that the Juniper forests surrounding the town of Angren were under environmental constrain, possibly due to massive industrial activities....
Authors
Kari Skjånes Stig A. Borgvang Thorsten Heidorn Celine Rebours Christian Guido Bruckner Margarita Novoa Garrido Åsbjørn KarlsenAbstract
No abstract has been registered
Authors
Marie Davey Einar Heegaard Rune Halvorsen Håvard Kauserud Mikael OhlsonAbstract
Although bryophytes are a dominant vegetation component of boreal and alpine ecosystems, little is known about their associated fungal communities. HPLC assays of ergosterol (fungal biomass) and amplicon pyrosequencing of the ITS2 region of rDNA were used to investigate how the fungal communities associated with four bryophyte species changed across an elevational gradient transitioning from conifer forest to the low-alpine. Fungal biomass and OTU richness associated with the four moss hosts did not vary significantly across the gradient (P > 0.05), and both were more strongly affected by host and tissue type. Despite largely constant levels of fungal biomass, distinct shifts in community composition of fungi associated with Hylocomium, Pleurozium and Polytrichum occurred between the elevation zones of the gradient. This likely is a result of influence on fungal communities by major environmental factors such as temperature, directly or indirectly mediated by, or interacting with, the response of other components of the vegetation (i.e. the dominant trees). Fungal communities associated with Dicranum were an exception, exhibiting spatial autocorrelation between plots, and no significant structuring by elevation. Nevertheless, the detection of distinct fungal assemblages associated with a single host growing in different elevation zones along an elevational gradient is of particular relevance in the light of the ongoing changes in vegetation patterns in boreal and alpine systems due to global climate warming.