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.
2018
Authors
Marte Persdatter TangvikAbstract
Free-living plant-parasitic nematodes (PPN), including migratory endoparasites such as Pratylenchus spp., cause yield reduction in agriculture and horticulture world-wide. In Norway, nematicides are banned due to their adverse effect on human health and the environment. Thus, management of plant-parasitic nematodes rely on cultural practices, such as crop rotation. Free-living PPN tend to have broad host-ranges, which complicates the design of effective crop rotations. Information on the reproductive rate and damage potential of nematode species on different crops is of crucial importance when designing a successful crop rotation. Results from several experiments indicate that in order to reduce the numbers of free-living PPN, the sequence of crops is more important than the length of the rotation. The crop rotation should aim at protecting the most economically valuable crop. An oat (Avena sativa) field in Norway was heavily infested with Tylenchorhynchus dubius (1200 ind/250 ml soil) and a low population of Pratylenchus crenatus (10 ind/250 ml soil). The primary goal was to reduce T. dubius by growing turnip rape (Brassica rapa ssp. oleifera), with carrot as the following crop. T. dubius was reduced with 77-85% after turnip rape. In contrast, the population of P. crenatus increased by more than tenfold. The increased numbers of P. crenatus could be damaging to the carrot crop. This illustrates that crop rotation should be a long-term strategy, with carefully designed rotations to protect the most economically valuable crop (e.g. carrot). This also illustrates the challenges of designing a crop rotation that effectively reduces multiple nematode populations. In a started project, we will use photography with Unmanned Aerial Vehicles and transects to monitor nematode populations and damage in several fields throughout the growing season, and over several seasons. These fields will serve as naturally occurring experiments. We want to develop decision-making tools for nematode management in Norway.
Authors
Jing-Wei Li Min-Rui Wang Hai-Yan Chen Lei Zhao Zhen-Hua Cui Zhibo Hamborg Dag-Ragnar Blystad Qiao-Chun WangAbstract
No abstract has been registered
Abstract
The forest understory is often associated with rapid rates of carbon and nutrient cycling, but cost-efficient quantification of its biomass remains challenging. We tested a new field technique for understory biomass assessment using an off-the-shelf handheld laser rangefinder. We conducted laser sampling in a pine forest with an understory dominated by invasive woody shrubs, especially Rhamnus frangula L. Laser sampling was conducted using a rangefinder, mounted on a monopod to provide a consistent reference height, and pointed vertically downward. Subsequently, the understory biomass was measured with destructive sampling. A series of metrics derived from the airborne LiDAR literature were evaluated alone and in combination for prediction of understory biomass using best-subsets regression. Resulting fits were good (r2 = 0.85 and 0.84 for the best single metric and best additive metric, respectively, and R2 = 0.93 for the best multivariate model). The results indicate that laser sampling could substantially reduce the need for costly destructive sampling within a double-sampling context.
Authors
Maryia Khomich Filipa Cox Carrie Joy Andrew Tom Andersen Håvard Kauserud Marie Louise DaveyAbstract
Insufficient reference database coverage is a widely recognized limitation of molecular ecology ap-proaches which are reliant on database matches for assignment of function or identity. Here, we use datafrom 65 amplicon high-throughput sequencing (HTS) datasets targeting the internal transcribed spacer(ITS) region of fungal rDNA to identify substrates and geographic areas whose underrepresentation in theavailable reference databases could have meaningful impact on our ability to draw ecological conclu-sions. A total of 14 different substrates were investigated. Database representation was particularly poorfor the fungal communities found in aquatic (freshwater and marine) and soil ecosystems. Aquaticecosystems are identified as priority targets for the recovery of novel fungal lineages. A subset of the datarepresenting soil samples with global distribution were used to identify geographic locations andterrestrial biomes with poor database representation. Database coverage was especially poor in tropical,subtropical, and Antarctic latitudes, and the Amazon, Southeast Asia, Australasia, and the Indian sub-continent are identified as priority areas for improving database coverage in fungi.
Authors
Guro Brodal Heidi Røsok Bye May Bente Brurberg Inger Sundheim Fløistad Øyvind Meland Edvardsen Venche TalgøAbstract
No abstract has been registered
Authors
Arne SteffenremAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Frode Sundnes Marianne Karlsson Froukje Maria Platjouw Salar Valinia Nicholas Clarke Øyvind KasteAbstract
No abstract has been registered
Abstract
In the Nordic-Baltic region, there has been a growing concern about an increasing occurrence of multiple tops in young stands of Norway spruce. There is however a lack of documentation on the amount of such damages, and the causal agents involved. In two separate studies in SE Norway, we assessed the frequency of multiple tops in young sapling-sized stands, and studied the relationship between the occurrence of multiple tops and lammas growth the previous growing season on the sample trees. Study 1 included 44 planted and 10 naturally regenerated stands, while Study 2 included 68 planted stands with information on seed source. Among sample trees with multiple tops, 57% (Study 1) and 32% (Study 2) had signs of lammas growth the previous autumn, either in the form of an extended leading shoot or swollen bud. Site index as well as sample tree height were positively correlated to the occurrence of both lammas growth and multiple tops in both studies. In Study 1 we show that the probability of lammas growth was significantly higher in planted than in naturally regenerated stands. In Study 2 we show that it was higher in stands planted with seedlings grown from stand-origin seeds compared with improved seed material. Furthermore, the results of both studies show that lammas growth occurs most frequently among the dominant trees in the stand.
Authors
Antonio Carlos Ferraz Filho Blas Mola-Yudego José Ramón González-Olabarria José Roberto Soares ScolforoAbstract
No abstract has been registered