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
M. Bauer R. Harzer K. Strobl Johannes KollmannAbstract
River restoration is widely applied, although its effects are poorly understood, and degraded habitats might be difficult to improve. Moreover, there is a lack of monitoring as well as few systematic comparisons of restoration methods. This study presents results of a 4‐year monitoring on River Inn (southern Germany) investigating restoration by gravel or sand addition or embankment removal. The results were compared with reference sites that represent the pre‐restoration conditions. At the landscape scale, we analysed vegetation types based on aerial photographs, whereas at a smaller scale, we undertook vegetation surveys and evaluated species composition, growth, and life form, as well as the proportion of the target vegetation. After 4 years, the data indicated a “negative resilience” of the vegetation back to the state prior to restoration. The structural analysis revealed an extensive spread of reed at expense of bare soil. Thus, the species composition largely regressed to the pre‐restoration conditions, and neither annuals nor other pioneer species showed a long‐term benefit of river restoration. There were differences among the three restoration treatments after 2 years, but no longer after 4 years. However, the river restoration had three positive outcomes: (a) There was a temporary benefit for pioneer vegetation that most likely replenished the seed bank of the respective species, (b) the valuable reed communities showed resilience, and (c) the measures allowed some practical learning as expected for adaptive restoration.
Abstract
No abstract has been registered
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
No abstract has been registered
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