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.
2024
Authors
Mette Thomsen Randi Seljåsen Reidun Pommeresche Till Seehusen Belachew Asalf Tadesse Tatiana Francischinelli Rittl Anne-Kristin LøesAbstract
No abstract has been registered
Authors
Muath Alsheik Merethe Bagge May Bente Brurberg Aakash Chawade Timmermann Christiansen Pawel Chrominski Jahn Davik Susann Herzog Liina Jakobson Hans-Arne Krogsti Fredrik Reslow Terje Tähtjärv Ramesh Vetukuri Susanne Windju Nikolai Ødegaard Rodomiro OrtizAbstract
No abstract has been registered
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No abstract has been registered
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No abstract has been registered
Authors
Jarle W. Bjerke Kristin Magnussen Ryan Bright Ståle Navrud Rasmus Erlandsson Eirik Aasmo Finne Hans TømmervikAbstract
Reindeer (Rangifer tarandus) pastoralism utilizes vast boreo-arctic taiga and tundra as grazing land. Highly fluctuating population sizes pose major challenges to the economy and livelihood of indigenous herder communities. In this study we investigated the effect of population fluctuations on core provisioning and regulating ecosystem services in two Sámi reindeer herding districts with contrasting fluctuation trends. We compared 50-year long time series on herd size, meat production, forage productivity, carbon footprint, and CO2-equivalence metrics for surface albedo change based on the radiative forcing concept. Our results show, for both districts, that the economic benefits from the provisioning services were higher than the costs from the regulating services. Still, there were major contrasts; the district with moderate and stable reindeer density gained nearly the double on provisioning services per unit area. The costs from increasing heat absorption due to reduction in surface albedo caused by replacement of high-reflective lichens with low-reflective woody plants, was 10.5 times higher per unit area in the district with large fluctuations. Overall, the net economic benefits per unit area were 237 % higher in the district with stable reindeer density. These results demonstrate that it is possible to minimize trade-offs between economic benefits from reindeer herding locally and global economic costs in terms of climate-regulating services by minimizing fluctuations in herds that are managed at sustainable densities.
Authors
Jihong Liu ClarkeAbstract
No abstract has been registered
Abstract
Growth and flower bud initiation (FBI) were studied in single-stem plants of four biennial-fruiting cultivars in a controlled environment and under field conditions at 60°40′ N. Shoot growth varied widely among the cultivars but was significantly enhanced by high temperature (20 °C) in all cultivars, whereas photoperiod had a subordinate growth effect. FBI data from bud dissection after 6 weeks of cultivation in the phytotron were used to calculate FBI indices for the various cultivars and environment conditions. The indices also varied much among the cultivars but were enhanced by elevated temperature, being highest in ‘Natchez’ and ‘Sweet Royalla’, while ‘Natchez’ was the only cultivar in which FBI was significantly enhanced by short days. The non-vigorous and erect growing ‘Ouachita’ remained vegetative at both temperatures but flowered in spring after overwintering at 0.5 °C. The field experiment confirmed the superior growth vigor of ‘Loch Ness’ and ‘Sweet Royalla’ as well as the photoperiodic sensitivity of ‘Natchez’. The results also confirmed that floral initiation starts in lateral buds located 10–20 nodes below the apex, and from there it progresses in both acropetal and basipetal direction. We conclude that temperature is at least as important as the photoperiod for the control of FBI in biennial-fruiting blackberries.
Authors
Linn Vassvik Vigdis Vandvik Silje Andrea Hjortland Östman Anders Nielsen Aud Helen HalbritterAbstract
Plant reproduction in alpine environments is affected by climate both directly through climate impacts on growth and phenology, and indirectly through impacts on the biotic interactions affecting pollination success. These effects can be highly variable in time and space. In this study we investigated how different abiotic and biotic factors influence reproductive investment and success in populations of Ranunculus acris across an alpine landscape over a two-year period. In an alpine area at Finse, southern Norway, we measured reproductive investment (total seed mass) and reproductive success (seed-set rate) in 38 sites differing in temperature (related to elevation) and length of the growing season (related to time of snowmelt). To assess biotic interactions, we measured floral density and pollinator visits and conducted a supplemental pollen experiment. Reproductive investment and success increased with temperature, but only when floral density and/or number of pollinator visits was high, and only in the warmer year (2016). Reproduction in R. acris was pollen-limited in both years, especially at warmer temperature and in sites with early snowmelt. Pollinator visits increased with temperature and with higher floral density, suggesting a shift in relative importance of the biotic factors (from plants to pollinators) in limiting reproduction with increasing temperature. Our study shows that reproductive investment and success in R. acris is affected by climate through the interactive effects of abiotic and biotic processes. These effects vary between years and across the landscape, suggesting a potential for larger-scale buffering of climate change effects in heterogeneous landscapes.
Authors
Jean-Claude Grégoire Jochem Bonte Andy Bourke Dragos Cocos Nick Fielding Jostein Gohli Daegan Inward Maartje Klapwijk Christo Nikolov Bjørn Økland Martin Schroeder Florentine Spaans Jozef Vakula Max Blake Rafael De Andrade Moral Maria Destefanis Christine Griffin Andrej Kunca Archie Murchie Cathal Ryan Aoife Smith Hugh F. EvansAbstract
Six species of Ips de Geer (Coleoptera: Curculionidae; Scolytinae) occur in Europe. They attack weakened or dead conifers but may become aggressive and mass-attack living trees. All species have expanded their ranges in Europe since the late 19th century. Here, we analyse the patterns of this spread and discuss the factors at play. Starting with an assessment of distribution changes of the insects and of their host trees since the nineteenth century, we describe how and, when known, why territorial changes occurred in Fennoscandia (Norway, Sweden, Denmark, and Finland), Central Europe (Czechia, Slovakia, Hungary, Poland, Austria, Germany), the Netherlands, Belgium and Great Britain. Based on these country narratives, we discuss the conditions for, and causes of, territorial expansion. A necessary condition is the presence of host trees of vulnerable ages and sizes, resulting from the post-glaciation expansion of host range. Population changes and territorial expansion are influenced by environmental or anthropic drivers: climatic events (droughts and storms), silvicultural practices and trade. Three main factors favour or hamper the response of the different species to these drivers: active and passive flight capacity, dispersal upon emergence and response to pheromones after take-off, and pre-dispersal mating. These criteria enable identification of differences in the invasive capacities of the six species. In particular, Ips typographus appears to be a poor invader worldwide because of its wide dispersal upon emergence and its delayed response to pheromones. Finally, we discuss the risks to the Irish forests so far uncolonised by Ips species.
Authors
Pia Heltoft ThomsenAbstract
No abstract has been registered