Hopp til hovedinnholdet

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

To document

Abstract

Amphiboreal taxa are often composed of vicariant phylogroups and species complexes whose divergence and phylogeographic affinities reflect a shared history of chronic isolation and episodic trans-Arctic dispersal. Ecological filters and shifting selective pressures may also promote selective sweeps, niche shifts and ecological speciation during colonization, but these are seldom considered at biogeographical scales. Here we integrate genetic data and Ecologic Niche Models (ENMs) to investigate the historical biogeography and cohesion of the polymorphic rockweed Fucus distichus throughout its immense amphiboreal range, focusing on trans-Arctic asymmetries, glacial/interglacial dynamics, and integrity of sympatric eco-morphotypes. Populations were sampled throughout the Pacific and the Atlantic, from southern rear-edges to the high-Arctic. They were genotyped for seven microsatellites and an mtDNA spacer, and genetic diversity and structure were assessed from global to local scales. ENMs were used to compare niche divergence and magnitude of post-glacial range shifts in Pacific versus Atlantic sub-ranges. Haplotypic and genotypic data revealed distinct and seemingly isolated Pacific vs Arctic/Atlantic gene-pools, with finer-scale regional sub-structuring pervasive in the Pacific. MtDNA diversity was highly structured and overwhelmingly concentrated in the Pacific. Regionally, Alaska showed the highest intra-population diversity but the lowest levels of endemism. Some sympatric/parapatric ecotypes exhibited distinct genotypic/haplotypic compositions. Strikingly, niche models revealed higher Pacific tolerance to maximum temperatures and predicted a much more consolidated presence in the NE Atlantic. Glacial and modern ranges overlapped extensively in the Pacific, whereas the modern Atlantic range was largely glaciated or emerged during the Last Glacial Maximum. Higher genetic and ecogeographic diversity supports a primary Pacific diversification and secondary Atlantic colonization, also likely reflecting the much larger and more stable climatic refugia in the Pacific. The relic distribution and reduced ecological/morphological plasticity in the NE Atlantic are hypothesized to reflect functional trans-Arctic bottlenecks, recent colonization or competition with congeners. Within the Pacific, Alaska showed signatures of a post-glacial melting pot of eastern and southern populations. Genetic/ecotypic variation was generally not sufficiently discontinuous or consistent to justify recognizing multiple taxonomic entities, but support a separate species in the eastern Pacific, at the southern rear-edge. We predict that layered patterns of phylogeographic structure, incipient speciation and niche differences might be common among widespread low-dispersal amphiboreal taxa.

To document

Abstract

Phytophthora cactorum is a plant pathogenic oomycete that causes crown rot in strawberry leading to significant economic losses every year. To invade the host, P. cactorum secretes an arsenal of effectors that can manipulate host physiology and impair its defense system promoting infection. A transcriptome analysis was conducted on a susceptible wild strawberry genotype (Fragaria vesca) 48 hours post inoculation with P. cactorum to identify effectors expressed during the early infection stage. The analysis revealed 4,668 P. cactorum genes expressed during infection of F. vesca. A total of 539 secreted proteins encoded by transcripts were identified, including 120 carbohydrate-active enzymes, 40 RXLRs, 23 proteolytic enzymes, nine elicitins, seven cysteine rich proteins, seven necrosis inducing proteins and 216 hypothetical proteins with unknown function. Twenty of the 40 RXLR effector candidates were transiently expressed in Nicotiana benthamiana using agroinfiltration and five previously unreported RXLR effector genes (Pc741, Pc8318, Pc10890, Pc20813, and Pc22290) triggered cell death when transiently expressed. The identified cell death inducing RXLR effectors showed 31–66% identity to known RXLR effectors in different Phytophthora species having roles in pathogenicity including both activation and suppression of defense response in the host. Furthermore, homology analysis revealed that these cell death inducing RXLR effectors were highly conserved (82 - 100% identity) across 23 different strains of P. cactorum originating from apple or strawberry.

Abstract

On the Ground: -Precision livestock management through sensor technology using the Internet of Things offers enhanced surveillance and monitoring of the ranching operations. -At the ranch scale, the integration of sensor technology, including on-animal sensors, environmental monitoring equipment, and remote sensing can shift livestock operations from a solely reactive, traditional, knowledge-based approach toward a proactive, data-driven, decision-making process. -Leveraging data from sensors at the ranch scale can address logistical challenges and create efficiency in decision-making processes concerning resource management.

To document

Abstract

The food system significantly impacts the environment and society. This study examined a shift from a continuation of the current trend (policy as usual scenario) towards a biomass value hierarchy scenario, which focused on optimizing land and biomass use and rethinking the role of livestock production. The biomass value hierarchy was based on circular economy principles, the waste hierarchy, and national self-sufficiency, which eliminated feed import and redistributed protein sources in the diet. A Multi-Criteria Decisions Analysis (MCDA) framework was used to assess the two scenarios across four sustainability dimensions: environmental, social, economic and policy. Environmental and social impacts were analysed using life cycle assessment methodology, while economic and policy implications were explored using partial equilibrium modelling, with the Norwegian food system as a case study. The results for the environmental dimension indicated that, compared to the policy as usual scenario, the biomass value hierarchy reduced environmental impacts by 8% to 18% across the indicators, including climate change, acidification, particulate matter, terrestrial eutrophication and occupation of arable land. Social impacts also improved in categories with the highest social risks, such as equal opportunities for workers, health and safety for farmers, cultural heritage, food security, fair competition, and promoting social responsibility. Contrarily, indicators within the economic dimension revealed reduced profitability, and results within the policy dimension showed a considerable increase in required subsidies, border measures and governmental restrictions on consumption. The study findings indicate that an environmentally and socially sustainable food system is feasible but requires significant political and economic support. Additionally, the study highlights the value of using MCDA when combining different research methods in cross-disciplinary assessments. These results underscore the need for a societal debate on acceptable levels of political intervention and the role of consumers and taxpayers in shaping the future food system.

Abstract

On European golf courses, small lightweight robotic mowers have recently been introduced for fairway and rough mowing. In this study, turfgrass quality and the coverage of broadleaf weeds in three cool-season grasses were compared in response to robotic and traditional fairway mowing. Experiments with pure swards of red fescue (Festuca rubra L.), colonial bentgrass (Agrostis capillaris L.), and Kentucky bluegrass (Poa pratensis L.) were carried out at NIBIO Landvik, Norway, to evaluate differences between lightweight robotic mowing and reel mowing. In a mixture of the three species turfgrass quality and the coverage of broadleaf weeds were compared in response to robotic and reel mowing at yearly fertilizer levels from 0 to 120 kg N ha−1. The results showed that both robotic and reel mowing were found to provide high turfgrass quality, while lower coverage of broadleaf weeds (predominantly white clover [Trifolium repens L.]) was found with robotic mowing independent of grass species. In the mixed stand, higher turfgrass quality was found with robotic mowing regardless of N rate, but N rates above 60 kg ha−1 year−1 were necessary to keep the coverage of white clover in fall on an acceptable low level. Our results suggest that robotic mowing can decrease the spread of white clover at a fairway mowing height of 15 mm, but more research is needed to clarify at which mowing heights, mowing frequencies, and fertilizer levels we can get the best competitiveness against broadleaf weeds on fairways with robotic mowing.