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
Paal KrokeneAbstract
No abstract has been registered
Authors
Dominique Gravel Benjamin Baiser Jennifer A. Dunne Jens-Peter Kopelke Neo D. Martinez Tommi Nyman Timothee Poisot Daniel B. Stouffer Jason M. Tylianakis Spencer A. Wood Tomas RoslinAbstract
Biogeography has traditionally focused on the spatial distribution and abundance of species. Both are driven by the way species interact with one another, but only recently community ecologists realized the need to document their spatial and temporal variation. Here, we call for an integrated approach, adopting the view that community structure is best represented as a network of ecological interactions, and show how it translates to biogeography questions. We propose that the ecological niche should encompass the effect of the environment on species distribution (the Grinnellian dimension of the niche) and on the ecological interactions among them (the Eltonian dimension). Starting from this concept, we develop a quantitative theory to explain turnover of interactions in space and time – i.e. a novel approach to interaction distribution modeling. We apply this framework to host–parasite interactions across Europe and find that two aspects of the environment (temperature and precipitation) exert a strong imprint on species co-occurrence, but not on species interactions. Even where species co-occur, interaction proves to be stochastic rather than deterministic, adding to variation in realized network structure. We also find that a large majority of host-parasite pairs are never found together, thus precluding any inferences regarding their probability to interact. This first attempt to explain variation of network structure at large spatial scales opens new perspectives at the interface of species distribution modeling and community ecology.
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Authors
Jonathan Rizzi Clara Antón Fernández Paulo Jorge de Almeida Borges Ryan Bright Rasmus AstrupAbstract
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Bilberry (Vaccinium myrtillus L.) is one of the important economical berry species found in the boreal forests of northern latitudes such as Norway and Finland. They are rich in anthocyanins, carotenoids vitamins and other flavonoids that accumulates in skin and flesh of the fruit. Berries from northern latitudes are found to contain more phytochemicals with anti-oxidant capacity than southern clones. It is mainly due to the environmental conditions of northern hemisphere and genetic adaptation that favors higher accumulation of bioactive metabolites such as anthocyanins. The phenylpropanoid pathway is the major key regulatory system for most of the bioactive compounds including anthocyanins which are synthesized via a branch called as flavanoid pathway. Abiotic factors, such as temperature, photoperiodism, light quality & quantity has a major role in biosynthesis and regulation mechanisms. It is usually mediated by MBW complex (R2R3 MYB transcription factors, basic helix-loop-helix and WD 40 repeat proteins). Our studies has been currently focussed on understanding the developmental and environmental regulation of anthocyanin biosynthesis in early to late ripening stages of non-climacteric bilberry fruit in response to different light conditions. The bilberry clones were collected from an island near Tromsø and were subjected to different light conditions such as red, far-red and blue wavelength from Heliospectra lamps during the onset of ripening stages. Simultaneously, the unriped berries were also detached and kept in petri dishes under the lamps to analyze the response of anthocyanin accumulation. Morphological changes in berry skin color were scored from the petri plates. Also, the fruit and leaf tissues were collected from the plants for gene expression analysis of biosynthetic structural genes such as anthocyanin synthase, chalcone synthase and regulatory genes (MBW transcrption factors) at different time points. Our preliminary results has shown that red and blue wavelengths are positively upregulating the anthocyanin accumulation during different developmental stages of bilberry.
Authors
Tao Zhao Dineshkumar Kandasamy Paal Krokene Jingyuan Chen Jonathan Gershenzon Almuth HammerbacherAbstract
No abstract has been registered