Ellen Elverland
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Farmers in Northern Norway frequently experience winter damaged fields caused by ice encasement. The economic consequences are severe due to loss of fodder and costs with reestablishment of swards. It is therefore important to choose the best available varieties for the local climatic and environmental conditions. We tested eight Norwegian cultivars of timothy (Phleum pratense), for tolerance to ice encasement and their regrowth capacity. Both old and new cultivars, and cultivars with good overwintering capacity and less biomass production were tested against more productive cultivars with less overwintering capacity. The experiment was a semi-field setup and plants were established in pots which were placed outside. Half of the pots were covered with ice and half were kept under snow cover. During four months, pots were brought, once per month, into a greenhouse for thawing and measurement of biomass production under normal growth conditions. The results indicate that the old winter hardy cultivar ‘Engmo’ is least affected by ice encasement but produces little biomass. The joint Nordic cultivar ‘Snorri’ produced most biomass of all the cultivars after a treatment with ice cover. In conclusion, there is a large difference between cultivars in ice encasement tolerance, and ice cover affected regrowth capacity far more than snow cover
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Forfattere
Jarle W. Bjerke Ellen Elverland Laura Jaakola Leidulf Lund Bogdan Zagajewski Zbigniew Bochenek Andrzej Kłos Hans TømmervikSammendrag
Climate change-induced snow thaw and subsequent accumulation of ice on the ground is a potential, major threat to snow-dominated ecosystems. While impacts of ground-ice on arctic wildlife are well explored, the impacts on tundra vegetation is far from understood. We therefore tested the vulnerability of two high-arctic plants, the prostrate shrub Salix polaris and the graminoid Luzula confusa, to ice encasement for 60 days under full environmental control. Both species were tolerant, showing only minor negative responses to the treatment. Subsequent exposure to simulated late spring frost increased the amount of damaged tissue, particularly in S. polaris, compared to the pre-frost situation. Wilting shoot tips of S. polaris increased nearly tenfold, while the proportion of wilted leaves of L. confusa increased by 15%. During recovery, damaged plants of S. polaris responded by extensive compensatory growth of new leaves that were much smaller than leaves of non-damaged shoots. The results suggest that S. polaris and L. confusa are rather tolerant to arctic winter-spring climate change, and this may be part of the reason for their wide distribution range and abundance in the Arctic.
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Lise Haug Ellen Elverland Jarle W. Bjerke Marit Jørgensen Anne Linn Hykkerud Hilde HallandSammendrag
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Laura Parducci Tina Jørgensen Mari Mette Tollefsrud Ellen Elverland Torbjørn Alm Sonia L. Fontana Keith D. Bennett James Haile Irina Matetovici Yoshihisa Suyama Mary E. Edwards Kenneth Andersen Morten Rasmussen Sanne Boessenkool Eric Coissac Christian Brochmann Pierre Taberlet Michael Houmark-Nielsen Nicolaj K. Larsen Ludovic Orlando M. Thomas P. Gilbert Kurt H. Kjær Inger Greve Alsos Eske WillerslevSammendrag
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Forfattere
Laura Parducci Mary E. Edwards Keith D. Bennett Torbjørn Alm Ellen Elverland Mari Mette Tollefsrud Tina Jørgensen Michael Houmark-Nielsen Nicolaj Krog Larsen Kurt H. Kjær Sonia L. Fontana Inger Greve Alsos Eske WillerslevSammendrag
Birks et al. question our proposition that trees survived the Last Glacial Maximum (LGM) in Northern Scandinavia. We dispute their interpretation of our modern genetic data but agree that more work is required. Our field and laboratory procedures were robust; contamination is an unlikely explanation of our results. Their description of Endletvatn as ice-covered and inundated during the LGM is inconsistent with recent geological literature.