Contrasting survival and physiological responses of sub‑Arctic plant types to extreme winter warming and nitrogen
|Author:||Bokhorst, Stef1,2; Jaakola, Laura3,4; Karppinen, Katja3,5;|
1Norwegian Institute for Nature Research (NINA), FRAM – High North Research Centre for Climate and the Environment, Langnes, PO Box 6606, 9296 Tromsø, Norway
2Department of Ecological Science, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
3Climate Laboratory Holt, Department of Arctic and Marine Biology, UIT The Arctic University of Norway, 9037 Tromsø, Norway
4Norwegian Institute of Bioeconomy Research (NIBIO), PO Box 115, 1431 Ås, Norway
5Genetics and Physiology Unit, University of Oulu, PO Box 3000, FI‑90014 Oulu, Finland
6Faculty of Biosciences, Fisheries and Economics, Norwegian College of Fishery Science, UIT The Arctic University of Norway, 9037 Tromsø, Norway
|Online Access:||PDF Full Text (PDF, 1.2 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe201803094632
|Publish Date:|| 2018-03-09
Main conclusion: Evergreen plants are more vulnerable than grasses and birch to snow and temperature variability in the sub-Arctic.
Most Arctic climate impact studies focus on single factors, such as summer warming, while ecosystems are exposed to changes in all seasons. Through a combination of field and laboratory manipulations, we compared physiological and growth responses of dominant sub-Arctic plant types to midwinter warming events (6 °C for 7 days) in combination with freezing, simulated snow thaw and nitrogen additions. We aimed to identify if different plant types showed consistent physiological, cellular, growth and mortality responses to these abiotic stressors. Evergreen dwarf shrubs and tree seedlings showed higher mortality (40–100%) following extreme winter warming events than Betula pubescens tree seedlings and grasses (0–27%). All species had growth reductions following exposure to − 20 °C, but not all species suffered from − 10 °C irrespective of other treatments. Winter warming followed by − 20 °C resulted in the greatest mortality and was strongest among evergreen plants. Snow removal reduced the biomass for most species and this was exacerbated by subsequent freezing. Nitrogen increased the growth of B. pubescens and grasses, but not the evergreens, and interaction effects with the warming, freezing and snow treatments were minor and few. Physiological activity during the winter warming and freezing treatments was inconsistent with growth and mortality rates across the plants types. However, changes in the membrane fatty acids were associated with reduced mortality of grasses. Sub-Arctic plant communities may become dominated by grasses and deciduous plants if winter snowpack diminishes and plants are exposed to greater temperature variability in the near future.
|Pages:||635 - 648|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1181 Ecology, evolutionary biology
1184 Genetics, developmental biology, physiology
This work was financed by a Grant from the Research Council of Norway (Grant no. 225006) to J.W.B. and S.B., and by financial support from the Flagship Programme “Effects of climate change on terrestrial ecosystems, landscapes, society and indigenous peoples” of FRAM–High North Research Centre for Climate and the Environment.
Electronic supplementary material
The online version of this article (doi: 10.1007/s00425-017-2813-6) contains supplementary material, which is available to authorized users.
© The Author(s) 2017. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.