Ecological and evolutionary consequences of experimental and natural warming in the high Arctic tundra
department or school: Arts, Faculty of
department or school: Geography, Department of
data provider: DSpace
degree campus: UBCV
creator: Bjorkman, Anne Donahey
issued: 2015-01-14T16:42:30Z
issued: 2015
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Recent increases in global temperatures are having substantial and often unpredictable consequences for the earth’s biota. Species’ responses to environmental change depend on 1) the ability of individuals to adjust in situ through phenotypic plasticity, 2) the rate at which evolutionary adaptation can occur, and 3) the ability of individuals to colonize newly suitable habitat through migration or propagule dispersal. Temperatures in the Arctic are increasing faster than anywhere else, yet our understanding of the consequences of climate change in the Arctic lags behind that of temperate ecosystems. In this thesis, I ask whether plant phenology has advanced in response to 21 years of experimental and ambient warming at Alexandra Fiord, Ellesmere Island, Canada. While experimental warming led to earlier flowering in three out of four species, flowering dates in the control plots were unchanged or delayed despite more than 1 °C of ambient warming over the 21-year period, likely due to concurrent delays in snowmelt. This suggests that the effects of altered snowmelt patterns can counter the effects of warmer temperatures, even generating phenological responses opposite to those predicted by warming alone. I then use reciprocal transplant experiments to test for evidence of evolutionary adaptation in two plant species to differing environmental conditions between two spatially proximate habitat types and in response to 18 years of experimental warming treatments. Results were consistent both with substantial phenotypic plasticity in response to site-to-site and year-to-year variability, and with evolutionary adaptation to site and treatment conditions. Differences across natural habitats were stronger than those across experimental treatments. This indicates that plastic and genetic responses to climate change are likely to play an important role in structuring future Arctic plant communities. Finally, I test the hypothesis that warming will confer a fitness advantage t…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/51901
note: ECOLOGICAL AND EVOLUTIONARY CONSEQUENCES OF EXPERIMENTAL AND NATURAL WARMING IN THE HIGH ARCTIC TUNDRA by Anne Donahey Bjorkman B.A., Cornell University, 2004 M.Sc., The University of British Columbia, 2009 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Geography) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) January 2015 © Anne Donahey Bjorkman, 2015 ii Abstract Recent increases in global temperatures are having substantial and often unpredictable consequences for the earth’s biota. Species’ responses to environmental change depend on 1) the ability of individuals to adjust in situ through phenotypic plasticity, 2) the rate at which evolutionary adaptation can occur, and 3) the ability of individuals to colonize newly suitable habitat through migration or propagule dispersal. Temperatures in the Arctic are increasing faster than anywhere else, yet our understanding of the consequences of climate change in the Arctic lags behind that of temperate ecosystems. In this thesis, I ask whether plant phenology has advanced in response to 21 years of experimental and ambient warming at Alexandra Fiord, Ellesmere Island, Canada. While experimental warming led to earlier flowering in three out of four species, flowering dates in the control plots were unchanged or delayed despite more than 1 °C of ambient warming over the 21-year period, likely due to concurrent delays in snowmelt. This suggests that the effects of altered snowmelt patterns can counter the effects of warmer temperatures, even generating phenological responses opposite to those predicted by warming alone. I then use reciprocal transplant experiments to test for evidence of evolutionary adaptation in two plant species to differing environmental conditions between two spatially proximate habitat types and in response to 18 years of experimental warming treatments. Results were consistent both with substant…
has type: Thesis/Dissertation
date issued: 2015-02
is shown at: 10.14288/1.0167102
language: eng
degree discipline: Geography
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivs 2.5 Canada
rights URI: http://creativecommons.org/licenses/by-nc-nd/2.5/ca/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/51901