Cassiope tetragona as a dendroecological proxy : a retrospective analysis of experimental warming in the Arctic Tundra ...

• Main Author: Gallois, Elise
• Format: Text
• Language: English
• Published: University of British Columbia 2019
• Subjects: Alexandra Fiord; Arctic; Cassiope tetragona; Ellesmere Island; Tundra
• Online Access: https://dx.doi.org/10.14288/1.0380613; https://doi.library.ubc.ca/10.14288/1.0380613

Annual stem growth and reproductive effort of the evergreen dwarf-shrub, Cassiope tetragona, exhibit a strong positive relationship to summer temperature and have been used in dendroclimatological analyses to reconstruct climate in the High Arctic through the application of transfer function equations. Retrospective analysis of the annual growth increments have also previously been used to examine the impact of short term warming in a few tundra sites. This thesis presents a full retrospective analysis approach to reconstruct the impact of long-term experimental warming in tundra communities at Alexandra Fiord (Ellesmere Island) from before the installation of open-top-chambers in 1992 to the present day, using a before-after-control-intervention design on growth and reproduction variables. We found a positive, significant effect of experimental warming on the stem growth of C. tetragona and revealed that phenology stages (such as bud break, flowering, and fruit production) take place significantly earlier ...