Effects of a short-term freeze on Sphagnum girgensohnii grown under different light-temperature regimes

Authors

Jane Sarah Colby, Florida International University

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Biology

First Advisor's Name

Steven F. Oberbauer

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Michael S. Ross

Third Advisor's Name

Jennifer H. Richards

Date of Defense

10-29-2007

Abstract

During the short, snow-free growing seasons in the Arctic, sudden “cold snaps” or freeze thaw events (FTE) frequently occur when temperatures fall subzero for 24 to 72 h. Vascular plants exposed to FTE are often irreversibly damaged, but despite their importance, the responses of nonvascular plants to FTE have been little studied. I grew plants of Sphagnum girgensonhii under high and low light and temperature conditions to investigate whether pre-freeze conditions influence damage and recovery of this important moss species. Plants grown at low light and high temperature showed the greatest growth. Upon freezing they also showed irreversible physiological damage and the greatest reduction in growth. Furthermore, some growing conditions resulted in increased production of new branches that were lost during freezing. The findings of this study suggest that the responses of Sphagnum species to climate variation may be important for the structure of arctic plant communities.

Identifier

FI14060873

Comments

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Recommended Citation

Colby, Jane Sarah, "Effects of a short-term freeze on Sphagnum girgensohnii grown under different light-temperature regimes" (2007). FIU Electronic Theses and Dissertations. 2403.
https://digitalcommons.fiu.edu/etd/2403