Date of Award
2011
Degree Type
Thesis
Degree Name
Master of Science
Program
Biology
Supervisor
Dr. Hugh Henry
Abstract
In northern temperate regions, climate warming is predicted to increase the
frequency of soil freeze-thaw cycles (FTC) and reduce plant cold acclimation in late fall and early spring. To test if FTC inhibit plant nitrogen (N) uptake, I exposed Poa
pratensis tillers to FTC in late fall, mid winter, and early spring, then used a 15N tracer to assess N uptake from a hydroponic solution. To assess the direct effects of FTC on plant growth, I exposed P. pratensis tillers to FTC on the same dates, then measured plant biomass the following summer. Freezing of short duration at -10 °C and longer freezing a t - 5 °C in fall and spring decreased N uptake significantly. Plant growth decreased the most after spring FTC. Reduced plant cold acclimation in fall and spring must thus be coupled with extreme soil freezing to hinder plant N acquisition and growth.
Recommended Citation
Malyshev, Andrey, "SUBLETHAL FREEZING EFFECTS ON NITROGEN UPTAKE AND GROWTH IN POA PRATENSIS" (2011). Digitized Theses. 3515.
https://ir.lib.uwo.ca/digitizedtheses/3515