Electronic Thesis and Dissertation Repository


Master of Science




Dr. F.J. Longstaffe

2nd Supervisor

Dr. E.A. Webb

Joint Supervisor


Seasonal and annual variations in foliar δ13C and δ15N of a C3 grass Ammophila breviligulata and a C4 grass Calamovilfa longifolia from the sand dunes of Pinery Provincial Park in southern Ontario, Canada were investigated to assess isotopic variability at a single site within a temperate-humid climatic zone. This work quantifies seasonal δ13C and δ15N variation, tests for correlation of δ13C and δ15N with weather parameters, and evaluates the isotopic responses of these grasses to location within the dune system. Throughout the 2014 growing season, there was ~ 1 to 2 ‰ change in δ13C and ~ 3 to 4 ‰ change in δ15N that was related to plant development. Foliar δ13C and δ15N are significantly correlated to total summer precipitation amount and, under some conditions, temperature. The foliar isotopic variations are too small, however, to affect paleoclimatic interpretation of such proxies within such a climatic regime.