Date of Award

12-15-2014

Document Type

Open Access Thesis

Department

Earth and Ocean Sciences

First Advisor

Jill Anderson

Abstract

Climate change is having demonstrable, worldwide impacts on ecological systems in ways that have modified aspects of organism behavior. Plant phenologies have responded to warmer temperatures in a variety of ways that may have implications for long-term species survival. How germination phenology changes in response to warmer climate is a largely unexplored question yet the ability of a plant to advance or delay germination in unfavorable conditions is critical for survival. Knowing the relative success and timing of germination under different climate regimes is important in understanding whether species can keep pace with the rate of climate change via migration or adaptation. We examined germination success and phenology under different simulated climate conditions within wild mountain populations of Boechera stricta. We found germination success to be heritable within the species. We also found that germination success is lower under snow removal conditions designed to simulate predicted trends in climate. We discovered that B. stricta germinants are highly sensitive to environmental conditions and predicted future climate and that the most successful germinants are those inhabiting actual or simulated conditions most similar to those of their home range. Transplanted germinants placed in dissimilar conditions range fare poorly, particularly transplanted high elevation genotypes. Germination occurs earlier under warm-climate conditions with a pronounced effect under both control and warm conditions occurring within low elevation seed families. Implications for these findings on community dynamics, migratory potential, species survivability and management practices are also discussed. Germination success can limit the migratory potential of a species and the suitable range available for species establishment or relocation and this poorly-understood developmental stage may act as a significant check on a species’ or population’s ability to survive changing environmental conditions.

Rights

© 2014, Samuel Johnson

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