Senescence in duckweed: an interspecific comparison and the influence of temperature

Abstract

The focus of this thesis was to compare the life history traits of three species of duckweed and investigate the impact of temperature on duckweed lifespan. A generalized pace and shape framework was employed to measure six life history traits. Results revealed pace and shape of survivorship to be conserved, while fecundity and frond size were more variable. Two temperatures were then used to determine whether duckweed lifespan was directly impacted by temperature. Results demonstrated that lower temperatures extended lifespan while higher temperatures reduced lifespan, and temporal scaling of survivorship trajectories was observed. A linear model was able to predict the average change in lifespan associated with spending a certain number of days at a high temperature and switching to a low temperature. This study provides an example of how duckweed species remain a useful model system at the forefront of evolutionary and ecological studies focusing on plant senescence.