Physiology and Life History in a Tropical Plant

Differences in life history traits (growth and reproductive rates) among individuals within a species can be explained by the existence of tradeoffs that prevent natural selection from optimizing all traits in all individuals. One phenomenon often responsible for generating tradeoffs is resource limitation where resources can be allocated to improve one trait, e.g. growth rate, or another trait, e.g. reproductive rate, but not both. In plants, one major limiting resource can be fixed carbon, which is produced by photosynthesis. Variation in photosynthesis can result in differences in the fixed carbon budget, leading to variation in life history traits among individuals. The goal of this project is to determine the relationship between photosynthetic levels and trait variation among individual plants. The study involves measuring photosynthesis and life histories of individual plants in controlled and natural environments. In general, linking different fields/approaches often results in synergisms facilitating significant scientific advances. The proposed project will train the principal investigator to measure photosynthesis and interpret photosynthetic levels within the context of life history tradeoffs. In plants, there are few reports on the relationship between photosynthesis and life history, and understanding this relationship will provide insight into how plants respond to the environment. The project also allows for undergraduate student participation, thus enriching the educational experience of current and future student participants in the PI's laboratory.