This project continues a 7-year study of environmental and demographic variation across the geographic range of a native California plant in order to understand the ecological and evolutionary limits on an organism's distribution. Prior work showed that environmental variables related to climate, soils, and interactions with insect pollinators and seed-eaters all change across the plant's range. Population growth rates, a measure of population viability, also decline toward the range edge. Over the next five years, research will examine the role that dormant seeds, which remain buried in the soil for 2-5 years, play in allowing populations to weather adverse environments and persist long-term. The project will also determine range-wide differences in the longevity of dormant seeds.
With impending climate change, parts of the current geographic range of many organisms are likely to become unsuitable for continued persistence. Understanding what limits species from colonizing unfavorable environments now can help forecast species responses to deteriorating conditions within their current range. In addition to its scientific impacts, the project will serve an important educational mission by engaging high school students, undergraduate students from research and primarily undergraduate institutions, and graduate students in research. Project leaders will work with high school students from a rural California high school and from a charter school in St Paul Minnesota through in-class activities and field projects.
