This project extends a 30-year study of desert plant populations to understand how populations persist and coexist in the face of short-term environmental variation and long-term climate shifts. Data on seed germination, plant survival, and reproduction will continue to be collected to determine how seeds are triggered to germinate and when - or why - germination is delayed to take advantage of different environmental conditions. These decisions are largely responsible for changes in plant abundance and species coexistence in this community. Field measures will be combined with experiments to develop models to explore how seed 'banks,' or accumulations of ungerminated seeds, buffer populations and communities against short- and long-term environmental variation. These models will also be used to investigate how differences among species promote their coexistence and species diversity and to predict how desert plant communities will respond to emerging novel climatic conditions.
Like human communities, natural communities are challenged by increasing environmental variation and shifting climate. This research will determine how plant communities cope with normal environmental variability and how they will respond to a hotter, drier, more variable environment. Graduate and undergraduate students will receive hands-on training in research that complements formal coursework. Several activities will extend the impact of the research to the public, K-12 students and teachers, and ecosystem management professionals. These include an educational kiosk at the University of Arizona's Biosphere 2 facility, coordination with the Arizona Center for STEM Teachers, and participation in a new Center for Environmental Biology that brings together land managers and university scientists from the southwestern U.S.
