CAREER: Synthesizing Experiments and Education in Dispersal Science (SEEDS) to understand how seed arrival maintains biodiversity

About This Grant

Plant species are increasingly threatened with local extinction because of habitat destruction, changes in weather patterns, and competition with introduced species. Maintaining diversity of plant species in a local area (i.e., community) requires the arrival and establishment of seeds. Seed dispersal is critical because many plant populations cannot persist if seeds do not arrive. However, seeds are small and difficult to follow and, consequently, little is known about their dispersal and establishment, and how seed traits affect it. This research will establish a grassland experiment manipulating availability of seed habitat, and the rate (i.e. the number of seeds per unit time) and pattern (i.e. even, or clumped, pattern onto a plot) of seed arrival to determine which aspects of seed dispersal increase biodiversity. A partnership of 25-30 grassland scientists from around the world will experimentally collect seeds that fall in their grasslands to scale up these findings. Comparisons of seed arrival among experimental treatments in relation to temperature, precipitation and plant composition will assess how environmental parameters alter the rate and pattern of seed arrival in grasslands around the globe. This project will contribute to STEM workforce development by training Michigan State University’s (MSU) introductory ecology students in the classroom how to conduct research. Undergraduate students will measure characteristics of each seed (e.g. size, number of hairs, etc.) taken from images of seeds collected by our global grassland partners to address questions about how seed characteristics alter their ability to arrive to an area. Students will create novel research infrastructure through this project by building a large, publicly available database of seed characteristics. The project will partner with K-12 teachers, as well as MSU pre-service teachers, to create lesson plans incorporating pieces of this research into their classrooms that meet next-generation science standards. Lesson plans will be driven by teachers’ classroom needs. Critical connections between pre-service teacher students and experienced K-12 teachers will help prepare these students to teach cutting-edge science to middle and high school students. Global change factors (e.g., changing weather patterns and land use) are causing unprecedented losses of plant biodiversity. Seed dispersal is a key process enabling plants to establish in new habitats thereby increasing local diversity. Understanding the relative importance of seed dispersal to plant diversity is constrained by use of seed arrival patterns and rates in manipulative experiments that differ from variation observed in nature. This calls into question whether ecological theory matches realistic empirical outcomes. The researchers will conduct a controlled experiment and construct a global observational dataset to empirically test long-standing hypotheses that seed arrival maintains plant biodiversity. The grassland experiment will explore two important factors of seed arrival, rate (i.e. number of seeds per unit time) and pattern (i.e. settling in a clumped or distributed fashion), to determine if either one alters biodiversity, and cross these effects with removals, or not, of competing species. A partnership with 25-30 scientists to estimate rates and patterns of seed arrival in grasslands around the globe and environmental factors affecting their arrival provides a means to scale up the results of local experiments. Partners sent seed collectors by the research team will return them for counting and morphospecies identification from plots at each site. Data of size and shape of seeds will be collected from these samples of seeds from around the world to create a publicly available seed trait database. Trait data will inform how seed morphology influences dispersal distance. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.