Living Earth Collaborative – Washington University
• Pollination ecology
• Global change biology
• Biodiversity conservation
Investigating the effects of climate change on mixed mating systems: Do changes to water availability affect outcrossing rates? Austin is a postdoctoral fellow with the Living Earth Collaborative, whose research focuses on how plant-pollinator communities respond to environmental variability. Species with dimorphic cleistogamy produce two types of morphologically distinct flowers: cleistogamous (CL) flowers that obligately self-fertilize and chasmogamous (CH) flowers that facultatively outcross. CL flowers are produced as a bet-hedging strategy in stressful environments, while CH flowers are produced under good growing conditions. Our prior research has found that the common blue violet (Viola sororia), a dimorphic cleistogamic perennial native across eastern North America, has responded to climate change in Missouri by increasing investment in CH flower production. As climate change in Missouri has been characterized by increased precipitation, the increased investment in CH flower production by V. sororia is likely a response to greater water availability. Here, the student will expand this work to other species and locations across North America to test whether the positive relationship between water availability and CH flower production is generalizable across species with dimorphic cleistogamy. To accomplish this, the student will quantify CH and CL flowers on herbarium sheets, pair these flowering data with historic climate data, and test for associations between water availability and CH flower production. As outcrossing can facilitate future adaptation, while selfing can lead to inbreeding depression, understanding the effects of climate change on reproductive strategy investment is crucial for a comprehensive assessment of the biological impacts of global change. It is possible for the student participating in this project to receive co-authorship on a publication resulting from this work.