Waananen, Amy2023-09-192023-09-192023-06https://hdl.handle.net/11299/257036University of Minnesota Ph.D. dissertation. June 2023. Major: Ecology, Evolution and Behavior. Advisor: Ruth Shaw. 1 computer file (PDF); xi, 134 pages.Habitat destruction leads to not only local extinction, but often increases isolation within and among the populations that remain. Plants, being sessile, are susceptible to reproductive failure due to isolation from mates, which can further compromise population persistence. However, persistence depends not only on the production of offspring but also on their survival. Furthermore, the isolation between two plants may correspond to patterns of genetic differentiation, such as relatedness or local adaptation, which can influence the fitness of their offspring. Here, I study how plants’ isolation from potential mates links to both their reproductive rates and offspring fitness. I focus on Echinacea angustifolia, a bee-pollinated perennial forb of the North American tallgrass prairie, which has lost 96-99% of its extent over the past 180 years. I expand upon previous work by considering isolation not only in space (distance to prospective mates) but also in time (overlap in flowering time). In Chapter 1, using ten-year dataset of reproductive success, I found that both spatial isolation and flowering asynchrony reduce reproductive outcomes to a similar degree. In Chapter 2, I assessed how distance between parental plants and their asynchrony of flowering influence the fitness of their offspring, revealing that offspring fitness increases with distance between parents and the difference in their flowering time. In Chapter 3, I evaluated whether isolation from mates has consequences for reproductive fitness after accounting for the precarious transitions between seedling emergence and survival to adulthood. While mate density increased seedling emergence, it had no effect on offspring survival, so its fitness benefits eroded over time. Together these chapters provide an integrative understanding of how pollen movement patterns influence plant fitness, which can inform conservation and management in fragmented landscapes.enThesis or Dissertation