Browsing by Author "Waananen, Amy"
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Item Fitness consequences of pollen movement and its dependence on spatiotemporal isolation: Field studies in Echinacea angustifolia(2023-06) Waananen, AmyHabitat 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.Item R Code and Data for: High juvenile mortality overwhelms benefits of mating potential for reproductive fitness(2022-04-29) Waananen, Amy; Richardson, Lea K; Thoen, Riley D; Nordstrom, Scott W; Eichenberger, Erin G; Kiefer, Gretel; Dykstra, Amy B; Shaw, Ruth G; Wagenius, Stuart; waana001@umn.edu; Waananen, AmyAn individual’s fitness depends not only on its fecundity, but also on the viability of its offspring. Plant ecologists typically equate fecundity, or seed yield, with reproductive fitness, but fecundity might not correspond to offspring survival. Furthermore, individual fecundity and survival of the offspring might respond differently to external factors affecting fitness. One factor that may influence reproductive fitness through effects on both fecundity and offspring survival is mating opportunity, e.g., an individual’s access to potential mates. We investigated the relationship between maternal mating opportunity and both fecundity and offspring survival in populations of a long-lived herbaceous perennial, Echinacea angustifolia. Across seven years and 14 sites, we quantified the mating opportunity of 1279 plants and followed the progeny from these mating bouts over eight subsequent years. We used aster models to evaluate the relationship between mating opportunity and both the number of seedlings emerging and the number of progeny alive after 8 years. Seedling emergence increased strongly with mating opportunity, but we did not detect a significant relationship between progeny count after eight years and mating opportunity. These results show that mating opportunity increases fecundity, but its benefit to overall fitness may be weak.