Sponsor
Portland State University. Department of Biology
First Advisor
Mitchell Cruzan
Term of Graduation
Spring 2024
Date of Publication
6-4-2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (Ph.D.) in Biology
Department
Biology
Language
English
DOI
10.15760/etd.3772
Physical Description
1 online resource (x, 136 pages)
Abstract
Dispersal is a crucial ecological and evolutionary process in plants. Seed dispersal is responsible for the colonization of novel locations and for range expansion in response to climate change, and pollen dispersal is important for the maintenance of genetic diversity in populations, particularly through long-distance dispersal events. Because plants are sessile, many species are dependent upon dispersal vectors to facilitate gene flow. Dispersal in the wind is a common vector in multiple plant families, as dispersal by abiotic vectors does not depend on community composition and is therefore more reliable than dispersal by biotic vectors. Despite prevalence among plant systems, pollen and seed dispersal in wind is notoriously difficult to track. However, the use of genetic methods offers a unique opportunity to evaluate effective dispersal patterns in the context of wind behavior.
In this work, I utilized several genetic techniques to explore the consequences of wind dispersal in plants across multiple spatial and temporal scales. In Chapter 2, I considered the effects of the local habitat on dispersal potential in a plant with wind-dispersed seed characteristics. I estimated dispersal potential based on seed morphology and separate the contributions of environmental and genetic factors to morphological variation of dispersal traits. In Chapter 3, I considered the impact of landscape structure on single-generation dispersal events for continuous and clear-cut stages of a pine forest. Using a parentage analysis, I calculated dispersal kernels for pollen and seeds and compare dispersal trajectories to the surrounding canopy structure. Finally, in Chapter 4, I analyzed the rate of gene flow among populations in the context of anthropogenic and natural landscape features at a mesoscale. I contrasted two species with disparate dispersal syndromes using different genetic markers: chloroplast haplotypes, which reflected historic seed dispersal, and nuclear SNPs, which demonstrated contemporary trends in pollen and seed dispersal. This work contributes to our understanding of wind dispersal in plant systems, and assesses the complex interactions of landscape structure, vector behavior, and effective dispersal.
Rights
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Persistent Identifier
https://archives.pdx.edu/ds/psu/42239
Recommended Citation
Scott, Elizabeth Hendrickson, "The Genetic Consequences of Pollen and Seed Transport in the Wind" (2024). Dissertations and Theses. Paper 6640.
https://doi.org/10.15760/etd.3772