Dispersal across a heterogeneous landscapeMany factors influence long-distance dispersal, including dispersal vector behavior, landscape features, and availability and quality of habitat. I use genetic markers to model dispersal among populations located across a heterogeneous and fragmented landscape consisting of urbanization, preserved natural spaces, and agricultural conversion. I contrast the ecological and evolutionary consequences of gene flow for two upland prairie species: Achyrachanea mollis and Plectritis congesta.
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Pollen dispersal of Pinus ponderosaTimber represents a multibillion-dollar industry in the United States, however years of unsustainable management has degraded timber sources leaving forests vulnerable to disease, pests, and climate change. To preserve the economic and ecosystem services of our forest systems, sustainable forestry is required for the continuous growth of productive and resilient forests. A pillar of sustainable forestry is the maintenance of population genetic diversity. My research examines the interaction between logging patterns and genetic diversity of the economically-important timber species, Pinus ponderosa. Using genetic methods, I will examine how logging patterns affect wind behavior responsible for dispersing pollen.
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Seed dispersal of an anemochoric speciesSeed dispersal is a key ecological process that determines the geographic distribution of plants. Seed dispersal is responsible for colonizing new sites, maintaining genetic diversity, and facilitating range shifts and biological invasions in response to our rapidly changing climate. Because anemochoric propagules—wind-dispersed seeds—possess a hairy plume known as a coma or pappus and are small in mass, they are particularly likely to experience long-distance dispersal events.
Using the study species, Achyrachaena mollis (Asteraceae) I am evaluating local seed-dispersal potential using morphological attributes of seeds in a wind tunnel, modeling regional long-distance dispersal events, and using genetic markers to estimate dispersal among plant populations in southern Oregon. |
Population density effects on pollinationPollinator response to visual characteristics of plants is crucial to understanding how plant-pollinator interactions contribute to plant reproductive processes. For aggregated patch species, the spatial distribution and density of flowering plants in and around patches may influence pollinator foraging behavior and pollen movement. The influence of patch characteristics- such as size and density- on pollinator visitation to Lasthenia californica (Asteraceae) was evaluated using pollen load size and pollen germination rates to infer visitation patterns. Patch traits were estimated using drone aerial photographs and a custom Python image-analysis pipeline.
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