Sarah K. Ortiz
Ph.D Candidate
I am a Ph. D candidate at The University of Texas at Austin in the Wolf Lab. I'm broadly interested in the stoichiometric, ecological, and biogeochemical ramifications of different nutrient acquisition strategies in plants, particularly those involving facilitative soil microbes, and how these effects are mediated by plant traits as well as the abiotic environment. I hope to understand how plants will change their resource uptake strategies under anthropogenic stress and uncover the downstream effects of these changes in natural communities.
Research Interests
How do plants regulate different resource acquisition strategies, particularly those reliant on soil microbes? Under what abiotic conditions do plants switch strategies? How are these strategies mediated by functional root traits? What are the large-scale ramifications of these different strategies? These are a few big questions I aim to answer in my research.
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I use Nitrogen-fixing legumes as a model system because of their unique symbioses with rhizobia (a N-fixing bacteria) and arbuscular mycorrhizal fungi (AMF). This "dual-symbiosis" allows me to explore complex questions about mutualism regulation in plants.
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To answer these questions, I use a combination of field and greenhouse studies in tandem with theoretical modeling. Greenhouse experiments allow me to explore how individual plants can change and mitigate their nutrient acquisition strategies under various abiotic and biotic conditions. In combination with theoretical modeling, this will add insight into how the stoichiometry of plants can impact mutualism regulation and explore the possible mechanisms of nutrient allocation that control Carbon investment. By incorporating field studies in my work, I can scale up to the community and ecosystem levels to understand changes to plant community dynamics and ecological processes as a result of these individual changes.
Publications
Menge, D., Wolf, A. A. Funk, J., Perakis, S., Akana, P. R., Arkebauer, R., Bytnerowicz, T., Carreras P. K., Huddell, A., Kou-Giesbrecht, S., Ortiz, S. K. Tree symbioses sustain nitrogen fixation despite excess nitrogen supply 2023. Ecological Monographs.
Wolf, A. A, Ortiz S. K., Rakowski, C. J. Ecosystems: An Overview. The ecological and societal consequences of biodiversity loss. 2022.