Date of Award

2023

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy in Forest Science (PhD)

Administrative Home Department

College of Forest Resources and Environmental Science

Advisor 1

Molly Cavaleri

Committee Member 1

Andrew Burton

Committee Member 2

Carsten Kuelheim

Committee Member 3

Xin Xi

Abstract

Tropical forests exchange more carbon with the atmosphere than any other biome, but their responses to climate change are largely understudied. The work presented in this dissertation uses a tropical understory warming experiment that was hit by a hurricane disturbance to investigate how plant physiology responds to multiple types of climate change pressures. We measured the potential for root respiration, leaf photosynthesis & respiration, and leaf thermotolerance acclimation to experimental warming while recovering from hurricane disturbance. We found there was thermal acclimation via decreased ecosystem root respiration, increased photosynthetic thermal niche breadth, and decreased quantum efficiency for some species at higher temperature. We also saw that photosynthesis was highest in early successional stages, when the canopy was more open, but photosynthetic rates were lower in experimentally warmed plots. Together those results point towards an overall reduction of carbon assimilation to tropical forest ecosystems. We found that plants at our study site were adapted for early successional stages and will likely perform better than other successional stage plants in a future climate scenario with higher atmospheric temperatures and more frequent hurricane disturbances. As the plant communities stand now, the forests at our site will likely capture less carbon from the atmosphere than they do now; however, with changing communities, they could maintain the high rates of carbon assimilation as they have done historically.

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

Available for download on Wednesday, May 01, 2024

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