Degree
Doctor of Philosophy (PhD)
Department
Oceanography and Coastal Sciences
Document Type
Dissertation
Abstract
This dissertation focuses on carbon dioxide (CO2) dynamics in flowing freshwaters, contributing to the growing body of knowledge about inland water carbon cycles. The research is structured into three main chapters, each progressing towards the objective of utilizing variability in flowing freshwaters to further understand carbon dynamics, anthropogenic land cover impacts, and potential impacts from a changing climate. Chapter one compiles a 30-year dataset of pCO2 measurements from flowing freshwater systems across the contiguous United States. This dataset, referred to as CDFLOW, includes over 750,000 pCO2 estimates from more than 35,000 locations. It serves as a critical resource for large-scale spatiotemporal analyses of pCO2 in flowing freshwater ecosystems. Chapter two investigates the impact of pH measurement errors on the estimation of pCO2 in flowing freshwater. pH is a key factor in calculating pCO2, and systematic biases in pH measurements can lead to overestimation of pCO2. By addressing these biases and integrating them into a modeling framework, this chapter provides insights into pCO2 estimation bias and modeling pCO2 estimates. Chapter three explores cross-scale interactions (CSIs) between local land use, such as agriculture and development, and regional drivers affecting pCO2 in flowing freshwater systems. The chapter demonstrates how anthropogenic land cover influences carbon dynamics at the local scale while being modulated by broader environmental conditions and anthropogenic activities. These findings highlight opportunities for better management and mitigation of human impacts on freshwater carbon fluxes. Overall, this work emphasizes the complexity of pCO2 dynamics in freshwater ecosystems and provides valuable data and methodological advancements for future research and environmental management.
Date
12-22-2024
Recommended Citation
Toavs, Timothy R., "CO2 in Flowing Freshwaters: Macro Scale Database Compilation, Addressing pH Bias in CO2 estimates, and Quantifying Cross-Scale Interactions" (2024). LSU Doctoral Dissertations. 6652.
https://repository.lsu.edu/gradschool_dissertations/6652
Committee Chair
Stephen Midway