Date of Award
2024-08-01
Degree Name
Doctor of Philosophy
Department
Biological Sciences
Advisor(s)
Vanessa L. Lougheed
Abstract
Due to the ecological and physical responses of arctic tundra to warming, organic carbon (C) stored in frozen permafrost soils is increasingly at risk of mineralization and export to aquatic systems, the coast, and atmosphere. Although many coastal aquatic systems in the Arctic are likely net sources of CO2 to the atmosphere, little is known about the drivers of inorganic C flux and how these systems contribute to regional C budgets. This dissertation addresses several lapses in our understanding of coastal inorganic C dynamics in arctic Alaska via three data chapters. In chapter 2, I examine seasonal and regional variability in carbon cycling and CO2 flux in five shallow arctic estuaries with varying connectivity to the adjacent shelf sea and terrestrial inputs. We found that heterotrophic conditions during the ice covered season led to CO2 accumulation in bottom waters. In contrast, all of the estuaries were atmospheric CO2 sinks during spring breakup and open water periods, however, the degree of terrestrial influence determined the overall strength of CO2 uptake. Chapter 3 is a spatially and temporally integrative study of CO2 fluxes in one arctic estuary during the open water season. We found that wind-driven currents controlled where water from rivers or incoming oceanic influence was distributed in the lagoon, which created a mosaic of CO2 release and uptake events across the estuary. Chapter 4 examines how organic C and lateral connectivity of Alaskan Coastal Plain tundra streams influence metabolism and CO2 efflux. We especially highlight the impact of varying stream geomorphologies and hydrological regimes, including extreme rainfall events, in controlling soil C movement and processing. Overall, this dissertation will contribute to better understanding of the movement of terrestrially derived C across the stream-ocean shelf continuum in critically understudied small, coastal arctic watersheds.
Language
en
Provenance
Received from ProQuest
Copyright Date
2024-08-01
File Size
164 p.
File Format
application/pdf
Rights Holder
Alina Spera
Recommended Citation
Spera, Alina, "Ecological, Climatic, And Geomorphic Controls Of The Transport And Fate Of Co2 In Coastal Arctic Aquatic Ecosystems" (2024). Open Access Theses & Dissertations. 4209.
https://scholarworks.utep.edu/open_etd/4209