2022 Early Hearing Detection & Intervention Virtual Conference

March 13 - 15, 2022

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5/24/2021  |   8:30 AM - 10:30 AM   |  DISSOLVED ORGANIC CARBON CHEMOSTASIS IN ANTARCTIC POLAR DESERT STREAMS   |  Virtual Platform

DISSOLVED ORGANIC CARBON CHEMOSTASIS IN ANTARCTIC POLAR DESERT STREAMS

In the McMurdo Dry Valleys [MDV], Antarctica, little is known about concentration-discharge (C-q) relationships for biological solutes like DOC. Because MDV streams are low in organic carbon and experience large diel fluctuations in discharge(q), we expected that the MDV DOC-q relationship would be dilution-based and limited by the DOC generation rate, not the fluid transit time. To evaluate the DOC-q relationship in these glacial-meltwater streams, we fit the long-term DOC-q data to two models: a power law and an advection-reaction model. We then used model outputs and other common metrics to quantify the DOC-q relationship. Surprisingly, our results demonstrate this relationship is chemostatic; however, they do not provide a clear explanation why. After examining and eliminating various potential DOC-q drivers, we propose a conceptual model where hyporheic carbon storage, hyporheic exchange rates, and net DOC generation rates are key interacting components that enable chemostatic DOC-q behavior in MDV streams. This model clarifies the role of autochthonous carbon stores in maintaining DOC-q chemostasis and may be useful for examining these relationships in temperate systems, where the role of autochthonous carbon is masked by a far larger allochthonous signal.

  • Ecosystem Dynamics
  • Carbon cycle
  • Biogeochemistry

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Presenters/Authors

Christa Torrens (), University of Colorado at Boulder, christa.torrens@colorado.edu;


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Michael Gooseff (), University of Colorado, michael.gooseff@colorado.edu;


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Diane McKnight (), University of Colorado, diane.mcknight@colorado.edu;


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