Wildfire impacts on organic matter bioavailability and river corridor biogeochemistry
EMSL Project ID
51840
Abstract
Disturbances can modify landscape hydrologic flows and alter the quantity and quality of organic matter delivered to rivers, thereby affecting the hydro-biogeochemistry of freshwater terrestrial-aquatic interfaces. Wildfire disturbances are increasing in frequency and intensity in the American West, making fires relevant and important to represent in predictive biogeochemical models. Generally, wildfire-impacted river corridors have elevated concentrations of pyrogenic organic matter (PyOM), which contains carbon (C), nitrogen (N) and phosphorus (P). PyOM is chemically diverse and has poorly constrained implications for terrestrial-aquatic biogeochemical cycles. However, our understanding of PyOM in the environment has undergone a paradigm shift in the last decade or so, with emerging research highlighting the potential importance of PyOM in biogeochemical processes. Multiple, complementary organic matter datasets are required for understanding the chemical and functional diversity of PyOM across burn severities and will serve as input data for mechanistic models. Here, we propose an investigation into wildfire impacts on riverine solid and dissolved phase organic matter chemistry. The impact of factors such as burn severity and parent source material on biogeochemical rates will be detailed in laboratory experiments. The transferability of this knowledge to natural settings and the functional representation of PyOM in mechanistic models will be further elucidated. Specifically, we propose to examine: a) the chemistry of PyOM created from differing burn conditions and feedstocks, b) the influence of the PyOM continuum on C-, N- and P- biogeochemical rates in laboratory experiments, c) the transferability of the results in a) and b) to watersheds influenced by different fire conditions, and d) the functional representation of PyOM in mechanistic models. This information will allow for increased predictive understanding of the impact fires have on freshwater terrestrial-aquatic interface hydro-biogeochemistry.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2021-10-01
End Date
2023-10-01
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members