James Stegen

Soil Function Across Variably Inundated Environments - Tidal Systems

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

Peter Regier

Project type

MONet

We aim to generate knowledge, data, and models that are transferable across Earth’s variably inundated ecosystems. We are focused on the integrated hydro-biogeochemistry of soils in these diverse…

River Corridor Hydrobiogeochemistry from Reaction to Basin Scale

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

Vanessa Garayburu-Caruso

Project type

Contracted Time

The Pacific Northwest National Laboratory (PNNL) Environmental System Science River Corridor Scientific Focus Area (RCSFA) (https://sbrsfa.pnnl.gov/) will transform understanding of spatial and…

River Corridor Hydrobiogeochemistry from Reaction to Basin Scale

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

The Pacific Northwest National Laboratory (PNNL) Environmental System Science River Corridor Scientific Focus Area (RCSFA) (https://sbrsfa.pnnl.gov/) will transform understanding of spatial and…

Control of methane and carbon dioxide emissions by sulfur biogeochemistry in terrestrial ecosystems

Lead Institution

Environmental Molecular Sciences Laboratory

Principal Investigator

John Cliff

Project type

Large-Scale EMSL Research

Freshwater wetlands are responsible for 40% of the methane emissions worldwide. Despite very low amounts of ambient sulfate, these ecosystems often support high rates of sulfate reduction, rivaling…

Influences of Hydrologic Exchange Flows on River Corridor and Watershed Biogeochemical Function

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

We are developing predictive understanding of the processes that govern influences of hydrologic exchange flows on water quality, nutrient dynamics, and ecosystem health in dynamic river corridor…

Assessment of short term changes in hyporheic zone organic carbon character in response to re-inundation

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

Project type

Limited Scope

Understanding processes that govern organic carbon (OC) oxidation is paramount in achieving PNNL’s Subsurface Biogeochemical Research Science Focus Area’s goal of (i) transforming fundamental…

Hydrologic imprinting across terrestrial-aquatic gradients: unraveling the spectrum of ecosystem responses to freshwater limitation and salt exposure

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

Nicholas Ward

Project type

Large-Scale EMSL Research

The availability of freshwater exerts a direct influence on the growth and health of plants both in terrestrial and aquatic ecosystems (e.g., wetlands). Upland soils can experience accumulation of…

Integrating thermodynamic and microbial mechanisms to understand coupled controls of carbon and nitrogen on hyporheic zone metabolism

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

Project type

Large-Scale EMSL Research

Terrestrial-aquatic interfaces are widely recognized as active zones of organic matter metabolism, and hyporheic zones in particular are critical in determining the fate of organic matter globally…

Influences of Hydrologic Exchange Flows on River Corridor and Watershed Biogeochemical Function

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

We are developing predictive understanding of the processes that govern influences of hydrologic exchange flows on water quality, nutrient dynamics, and ecosystem health in dynamic river corridor…

Influences of Hydrologic Exchange Flows on River Corridor and Watershed Biogeochemical Function

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

We are developing predictive understanding of the processes that govern influences of hydrologic exchange flows on water quality, nutrient dynamics, and ecosystem health in dynamic river corridor…

Multi-watershed perturbation-response traits derived through ecological theory

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

Project type

Large-Scale EMSL Research

This project will transform our ability to understand and predict how the influences of biogeochemical hot spots and hot moments on surface-subsurface systems are altered by disturbance. New theory…

Understanding Biases in Natural Organic Matter FTICR Mass Spectrometry to More
Accurately Model Complex Environmental Systems

Lead Institution

Environmental Molecular Sciences Laboratory

Principal Investigator

Rosalie Chu

Characterization of natural organic matter (NOM) by direct infusion (DI) Fourier transform mass spectrometry (FTMS) yields rich and complex information about environmental systems. However, the…

River Corridor Hydrobiogeochemistry from Reaction to Basin Scale

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

The PNNL SBR SFA will transform understanding of spatial and temporal dynamics in river corridor hydrobiogeochemistry from reaction to watershed and basin scales, enabling mechanistic representation…

Tracking the degradation of fresh particulate organic matter in permeable riverbed sediments using FT-ICR-MS and metagenomic/transcriptomic sequencing

Lead Institution

University of Wisconsin, Madison

Principal Investigator

Eric Roden

Project type

FICUS Research

The hyporheic zone, where groundwater and river water mix within riverine corridors, represents a highly active zone of biogeochemical cycling in which key transformations of many critical elements…

River Corridor Hydrobiogeochemistry from Reaction to Basin Scale

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

The PNNL River Corridor SFA will transform understanding of spatial and temporal dynamics in river corridor hydrobiogeochemistry from reaction to watershed and basin scales, enabling mechanistic…

Linking Microbial Communities to Subsurface Geochemistry and Hydrology at the Field-Scale

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

Project type

Large-Scale EMSL Research

Background and Key Challenges: A major challenge in subsurface science is understanding how microbial communities, geochemistry, and hydrology interactively govern the fate and transport of…

Quantifying the functional and structural states of dynamic microbial communities

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Fredrickson

Project type

Large-Scale EMSL Research

The overall goal of this proposal is to provide a quantitative framework in which to compare species-resolved patterns of gene expression, allowing comparison of the effects of perturbations of…

Coupling Microbial Communities to Carbon and Contaminant Biogeochemistry in the Groundwater-Surface Water Interaction Zone

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James Stegen

Project type

FICUS Research

The proposed study will integrate molecular data generated through a combination of JGI and EMSL capabilities to support research activities under the Subsurface Biogeochemical Research-Science Focus…

Projects