Public Abstract

DE-SC0016221: Understanding Ecohydrological Controls of Biogeochemical Reactions and Fluxes: Comparison of Two Contrasting Watersheds

Award Status: Inactive

Institution: The Pennsylvania State University, University Park, PA
UEI: NPM2J7MSCF61
DUNS: 003403953

Most Recent Award Date: 10/23/2018
Number of Support Periods: 1
PM: Bayer, Paul

Current Budget Period: 08/15/2016 - 06/30/2019
Current Project Period: 08/15/2016 - 06/30/2019
PI: Li, Li

Supplement Budget Period: N/A

Public Abstract

Understanding Ecohydrological Controls of Biogeochemical Reactions and Fluxes at the East River Watershed, Colorado Li Li, The Pennsylvania State University Jason Kaye, The Pennsylvania State University Yuning Shi, The Pennsylvania State University Carl Steefel, Lawrence Berkeley National Laboratory Kenneth Williams, Lawrence Berkeley National Laboratory OBJECTIVES. We propose to answer the question *how do ecohydrological processes drive soil biogeochemical reactions and fluxes?* The proposed work aims to cross disciplinary boundaries and to obtain an integrated, system-level understanding on ecohydrological and biogeochemical coupling at the East River watershed in Colorado. We aim to test two hypotheses: 1) biogeochemical reaction rates are controlled by the area of critical interfaces where water flow paths converge; 2) biogeochemical fluxes are governed by dynamic connectivity between upland and stream. PROJECT DESCRIPTION. Ecohydrological processes drive water partition and reactions between water and soil reactive components (carbon, minerals, root exudates, microbes, and gases) at the watershed scale. They also govern the fluxes of reaction products into surface and ground waters. Understanding hydrobiogeochemical coupling require an integrated approach at the watershed scale. Extensive studies focusing on distinct aspects have significantly advanced soil biogeochemistry and hydrology sciences. The lack of understanding on the connections between ecohydrological drivers and biogeochemical fluxes, however, has limited our ability to predict, to scale up, and to address broader environmental problems. METHODS. Here we will test the hypotheses by 1) augmenting a recently-developed watershed-scale code RT-Flux-PIHM into a not-yet-existing bioRT-Flux-PIHM that integrates land-surface interactions, hydrological processes and belowground root-microbe-soil-water interactions; 2) understanding key controls of biogeochemical rates across scales and concentration-discharge relationships; 3) developing indices (i.e., dynamic connectivity and critical interface areas) for watershed process prediction. We propose to study the ecohydrological and biogeochemical processes in the East River catchment (ER) in mid Colorado, the Lawrence Berkeley National Laboratory (LBNL) site supported by the DOE SBR. The site has intensively measured data. We will train our model to reproduce the data and to use bioRT-Flux-PIHM to carry out virtual experiments to isolate the relative importance of different conditions. PROJECT BENEFITS AND OUTCOME. Soil represents the largest terrestrial pool of organic carbon and plays a key role in determining global carbon cycles. Soil biogeochemical reactions release abiotic and biotic solutes that govern water quality, aquatic primary production, heterotrophic activities, and nutrient cycles. The bioRT-Flux-PIHM development will offer a powerful machinery for virtual experiments to mechanistically understand complex process coupling in the highly nonlinear biogeochemical systems in the East River Watershed, and to predict watershed response to the changing climate.

Understanding Ecohydrological Controls of Biogeochemical Reactions and Fluxes at the East River Watershed, Colorado

Li Li, The Pennsylvania State University

Jason Kaye, The Pennsylvania State University

Yuning Shi, The Pennsylvania State University

Carl Steefel, Lawrence Berkeley National Laboratory

Kenneth Williams, Lawrence Berkeley National Laboratory

OBJECTIVES. We propose to answer the question how do ecohydrological processes drive soil biogeochemical reactions and fluxes? The proposed work aims to cross disciplinary boundaries and to obtain an integrated, system-level understanding on ecohydrological and biogeochemical coupling at the East River watershed in Colorado. We aim to test two hypotheses: 1) biogeochemical reaction rates are controlled by the area of critical interfaces where water flow paths converge; 2) biogeochemical fluxes are governed by dynamic connectivity between upland and stream.

PROJECT DESCRIPTION. Ecohydrological processes drive water partition and reactions between water and soil reactive components (carbon, minerals, root exudates, microbes, and gases) at the watershed scale. They also govern the fluxes of reaction products into surface and ground waters. Understanding hydrobiogeochemical coupling require an integrated approach at the watershed scale. Extensive studies focusing on distinct aspects have significantly advanced soil biogeochemistry and hydrology sciences. The lack of understanding on the connections between ecohydrological drivers and biogeochemical fluxes, however, has limited our ability to predict, to scale up, and to address broader environmental problems.

METHODS. Here we will test the hypotheses by 1) augmenting a recently-developed watershed-scale code RT-Flux-PIHM into a not-yet-existing bioRT-Flux-PIHM that integrates land-surface interactions, hydrological processes and belowground root-microbe-soil-water interactions; 2) understanding key controls of biogeochemical rates across scales and concentration-discharge relationships; 3) developing indices (i.e., dynamic connectivity and critical interface areas) for watershed process prediction. We propose to study the ecohydrological and biogeochemical processes in the East River catchment (ER) in mid Colorado, the Lawrence Berkeley National Laboratory (LBNL) site supported by the DOE SBR. The site has intensively measured data. We will train our model to reproduce the data and to use bioRT-Flux-PIHM to carry out virtual experiments to isolate the relative importance of different conditions.

PROJECT BENEFITS AND OUTCOME. Soil represents the largest terrestrial pool of organic carbon and plays a key role in determining global carbon cycles. Soil biogeochemical reactions release abiotic and biotic solutes that govern water quality, aquatic primary production, heterotrophic activities, and nutrient cycles. The bioRT-Flux-PIHM development will offer a powerful machinery for virtual experiments to mechanistically understand complex process coupling in the highly nonlinear biogeochemical systems in the East River Watershed, and to predict watershed response to the changing climate.