Multi-watershed perturbation-response traits derived through ecological theory
EMSL Project ID
51399
Abstract
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 and models will be developed across a broad range of watersheds to ultimately inform next-generation Earth system models and help to preserve long-term national clean water security.A major challenge in watershed hydrobiogeochemistry is predicting how disturbance changes the influences of hot spots and hot moments over aggregate biogeochemical function. Studies of hot spot/moments are often done at single sites; these studies are powerful for revealing mechanisms, but do not immediately provide knowledge and models that are transferable across watersheds. We propose a unique multi-watershed study that uses existing field sites across federal agencies to generate transferable knowledge and models and that builds from our experience leading the World-wide Hydrobiogeochemical Observation Network for Dynamic River Systems (WHONDRS) consortium.
This study builds from the recent merging of hot spots/moments into the concept of ecosystem control points, defined as "...areas of the landscape that exert disproportionate influence on the biogeochemical behavior of the ecosystem." We extend this notion of control points to the new concept of control point influence (CPI): the contribution of elevated biogeochemical rates in space (hot spots) or time (hot moments) to the net aggregated rate within a defined system. CPIs are elevated when hot spots/moments are common enough and have high enough rates to drive aggregated rates. This study will reveal mechanisms underlying cross-watershed variation in CPI through a mechanism-informed trait-based framework. We will deliver a trait framework that predicts post-disturbance CPIs across watersheds and can be integrated with state-of-the-art hydrobiogeochemical models to enhance predictions from reach to multi-watershed scales. While the trait framework can be applied to any watershed component, we will use variably inundated hyporheic zones as a biogeochemically active, tractable model system to test underlying hypotheses and multi-watershed transferability.
We will achieve objectives and test hypotheses informed by a significant body of work from our research groups. The hypotheses and objectives address (1) spatial variation in traits of dissolved organic matter (DOM) using broadly distributed field sampling, (2) connections among environmental traits, DOM traits, and post-disturbance CPIs using lab incubations of field collected sediments, and (3) multi-watershed predictions of post-disturbance CPIs derived from statistical models using environmental and DOM traits. The study's concepts and methods can be extended to any watershed component (e.g., hill slopes), and outcomes can help build next-generation reactive transport models linking environmental conditions, DOM chemistry, microbial metabolism, and CPI to improve predictions of energy and material fluxes relevant to the Earth system and national water quality.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2020-10-01
End Date
2023-03-31
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members