Journal article
Hydraulic Connectivity and Hydrochemistry Influence Microbial Community Structure in Agriculturally Affected Alluvial Aquifers in the Midwestern United States
Environmental science & technology, Vol.59(24), pp.12279-12291
06/12/2025
DOI: 10.1021/acs.est.5c03155
PMCID: PMC12199460
PMID: 40504009
Appears in UI Libraries Support Open Access
Abstract
Alluvial aquifers can provide ecosystem services and drinking water, but much remains unknown about human effects on aquifer microbiomes. Therefore, we used amplicon sequencing and hydrochemical characterization to pair microbial communities with environmental conditions across 37 alluvial aquifer wells. The study region spanned eastern Iowa and southern Minnesota (USA) and contained a combination of drinking water and monitoring wells. In terms of microbial ecology, dominant phyla across the wells included Proteobacteria, Bacteroidota, Patescibacteria, Planctomycetota, and Nitrospirota. Tritium, an indicator of infiltration and surface water influence, was the highest correlated variable with the Shannon index (α-diversity) by the Spearman rank sum (ρ = 0.60) and one of only four significant environmental variables in the constrained correspondence analysis. We built random forest regression models to predict tritium concentrations from microbial family relative abundance (held-out testing coefficient of determination (
) = 0.77 and mean absolute percentage error = 7%) and interpreted the models with Shapley additive explanation values. The most important families for predicting tritium concentrations were
and
. Upwelling methane could contribute to the unusual coupling of ammonia oxidation by
with simultaneous nitrite-dependent methane oxidation by
. Taken together, we illuminate the relationship among hydrochemistry, hydraulic connectivity, and alluvial aquifer microbiomes.
Details
- Title: Subtitle
- Hydraulic Connectivity and Hydrochemistry Influence Microbial Community Structure in Agriculturally Affected Alluvial Aquifers in the Midwestern United States
- Creators
- Hunter W Schroer - IIHR - Hydroscience and Engineering, University of Iowa, Iowa City, Iowa 52240, United StatesKendra Markland - United States Geological Survey, Iowa City, Iowa 52240, United StatesFangqiong Ling - Washington University in St. LouisCraig L Just - Department of Civil & Environmental Engineering, University of Iowa, Iowa City, Iowa 52240, United States
- Resource Type
- Journal article
- Publication Details
- Environmental science & technology, Vol.59(24), pp.12279-12291
- DOI
- 10.1021/acs.est.5c03155
- PMID
- 40504009
- PMCID
- PMC12199460
- NLM abbreviation
- Environ Sci Technol
- ISSN
- 1520-5851
- eISSN
- 1520-5851
- Publisher
- American Chemical Society
- Language
- English
- Date published
- 06/12/2025
- Academic Unit
- Civil and Environmental Engineering; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984829028302771
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