Linkages between mineral element composition of soils and sediments with
hyporheic zone dissolved organic matter chemistry across the contiguous
United States
Abstract
The hyporheic zone is a hotspot for biogeochemical cycling where
interactions with mineral metals preserve the release and biodegradation
of organic matter (OM). A small fraction of OM can still be exchanged
between localized sediments and the overlying water column, and recent
evidence suggest there exists a longitudinal structuring in sediment
dissolved OM (DOM) chemistry across the continental United States
(CONUS). In this study, we tested a hypothesis that water extractable
sediment DOM chemistry could be explained by sediment metal contents and
integrative watershed scale features at the CONUS scale. Crowdsourced
samples were characterized for high resolution mass spectrometry and
coupled with sediment metals determined via x-ray fluorescence as well
as with land cover and soil elemental information obtained from national
databases. Our results highlight weak relationships between DOM
chemistry and elemental composition at the CONUS scale indicating
limited transferability of organo-metal linkages into multi-scale
hydrobiogeochemical models.