Establishing fluvial silicon regimes and their stability across the Northern Hemisphere

• Published in: Limnology and oceanography letters 2024-06, Vol.9 (3), p.237-246
• Main Authors: Johnson, Keira, Jankowski, Kathi Jo, Carey, Joanna, Lyon, Nicholas J., McDowell, William H., Shogren, Arial, Wymore, Adam, Sethna, Lienne, Wollheim, Wilfred M., Poste, Amanda E., Kortelainen, Pirkko, Heindel, Ruth, Laudon, Hjalmar, Räike, Antti, Jones, Jeremy B., McKnight, Diane, Julian, Paul, Bush, Sidney, Sullivan, Pamela L.
• Format: Article
• Language: English
• Subjects: BASIC BIOLOGICAL SCIENCES; biogeochemistry; Carbon sequestration; Climate; Climate change; Clustering; Creeks & streams; Ecosystems; ENVIRONMENTAL SCIENCES; fluvial; GEOSCIENCES; hydrology; Land use; Oceanografi, hydrologi, vattenresurser; Oceanography, Hydrology, Water Resources; Primary production; Productivity; River ecology; Seasonal variations; Silicon; Time series; Water quality; Water quality control; Watersheds
• ISSN: 2378-2242; 2378-2242
• DOI: 10.1002/lol2.10372

Fluvial silicon (Si) plays a critical role in controlling primary production, water quality, and carbon sequestration through supporting freshwater and marine diatom communities. Geological, biogeochemical, and hydrological processes, as well as climate and land use, dictate the amount of Si exported by streams. Understanding Si regimes—the seasonal patterns of Si concentrations—can help identify processes driving Si export. We analyzed Si concentrations from over 200 stream sites across the Northern Hemisphere to establish distinct Si regimes and evaluated how often sites moved among regimes over their period of record. We observed five distinct regimes across diverse stream sites, with nearly 60% of sites exhibiting multiple regime types over time. Our results indicate greater spatial and interannual variability in Si seasonality than previously recognized and highlight the need to characterize the watershed and climate variables that affect Si cycling across diverse ecosystems.