Thinking Outside the Rocks: Subsurface Water Storage, Topography, and Land Cover Are Key Modulators of Large‐Scale Riverine Dissolved Silicon Dynamics
Year: 2026
Type: article
Abstract: Riverine dissolved silicon (DSi) dynamics reflect integrated geologic, hydrologic, climatic, and ecological controls. We compiled annual DSi data for 337 rivers across four continents and trained interpretable machine‐learning models to predict concentrations and yields from 28 watershed variables. Both models reproduced testing data ( R 2 = 0.85 for concentration and 0.96 for yield) and withheld‐site validation ( R 2 = 0.91 and 0.93). Lithology, especially volcanic rock fraction, strongly controlled DSi while subsurface storage, topography, and land cover further shaped DSi dynamics. DSi concentrations and yields exhibited nonlinear responses to basin slope, recession‐curve slope, proportion of open‐water cover, and nutrient availability. Concentrations showed sharper threshold responses to hydrologic and biotic variables, whereas yields varied more gradually with climate and lithology. These results provide a framework for forecasting DSi under land cover and climate change and for embedding realistic, nonlinear processes in mechanistic models.
Source: Geophysical Research Letters
DOI: 10.1029/2025gl118853
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,190
Awards: LTER National Coordination Office: Facilitating Collaboration, Accelerating Synthesis, ADVANCING A WATERSHED HYDRO-BIOGEOCHEMICAL THEORY: LINKING WATER TRAVEL TIME AND REACTION RATES UNDER CHANGING CLIMATE, Long Term Ecological Research (LTER) National Communications Office (LNCO), SitS: Collaborative Research: Soils are signaling shifts in aggregate life-cycles: What does this mean for water, carbon and climate feedbacks in the Anthropocene?, Collaborative Research: Network Cluster: Quantifying controls and feedbacks of dynamic storage on critical zone processes in western montane watersheds, Collaborative Research: ULTRA-Data: Developing global riverine solute regime and synchrony frameworks for understanding watershed-scale controls on river biogeochemical signals
OpenAlex ID: W7125976930