Long-term change in river silicon from the poles to the tropics
Abstract
Riverine exports of silicon (Si) influence global carbon cycling through the growth of diatoms, which account for ~25% of global primary production. Climate change will likely alter river Si exports in biome-specific ways due to interacting shifts in chemical weathering rates, hydrologic connectivity, and metabolic processes in aquatic and terrestrial systems, yet factors driving long-term changes in Si exports remain unexplored at local, regional, and global scales. To address this uncertainty, we used long-term (>20 yrs) data from 65 rivers and streams that span the globe (e.g., Antarctic, tropical, temperate, boreal, alpine, Arctic systems) to evaluate how concentrations and total exports of Si changed over the last several decades of rapid climate warming. Our data show that river Si concentration and flux have been dynamic over time, with widespread increasing trends observed in the Arctic, alpine, tropical and temperate forests. Many of these shifts were independent of changes in discharge and not limited to regions with the most rapid warming. Finally, based on shifts in seasonality and hydrologic conditions over time, we will present a framework for understanding the sensitivity of river Si to a changing climate.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H25X1302J