Hydrologic processes governing near surface saturation of alpine wetlands in the Canadian Rockies
Abstract
Alpine wetlands are vital for habitat, biodiversity, carbon cycling and water storage, but little is known about their hydrologic condition. Climate trends toward smaller mountain snowpacks that melt earlier are thought to pose a threat to the continued provision of alpine wetland ecological functions, and their existence, as it is believed they derive their water mainly from snowmelt. Our objective was to determine the hydrologic processes governing near surface saturation in alpine wetlands. We monitored the water table dynamics of three alpine wetlands in contrasting hydrogeomorphic landscape positions for two summers in Banff National Park, Canada. We concurrently monitored water balance components, and analyzed soil properties and source water geochemistry. Despite very different snow conditions between the two study years, water tables remained near the surface and relatively stable in both years, indicating wetlands are more hydrologically buffered from snowpack variations than expected. We did not find convincing evidence of hydrogeomorphic position influencing wetland water table dynamics. Instead, peat thickness seemed to be critical in regulating water table as the wetland with the thickest peat soil (>1 m) maintained water tables closest to the ground surface for the longest period of time. Thicker peat deposits may develop under convergent hydrologic flow path conditions. Our results indicate that alpine wetlands are more resilient to shifting environmental conditions than previously reported.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.H13L1580W
- Keywords:
-
- 0740 Snowmelt;
- CRYOSPHEREDE: 1621 Cryospheric change;
- GLOBAL CHANGEDE: 1813 Eco-hydrology;
- HYDROLOGYDE: 1817 Extreme events;
- HYDROLOGY