Item: An Elevational Gradient in Snowpack Chemical Loading at Glacier National Park, Montana: Implications for Ecosystem Processes
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Title: An Elevational Gradient in Snowpack Chemical Loading at Glacier National Park, Montana: Implications for Ecosystem Processes
Proceedings: Proceedings of the 2000 International Snow Science Workshop, October 1-6, Big Sky, Montana
Authors:
- Daniel Fagre [ U.S. Geological Survey, Glacier National Park, West Glacier, Montana ]
- Kathy Tonnessen [ National Park Service, University of Montana, Missoula, Montana ]
- Kristi Morris [ U.S. Fish and Wildlife Service, Denver, Colorado ]
- George Ingersoll [ U.S. Geological Survey, Federal Center, Denver, Colorado ]
- Lisa McKeon [ U.S. Geological Survey, Glacier National Park, West Glacier, Montana ]
- Karen Holzer [ U.S. Geological Survey, Glacier National Park, West Glacier, Montana ]
Date: 2000
Abstract: The accumulation and melting of mountain snowpacks are major drivers of ecosystem processes in the Rocky Mountains. These include the influence of snow water equivalent (SWE) timing and amount of release on soil moisture for annual tree growth, and alpine stream discharge and temperature that control aquatic biota life histories. Snowfall also brings with it atmospheric deposition. Snowpacks will hold as much as 8 months of atmospheric deposition for release into mountain ecosystems during the spring melt. These pulses of chemicals influence soil microbiota and biogeochemical processes affecting mountain vegetation growth. Increased atmospheric nitrogen inputs recently have been documented in remote parts of Colorado's mountain systems but no baseline data exist for the Northern Rockies. We examined patterns of SWE and snow chemistry in an elevational gradient stretching from west to east over the continental divide in Glacier National Park in March 1999 and 2000. Sites ranged from 1080m to 2192m at Swiftcurrent Pass. At each site, two vertically-integrated columns of snow were sampled from snowpits Up to 600cm deep and analyzed for major cations and anions. Minor differences in snow chemistry, on a volumetric basis, existed over the elevational gradient. Snowpack chemical loading estimates were calculated for NH4, S04 and N03 and closely followed elevational increases in SWE. N03 (in microequivalentsl square meter) ranged from 1,000 ueq/m2 at low elevation sites to 8,000+ueq/m2 for high elevation sites. Western slopes received greater amounts of SWE and chemical loads for all tested compounds.
Object ID: issw-2000-462-467.pdf
Language of Article: English
Presenter(s): Unknown
Keywords: atmospheric deposition, nutrient loading, ecosystems, snowpack variability
Page Number(s): 462-467
Subjects: chemical loading elevational gradient snowpack
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