Avalanches: Disaster or Miracle? A Changing Ecological Effect

1. Avalanches: Disaster or Miracle?A Changing Ecological Effect Jason Blair February 21, 2009 Winter Ecology Spring 2009 Mountain Research Station, University of Colorado, Boulder

2. Introduction • A commom natural disaster with frequently overlooked ecological benefits. • Inherent Danger and Destuctive Nature • Avalanche Corridors • Climate Change

3. Avalanche Path

4. Habitats • Avalanches not only destroy habitats, but they create new ones. • Increase Ecotones • “The biodiversity within avalanche tracks is highly increased compared to the surrounding forest. The more avalanches occur, the more significant the difference becomes.” (Rixen)

5. Biodiversity • Avalanche Corridors • Forest Complexity • Avalanche Cylces • “Over 80% of the 141 observed species grew in less than 5% of the investigated plots, although the undisturbed vegetation outside of the avalanche tracks consisted of a larch-spruce forest throughout the entire monitoring area” (Rixen.)

6. Climate Change • “In the past 15 years the frequency of avalanches has increased from 1 every decade to one every 3-5 years” (Huggel) • Reflects changes in trigger mechanisms • Wet Avalanches • Permafrost • Impermeable by meltwater • Failing to freeze

7. Wet Avalanches Effect on Ecosystem: -Slower Moving -Less total snowpack -Occur on more gentle slopes (5-20 degrees ) -Lower Elevations -Heavier debris Danger to Humans: -Harder to Predict -Harder to control with explosives

8. Aspen Mountain Research • A 2007 study modeled climate change in CO ski areas • “evaluated how climate change resulting from increased greenhouse gas emissions may affect the timing of wet avalanches and snow quality at Aspen Mountain in the years 2030 and 2100.”(Lazar, Williams) • Potential to change the timing of wet avalanches and snow quality • Air Temperature

9. Graphs Top of Aspen Base of Aspen

10. Conclusion • Avalanches are a natural disturbance like fire • Integral part in shaping the forest community • Patterns of Forest Cover • Biodiversity • New Seedling Establishment • More Complex and Balanced Ecosystem • Dynamics and ecology of Avalanches being directly effected by climate change. • Changing Cycle • Wetter Snowpack • Less disturbance avalanches • More reasearch is necessary • Further testing on how wet avalanches effect enivronment differently.

11. Literature Cited • Armstrong R, Ives J.D.; “Wet snow avalanches” in “Avalanche release and snow characteristics, San Juan Mountains, Colorado.” 1976 p. 67 • Baggi, Stefano, Schweizer, Jurg; Characteristics of wet-snow avalanche activity: 20 years of observations from a high alpine valley; November 2008; http://www.wsl.ch/personal_homepages/schweizj/publications/Baggi_Schweizer_wet_snow_avalanches_preprint.pdf • Huggel, Christian; “Recent Extreme Avalanches: Triggered by Climate Change?” Eos, Vol. 89, No. 47, P. 469; 18 November 2008 • Lazar, Brian, and Williams, Mark; “Climate change in western ski areas: Potential changes in the timing of wet avalanches and snow quality for the Aspen ski area in the years 2030 and 2100” Cold Regions Science and Technology 51(2008) p. 219 • Rixen, Christian; “Avalanches Create New Habitats for Plants” June 25, 2003http://www.waldwissen.net/themen/naturgefahren/schnee/wsl_lawinen_pflanzen_EN?-C=& • Simonson,S., Fassnacht,S.R.; “Snow Avalanche Disturbance Ecology: Examples From the San Juan Mountains, Colorado.” American Geophysical Union, December 2008 • Fagre, Daniel B., Reardon, Blase A; “Avalanches in Glacier National Park” Park Science; Vol. 24 No. 1, Summer 2006. P. 37 www.nrmsc.usgs.gov/files/norock/products/GCC/ParkScience_WMI_Reardon_06.pdf