The Changing Ecological Effect of Avalanches Due to

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Transcript The Changing Ecological Effect of Avalanches Due to

Disaster or
A Changing
Jason Blair
February 21, 2009
Winter Ecology Spring 2009
Mountain Research Station, University of Colorado, Boulder
A commom natural disaster with frequently
overlooked ecological benefits.
 Inherent Danger and Destuctive Nature
 Avalanche Corridors
Climate Change
Avalanche Path
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)
 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 larchspruce forest throughout the entire
monitoring area” (Rixen.)
Climate Change
 “In the past 15 years the frequency of avalanches
has increased from 1 every decade to one every 35 years” (Huggel)
 Reflects changes in trigger mechanisms
 Wet Avalanches
 Permafrost
 Impermeable by meltwater
 Failing to freeze
Wet Avalanches
Danger to Humans:
-Harder to Predict
-Harder to control
with explosives
-Occur on more
gentle slopes
(5-20 degrees )
-Lower Elevations
-Heavier debris
Effect on Ecosystem:
-Slower Moving
-Less total snowpack
Aspen Mountain Research
 A 2007 study modeled climate change in CO ski
 “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
 Air Temperature
Top of Aspen
Base of Aspen
 Avalanches are a natural disturbance like fire
 Integral part in shaping the forest community
Patterns of Forest Cover
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.
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;
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, 2003
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