EDGE EFFECT: Wildfire

September 2012
Montana

According to the New York Times, during the summer of 2012 the United States experienced the most widespread drought in more than half a century. The hottest year since records began in 1895, “fifty-five percent of the continental United States — from California to Arkansas, Texas to North Dakota — is experiencing moderate to extreme drought, according to the government, the largest such area since December 1956.” Following exceptionally hot conditions marked by dry thunderstorms, low humidity and gusty winds over 45 mph, lightning strikes and manmade accidents have burned over 800,000 acres throughout the state of Montana. The crisis came to a head in the Paradise Valley at 2 PM on August 29 when a blaze ripped through the town of Pine Creek, burning homes and displacing residents, closing multiple campgrounds, trails and roads throughout the region. These images also include the remains of the Mill Creek fire of 2007 and examples of mountain pine beetle effects throughout the Gallatin National Forest.

The edge effect refers to the juxtaposition of contrasting environments on an ecosystem, commonly used in conjunction with the boundary between forest habitats and disturbed or developed land. “It often seems that the common impression about the American West is that, before the arrival of people of European descent, Native Americans had essentially no effect on the land, the wildlife, or the ecosystems, except that they harvested trivial amounts that did not affect the ‘natural’ abundances of plants and animals . . . to claim that people did not or could not create major changes in natural ecosystems can be taken as Western civilization’s ignorance, chauvinism, and old prejudice against primitivism–the noble but dumb savage.”

There is ample evidence that Native Americans greatly changed the character of the landscape with fire. “Generally, the American Indians burned parts of the ecosystems in which they lived to promote a diversity of habitats, especially increasing the “edge effect,” which gave the Indians greater security and stability to their lives. Their use of fire was different from white settlers who burned to create greater uniformity in ecosystems. In general, during the presettlement period, Indian caused fires were often interpreted as either purposeful (including fires set for amusement) or accidental (campfires left or escaped smoke signaling).”

Wildfires are a natural force in the forest cycles of the West; the cones of the lodgepole pine and other species require high temperatures to open and reseed old growth every 25-50 years, infamously observed in the 1988 fire of Yellowstone National Park. The unprecedented acceleration of global climate change is creating new stressors on this ecosystem altering its traditional patterns. Inhabiting the native tree species, the mountain pine beetle normally “plays an important role in the life of a forest, attacking old or weakened trees, and speeding development of a younger forest. However, unusual hot, dry summers and mild winters during the last few years, along with forests filled with mature lodgepole pine, have led to an unprecedented epidemic; it may be the largest forest insect blight ever seen in North America” more than “ten times larger than previous outbreaks.” A new study reported by the New York Times indicates that their evolution has led to the production of two generations of beetle per year. “’It’s not twice as many beetles, it’s an exponential increase,’ [Dr. Jeffry Mitton, a professor of ecology at the University of Colorado at Boulder] said. Each beetle lays 60 eggs and, since nearly all survive, each of those beetles goes on to lay 60 eggs in the same summer, which means 3,600 more beetles.” Populations are usually killed off in the winter with temperatures below 30 degrees for weeks, but the West continues to experience some of the warmest winters ever recorded never falling below zero.

Though the Arctic and Greenland have seen record ice sheet melt unimaginable 10 years ago, which according to scientists might drive arctic wind patterns south prolonging acutely colder winters, the pine beetle infestation and occurrence of drought and wildfire in the future remain uncertain. Entire forests in New Mexico have been converted to arid shrubland at an alarming pace, and if conditions persist the famous alpine forests of the Rocky Mountains might experience a similar fate.

REFERENCES –
Botkin, Daniel B. 1990 Discordant Harmonies: A New Ecology for the Twenty-First Century. New York, NY: Oxford University Press. Drought (U.S. Drought of 2012).” – News. New York Times, 09 Sept. 2012. Web. 09 Sept. 2012. <http://topics.nytimes.com/top/news/science/topics/drought/index.html>.
“edge effect.” Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica, 2011. Web. 06 Jan. 2011. <http://www.britannica.com/EBchecked/topic/179088/edge-effect>.
“KTVQ.com.” KTVQ.com. N.p., 07 Sept. 2012. Web. 09 Sept. 2012. <http://www.ktvq.com/news/pine-creek-fire-down-but-not-out/>.
“Pine Beetle.” Wikipedia. Wikimedia Foundation, 29 Aug. 2012. Web. 09 Sept. 2012. <http://en.wikipedia.org/wiki/Pine_beetle>.
Robbins, Jim. “Double Trouble From Mountain Pine Beetles?” Green Blog. New York Times, 19 Mar. 2012. Web. 09 Sept. 2012. <http://green.blogs.nytimes.com/2012/03/19/double-trouble-from-mountain-pine-beetles/>.
Williams, Gerald W., PhD, Boise NF, Sandra Morris, Region 1, Henry T. Lewis, and William Reed. “American Indian Use of Fire in Ecosystems References.” American Indian Use of Fire in Ecosystems References. USDA Forest Service, 018 May 2001. Web. 09 Sept. 2012. <http://www.wildlandfire.com/docs/biblio_indianfire.htm>.