Drought is one of many factors contributing to the complexity of frequent fire adapted forest ecosystems. Drought increases the potential for catastrophic wildfire, but drought cannot be singled out as the cause of wildfires. Other factors include fuels accumulated during many decades of unwise fire suppression, overcrowded “dog-hair” tree stands, and the long-term effects of overgrazing. These factors in combination with drought spell trouble for Western forests.
Drought occurs as a result of complex interactions of global climate cycles. Drought severity and duration is difficult to predict but we can be sure that eventually droughts will recur.
Are we in a drought, and if so, how severe is it? Some climatologists suggest that the current dry spell in the Southwest is actually a return to normal conditions following 20 years of unusually wet weather during the 1970s and 80s. Others argue that we are indeed experiencing a drought more severe than any in the past 1400 years.
According to the National Geophysical Data Center:
The set of figures below provide data on the last major drought in the Southwest during the 1950s. Note the connection between the decrease in annual precipitation and the long-term decrease in percent forest area. The magnitude of the 1950s drought was exceeded only by the drought of the late 1500s.
Regardless of how we choose to define drought, we should understand that drought is not an anomally but a recurring condition. Forest management practices that take the recurrence of drought into account will help insure long-term health for Western forests.
Allen, C.D., and D.D. Breshears. 1998. Drought-induced shift of a forest-woodland ecotone: Rapid landscape response to climate variation. Proceedings of the National Academy of Sciences 95:14839-14842. Available online at http://www.pnas.org/cgi/content/full/95/25/14839
Colorado State University. 2003. "Drought.ColoState.edu." http://drought.colostate.edu/ 4/30/03. Information for government leaders, businesses and individuals as they plan for and manage drought events in Colorado.
National Geophysical Data Center. "Drought: A Paleo Perspective -- What is Drought?" http://www.ngdc.noaa.gov/paleo/drought/drght_what.html 4/22/03.
National Oceanic and Atmospheric Administration. 2000. “North American
Drought: A Paleo Perspective.” http://www.ngdc.noaa.gov/paleo/drought/drght_home.html
Patterson, Mark W. 1997. “Forest Fires and Drought in the U.S.
McKinnon, Shaun. 2003. “Southwest's drought may last for years.” The Arizona Republic http://www.azcentral.com/specials/special26/articles/0212droughtadd12.html 4/22/03. On-line news story with drought history and predictions.
National Drought Mitigation Center. http://drought.unl.edu/ 5/14/03. NDMC stresses drought preparation and risk management rather than crisis management.
Shaw, Robinson. 2000. “Southwest warned to plan for dry decade.” Environmental News Network. http://www.enn.com/news/enn-stories/2000/02/02212000/pdo_10139.asp 4/22/03. On-line news story describes how of the Pacific Decadal Oscillation (PDO) effects drought in the Southwest.
Stade, Kirsten and Nicole Rosmarino. 2002. “Administrative Procedures Act Petition to Develop Regionwide Drought Policy.” http://www.fguardians.org/docs/drought-petition.htm 4/22/03. Forest Guardians request Regional forestry officials to adopt drought policies where none are in place.
U.S. Drought Monitor. 2003. http://www.drought.unl.edu/dm/monitor.html
Last edited May 21, 2003