Microbial communities of fire-affected soil

Abstract

Over 100 years of fire suppression and over grazing by cattle have left profound changes to some of the ponderosa pine forests in Colorado. The forest stand structure has shifted from a wide open savanna-like structure to one with very high tree densities, which in turn has contributed to destructive forest fires such as the Hayman fire of 2002 (Graham, 2003). The current restoration program for the ponderosa pine ecosystem in the Colorado Rocky Mountains involves thinning and reintroduction of fire through prescribed burns to bring back the historical forest structure and function (Dahms and Geils, 1997). Thinning for restoration purposes, in combination with traditional harvesting practices, produces large amounts of slash material, which commonly is disposed of by burning them in large piles. Disposal of slash by piling and burning presents a dilemma to forest land managers. While it is an effective method for removal of unmarketable debris and small trees, soil scorching is detrimental to soil microorganisms (Jimenez-Esquilln et al., 2007), results in unattractive scars, and may assist in the establishment and spread of non-native plants (Korb et al., 2004).

Citation

Stromberger, Mary E. 2008. Microbial communities of fire-affected soil. Final report: Joint Venture Agreement between U.S. Forest Service, Rocky Mountain Research Station and Colorado State University. No. 03-JV-11221616-093. Fort Collins, CO: Colorado State University, Department of Soil and Crop Sciences. 34 p.