Restoring Ecosystem Health in Ponderosa Pine Forests of the Southwest
Journal of Forestry
Previous research has established that presettlement ponderosa pine (Pinus ponderosa) forests in the southwestern USA were much more open. After Euro-American settlement, heavy livestock grazing, fire suppression, logging and climatic events favored dense pine regeneration. Studies were established within the Fort Valley Experimental Forest, near Flagstaff, Arizona, to determine: how the structure (by biomass component) and nutrient storage changed over the last century of fire exclusion in a ponderosa pine/bunchgrass ecosystem; the implications of these changes for net primary production, decomposition and cycling; and whether partial restoration (thinning of post-settlement trees alone) differs from complete restoration (thinning, forest floor manipulation and prescribed burning) in its effects on ecosystem structure and function. Preliminary results have been encouraging. The combination of thinning and burning has changed forest structure from fire behavior fuel model 9 (in which crown fires are common), to fuel model 2, in which surface fires occur but crown fires are highly improbable. Implementation of the research treatments on an operational scale are discussed briefly.
Covington, W., Fule, P., Moore, M., Hart, S., Kolb, T., Mast, J., Sackett, S. and Wagner, M. (1997). Restoring ecosystem health in ponderosa pine forests of the southwest. Journal of Forestry, 95(4): 23-29.