Do thinning and/or burning treatments in western USA ponderosa or Jeffrey pine-dominated forests help restore natural fire behavior?

• Published in: Forest ecology and management Vol. 269; pp. 68 - 81
• Main Authors: Fulé, Peter Z., Crouse, Joseph E., Roccaforte, John Paul, Kalies, Elizabeth L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.04.2012; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; bulk density; burning; canopy; coniferous forests; fire behavior; forest thinning; Forestry; Fuel; fuel loading; Fundamental and applied biological sciences. Psychology; Meta-analysis; Pinus jeffreyi; Pinus ponderosa; stand basal area; stand density; Synecology; systematic review; Terrestrial ecosystems; United States; Wildfire; wildfires; United States; North America; America; Wildfire; Pinus ponderosa; Pinus jeffreyi; Fuel; Meta-analysis; Forest ecology; Natural; Burning; Metaanalysis; Restoration; Softwood forest tree; Gymnospermae; Forestry; Coniferales; Spermatophyta; Vegetation fire; Behavior; Coniferous forest
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2011.12.025

► Systematic review and meta-analysis of forest thinning and burning treatments. ► Pinus ponderosa and Pinus jeffreyi dense stands and high fuels, severe fires. ► Fifty four studies with quantitative data on treatments. ► Combined thinning+burning had the greatest effect. ► There are a number of qualifications to the findings. We carried out a systematic review and meta-analysis of the effects of forest thinning and burning treatments on restoring fire behavior attributes in western USA pine forests. Ponderosa pine (Pinus ponderosa) and Jeffrey pine (Pinus jeffreyi), with co-occurring species, are adapted to a disturbance regime of frequent surface fires, but extended fire exclusion and other factors have led to historically uncharacteristically dense stands and high fuel loadings, supporting high-severity fires. Treatments to begin to reverse these changes and reduce fuel hazards have been tested experimentally and observations of wildfire behavior in treated stands have also been reported. Using a systematic review methodology, we found 54 studies with quantitative data suitable for meta-analysis. Combined treatments (thinning+burning) tended to have the greatest effect on reducing surface fuels and stand density, and raising modeled crowning and torching indices, as compared to burning or thinning alone. However, changes in canopy base height and canopy bulk density were not consistently related to treatment intensity, as measured by basal area reduction. There are a number of qualifications to the findings. First, because it is not feasible to subject treated areas to severe fire experimentally, inferences about potential fire behavior rely on imperfect modeling techniques. Second, research has not been carried uniformly over the ranges of the pine forests, although we found no significant differences in treatment effects between regions or forest types. Overall, however, meta-analysis of the literature to date strongly indicates that thinning and/or burning treatments do have effects consistent with the restoration of low-severity fire behavior.