Land and Ecosystem Management
The National Fire and Fire Surrogate Study
Location of study sites of the National Fire and Fire Surrogate study.
Frequent, low-intensity fires have historically been a common feature in many dry forests throughout the United States. Today, largely owing to fire suppression, many of these fire-dependent forests contain significantly more small trees and fewer large trees than occurred under the natural fire regime. These altered conditions increase the probability of unnaturally severe wildfires, susceptibility to uncharacteristic insect outbreaks, and drought-related mortality. Restoration of these forests is a critical priority for forest managers throughout the country. Unfortunately, little information exists regarding the effectiveness or ecological consequences of commonly used restoration strategies. In response, a national research program, called the Fire and Fire Surrogates (FFS) study, was started to conduct innovative, operational-scale experiments to evaluate restoration treatments at 12 sites distributed across the United States.
One of the 12 sites was in northeastern Oregon on the Wallowa-Whitman National Forest. This area is dominated by stands of ponderosa pine and Douglas-fir. Understory vegetation is dominated by relatively few shrubs and graminoids. Soils are formed from weathering of the basaltic parent rock, and from accumulated or redeposited volcanic ash and wind-blown loess. The study site was first logged in the early 20th century and as recently as 1986. Fires were excluded since the early 1900s. The area has been grazed most years.
Pretreatment stand structure in a representative stand of the
national Fire and Fire Surrogates study in northeastern Oregon.
Mechanical treatments were conducted in 1998; selected trees were felled, limbed, and bucked with single-grip harvesters, yarded with forwarders, and residue left on site in designated corridors. Prescribed underburns were conducted in the fall of 2000 by using strip head fires. Pretreatment data were collected in 1998, and posttreatment data collected through 2006.
Wallowa Valley Ranger District, Wallowa-Whitman National Forest Service
James McIver, Eastern Oregon Agriculture Research Center
- Thinning and the combination of thinning and burning reduced the density of live overstory trees, whereas burning and the combination of thinning and burning reduced the density of small-diameter trees.
- No treatment fully met the restoration goals; the combination thin and burn was the only treatment that reduced tree density below the threshold where serious mortality from bark beetles might be expected.
The same stand in 2004, after thinning and broadcast underburning.
- No single application of prescribed burn or thinning treatment fully restored ecosystem structure and function within the dry forests of this study that had been removed from their natural fire regime over the past century.
- Structural equation modeling showed that the probability of latent mortality of ponderosa pine is related to insect species, fire severity, fuel accumulation, and treatments that influence fuel sizes. Traditional variance partitioning and univariate models rarely account for this whole-system approach in experimental studies.
- A synthesis across seven Western United States fire-prone, low-elevation dry forest, based on meta-analysis of fuel reduction and restoration treatment responses, indicated that the active treatments were effective in shifting diameter distributions toward larger trees, yet no single treatment or entry was sufficient to mitigate structural changes resulting from nearly a century of fire exclusion.
Youngblood, A.; Metlen, K.; Knapp, E.; Outcalt, K.; Stephens, S.; Waldrop, T.; Yaussy, D. 2005. Implementation of the Fire and Fire Surrogate study, a national research effort to evaluate the consequences of fuel reduction treatments. In: Peterson, C.E.; Maguire, D.A., eds. Balancing ecosystem values: innovative experiments for sustainable forestry: proceedings of a conference. Gen. Tech. Rep. PNW-GTR-635. Portland, Oregon. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 315-321.
Youngblood, A.; Metlen, K.L.; Coe, K. 2006. Changes in stand structure and composition after restoration treatments in low elevation dry forests of northeastern Oregon. Forest Ecology and Management. 234: 143-163.
Youngblood, A.; Bigler-Cole, H.; Fettig, C.J.; Fiedler, C.; Knapp, E.L.; Lehmkuhl, J.F.; Outcalt, K.W.; Skinner, C.N.; Stephens, S.L.; Waldrop, T.A. 2007. Making fire and fire surrogate science available: a summary of regional workshops with clients. Gen. Tech. Rep. PNW-GTR-727. Portland, Oregon. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station.
Forwarder with boom used to yard logs at the national Fire and Fire Surrogate
study site in northeastern Oregon.
Youngblood, A.; Wright, C.; Ottmar, R.; McIver, J. 2008. Changes in fuelbed characteristics and resulting fire potentials in dry forests of the Blue Mountains, northeastern Oregon. Forest Ecology and Management. 255: 3151-3169.
PNW Station Science Findings,Issue 106 / September 2008. Fuel reduction and forest restoration treatments: once is not enough.
Youngblood, A.; Grace, J.; McIver, J. 2009. Delayed conifer mortality after fuel reduction treatments: interactive effects of fuel, fire intensity, and bark beetles. Invited Feature Article, Ecological Applications. 19: 321-337.
Youngblood, A. 2010. Thinning and burning in ponderosa pine forests of the West: effectiveness in altering diameter distributions. Special Issue, Forest Science. 56: 46-59.
McIver, J.; Erickson, K.; Youngblood, A. 2012. Principal short-term findings of the national Fire and Fire Surrogate study. USDA For. Serv. Gen. Tech. Rep. PNW-GTR-860. Portland, Oregon. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 210 p.
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