IJWF Publishes Special Ecology Issue

The International Association of Wildland Fire has released a special issue of the International Journal of Wildland Fire on fire climatology, based on presentations at the Third International Fire Ecology and Management Congress in 2006. Guest editors for this special issue are Tom Swetnam and Scott Anderson, who wrote the introduction, “Fire Climatology in the Western United States.”

A defining feature of the issue are papers presenting both the modern and palaeofire perspectives, working with a broad range of data over a range of temporal and spatial scales. There were three themes: modern fire climatology from documentary records, palaeofire climatology from tree rings and fire scars, and palaeofire climatology from sedimentary charcoal and pollen. These themes provide contrasting or complementary insights about fire regime changes and responses to climate. Articles include:

Temporal and Spatial Structure in a Daily Wildfire-Start Data Set from the Western United States (1986-96), by P.J. Bartlein, S.W. Hostetler, S. L. Shafer, J.O. Holman and A.M. Solomon. Daily fire-start records from the western United States exhibit considerable temporal and spatial structure. Lightning-caused fires display greater intra- and inter-annual variability than human-caused fires, reflecting the influence of prevailing weather and climate, while human-caused fires display a close association with population centers, transportation corridors, and outdoor activity areas.

Evaluating Predictive Models of Critical Live Fuel Moisture in the Santa Monica Mountains, California, Philip E. Dennison, Max A. Moritz and Robert S. Taylor. Fire history data was used to determine potential critical live fuel moisture thresholds, below which large fires become more likely. Spring precipitation was found to be the best predictor of the timing of two potential thresholds at 71% and 77% live fuel moisture.

Climate Effects on Historical Fires (1630-1900) in Utah, by Peter M. Brown, Emily K. Heyerdahl, Stanley G. Kitchen and Marc H. Weber. New fire-scar chronologies from 19 sites in Utah and Nevada provide the first assessment of historical climate effects on wildfires in this region. Data confirm the importance of fire-season drought and the role of Pacific Ocean teleconnections, and suggest north-south variation in the effects of El Niño-Southern Oscillation.

Climate Drivers of Regionally Synchronous Fires in the Inland Northwest (1651-1900), by Emily K. Heyerdahl, Donald McKenzie, Lori D. Daniels, Amy E. Hessl, Jeremy S. Littell and Nathan J. Mantua. In the past, spring and summer were warm and summers were warm and dry when surface fires burned synchronously in dry forests across interior Oregon, Washington and southern British Columbia. Coincident warm phases of El Niño-Southern Oscillation and Pacific Decadal Oscillation also favored warm and dry conditions that led to synchronous fires in this region.

Variability in Fire — Climate Relationships in Ponderosa Pine Forests in the Colorado Front Range, by Rosemary L. Sherriff and Thomas T. Veblen. Differences in fire-climate relationships were examined in low- versus high-elevation ponderosa pine forests. Below 2,100 meters, fires were dependent on moist conditions prior to dry fire years. Above 2,100 meters, fires were dependent primarily on drought. Regional fire years were associated with drought and the interactions of El Niño-Southern Oscillation, Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation.

Climatic Influences on Fire Regimes in Montane Forests of the Southern Cascades, California, by A.H. Taylor, V. Trouet and C.N. Skinner. This study identifies the relationships between climate variability and fire occurrence and extent in the southern Cascades before the onset of organized fire suppression in 1905. Widespread burning occurred mainly in warm dry years but fire-climate relationships were not stable over the period from 1700-1900.

Long-Term Relations Among Fire, Fuel, and Climate in the Northwestern U.S. Based on Lake-Sediment Studies, by Cathy Whitlock, Jennifer Marlon, Christy Briles, Andrea Brunelle, Colin Long and Patrick Bartlein. Pollen and high-resolution charcoal records from 15 sites across the northwestern United States provide information on late-glacial and Holocene fire and vegetation history. The data suggest that past fire activity was closely linked to changing climate and fuel conditions, and fire frequency was highest during periods of drought. Variability in the timing and duration of fire maxima points to the importance of local and sub-regional controls on fire occurrence and highlights the need for a network of long fire-history records to reconstruct regional patterns.

Long-Term Fire History from Alluvial Fan Sediments: The Role of Drought and Climate Variability, and Implications for Management of Rocky Mountain Forests, by Jennifer Pierce and Grant Meyer. Alluvial fan deposits preserve millennial-length records of fire. We used these records to examine changes in fire over the last 2,000 years in Yellowstone National Park mixed-conifer forests and drier central Idaho ponderosa pine forests. Severe fires occurred in both areas during past intervals of drought and increased climate variability.

Holocene Vegetation and Fire Regimes in Subalpine and Mixed Conifer Forests, Southern Rocky Mountains, by R.S. Anderson, C.D. Allen, J.L. Toney, R.B. Jass and A.N. Bair. They examined pollen and charcoal from sediments in the southern Rocky Mountain lakes and bogs to determine climate, vegetation change and fire history during the post-glacial period. Fires were most common between 12,000 to 9,000, and 2,000 to 1,000 years ago. The lack of fire due to suppression during the 20th century is an anomaly.

Paired Charcoal and Tree-Ring Records of High-Frequency Holocene Fire from Two New Mexico Bog Sites, by Craig D. Allen, R. Scott Anderson, Renata B. Jass, Jaime L. Toney and Christopher H. Baisan. Bog charcoal and tree-ring fire records show replicate sediment cores can reproduce key charcoal patterns, despite complications with bog sediments; fire scars and charcoal both document an unusual lack of fire since about 1900; and charcoal records probably underestimate fire event recurrence at these high-frequency fire sites.

The issue concludes with two general wildland fire research papers:

Long-Term Impacts of Prescribed Burns on Soil Thermal Conductivity and Soil Heating at a Colorado Rocky Mountain Site: A Data/Model Fusion Study, by W.J. Massman, J.M. Frank and N.B. Reisch. Observational evidence indicates that prescribed burns alter the thermal conductivity of soils to a depth of at least 0.20 meters without altering its bulk density. Model data fusion results suggest that soil thermal energy flow can be affected for several months to years following the fire and that these effects propagate to depths exceeding one meter.

Estimating Crown Fuel Loading for Calabrian Pine and Anatolian Black Pine, by Ömer Küçük, Ertugrul Bilgili and Bülent Saglam. This paper presents the results of a study conducted to predict above-ground fuel loading for calabrian and Anatolian black pine. Regression equations, developed from a total of 418 destructively sampled calabrian and anatolian black pine trees and saplings, were able to effectively predict foliage, fine branch, medium branch, active fuels, thick branch, and total fuel loading.

April 29-May 2: The IAWF will co-sponsor of the Third International Symposium on Fire Economics, Planning and Policy: Common Problems and Approaches to be held in Carolina, Puerto Rico. Visit www.fireeconomics.com.

Sept. 22-27: The International Association of Wildland Fire in association with the Ninth Biennial Scientific Conference on the Greater Yellowstone Ecosystem will sponsor “The Fires of '88: Yellowstone and Beyond” to remember the events of the Yellowstone-area fires of 1988. The conference will be held in Jackson Hole, Wyo. These history-making fires will provide springboards for discussions and presentations about lessons learned, fire effects, large-fire management, policy, research related to the fires, the use of fire as a management tool, and many other issues. Go to www.iawfonline.org/yellowstone for a flyer on this event. This event also will host the IAWF's annual membership meeting — time and place to be announced.

The IAWF presented its Managers Award for Relevant Research to Dr. J.D. Carlson from Oklahoma State University at the Seventh Symposium on Fire and Forest Meteorology. Carlson was honored for his presentation, “Field Validation of PB Piedmont,” co-authored by Dr. Gary Achtemeier of the U.S. Forest Service Southern Research Station. This presentation and many others from the symposium can be found at http://ams.confex.com/ams/7firenortheast/techprogram/programexpanded_430.htm