@article {13093,
	title = {Fuels and fire behavior dynamics in bark beetle-attacked forests in Western North America and implications for fire management},
	journal = {Forest Ecology and Management},
	volume = {275},
	year = {2012},
	month = {Jul 1},
	pages = {23-34},
	abstract = {Declining forest health attributed to associations between extensive bark beetle-caused tree mortality, accumulations of hazardous fuels, wildfire, and climate change have catalyzed changes in forest health and wildfire protection policies of land management agencies. These changes subsequently prompted research to investigate the extent to which bark beetle-altered fuel complexes affect fire behavior. Although not yet rigorously quantified, the results of the investigations, in addition to a growing body of operational experience, indicate that predictable changes in surface, ladder and canopy fuel characteristics do occur over the course of a bark beetle rotation. Input of these changes in fuel characteristics into conventional fire behavior modeling systems can readily provide predictions of potential fire behavior, including the likelihood of crowning. However, several factors limit the direct application of these modeling systems in their current form and consequently, they may largely under predict fire potential in such stands. This presents a concern where extreme fire behavior involving both crowning and spotting coupled with flammable fuel conditions can pose serious challenges to incident management and threaten the safety of firefighters and the general public alike. In this paper, we review the nature and characteristics of bark beetle-altered fuel complexes in the conifer forests of the Interior West and the challenges of understanding the effects on extreme fire behavior, including the initiation and spread of crown fires. We also discuss how emerging fire management plans in the U.S. have begun to integrate wildfire management and other forest health objectives with the specific goal of achieving biodiversity and ecosystem resiliency while simultaneously reducing the existence of hazardous fuel complexes. [copyright] 2012 Elsevier B.V. All rights reserved.},
	isbn = {0378-1127},
	author = {Jenkins, Michael J. and Page, Wesley G. and Hebertson, Elizabeth G. and Alexander, Martin E.}
}
@article {13091,
	title = {Bark beetles, fuels, fires and implications for forest management in the Intermountain West},
	journal = {Forest Ecology and Management},
	volume = {254},
	number = {1},
	year = {2008},
	month = {January 15},
	pages = {16-34},
	type = {Article},
	abstract = {Bark beetle-caused tree mortality in conifer forests affects the quantity and quality of forest fuels and has long been assumed to increase fire hazard and potential fire behavior. In reality, bark beetles, and their effects on fuel accumulation, and subsequent fire hazard, are poorly understood. We extensively sampled fuels in three bark beetle-affected Intermountain conifer forests and compared these data to existing research on bark beetle/fuels/fire interactions within the context of the disturbance regime. Data were collected in endemic, epidemic and post-epidemic stands of Douglas-fir, lodgepole pine and Engelmann spruce. From these data, we evaluated the influence of bark beetle-caused tree mortality on various fuels characteristics over the course of a bark beetle rotation. The data showed that changes in fuels over time create periods where the potential for high intensity and/or severe fires increases or decreases. The net result of bark beetle epidemics was a substantial change in species composition and a highly altered fuels complex. Early in epidemics there is a net increase in the amount of fine surface fuels when compared to endemic stands. In post-epidemic stands large, dead, woody fuels, and live surface fuels dominate. We then discuss potential fire behavior in bark beetle-affected conifer fuels based on actual and simulated fuels data. Results indicated that for surface fires both rates of fire spread and fireline intensities were higher in the current epidemic stands than in the endemic stands. Rates of spread and fireline intensities were higher in epidemic stands due, however, to decreased vegetative sheltering and its effect on mid-flame wind speed, rather than changes in fuels. Passive crown fires were more likely in post-epidemic stands, but active crown fires were less likely due to decreased aerial fuel continuity. We also discuss the ecological effects of extreme fire behavior. Information is presented on managing forests to reduce the impact of bark beetle outbreaks and the interplay between management, bark beetle populations, fuels and fire hazard and behavior. (C) 2007 Elsevier B.V. All rights reserved.},
	keywords = {Dendroctonus ponderosae, Dendroctonus pseudotosugae, Dendroctonus rufipennis},
	isbn = {0378-1127},
	author = {Jenkins, Michael J. and Hebertson, Elizabeth and Page, Wesley and Jorgensen, C. Arik}
}
@article {11997,
	title = {The influence of fallen tree timing on spruce beetle brood production},
	journal = {Western North American Naturalist},
	volume = {67},
	number = {3},
	year = {2007},
	month = {July},
	pages = {452-460},
	abstract = {This study compared brood production of the spruce beetle (Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae. Scolytinae)) in downed host material felled during summer and spring seasons on the Wasatch Plateau in south central Utah. Thirty-three matched pairs of Engelmann spruce (Picea engelmannii Parry ex Engelm.) trees were selected for study in spring 1996. One tree of each pair was cut during August 1996 (summer-felled) and the other tree was cut in early April 1997 (spring-felled), so that trees would be colonized by spruce beetles of the same flight period. Brood adults were collected and counted from bark samples, which were removed from the top, bottom. and sides of all sample trees in October 1998. The number of emergent adults produced in June 1999 was determined from exit holes counted in bark samples removed form these same locations. Mixed-model procedures were used to compare differences in the mean number of adults produced in summer-felled verus spring-felled trees in each year. The results indicated that significantly fewer spruce beetles were produced in summer-felled trees than in spring-felled trees. More brood adults were also present in, or emerged form, unexposed hole aspects (bottom, north, and east) of sample trees than exposed aspects (top, south and west). These finding suggest that disturbances providing spruce beetles with an abundance of fresh host material in the spring result in the greatest potential for spruce beetle production, particularly beneath unexposed bark aspects. Examples of such disturbances include snow avalanches, blowdown, and snow and ice damage.},
	keywords = {Dendroctonus rufipennis},
	isbn = {1527-0904},
	author = {Hebertson, Elizabeth G. and Jenkins, Michael J.}
}
@article {11998,
	title = {Climate factors associated with historic spruce beetle (Coleoptera: Curculionidae) outbreaks in Utah and Colorado},
	journal = {Environmental Entomology},
	volume = {37},
	number = {2},
	year = {2008},
	month = {April},
	pages = {281-292},
	type = {Article},
	abstract = {This study investigated relationships between climate and historic spruce beetle, Dendroctonits rufipennis Kirby (Coleoptera: Curculionidae), outbreaks in northern and southeastern Utah and western Colorado between 1905 and 1996. A chronology of outbreak years was constructed from historic records, research papers, newspapers, and other sources of information. Historic climate data for the region included annual and mean monthly temperature and precipitation, in addition to Palmer drought severity index (PDSI) values estimated from tree rings. Classification and regression tree analysis (CART) was used to identify those climate factors most important for predicting historic spruce beetle outbreaks. The factors identified by the best CART model included mean December temperature, mean September temperature 1 yr before outbreak years, the mean estimated PDSI value of the 5-yr period before outbreak years, and mean October precipitation. The resulting model correctly classified nonoutbreak and outbreak years 67 and 70\% of the time, respectively.},
	keywords = {Dendroctonus rufipennis},
	isbn = {0046-225X},
	author = {Hebertson, Elizabeth G. and Jenkins, Michael J.}
}
