In western Canada, the operational risk rating system for mountain pine beetle is based on biological knowledge gained from a rich legacy of stand-scale field studies. Owing to the large spatial and temporal extents of the current epidemic, new research into large-area mountain pine beetle processes has revealed further insights into the landscape-scale characteristics of beetle infested forests. This research evaluates the potential for this new knowledge to augment an established system for rating the short-term risk of tree mortality in a stand due to mountain pine beetle.--Publisher's website.

The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a significant agent of tree mortality in lodgepole pine (Pinus contorta Dougl. ex Loud.) forests throughout western North America. A large outbreak of mountain pine beetle caused extensive tree mortality in north-central Colorado beginning in the late 1990s. We use data from a network of plots established in 2006-2007 on the Sulphur Ranger District of the Arapaho and Roosevelt National Forests to develop simple probability of infestation and extent of mortality models using classification and regression trees, respectively. A classification tree indicated that when live lodgepole pine basal area was equal to or greater than 59.3 ft2/acre pre-outbreak, the probability of infestation increased. A second classification tree added lodgepole pine mean diameter as a second splitting variable. The rate of correct classification for both models was greater than 0.79. Two regression trees also used live pre-outbreak lodgepole pine basal area as a splitting variable and indicated increasing basal area killed with increasing live lodgepole pine basal area. These simple models use readily available data from forest inventories and can be used to identify stands, based on forest stand conditions, where mountain pine beetle is more likely to occur and the potential extent of lodgepole pine tree mortality should an outbreak occur.

Two empirical methods for rating susceptibility of mountain pine beetle attack in ponderosa pine were evaluated. The methods were compared to stand data modeled to objectively rate each sampled stand for susceptibly to bark-beetle attack. Data on bark-beetle attacks, from a survey of 45 sites throughout the Colorado Plateau, were modeled using logistic regression to estimate the probability of attack on individual trees from tree and stand variables. The logistic model allowed flexibility to easily scale results up to a stand level for comparison to the empirical methods. The empirical method, developed by Munson and Anhold, most closely correlated to the logistic regression results. However, the Munson/Anhold method rated all 45 study sites as either moderately or highly susceptible to bark-beetle attack, which raises concern about its lack of sensitivity. Future work on evaluating risk of bark-beetle impact should consider more than stand characteristics.

Years of drought and decades of aggressive fire exclusion have left North American forests at high risk for future catastrophic fires. Forest settings are a magnet for recreational opportunities and for rapidly growing residential developmentputting an increasing number of citizens and their property into the path of wildfires. Recordsetting wildfires initiated the twentyfirst century and motivated the rise to prominence of wildfire on the political agenda, prompting important and farreaching new public policy initiatives. To be effective, these policies must be informed by sciencebut that requires more than just improved knowledge about the physical and biological dynamics of fire and forest ecosystems. Social values, socioeconomic factors, demographic trends, institutional arrangements, and human behavior must also be taken into consideration by the agencies and individuals responsible for wildland fire decision making. The first book to integrate the social science literature on the human dimensions of wildfire, People, Fire, and Forests reviews current studies from this broad, interdisciplinary field and synthesizes them into a rich body of knowledge with practical management implications. Chapters in the book highlight principal findings and common threads in the existing research and identify strengths and gaps. They cover such topics as public perception of wildfire risk, acceptability of fire management policies, and community impacts of wildfire. Designed to make relevant social science information more available and useful to wildfire risk managers and policy makers, People, Fire, and Forests is also intended to encourage and guide further research into wildfire. By exploringthe theoretical and methodological issues surrounding human interactions with wildfire and describing the practical implications of this research, this volume provides an essential resource for students, scholars, and professionals.

This study is part of a series of research papers that explore the biological, social, and economic aspects of British Columbia's mountain pine beetle epidemic. The objective of this study is to compare two different approaches for calculating beetle pressure, and to assess the impact these approaches have on the subsequent calculation of risk ratings. To meet this objective, beetle pressure was calculated using the traditional distance-based model, as well as using an alternative density-based model, implemented with a Voronoi tessellation generated from helicopter-GPS point survey data of known beetle infestation locations.--Includes text from document.

Periodic diameter and basal area growth were determined for partially cut stands of lodgepole pine at five locations over approximately 10 year periods. After cutting, average diameters in the partially cut plots generally increased by 0.8 inches or more, while average diameter in the uncut controls increased by 0.6 inches or less. Diameter growth in the partially cut plots was generally significantly greater than diameter growth in the controls. Individual tree growth is discussed in relation to potential susceptibility to mountain pine beetle infestation. Basal area decreased in three of the four GSL (growing stock level) 40 stands because of windthrow. Basal area generally increased >1.0 ft 2 / acre/year in partially cut plots except in the GSL 40 stands with substantial windthrow and one GSL 100 with an Armillaria infection pocket. Basal area increases in the control plots ranged from 0.2 to 1.1 ft 2 /acre/year, although the one control with a BA growth rate of 1.1 ft 2 /acre/year had a relatively low initial BA. Data from the stands are employed in the susceptibility rating methods of Amman et al.(1977), Shore and Safranyik (1992),and Anhold et al. (1996 to determine stand susceptibility and the results discussed in terms of general applicability of these methods to partially cut stands. Basal area growth is used to estimate the length of time required for various stand densities to reach specific susceptibility thresholds for mountain pine beetle infestation. Several of the GSL 40 stands are not projected to reach the susceptibility thresholds in 100 years because of windthrow. Barring mortality 1%,GSL 80 stands are estimated to reach the basal area threshold of 120 ft 2 per acre in