WWETAC Projects

Project Title:  Impacts of bark beetles on ecosystem values in western forests:  A synthesis

Principal Investigator:   John E. Lundquist; Pacific Northwest Research Station and Region 10 Forest Health Protection, Anchorage, Alaska


Collaborators:   The Western Bark Beetle Research Group comprising all U.S. Forest Service bark beetle scientists in the western U.S. Some additional professionals from FHTET and FHP will also participate.  Within this mix there is a wide variety of expertise represented, including insect and disturbance ecology, bark beetle biology, climate change effects, chemical ecology, genetics, landscape ecology, population dynamics and damage modeling, and non-timber valuation.

Key Issues/Problem Addressed:     

Pest impact assessment was a ‘hot topic’ a decade or two ago, but few recent research advances have been made within this topic.  Yet, the need for estimates of potential pest impacts has never been greater.  The economic loss that has resulted from recent bark beetle outbreaks in the western United States and Canada can be quantified/estimated only with great difficulty, if at all.  Demands for sustainable management of water, recreation, wildlife habitat, and other non-timber ecosystem services continue to increase, and the ecological and socioeconomic impacts of insect outbreaks, diseases, and invasive plants have become increasingly complex.  Not all impacts are negative.  In fact, some impacts are important in sustaining ecosystems.  Furthermore, different human communities react differently to the same types and levels of forest disturbance.  Most currently used assessment, costing, and valuation methods of pest impacts are based on timber production.  Many new insights and valuation techniques have been developed for non-timber resources, but few of these have been adapted for pest impact assessments.  The challenge is to adapt these techniques to forest insect pest assessment and invent not only new techniques, but also new ways of communicating new concepts and approaches associated with them.  A synthesis linking this information is greatly needed.

Setting and Approach:  

Although basic outbreak dynamics and impacts of some bark beetle species have been described, characterizing and quantifying these impacts on ecosystem functions and services remains a significant challenge. The range of ecosystem services and resources impacted by bark beetles is wide and diverse, but most pest impact assessments and valuations are still based on timber production.  New information has been generated that addresses the wider range of impacts on non-timber services and resources but much of it remains scattered in the literature and databases pertaining to individual insect species.  Quantifying the various kinds of impacts on different resources may require different metrics. 

We will review and synthesize the literature involving currently used pest assessment methods, including monitoring and survey methods, summary analyses, valuation procedures, reporting metrics and standards and error and accuracy estimation.   This review will encompass most major bark beetle pests in the western USA.  At least one bark beetle system will be selected as a test case to display bark beetle impact using the profiling method as it varies in space using spatial models.  We will go one step further and examine the potential for adapting current methods of financial valuation (viz., discounted cash flow and real options analyses).  This case study should highlight strengths and weaknesses of current assessment and valuation techniques with an emphasis on spatial applications. 

Progress to Date:

A rough draft synthesis of the impacts of bark beetles partitioned by ecosystem service was completed.  Six case studies were included: western pine beetle in southern California by Chris Fettig (PSW Res Stn), mountain pine beetle in Colorado by Jose Negron (RMRS Res Stn), Douglas fir beetle in the northern Rockies by Rob Progar (PNW Res Stn), pest complexes involving subalpine fir engraver in the Sky Islands of Arizona by Ann Lynch (RMRS), walnut twig beetle by Steve Seybold (PSW), and spruce beetle on the Kenai Peninsula by John Lundquist (PNW and R10 FHP).  These cases studies are being integrated with an earlier contribution describing current status of valuation of non-timber resources by Dan MacCollum (RMRS).  Still lots of work needed on filling in less complete case studies, balancing among them and editing. 


Our aim is to stimulate a renewed interest in a vital subject that in our opinion has laid mostly dormant for much too long.  We hope that this effort serves as a framework for the development and discovery of new techniques of assessing and communicating western bark beetles impacts that are more in tune with current socioeconomic and ecological values.

WWETAC ID:      FY11NG95