WWETAC Projects

Project Title: Fire, bark beetles and salvage logging in the Greater Yellowstone Ecosystem

Status: Ongoing

Principal Investigators: Monica G. Turner, Department of Zoology, Birge Hall, University of Wisconsin; Kenneth F. Raffa, Department of Entomology, Russell Labs, University of Wisconsin; Jacob A. Griffin, Department of Zoology, Birge Hall, University of Wisconsin; Erinn Powell, Department of Entomology, Russell Labs, University of Wisconsin; Martin Simard, Department of Zoology, Birge Hall, University of Wisconsin.

E-mail Contact: Monica G. Turner, turnermg[at]wisc.edu

Other E-mail Contacts:
Ken Raffa, raffa[at]entomology.wisc.edu
Martin Simard, simard[at]wisc.edu
Jake Griffin, jgriffin2[at]wisc.edu
Erinn Powell, epowell2[at]entomology.wisc.edu

Study Objectives and Goals: Forest managers are increasingly interested in how potential wildfire risk changes after bark beetle epidemics. Forest Service efforts to examine this question with the Forest Vegetation Simulator modeling system have been frustrated by the lack of reference data to validate observed modeling outcomes. Real-world data are needed to advance the modeling environment and enhance predictive capacity. A reasonable modeling system in FVS would allow managers to examine potential mitigation options for beetles, wildfire, and the interactions between these threats. One aspect that strongly influences the long-term outcome of the beetles on fire behavior is the rate of forest regeneration. The effects of post-disturbance management (e.g., salvage logging) on tree regeneration and subsequent fire risk is also a key unknown. Data on the effects of post-disturbance management would be immediately useful to forest managers and would also be important for improving the predictive capabilities of models. We will help address these needs by providing field data from the Greater Yellowstone Ecosystem (GYE) located in the northern Rockies, primarily in Wyoming and Montana. The GYE has a natural crown-fire regime with long fire-return intervals (150 to 300 years), and it is currently experiencing extensive outbreaks of three bark beetles (mountain pine beetle (MPB), spruce beetle, and Douglas-fir beetle). Thus, it serves as an excellent natural laboratory in which to study fire-beetle interactions. Our field studies will be located primarily in Bridger-Teton National Forest and Yellowstone National Park.

(1) We will evaluate fire risk in response to current and historical outbreaks of bark beetles in the GYE by conducting field studies to evaluate fuels and local environmental conditions (temperature and moisture) within stands of differing time-since-beetle attack. We will also determine whether fire-damaged lodgepole pine (Pinus contorta Dougl. ex Loud.) trees are more likely to be attacked by MPB. The majority of the data collection is funded through an award from the Joint Fire Sciences Program. However, we will augment the ongoing study by adding measurements of how microclimate changes immediately after beetle attack and in subsequent decades. We expect temperature and moisture conditions to vary with the beetle-caused changes in stand structure and regeneration and to influence nutrient availability, which, in turn, should relate to regeneration rates. The among-stand variation in fuels and environmental conditions is also expected to influence fire behavior during “normal” dry years, although not during extreme years such as 1988. Current fire models, including FVS, include fine-fuel moisture as an important component of fire spread and intensity, which in turn influence probability of crowning.

(2) We initiated field studies during summer 2007 to quantify effects of post-beetle salvage logging on stand structure, regeneration, fuel loading, and nutrient availability in lodgepole pine forests in the Green River vicinity of the Bridger-Teton National Forest. Within the beetle-killed areas, we collected presalvage data in June 2007 from 10 stands that are scheduled to be salvage logged and 10 comparable stands that will not be salvage logged (total n = 20). In each stand, we measured tree mortality and regeneration; surface and crown fuels; serotiny level; and soil nutrients, nitrogen availability, temperature and moisture. The national forest staff provided the polygons of the salvage locations that are being put out for sale, and they anticipate that logging will occur in summer 2008. All stands were permanently marked in 2007 and will be resampled during summer 2008 (with the plan to continue these measurements in subsequent years) after the salvage treatment.

If time and subsequent resources permit, we may implement a comparable field study of salvage logging in nearby sites that were affected by stand-replacing fire during summer 2006.


(1) A short but highly relevant annotated bibliography of key references and synthesis of fire and beetle interactions with a focus on forest management will be developed for posting on WWETACs Web site.
Due date: 15 January 2008.

(2) An interim report on the post-beetle salvage study will summarize the pre-salvage conditions in the 20 stands that were sampled in June, 2007.
Due date: 15 March 2008.

(3) We will participate in teleconferences with WWETAC staff to provide scientific information regarding ecological effects of bark beetles and fire and their interactions.
Due date: as requested.

Web sites:

Turner lab research: http://landscape.zoology.wisc.edu/Research.html

Raffa lab research: http://entomology.wisc.edu/%7Eraffa/Research/programs.html


See related WWETAC project: Evaluating interactions between insect infestations and fire extent and fire severity: A preliminary investigation in Washington and Oregon


Project ID: FY07BK33