Carbon storage responses of subalpine forests to mountain pine beetle outbreaks under current and altered climate regimes in western North America.

Principle Investigator: Daniel Kashian, Wayne State University, dkash@wayne.edu

Abstract:: Understanding how climate, disturbances, and carbon storage interact in subalpine forests is critical for assessing the role of this ecosystem in the global carbon budget under altered climate scenarios. Most research to date in western North American forests has focused on wildfire effects on carbon storage and net ecosystem productivity (NEP). The current extensive insect outbreak in this region, however, suggests that insects such as the mountain pine beetle are an important driver of carbon dynamics and may determine whether western landscapes are carbon sinks or sources. The overall objective of this study is to understand how mountain pine beetle outbreaks affect forest carbon storage at stand and landscape scales under multiple climate scenarios.

Location: This research will take place in the Greater Yellowstone Ecosystem, particularly Yellowstone National Park. The study location is ideal for post-outbreak carbon cycling research because of its current and historical outbreaks, relatively uniform background environmental conditions, and its relatively unmanaged forests following outbreaks and other disturbances.

Hypotheses: The proposed research will address the following questions:
1. How does carbon storage vary with forest stand development following a beetle outbreak?
2. How do beetle outbreak extent, frequency, and post-outbreak stand development patterns interact
to influence carbon storage at landscape scales?
3. What is the potential for climate change over the next 50-100 years to strengthen the feedback between beetle outbreaks and climate?

Methods: Research questions will be addressed using a combination of field measurements, GIS, and modeling techniques:
Question #1: All important C components of stands will be measured along replicated post-outbreak
chronosequences to estimate post-outbreak NEP;
Question #2: Stand-level NEP estimates will be scaled up to the YNP landscape within a GIS, and landscape NEP under current and experimental scenarios will be calculated;
Question #3: Future MPB outbreaks and their associated carbon dynamics in YNP will be modeled using a prognostic insect outbreak model, climate models, and an index of stand susceptibility.

Deliverables: This research will, for the first time, provide data documenting post-outbreak carbon dynamics under current and altered climate scenarios. These data will provide the basis for developing a carbon-based, ecological rationale for future outbreak management in western forests. Deliverables will include three peerreviewed journal articles, broad dissemination of these results at academic meetings, and two workshops for managers, policy makers, and the general public. Broader impacts include graduate and undergraduate student training in ecological research at an institution that will encourage the participation of underrepresented groups.


last updated: 28 February 2008 PLH