Carbon Storage Responses of Subalpine Forests to Mountain Pine Beetle Outbreaks Under Current and Altered Climate Regimes in Western North America.

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 (MPB) 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 therefore to understand how MPB outbreaks affect forest carbon storage at stand and landscape scales under multiple climate scenarios. Specific objective include examining how carbon storage changes with stand development following beetle outbreaks, how variability in outbreak extent, frequency, and post-outbreak stand development affect landscape-scale carbon storage, and how beetle outbreaks and climate interact. 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.  INTRODUCTION