USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Drought stress and bark beetle outbreaks in the future forest: extending an existing model to inform climate change adaptation

Principal Investigators:
Robert Scheller, Portland State University
Louise Loudermilk, USDA Forest Service-Southern Research Station
Matthew Hurteau, Pennsylvania State University
Peter Weisberg, University of Nevada-Reno

Proposal [pdf]

Final Report [pdf]

Please contact Dr. Robert Scheller with questions regarding the report.

Project Summary:

This project used an existing modeling framework (developed for the SNPLMA Round 10 project “Management options for reducing wildfire risk and maximizing carbon storage under future climate changes, ignition patterns, and forest treatments,” Loudermilk et al. 2012) of forest landscape processes (wildfires, climate change, succession, and fuel treatments) to include effects from drought and bark beetle outbreaks.

The Round 10 project evaluated climate change effects on net ecosystem carbon balance (Loudermilk et al. 2013), as well as a suite of fuel treatment scenarios to assess treatment effectiveness for reducing wildfire carbon emissions and maximizing total landscape C storage (Loudermilk et al. 2014). This project (Round 12), integrated the effects of drought and insects into the estimates of carbon dynamics and tree community response and feedbacks over the next 100 years, examined model accuracy of forest productivity (i.e., ANPP) with empirical estimates, and examined fuel treatment effectiveness for mitigating the effects from the interacting disturbances, i.e., climate (including drought), wildfires, and bark beetle outbreaks.

The primary objectives were to evaluate climate change effects associated with drought stress (reduced forest productivity), bark beetle outbreaks, and management mitigation options across the forested landscape of the Lake Tahoe Basin. In addition, in situ estimates of scaled ANPP from tree-ring data were compared with model outputs across a coincident 20-year period (1987-2006) climate to investigate model accuracy of forest productivity, as influenced by moisture sensitivity and bark beetle outbreaks.

This research leveraged the spatial data, model parameterization, and analysis for the Round 10 project, while incorporating drought-impact growth estimates from site-level data collected from the Round 9 SNPLMA project, “Modeling the influence of management actions on fire risk and spread under future climatic conditions,” (Hurteau et al. 2014).