Area burned in the western United States is unaffected by recent mountain pine beetle outbreaks

• DOI: 10.1073/pnas.1424037112
• Publication Date: 2015-03-24T03:17:43Z
• Authors: Sarah J. Hart; Tania Schoennagel; Thomas T. Veblen; Teresa B. Chapman
• Keywords: 0106 biological sciences; Geography; Temperature; Forests; 15. Life on land; Pinus; 01 natural sciences; Fires; United States; 6. Clean water; Disease Outbreaks; Droughts; Trees; Coleoptera; 13. Climate action; Animals; 0105 earth and related environmental sciences

SignificanceAcross western North America, abundant susceptible pine hosts and a suitable climate during the early 21st century have promoted widespread mountain pine beetle (MPB) outbreaks, leading to concern that dead fuels may increase wildfire risk. The assumption that outbreaks raise fire risk is driving far-reaching policy decisions involving expenditures of hundreds of millions of dollars. Contrary to the expectation that an MPB outbreak increases fire risk, spatial overlay analysis shows no effect of outbreaks on subsequent area burned during years of extreme burning across the West. These results refute the assumption that increased bark beetle activity has increased area burned; therefore, policy discussions should focus on societal adaptation to the effects of the underlying drivers: warmer temperatures and increased drought.