Climate effects on historical fires (1630–1900) in Utah
Citation
Stanley G Kitchen, Emily K Heyerdahl, Marc H Weber, and Peter M Brown, Climate effects on historical fires (1630–1900) in Utah: .
Summary
We inferred climate effects on fire occurrence from 1630 to 1900 for a new set of crossdated fire-scar chronologies from 18 forested sites in Utah and one site in eastern Nevada. Years with regionally synchronous fires (31 years with fire at 20% of sites) occurred during drier than average summers and years with no fires at any site (100 years) were wetter than average. Antecedent wet summers were associated with regional-fire years in mixed-conifer and ponderosa pine forest types, possibly by affecting fine fuel amount and continuity. NINO3 (an index of the El Nino-Southern Oscillation, ENSO) was significantly low during regional-fire years (La Ninas) and significantly high during non-fire years (El Ninos). NINO3 also was high during [...]
Summary
We inferred climate effects on fire occurrence from 1630 to 1900 for a new set of crossdated fire-scar chronologies from 18 forested sites in Utah and one site in eastern Nevada. Years with regionally synchronous fires (31 years with fire at 20% of sites) occurred during drier than average summers and years with no fires at any site (100 years) were wetter than average. Antecedent wet summers were associated with regional-fire years in mixed-conifer and ponderosa pine forest types, possibly by affecting fine fuel amount and continuity. NINO3 (an index of the El Nino-Southern Oscillation, ENSO) was significantly low during regional-fire years (La Ninas) and significantly high during non-fire years (El Ninos). NINO3 also was high during years before regional-fire years. Although regional fire years occurred nearly twice as often as expected when NINO3 and the Pacific Decadal Oscillation were both in their cool (negative) phases, this pattern was not statistically significant. Palmer Drought Severity Index was important for fire occurrence in ponderosa pine and mixed-conifer forests across the study area but ENSO forcing was seen only in southeastern sites. Results support findings from previous fire and climate studies, including a possible geographic pivot point in Pacific basin teleconnections at similar to 40 degrees N.
Published in International Journal Of Wildland Fire, volume 17, issue 1, on pages 28 - 39, in 2008.