Precipitation regime classification for the Mojave Desert: Implications for fire occurrence. (January 2016)

• Record Type: Journal Article
• Authors: Tagestad, Jerry; Brooks, Matthew; Cullinan, Valerie; Downs, Janelle; McKinley, Randy
• Is Part Of: Journal of arid environments. Volume 124(2016:Jan.)
• Page Start: 388
• Page End: 397
• Publication Date: 2016-01
• Subjects: Vegetation -- Seasonality -- Burn -- Lightning -- Climate -- Drought; Arid regions ecology -- Periodicals; Arid regions -- Periodicals; Écologie des régions arides -- Périodiques; Régions arides -- Périodiques; 577.54
• DOI: 10.1016/j.jaridenv.2015.09.002
• Languages: English
• ISSNs: 0140-1963

Abstract

Abstract: Long periods of drought or above-average precipitation affect Mojave Desert vegetation condition, biomass and susceptibility to fire. Changes in the seasonality of precipitation alter the likelihood of lightning, a key ignition source for fires. The objectives of this study were to characterize the relationship between recent, historic, and future precipitation patterns and fire. Classifying monthly precipitation data from 1971 to 2010 reveals four precipitation regimes: low winter/low summer, moderate winter/moderate summer, high winter/low summer and high winter/high summer. Two regimes with summer monsoonal precipitation covered only 40% of the Mojave Desert ecoregion but contain 88% of the area burned and 95% of the repeat burn area. Classifying historic precipitation for early-century (wet) and mid-century (drought) periods reveals distinct shifts in regime boundaries. Early-century results are similar to current, while the mid-century results show a sizeable reduction in area of regimes with a strong monsoonal component. Such a shift would suggest that fires during the mid-century period would be minimal and anecdotal records confirm this. Predicted precipitation patterns from downscaled global climate models indicate numerous epochs of high winter precipitation, inferring higher fire potential for many multi-decade periods during the next century. Highlights: Using spatial precipitation data we map four precipitation zones. Zonation is based on three precipitation seasons; winter, spring and summer. Most fires have occurred after wet winters in zones with summer precipitation. Blackbrush communities are impacted by fire out of proportion to its occurrence. Future climate models indicate more wet periods, suggesting more fires.