PS 31-185 - CANCELLED - Fire history reconstruction in the sky islands of Northern Sonora

Tuesday, August 9, 2011
Exhibit Hall 3, Austin Convention Center
Alexis A. Arizpe, School of Natural Resource and the Environment, University of Arizona, Tucson, AZ and Donald A. Falk, School of Natural Resources and the Environment, University of Arizona, Tucson, AZ

Reconstruction of fire history is a common application of dendrochronology in the Southwestern United States, but this technique is less common in Mexico. Northern Mexico and the Southwestern United States share biophysical and cultural characteristics that can act as variables that influence fire regimes. Both regions experience a bimodal precipitation regime dependent on the North American Monsoon and share similar forest vegetation associations. While human land use patterns have impacted forests in Northern Mexico much as they have in the Southwestern United States, a lack of widespread organized fire suppression means that these forests in Sonora have maintained many of the characteristics of historical forest structure and fire regimes. The similarities in these adjacent montane forest systems make the forests of northern Sonora an ideal location to examine 20th century fire regimes. We look at the role of both climate and land use history in determining these fire regimes.


 Fire scarred tree-ring samples were collected from three sites in Northern Sonora: Sierra Pan Duro, Sierra Los Ajos and Sierra de Bacadehuachi. Chronologies were created for each site and fire scars were used to analyze mean fire interval, fire seasonality, and common fire years. Composite mean fire intervals were calculated for each site, and compared to neighboring Madrean ecosystems. higher frequency lower severity fires have been recorded at all sites well into the 20th century. These sites provide an alternate 20th century fire history to the montane forest systems of the United States as well as an important baseline for ecosystem restoration and management.

Copyright © . All rights reserved.
Banner photo by Flickr user greg westfall.