Fire History of the Gila Wilderness, New Mexico

TitleFire History of the Gila Wilderness, New Mexico
Publication TypeThesis
Year of Publication1983
AuthorsSwetnam, T
Academic DepartmentDepartment of Renewable Natural Resources
DegreeMaster of Science
Number of Pages156
UniversityUniversity of Arizona
Keywordscrossdate, dendrochronology, fire, fire history, fire scar, gila national forest, gila wilderness, new mexico, pinus ponderosa, ponderosa pine, tree ring

A data base of fire occurrence was established for the Gila Wilderness by analyzing fire scars and compiling fire records. Cross sections of 44 fire scarred ponderosa pine trees (Pinus ponderosa Laws.) were collected from three study areas. Crossdating of more than 800 individual fire scars revealed that extensive surface fires were a common occurrence prior to 1900. Mean fire intervals for a 250-year period prior to 1900 were approximately four to eight years and fire intervals ranged from one to 26 years. Intensive grazing and fire suppression efforts after 1900 resulted in a sudden decrease in number of fires recorded by the sample trees.A 72-year record (1909-1980) of fire occurrence in the Gila National Forest was compiled from Forest Service records. The fire records and fire scar evidence suggest a need for continued emphasis on fuels reduction and greater flexibility in the Prescribed Natural Fire program.