Human impacts on the landscapes of the American Southwest increased significantly in response to the arrival of the railroad in the late 1800s. Higher elevation ponderosa pine forests along the routes were especially attractive to ranchers and herders for the greater moisture, cooler wealther and abundant grasses available to their livestock.
These early settlers saw no benefit to the frequent low intensity fires that consumed forest grasses. A reduction in ecosystem fire that began in the 1880s occurred at about the same time that livestock grazing levels increased substantially.
Loggers cut as many mature trees as they could, and soon began to worry about the sustainability of the forest. But good precipitation in the second decade of the 20th century led to a series of ponderosa regeneration pulses, and the dense thickets that we still see today sprang into being.
The suppression of low-intensity fire continued through the 20th century. Smokey Bear's fire prevention message took on special urgency when tinder-dry conditions accompanied periods of severe drought. Unchecked road building, fixed land ownership patterns, and questionable forestry practices all contributed to today's dangerous fire conditions.
Kessell, John L. 2002. Spain in the Southwest: A Narrative History of Colonial New Mexico, Arizona, Texas, and California. University of Oklahoma Press, Norman, 480 pp.
Langston, Nancy. 1995. Forest Dreams, Forest Nightmares: The Paradox of Old Growth in the Inland West. University of Washington Press.
Sheridan, T. E. 1995. Arizona: A history. University of Arizona Press, Tucson, 434 pp.
Wilkinson, C. F. 1999. Fire on the plateau: Confict and endurance in the American Southwest. Island Press/Shearwater Books, Washington, D.C., 402 pp.
Last edited June 6, 2003