By Jane Nielson, SCCA Board Member, 12/2/17
“We live in an ecosystem which has evolved to burn,” notes Michael Gillogly, Pepperwood Preserve ranch manager, as he considers that much of the preserve’s 900 acres of grasslands were burned.
The October Tubbs wildfire is not a new phenomenon, it overlaps the 1964 Hanly fire, the 1996 Porter Creek fires, and north of Calistoga, the 1960 Morrison and 1982 Silverado fires. Outlines of the Pocket fire, north of Geyserville, and the Atlas fire in Napa and Solano Counties, replicate areas that had burned in 1960s, 1980s, 2008, and 2013 fires.
In Sonoma Valley, the huge Nuns fire covered more territory than older burns in that area, but only two 1960s–1990s fire zones lie outside its footprint. An exception is the great 2015 Valley fire, which burned from Cobb to south of Middletown, and largely affected lands that had gone untouched by fire for more than a half-century.
Similar conditions present for each of these fires over the last decade spotlight two clear elements: high temperature and high wind speed conditions. Early on October 9th, wind speeds up to 77 miles per hour were recorded on a hilltop in Napa County, close to the estimated origin of the Tubbs Fire.
These and other data suggest that hot fires are likely to sweep across areas of north-coast California on a semi-regular basis—perhaps with about a 30 or 40- year periodicity.
The lifestyles of indigenous people conformed better to this natural fire cycle: building smaller and simpler dwellings of lightweight materials, and moving village sites seasonally. Indigenous people also set fires in woodlands to keep forests open and accessible, and to encourage food and medicinal plant growth.
We now need to examine the likelihood that wildfire will always be a fact of life in Sonoma and neighboring Counties. Rising temperatures due to climate warming may increase the frequencies and the heat of cyclic fires.
Based on past fire frequencies and threats, fire researchers and local leaders need to study if and how American construction and living patterns might adapt to the natural cycle of fire in lands that may not be tamable. ◊