Will Red Mountains lose their color?

Red Mountain is the name of two different Sonoma County peaks. One lies a couple miles west of Cloverdale and the other is in Sugarloaf Ridge State Park. Both are covered in chamise (Adenostoma fasciculatum) which is a type of chaparral, a plant community of shrubs adapted to dry summers and wet winters.

After chamise blooms, its white flowers dry up and darken to a reddish-brown, which turns the slopes of both Red Mountains a ruddy mosaic. It’s a subtle seasonal shift, but one that can easily be observed on many mountainsides at this time of year.

Red also suggests the intensity with which chamise burns. This is due to low moisture content and a concentration of an oily substance, which gives chamise its nickname, “greasewood.” One elder described chamise burning in a 1964 wildfire, as “just like an artillery barrage” with “fireballs 200 feet high.”

In the aftermath of such a fire, the blackened stems of chamise appear completely lifeless. Yet such burns are essential to its life cycle. Protected below ground, the root crown has buds that sprout after a fire. In addition, seeds in the soil are stimulated both by the fire’s heat and the chemicals leached from the burned stems with the fall of the first autumn rains.

Like the mythological phoenix, chamise is reborn from its own ashes. Just four years after burning like “an artillery barrage” in 1964, the chamise was back. Wildlife thrives on this new growth. Following a fire, deer populations can quadruple and jack rabbits increase by as much as a factor of 10.

Stands of chamise that haven’t burned for 30 or 40 years get overgrown and go into decline. Douglas firs and other trees begin sprouting in the shade below the chamise. Continued absence of fire allows these trees to overtop the chamise. Over the course of a century, a chamise patch can become a forest. In many places today, you can find dead and dying chamise on the forest floor, attesting to this long-term change.

Early surveyors recorded much more chaparral, which includes chamise and manzanita, than we have today. Many old survey maps have the notation “Chamizal Mountains,” the Spanish name for chamise. Studies suggest that chaparral cover in Sonoma County has shrunk by about one-third since the late 19th century, most of it replaced by forest.

Presumably, some of this shift is the result of fire suppression. With climate change now leading to more frequent and intense wildfires, this decline could reverse in coming decades. Will the name “Red Mountain” will still fit these landmarks a century from now? Only time will tell.