Impact of “defensible space” on wildlife and ecosystems

I have serious concerns about the suggestion that we embrace Firewise’s “defensible space” concept

Derek Churchill, one of our state’s foremost authorities on wildfire in forest ecosystems, makes many excellent points about wildfire risk in our region (“Understanding wildfire risk in Western Washington,” June 13). As Derek points out, the probability of wildfire in Western Washington, while increasing, is still very low. And I deeply appreciate that he urged us to reduce our carbon footprint if we want to address the impact of longer and drier summers and the concomitant risk to our western forests.

However, I have serious concerns about the suggestion that we embrace Firewise’s “defensible space” concept in Western Washington. Firewise’s focus is only on protecting human property and safety and fails to consider the impact of “defensible space” on wildlife habitat and other ecosystem functions. While we all value our safety, those of us who have chosen to live in or next to forests not only enjoy the beauty and quiet of such an ecosystem but have also, thoughtfully or not, assumed certain risks.

Clearing a 50- to 150-foot buffer in the forests around our houses, as Firewise suggests, would have a profound impact on these ecosystems. The area of a circle with a 150-foot radius around a point is a little more than 1.6 acres. If we multiply that figure by the number of homes in the woods on Vashon, large amounts of forestland would be transformed into non-forest. And if we apply this calculation to Western Washington as a whole, … well, you get the idea.

Implementing Firewise’s “defensible space” in Western Washington represents an extreme response to a low-probability event. It would be particularly harmful to do so now – at a time when wildlife species are facing unprecedented habitat loss and degradation, stresses that are only exacerbated by a warming planet.

—Jim Evans