Mark Schaeffer, thanks for bringing up Davis’ book. He makes some excellent points, however the concept that old-growth chaparral is “overgrown” and creates areas choked by vegetation is based on some seriously flawed notions about the chaparral ecosystem.
I addressed the Native American burning question earlier so I won’t repeat what I said here. So let’s think about what it means to make the chaparral more hospitable for game animals by presumably getting rid of the “overgrowth” and encouraging herbaceous plants.
After a fire, the chaparral will form another closed canopy within 6 to 10 years depending on rainfall. In order to prevent canopy re-closure (what some would call “overgrowth”), the fire return interval would need to be less than 10 years. This would quickly convert chaparral to non-native weedlands, an ecological disaster that has already occurred due to repeated fires along most of the front country in the Angeles and San Bernardino National Forests. In fact, one of the reasons for the extensive loss of habitat has been the elimination of native shrublands due to excessive fires.
Chaparral by definition is a dense shrubland. It is supposed to be thick and impenetrable. Shrubs grow. It’s a natural process, not a by-product of our efforts to suppress fires. The benefits native herbivores obtain from any post-fire flush of new growth will be temporary at best, lasting only a few years.
The natural fire return interval for many chaparral covered landscapes was likely a century or more before humans entered the scene. While it is important to perform proper vegetation management directly around communities, trying to mimic what we think Native Americans did in Malibu will only lead to the destruction of the very natural environment people live there to enjoy.
We REALLY need to move the whole Native American burning issue back to the field of anthropology where it is much more relevant. It’s not particularly helpful in developing strategies to reduce fire risk in our current situation.
— RICHARD HALSEY