The fundamental problem with prescribed fires in California's native shrublands is that
there is too much fire in these ecosystems already,
threatening their continued existence.
Why do Prescribed Burns Threaten Chaparral?
1. Chaparral is threatened by too much fire.
Fire return intervals under 30 years can seriously compromise the ecological health of chaparral either by eliminating keystone plant species (and their associated animal partners) such as non-resprouting ceanothus and manzanita.
The fire departure map of the Cleveland National Forest on the right demonstrates the threat. All the hot colors are areas that have more fire than was historically the case. In other words, these areas are now being threatened with type conversion from native shrublands to non-native, highly flammable weed patches.
The risk shown in the map is similar to all four of southern California's National Chaparral (Forest) Preserves. And due to climate change, the risk is heading north.
"The ecological subsections surrounding the San Diego, Los Angeles, and Santa Barbara metropolitan areas are among the most negatively departed in the state... In these areas, extensive landscapes characterized originally by dense native shrublands have been converted to degraded, open stands of native shrubs and exotic annual grasses and forbs, which are easily reignited. These fire-mediated changes in vegetation lead to higher rates of erosion, increased exotic species invasion, and higher fire hazard as grass fuels replace shrubs."
Fire Return Interval Departure Map. Hot colors (yellow, orange, red) mean too much fire. From Safford and Schmidt 2008, US Forest Service.
The impact of a cool season prescribed burn in the late 1980s: weeds and the destruction of the chaparral. Pinnacles National Park.
2. Unseasonal fire can eliminate chaparral.
There is a narrow window when prescribed burns can occur: in the cool season (late spring, just before summer). This is because in the winter and early spring months, chaparral plants have too much moisture within their tissues. They won't carry a fire. In the summer and fall, the wildfire risk is too high due to low moisture levels. As a consequence, prescribed burns are conducted in the chaparral when it is the most vulnerable: the plants are growing, the soil is still moist, many animal species are breeding, and birds are using the chaparral during their annual migrations.
Cool season burns cause significant damage to plant growth tissues and destroy seeds in the soil due to soil moisture turning into steam. The result? As can be seen in the photo of a hillside in Pinnacles National Park, California, unseasonal fires can lead to immediate type conversion to a non-native weedlot. This was the site of a cool season prescribed burn in the late 1980's. The chaparral was destroyed and has never come back.
2013 San Felipe Fire, San Felipe Valley Wildlife Area, CA. 2,781 acres burned. See below.
The 2006 Sierra Fire, an escaped prescribed burn. Not only does the fire cause damage, but so do fire suppression activities such as dozer lines. Photo: Stephen Francis
Why the National Park Service does NOT use prescribed fire
in the Santa Monica Mountains
"Prescribed burning is not effective in limiting the spread of wildfires under the conditions that burn the largest amount of land and cause the most home losses. Native shrublands are being burned too frequently because of human ignited wildfires. Prescribed fire does not fulfill any identified ecological need in chaparral or coastal sage scrub and would increase the probability of a damaging short fire interval following a prescribed burn. The most effective fire management strategies to protect local communities and the native ecosystem in the SMMNRA are to:
- PREVENT WILDFIRES, especially during severe weather conditions.
- Plan and implement effective SUPPRESSION strategies during severe weather conditions.
- Create defensible space from the house-out.
On May 23, 2013, with the approval of the California Department of Fish and Wildlife, Cal Fire started a 100 acre "prescribed" burn within the protected San Felipe Valley Wildlife Area which is just east of the mountain town of Julian in San Diego County. The fire escaped and proceeded to burn more than 2,700 acres of fragile habitat within the protected area. Much of it had previously burned in the 2002 Pines Fire. Considering the ecological fragility of the area due to recent fires and the lack of any community nearby, we are wondering what these two agencies were thinking. Reburning an area that had burned 11 years ago causes serious ecological damage.
We visited the burn site and have obtained documents relating to the fire from the California Department of Fish and Wildlife which has jurisdiction over the Wildlife Area. Here are our findings:
- the rationale for the Project was ecologically unsound
- claims that the Project would reduce wildfire impacts and provide indirect community protection to Julian and Shelter Valley are unsupportable
- the Project and the escaped fire caused significant environmental damage to a protected, rare, and environmentally sensitive habitat
- fire suppression activities damaged riparian areas and possibly cultural sites
- the Project violated the Dept. of Fish and Wildlife’s 2009 Land Management Plan for the San Felipe Valley Wildlife Area
- Cal Fire violated its burn prescription plan
- Cal Fire appears to have ignored a National Weather Service Wind Advisory on the date of the burn
In light of these conclusions we recommend the establishment of an official protocol for both the Department and Cal Fire to determine the efficacy and ecological impact of major vegetation treatments that includes an independent, outside review of projects while in the initial planning stages.
The entrance to the San Felipe Valley Wildlife Area.
The charred skeletons of burned, eleven-year-old chamise shrubs can be seen on the right in addition to the significant soil disturbance caused by the bulldozers during the fire suppression action. The fragile desert streambed was also compromised by dozer action.
Fire history map of the semi-desert area where the San Felipe escaped fire burned. This landscape does not have much left in terms of habitat that hasn't burned in recent decades. It is not resilient to damage caused by Cal Fire's escaped prescribed burn. Click on map to expand.
The burned Engelmann oak grove. These trees provided critical habitat before they were burned down by the fire. Engelmann oaks typically do not recover well post fire.
The future of the San Felipe Valley Wildlife area? Invasive grasses and weeds will likely invade the escaped burn area as they have the 2012 Vallecito Lightning Complex Fire burn area - just across the street from the San Felipe escaped burn.