What is the natural cause of fire? Lightning. Lightning caused fires at lower elevations in California are extremely rare. However, once humans (starting with Native Americans) entered the scene, the number of fires gradually increased to levels today that are damaging shrubland ecosystems (Photo of the famous Yahi Indian, Ishi).
Natural systems adapted and survived for millions of years before humans ever entered the scene. Fire was used in aboriginal times to modify the environment in a way that best suited survival needs. The historic observation that some Native Americans used fire to modify the landscape does not mean it is something we should emulate today.
The best fire history data we have applies to conifer forests using fire scar dendrochronology (tree ring studies). This information does not allow us to distinguish between anthropogenic (human caused) or lightning caused ignitions. So it is extremely difficult to determine the frequency or impact of Native American burning.
However, despite such limitations, it is still possible to conclude that in certain forests with high lightning frequencies, Native Americans had little, if any, significant impact. In those systems, modern fire suppression, over grazing, and past logging practices have created excessive fuel loading problems and an effort to return them to more natural conditions with fire is a reasonable goal.
In contrast, the relative impact of Native American burning in the coastal portions of California was probably quite significant. Ethnographic studies and other historical documents show that California Indians were responsible for extensive burning and type-conversion of chaparral and other shrublands to grasslands in order to increase favored game species, protect themselves from predators (the favored habitat of the California grizzly bear was chaparral), and as a tool of warfare. They almost certainly increased fire frequencies over what was naturally possible due to lightning. For example, in the 153,000 acre Santa Monica Mountain National Recreation Area only 2 lightning fires have been recorded over the past 25 years.
Ecosystems within the coastal region of Southern California were likely the most heavily impacted by Native American burning and may have ultimately set the stage for the successful spread of invasive European grasses in the early 1800's. Southern California oak savannas in the past, such as those seen along US Highway 101 between Lompoc and San Luis Obispo, were likely covered by an understory of sage scrub, not grass as we see today (see photos below). Native Americans probably began the elimination of sage scrub in favor of grass in these areas by burning, a process that was accelerated by Spanish and American ranching activity. Suggestions that Native American burning activity was an essential and natural part of the oak woodland environment are not reasonable when the ecosystem thrived for millions of years prior to the arrival of human beings on the North American continent.
The important point is that Native American burning practices were performed to modify the landscape in an artificial manner and probably resulted in the elimination of large tracts of native shrubland communities.
We cannot afford to emulate this pattern today because we have increased fire frequencies in many shrubland ecosystems beyond their ability to recover. In addition, increased fire frequency and other unnatural disturbances allow the spread of non-native, invasive weeds into native ecosystems, something Native Americans did not have to contend with.
Some have also claimed Native Americans used controlled burning to prevent large wildfires. Evidence for Native American burning is for localized management within a half-day’s walk from villages, not that they were able to reduce the severity and frequency of uncontrolled wildfires. There is little reason to believe Native Americans could prevent the occurrence of large wildfires on the broader landscape. Indeed, one ethnographic report describes a massive wildfire in San Diego County prior to the time of European contact that resulted in a significant migration of Native American residents to the desert.
It should be noted that decades ago fire agencies replaced the term "controlled burns" with “prescribed burns” in part because of the recognition that these fires often escape control. First-hand experience has demonstrated that trying to “control” a wildland fire is problematic at best, especially under unpredictable weather conditions that frequent Southern California. Such would likely have been the case with Native Americans as well, especially since they didn't have the vast fire suppression forces available today.
The notion that establishing a Native American burning regime will prevent catastrophic fires is demonstrably incorrect based on the 2007 re-burning of approximately 70,000 acres scorched in Southern California during 2003 fires. Instead of basing fire management practices on incomplete records from prehistory, we need to look forward and formulate plans based on fire science.
In Southern California, fire frequencies continue to increase with our growing population. Adding more fire to a landscape that already suffers from too much is neither desirable for the natural resources nor a realistic option for preventing catastrophic fires.
The impact of human-caused burning on the landscape has been demonstrated throughout the world. Here are two papers that have described the phenomenon:
"The report by McWethy et al. 2010 provides incontrovertible evidence that anthropogenic burning transformed temperate forested landscapes on the South Island of New Zealand. They show that Polynesian (Maori) firing commenced shortly after colonization around A.D. 1280 and transformed 40% of the original forest cover of the island to grassland and fern-shrubland."
"Fire was used by Neolithic people to create pastures at timberline and clear forests for arable farming in the valley. This had a significant, long-term effect on the mountain vegetation and a negative impact on keystone forest species such as Abies alba, Larix decidua and Pinus cembra."
This is what the inland portion of the central coast of California once looked like. A dense assortment of small shrubs, especially sagebrush, formed a perfect environment for oak seedlings and a rich habitat for an abundant number of animal species.
This is what the inland central coast of California looks like today. Nearly all the oaks are over 100 years old (seedlings fail because of cattle grazing) and the landscape is covered in non-native weeds.
Native Americans as Sovereign People
First European settlers tried to push them out of the way. Then the United States Government tried to exterminate their cultural identity, with a significant faction encouraging genocide. In an ironic twist, by the 1960's it seemed everyone wanted to be an "Indian." Now, after hard fought legal victories securing traditional hunting and fishing rights and regaining stolen land, in addition to newly gained wealth derived from gaming activities, predjudice is rising up again against American's original inhabitants. It's time to get educated.
Start here by reading the two books listed to the right. The first, "Neither Wolf nor Dog" by Kent Nerburn, gives an excellent account of how the Lakota (Sioux) see the dominant society today and how different the Native American perspective really is on a variety of issues (the land, nature, spirituality, ownership, and junk cars).
The second book, "Blood Struggle" by Charles Wilkinson, is an outstanding description of the past 75 years of Native American efforts to regain both their rights and their sovereignty.