Fire Safety – Page 10 – Conservation Sense and Nonsense

Open Letter to the Sierra Club

In this post we are writing an open letter to the Sierra Club about an article in their recent edition of the Yodeler, the newsletter of the Bay Area Chapter of the Club. The article is available here.

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Dear Sierra Club,

We are writing about an article in the Yodeler about the “Wildfire Hazard Reduction and Resource Management Plan” of the East Bay Regional Park District. A charitable description of that article is that it is misleading and inaccurate.

The most important flaw in the article is that it omits the most controversial issue in the “Wildfire Plan.” It describes the methods used to eradicate non-native plants and trees as follows: “Methods for removal include hand removal, grazing by cattle and goats, and limited controlled burns.”

In fact, herbicides are often used by EBRPD to kill non-native plants and trees. The failure to mention this use of herbicides in the Yodeler cannot be dismissed as ignorance of this fact since it is described in detail in the “Wildfire Plan” and was the most frequently mentioned issue in the meeting of the EBRPD Board of Directors at which the Plan was approved. The Sierra Club was represented at this meeting and surely noticed that many speakers expressed their concern regarding the use of herbicides officially designated “hazardous chemicals” by OSHA. The toxicity of these herbicides is reported here and here.

The description of controlled burns required by the Plan as “limited” is debatable. We believe that the use of controlled burns for the sole purpose of restoring native plants is dangerously irresponsible.

At the recent meeting of the Executive Committee of the Board of Directors of the EBRPD, the “fuel management” plans for 2011 were presented and approved. These plans included prescribed burns in 5 locations, on approximately 250 acres. These burns were described by the Assistant Fire Chief as unrelated to reduction of fuel loads, but rather for the purpose of supporting restoration of native plants to the parks. A representative of the California Native Plant Society expressed gratitude to East Bay Regional Park District for conducting these burns for the benefit of native plants.

We object to the use of controlled burns for this purpose because such burns have a history of causing major wildfires (reported here). Some of these controlled burns will occur in areas with many acres of eucalyptus and Monterey pine that both the Sierra Club and the East Bay Regional Park District claim are highly flammable. The burns are scheduled to occur during the height of the fire season. Such burns also reduce air quality and release carbon and particulates into the air.

It baffles us that the Sierra Club endorses the use of dangerous herbicides and prescribed fires. However, we aren’t surprised because the Club’s comments on the Draft EIR for the “Wildfire Plan” warned us that the Sierra Club considers the restoration of native plants a higher priority than the public’s safety. The lawyer representing the Club said on behalf of the Club, “Perhaps the most serious problem with the Plan is that it explicitly makes the preservation and enhancement of wildlife a secondary concern, with minimizing fire danger the primary concern” and concluded, “However, the over-emphasis on decreasing wildfire risks at the expense of habitat values is disturbing.”

The Club’s priorities reveal a misanthropic agenda that betrays its original ideals and its commitment to the environment on behalf of all living creatures, including humans.

Million Trees

More Fire Factors: Fire Ladders and Embers

Recently, a local news program broadcast an interview about the legal suit filed by the Hills Conservation Network (HCN) against the “Wildfire Hazard Reduction and Resource Management Plan” of the East Bay Regional Park District (EBRPD). Although both HCN and EBRPD are committed to reducing fire hazard, they disagree about how to achieve that goal. The spokesperson for HCN said there is no “scientific or factual evidence” that eliminating the canopy of non-native trees will reduce fire hazard. The spokesperson for EBRPD said the trees will be removed because they “burn intensely” and “loft embers into the wind, causing spot fires downwind” when their crowns begin to burn.

Is there scientific or factual evidence to support the claims of EBRPD? Are non-native trees more likely to burn than native trees and if so do they burn more intensely than native trees? Are non-native trees more likely to loft embers than native trees? This post will document the answers to these questions: NO, NO, and NO!

When fire spreads on the ground, through fine fuels such as grass, it bypasses trees unless there is a fire ladder to their canopy. The fire ladder is composed of low branches that extend from the ground, into the canopy of the tree. Tall eucalyptus trees usually do not provide such a fire ladder to their canopy.

We see a few of the eucalypts in the distance that EBRPD intends to destroy in Lake Chabot park. We notice that they are very tall and there is no fuel ladder to their canopy. In the foreground, on the right, we see some of the native bay laurels that EBPRD plans as replacements for the eucalypts. We notice that the bays are close to the road and that they grow to the ground, providing a fuel ladder to adjacent vegetation.

When tall trees, such as eucalypts have a fire ladder to their canopy, their lower limbs can be removed without harming the tree. This method of reducing fire hazard has been used effectively in the Mountain View Cemetery in Oakland. Obviously, this method of reducing fire hazard is cheaper and less destructive than destroying the trees and then killing their roots with poison. This was one of the strategies suggested by the Hills Conservation Network during negotiations with EBRPD before they filed suit after negotiations failed.

The fire ladders on these eucalypts have been removed in the Mountain View Cemetery.

In a wind-driven firestorm the fire may rapidly spread high above the ground. In that case, how likely is the canopy of eucalypts to ignite compared to other trees? The firestorm of 1991 in the Oakland/Berkeley hills is an example of such a fire. In our posts “FIRE!!! The Cover Story” and “The Power of a Legend” we have reviewed two official documents and one book about the 1991 fire which contain no evidence that eucalypts were responsible for that fire.

Please click here to see a picture of an entire neighborhood of homes destroyed by a wildfire in the Scripps Ranch in 2003.. The burned homes are entirely surrounded by tall eucalyptus trees that are untouched by the fire. Despite this obvious evidence that the eucalypts were blameless in this fire, native plant advocates seized upon this fire to demand that the eucalypts be destroyed. The residents of Scripps Ranch fought back and for the moment, they have succeeded in preventing the destruction of their eucalyptus forest.

The National Park Service is one of many managers of public lands that are engaged in massive restorations of native plants that frequently result in the destruction of non-native trees. And as most managers of public lands, it attempts to justify the destruction of the trees by claiming that they are a fire hazard. Reading the fine print of its literature about eucalyptus, we find that their claims are not supported by the evidence. Studying the table comparing the fuel loads of eucalyptus with native oaks and bays, we find that the table has been carefully constructed to support their case. If logs–which would take 1,000 hours to ignite*–are removed from this table, the available fuel load of eucalyptus is not greater than that of native oaks. Also, deeply embedded in the fine print, you find that the park service admits that the leaves of the eucalyptus are resistant to fire (“The live foliage [of the eucalypts] proved fire resistant, so a potentially catastrophic crown fire was avoided.”)

We conclude that all evidence from past fires indicates that eucalypts are unlikely to ignite in a wildfire. If they don’t ignite, they obviously will not “loft embers” to spread the fire. The final question is, in the unlikely event that there is a crown fire in eucalyptus, how likely is it that embers will be produced that spread the fire downwind? Although we don’t know the answer to that question, we have both scientific and experiential evidence that native trees are also capable of producing embers.

In “Ignition Behavior of Live California Chaparral Leaves,” Steven Smith, Joshua Engstrom, Jordan Butler, Thomas Fletcher (Brigham Young University, Provo, Utah) and David Wiese (USDA, Forest Service) report the results of laboratory tests on four species of native plants and trees, including oaks. They find that both native chamise and oaks loft embers absent any wind. In the case of oaks, they report that “Many of the oak leaves had sharp points (i.e., spines) around the outer edge. The oak leaves would ignite at these points, sometimes accompanied by small explosions of the points that led to the ejection of small brands.”

The Marin Independent Journal in its report of the Angel Island Fire of 2008 tells us that embers from the burning oaks were responsible for nearly igniting the historic buildings on the island: “’All the oaks up there were burning,” said the 28-year veteran of the department. “It was an ember shower that just rained on the entire building, and all the vegetation around us was burning.’” As we reported in our post about the Angel Island Fire, most of the eucalyptus had been removed from the island about 12 years before the fire in 2008. The fire stopped at the edge of the remaining 6 acres of eucalyptus.

There is overwhelming evidence that eucalyptus is not more flammable than native trees and has not played a role in the many wildfires in California. The myth that eucalypts are responsible for wildfires is propagated by native plant advocates who use the fear of fire to justify the destruction of eucalypts. Those who are willing to look closely at the evidence will see through this carefully constructed myth to the reality that destroying non-native trees will not reduce fire hazard.

*For a technical explanation of timelag, we quote from Sugihara’s Fire in California Ecosystems: “The proportion of a fuel particle that contains moisture is a primary determinant of fire behavior…Timelag is the amount of time necessary for a fuel component to reach 63% of its equilibrium moisture content at a given temperature and relative humidity……1,000-hour fuels reflect seasonal changes in moisture. The firewood analogy applies here as well. Your large logs would take several months to dry if left out in the rain for the winter, yet kindling, if brought inside, would dry in a few hours.”

Fire Factors: #1 Moisture

There are many factors involved in predicting fire hazard, such as:

How easily the fuel ignites
How quickly the fire spreads
How hotly the fire burns as measured by “flame lengths”

And there are many variables within these parameters. One of the variables that determine how easily fuel ignites is the amount of moisture both within the fuel and in the environment in which the fire occurs. At the most hazardous end of the spectrum, the driest fuel in the landscape is dead vegetation during our dry season on a hot day. At the least hazardous end of the spectrum is vegetation with high moisture content on a rainy day.

Using these variables we will consider how likely eucalypts and other non-native trees are to ignite compared to native trees. We were inspired to consider this topic today by a foggy morning in the East Bay. Foggy mornings are frequent events in the Bay Area, particularly during the summer months. When the interior valleys heat up, the hot air collides with the cool air from the ocean, producing fog. The hotter the air is in the interior, relative to the cool ocean air, the more fog we experience along the coast.

Walking a favorite trail in Redwood Park this morning, the fog shrouded the valley below us. It was otherwise a dry day. The dirt trail was dry except under the Monterey pines along the trail. The pines “caught” the fog and dripped water onto the trail, making puddles on the trail.

Although there are oaks and bays alongside the trail as well, they don’t condense as much fog because they are not as tall. Harold Gilliam in Weather of the San Francisco Bay Area is specific in crediting the tall, non-native trees for their ability to condense the fog drip: “Eucalyptus and pine groves planted there long ago intercept large amounts of fog and cause a rainlike deposit of moisture. The fog drip during the summer months has been measured at a surprising 10 inches, an amount nearly half as great as the total rainfall…” Average rainfall in the East Bay is 22 inches per year, so this fog precipitation adds nearly 50% to total precipitation. By contributing moisture during the otherwise dry time of the year, tall non-native trees reduce fire danger.

The moisture content of the vegetation itself is another factor in how easily it will ignite. Other conditions being equal, the more moisture within the vegetation the less likely it is to ignite. Carol Rice is a credible source of information about the moisture content of native vegetation in the East Bay hills because she is one of the authors of the East Bay Regional Park District’s “Wildfire Hazard Reduction and Resource Management Plan.” Ms. Rice monitored 7 species of native plants and trees in the North Coastal Scrub and Oak-Bay vegetation types for her Master’s Degree. Here are quotes from her Master’s Degree dissertation (“Live Fuel Moisture, Fuel Bed Characteristics, and Fire Vegetation in the Berkeley/Oakland Hills,” UC Berkeley, 1987).

“The dead to live fuel ratios [of the vegetation] were high: 46%…on the west aspect was dead, 60%..on the east aspect was dead.” Recall that dead vegetation is drier than living vegetation and is therefore easier to ignite.
“…the [moisture] of the live oak was fairly constant throughout the fire season and at a lower moisture content than the other species…the lowest moisture content was [47%] on September 30^th…” (1)

We don’t have comparable information regarding moisture for the eucalyptus because moisture content varies by specific location and climate conditions. However, the literature generalizes the moisture content of the eucalyptus leaf as roughly 50%, which suggests that the eucalyptus leaf does not contain less moisture than an oak leaf.

Another factor in the likelihood of ignition is the degree to which the leaf litter and duff layers under the trees absorb moisture. Generally, the more moist the leaf litter and duff layers, the more difficult they are to ignite by embers or fire spreading through the understory of the forest.

Robert Shroeder and Robert Martin (UC Berkeley) studied the ignitability of leaf litter and duff layers of Monterey pine and Redwood in the laboratory. In “Ember Ignitability of Pinus Radiata and Sequoia Sempervirens Litter: Methodology and Results” (in “Proceedings of California’s 2001 Wildfire Conference: 10 Years After the 1991 East Bay Hills Fire”) they report that although the litter of the Monterey pine is slightly more likely to ignite than equally moist litter of the Redwood, the litter of the Redwood is more resistant to moisture and is therefore more likely to ignite.

Isolating just one of many factors in predicting wildfire hazard–moisture– we conclude that there is no evidence that non-native trees are more likely to ignite than native trees in comparable conditions. We will examine other factors in determining fire hazard in later posts.

(1) Ms. Rice expressed percent of moisture as a ratio of (moisture plus dry weight) divided by dry weight. The more usual expression of moisture content is a ratio of moisture divided by dry weight. We have converted her numbers to conform to this standard method of describing moisture content of leaves.

(UN)controlled Burns

Today’s SF Chronicle reports that yet another “controlled” (AKA “prescribed”) burn is responsible for a wildfire in California. This fire in the Santa Cruz Mountains burned 485 acres in October 2009, injuring 4 of the 1,700 firefighters who fought it at a cost of $4 million. That cost doesn’t include the claims for damages of the property owners who lost their homes.

This isn’t the only controlled burn that has caused major wildfires in California and elsewhere. For historical perspective, let’s start with the Bandelier Monument Fire in New Mexico. This fire, began in May 2000 as a prescribed burn and eventually burned over 45,000 acres, threatened the Los Alamos National Laboratory and destroyed 235 structures. The Department of the Interior suspended all prescribed burns while an inquiry was conducted and policy was revised to theoretically prevent similar accidents.

Did revision of policy stop so-called controlled burns from causing wildfires in our national parks? No, it did not. In October 2009, the Big Meadow Fire in Yosemite began as a prescribed burn and eventually burned 7,425 acres. NPS apparently hadn’t learned much from their bad experience 9 years earlier at the Bandelier Monument.

Yosemite Big Meadow Fire copy — Yosemite Big Meadow Fire, NPS photo

The National Park Service isn’t the only manager of public land that has had bad luck with controlled burns. In 2003, the California State Park Department was responsible for starting a fire on San Bruno Mountain in South San Francisco intended to burn 6 acres that eventually burned 72 acres and came perilously close to homes, according to the SF Chronicle.

We should not be surprised by the unpredictable results of prescribed burns. Fire scientists at UC Berkeley conducted a series of experimental prescribed burns in chaparral in Northern California, hoping to arrive at a model of fire behavior that would improve the predictability of such burns. They arrived at the conclusion that “…it is extremely difficult to predict with certainty where the fire will spread…For more than half of the transects installed, the flaming front did not traverse the transects as predicted…” (1)

You might ask, “If these prescribed burns keep causing major wildfires, why do we continue starting them?” Good question, and we are going to answer that. The conventional wisdom is that because fires have been suppressed in the past century or so, fuel has built up that has become extremely dangerous. Theoretically, we must restore the “natural” fire cycle to prevent this dangerous build up of fuel that will inevitably cause a huge wildfire if we don’t reduce the fuel load with smaller (hopefully) fires. Sounds like a good argument, but is it true? Some scientists say it isn’t.

Jon E. Keeley, Ph.D. (Biologist, US Geological Service) says in “Fire Management in the California Shrublands,”

“Fire management of California shrublands has been heavily influenced by policies designed for coniferous forests, however, fire suppression has not effectively excluded fire from chaparral and coastal sage scrub landscapes and catastrophic wildfires are not the result of unnatural fuel accumulation. There is no evidence that prescribed burning in these shrublands provides any resource benefit and in some areas may negatively impact shrublands by increasing fire frequency. Therefore, fire hazard reduction is the primary justification for prescription burning, but it is doubtful that rotational burning to create landscape age mosaics is a cost effective method of controlling catastrophic wildfires.”

Obviously, there isn’t scientific consensus that prescribed burns reduce fire hazard, so perhaps there is another reason why we pursue this dangerous course. Yes, there is, and once again we turn to the native plant movement to explain why we are harming our environment and posing unnecessary dangers to animals, including humans.

The scientific literature is rampant with evidence that periodic fire is essential to the health of native plants. Here is an example from a renowned academic book about California’s ecology that has the status of a standard textbook:

“The [chaparral] community has evolved over millions of years in association with fires, and in fact requires fire for proper health and vigor. Thus it is not surprising that most chaparral plants exhibit adaptations enabling them to recover after a burn. Many species are sprouters; the aboveground parts may be killed, but new growth arises from roots or buds at the base of the stem…Other species have seeds that require fire in order to break dormancy; they will not germinate unless they have been heated. The cones of some chaparral conifers open only after they have been heated. Some herbaceous species will not germinate unless there is ash on the ground when it rains…In the absence of fire, a mature chaparral stand may become senile, in which case growth and reproduction are reduced.” (Schoenherr, A Natural History of California, 1992, UC Press)

This is also an opportunity to show how the native plant agenda has been adopted by local managers of our public lands. The “Wildfire Hazard Reduction and Resource Management Plan” of the East Bay Regional Park District announces its intention to conduct prescribe burns for the following purposes:

“Grassland and Herbaceous Vegetation…broadcast burns in the summer or early fall [fire season] are known to favor native plants.” (page 128)
“Maritime Chaparral…This [native] vegetation type and the Manzanita it supports are also fire dependent. Without disturbance by fire the Manzanita does not reproduce, becomes decadent, and is replaced by shade tolerant species.” (page 132)
“North Coastal Scrub…This plant community [of native plants] is adapted to natural fire cycles, and most species found within this plant community resprout easily to rejuvenate individual specimens after fire, or require fire to trigger germination.” (page 139)
“[Native] Coyote Brush Scrub…is adapted to natural fire cycles. Most species resprout easily to rejuvenate individual specimens after fire, or requires fire to trigger germination.” (page 149)

Are any of these purposes related to reducing fire hazard? You be the judge.

The management plan of San Francisco’s Natural Areas Program also announces its intention to use prescribed burns in the Initial Study (the first stage of environmental review under CEQA) of the program, but offers no information about the effect of these burns on the environment. In a city such as San Francisco, in which there is no history of wildfire, we must assume that the sole purpose of these burns will be to benefit native plants.

Clearly controlled burns frequently cause major wildfires. Fires, whether intentional or not, also release harmful particulates into the air and reduce air quality. There is no evidence that controlled burns prevent wildfires. Yet, there is considerable evidence that they benefit native plants. We conclude that the primary purpose of controlled burns is to benefit native plants.

(1) Scott Stephens, et. al., “Measuring the rate of spread of chaparral prescribed fires in Northern California,” Fire Ecology, Vol. 4, No. 1, 2008

Common Characteristics

Native plant advocates attempt to support their claim about the flammability of eucalypts by citing specific characteristics such as shreddy bark and volatile oils. Shreddy bark and volatile oils are characteristics of many plants, both native and non-native. They are not characteristics exclusive to eucalypts:

“The [chaparral] community has evolved over millions of years in association with fires, and in fact requires fire for proper health and vigor…Not only do chaparral plants feature adaptations that help them recover after a fire, but some characteristics of these plants, such as fibrous or ribbonlike shreds on the bark, seem to encourage fire. Other species contain volatile oils.” (page 341, A Natural History of California, Schoenherr, UC Press, 1992)

Madrone and Manzanita are examples of native plants with “ribbonlike shreds on the bark” that are highly flammable. Coyote brush and bay laurels are examples of native species which contain highly flammable oils.

Anyone with knowledge of the natural history of California could provide any number of such invidious comparisons between native and non-native plants with respect to their flammability. We hope the examples we have provided illustrate that flammability characteristics of plants are unrelated to whether the plants are native or non-native. The claim that non-native plants are more prone to fire than native plants is fallacious.

Fire on Angel Island 2008

The fire on Angel Island in October 2008, is an example of the bogus claims of the flammability of eucalypts. According to an “environmental scientist” from the California state park system, 80 acres of eucalypts were removed from Angel Island over 12 years ago. Only 6 acres of eucalyptus remain. (“Rains expected to help heal Angel Island,” SF Chronicle, October 14, 2008 ). The fire that burned 400 acres of the 740 acres of Angel Island stopped at the forest edge: “At the edge of the burn belt lie strips of intact tree groves…a torched swath intercut with untouched forest.” (“After the fire, Angel Island is a park of contrasts,” SF Chronicle, October 15, 2008).

Wildfire_on_Angel_Island_com — Wikimedia Commons/Mila Zinkova

The fire on Angel Island is not an isolated event. Rather it is typical of recent wildfires throughout California:

“It is estimated that no more than 3 percent of the recent 2007 fires…occurred in forests…the remaining 97 percent occurred in lower elevation shrublands and urban areas, burning native shrublands such as chaparral and sage scrub, non-native grasslands and urban fuels…” (Statement by Jon E. Keeley, USGS, before agencies of the US Senate, 2007)

Nativist myths die hard

A book about the 1991 wildfire in the Oakland/Berkeley hills illustrates the power of the legend that non-natives are more flammable than natives. In Firestorm: the study of the 1991 East Bay fire in Berkeley (Margaret Sullivan, 1993) the author states repeatedly that native plants and trees were involved in that fire. Every tree mentioned in the following quotes from that book is native to the Bay Area:

“…flames surging through the dry underbrush and live oaks that line the street…”
“…neighborhoods…are built into the contours of the grassy hills and live-oak-and-laurel studded canyons…”
“…hillsides covered in seasonal grasses or had overlooked ravines of oak and madrone…were devastated by the fire.”
On Vicente Road, “Two redwoods up the street caught fire like matchsticks.”
“Roble Road and… Roble Court, derive their name from the…Spanish word for the live oak tree that grows densely there…the devastation on lower Roble…was fairly complete…”

In the single mention of the role of eucalypts in the fire, the fire skips over the tree canopy: “The fire swept right over [the houses] scorching the crowns of surrounding eucalyptus trees.” And the Monterey pine—also targeted for eradication by native plant advocates—plays a similar role in a nearby location: “Across the street a grove of Monterey pines shields the white clapboard buildings of the private Bentley School…”

After presenting all this evidence about the role of native plants in the fire, the book concludes with the legend that non-natives are more flammable than natives: “Gardens of drought tolerant and fire-resistant California native plants have become symbols of the rebirth of the fire communities.” This statement is illustrated with a photo of a native plant garden.

Chamise is an example of a native plant in the chaparral community that is extremely flammable.

“The relationship between fire and Chamise is illustrated by the plant’s tendency to ‘encourage’ burning. A thermometer was placed within a Chamise shrub as a fire approached, and the following changes were documented. At about 200⁰F the plant began to wilt as its temperature approached the boiling point of water. At about 400⁰F the plant began to emit combustible gases such as hydrogen, alcohol, and methane. At about 600⁰F the shrub smoldered and began to turn black. At about 800⁰F the plant burst into flames! This species must have evolved in association with frequent fires to have reached the point where it seems to encourage burning.” (A Natural History of California, Schoenherr, page 344)

Chamise, Tilden Park Botanical Garden

As Mark Twain said, “A lie can get halfway around the world while the truth is still putting its boots on.”