Conservation Sense and Nonsense

CHANGE….the only constant

The conventional wisdom amongst native plant advocates is that native plants will return to the landscape if non-native plants are eradicated. In this post, we will examine this assumption and refute it.

Several different methods are used to eradicate non-native plants, but it doesn’t matter which method is used because the results are the same: native plants do not return when non-native plants are removed.

Spraying herbicides is a popular method of eradicating non-native plants because it is considered the most cost-effective method. In addition to the obvious health risks, the downside of herbicide use is that they are as likely to kill the natives as the non-natives. This problem is illustrated by a USDA study of the effects of a one-time aerial spraying of herbicides on grassland after 16 years. Although the herbicide is assumed to “dissipate” within a few years, the negative effect on the natives persisted 16 years later: “…the invasive leafy spurge may have ultimately increased due to spraying. Conversely, several desirable native herbs were still suffering the effects of the spraying,,,”

Even when native plants are removed, non-native plants occupy the cleared ground. Environmental scientists at UC Berkeley removed native chaparral from experimental plots in Northern California to test fuel reduction techniques using two different methods (prescribed burns and mechanical), in different seasons, over a period of several years. In every test, the result was on average from 23% (for prescribed burns)to 61% (for mechanical methods) non-native plants where they had not previously existed.

Jon E. Keeley (USGS) finds the same tendency for non-natives to replace natives in forests: “Forest fuel reduction programs have the potential for greatly enhancing forest vulnerability to alien invasions.” (1)

A scientist (2) arrived at the same conclusion after attempting to restore an oak-studded grassland on Vancouver Island. He tried several different methods of removing invasive grasses for several years only to find that “…the decline of the native plant species accelerated…”

Those who observe native plant restorations in the San Francisco Bay Area aren’t surprised by these studies. We know that native plant restorations are unsightly failures unless they are aggressively planted, irrigated for several years, and fenced. Examples of successful restorations can be seen at Crissy Field and the summit of Mt. Sutro. The East Bay hills provide examples of the opposite strategy. Where UC Berkeley has clear-cut all non-native trees and vegetation, non-native weeds quickly occupied the barren ground. After a particularly wet winter, the non-native poison hemlock in the East Bay hills is 6 feet tall along the roads.

Why are non-native plants apparently more competitive than native plants? Because the conditions that supported native plants 250 years ago, prior to the arrival of Europeans, have changed. The native plants are no longer well adapted to the current conditions.

Higher levels of CO2 and the associated climate change are promoting the growth of non-native plants. A USDA “weed ecologist” (3) studied the effects of higher temperatures and CO2 on the growth of non-natives (AKA weeds) by growing identical sets of seeds in a rural setting and an urban setting with higher temperatures and CO2 levels. Seeds grown in the urban setting produced substantially larger plants with much more pollen and therefore greater reproductive capability.

Other scientists reach the same conclusions by studying the changing ranges of native plants and insects. An ecologist at UC Berkeley (4) says that “California’s flora face a potential collapse…as the climate changes, many of these plants will have no place to go.” A scientist at the California Academy of Sciences (5) predicts that redwoods will disappear from California by the end of the century.

As the plants move, so do the insects and animals that need them. A study published in Nature magazine in December 2009 found that plants and animals must move as much as 6 miles every year from now to the end of the century to find the habitat they occupy now. An ecologist at UC Davis (6) has been studying native butterflies for over 35 years. He recently reported that native butterflies are moving to higher elevations, where temperatures are lower, but that ultimately, “There is nowhere else to go, except heaven.”

The local environmental organizations and public policy-makers must wake up to this reality and reorder their priorities. Instead of demanding that all non-native plants and trees be eradicated and that native plants be restored where they are no longer sustainable, they must make climate change their highest priority. The easiest and cheapest step to take to address this issue is to quit destroying healthy trees—just because they are non-native–that are sequestering tons of carbon.

(1) “Fire Management Impacts on Invasive Plants,” USGS, Jon E. Keeley, April 2006

(2) Andrew MacDougall, University of Guelph, Ontario, Canada, NY Times Magazine, 6/29/08

(3) Lewis Ziska, USDA, Beltsville, MD

(4) David Ackerly, UC Berkeley, Los Angeles Times, 6/25/08

(5) Healy Hamilton, Cal Academy, Center for Biodiversity Research

(6) Arthur Shapiro, UC Davis, Contra Costa Times, 1/19/10

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

What is natural?

The branch of San Francisco’s Recreation and Park Department dedicated to the preservation and restoration of native plants to the city’s parks calls itself the Natural Areas Program (NAP). And the 32 parks or portions of parks within NAP’s jurisdiction are called Natural Areas. In this post we will visit a few of these areas to ask if they are accurately described as “natural.”

Parcel 4 1868 — Parcel 4, Balboa & Great Highway, 1868

The Natural Area known as Parcel 4 is at the corner of Balboa and the Great Highway. A photograph taken in 1868 of that location indicates that it has been continuously built upon for nearly 150 years. Long-term residents of San Francisco will remember it as the location of Playland by the Beach. After Playland was closed, the city purchased the property for $3.05 million in 1993 with the intention of putting a sewer pipe under it, then restoring it to dune vegetation. The soil was essentially building rubble, so the city had to buy $47,000 of sand and disk it down 18 inches to amend the soil in preparation for planting dune vegetation. The sand was bulldozed into simulated dune shapes and planted in 2002. The restoration was described in the newsletter of the Coalition of San Francisco Neighborhoods in April 2003, in an article entitled “Sand Francisco.” Does this sound “natural” to you?

44157_10 — Parcel 4 under construction, 2002

India Basin is a Natural Area on the east side of the city, on the bay. The east shore of the city was where most industrial development was located until industry left the city beginning in the 1960s. Much of the soil was landfill. Like Parcel 4, the landfill was bull-dozed into a simulated wetland, hoping to restore tidal action. Native pickle-weed was planted several times in the mud-filled basins. We haven’t visited this area for several years. Perhaps they have finally been successful in that effort. This is what we found there on our last visit: native plants along the trail, surrounded by plastic and woodchips to discourage weeds and huge, empty, mud basins off shore. It didn’t look natural to us.

Many of the Natural Areas in San Francisco are less artificial than these two extreme examples. Some of the Natural Areas weren’t built upon in the past, but had no native plants in them when they were designated as Natural Areas. Pine Lake is an example of such a Natural Area. Even where native plants actually existed, their populations were small and isolated in comparison to the acreage designated as a Natural Area. Over 1,000 acres of city-managed parkland have been designated as Natural Areas, 25% of all parkland in San Francisco and 33% if Pacifica is included in the calculation.

Now we will visit the Albany Bulb for contrast. Albany Bulb is also landfill that was for many years the Albany city dump. When the dump was closed, the Bulb became a park. It is a wild and wonderful place. There are few native plants, other than the ubiquitous coyote bush that seems to thrive almost anywhere. In the spring, Albany Bulb is a riot of color. These are the competitive non-natives that native plant advocates wring their hands about. They are there because they are best adapted to the current conditions in this location…the heavily amended soil, the higher levels of CO₂, the warmer climate, the use by humans and their animal companions.

Valerian and wild mustard, Albany Bulb. Both are non-native plants.

If all of these non-native plants and trees were eradicated from the Albany Bulb, would native plants magically appear? Based on our experience, we don’t think so. The conditions that supported the plants that are native to the Bay Area are gone for good. It is a fantasy that the existence of non-native plants is the only obstacle to the return of the natives. Visiting a few places where this strategy has been tried will confirm this. Unless the natives are aggressively planted, irrigated for several years, fenced for protection, weeded or sprayed with herbicides regularly, they do not return. Can such intensive gardening be called “natural?”

Restoration or Destruction?

A recent trip to the Channel Islands off the coast of California inspires us to consider the pros and cons of restorations. Islands are particularly attractive targets for restorations. They often contain endemic species that do not exist anywhere else because they have adapted to unique conditions in isolation. And the relative isolation of islands implies that once non-native species of plants and animals are eradicated, re-introduction of those species can be prevented.

Santa_Cruz_Island 2 — Santa Cruz Island, Wikimedia Commons

Some of the Channel Islands were inhabited by Native Americans as long as 13,000 years ago. Ranching by Europeans began on some of the islands in the 1850s. Europeans brought sheep, cattle, pigs, mule deer, and elk to some of the islands. Five of the eight Channel Islands were designated as a National Park about 30 years ago.

Restoration began in earnest in the 1990s when ranching operations were ceased and tens of thousands of sheep and cattle were either removed from the islands or destroyed. Black rats were eradicated from some islands after native mice were herded into protective enclosures so the rats could be poisoned. Rabbits were eradicated from another island. We don’t know how that was achieved.

The next big effort was the eradication of about 6,000 feral pigs. When this was accomplished by sharp shooters, the first unintended consequence of this ambitious restoration was revealed. It seems that the feral pigs had been the chief diet of a population of Golden Eagles, considered non-native to the Channel Islands. When the pigs were removed from their menu, they turned to the rare, endemic Channel Island Fox.

Channel Island Fox 2 — Channel Island Fox, Wikimedia Commons

The population of Channel Island Foxes plummeted. Those that remained were captured so they could breed in protected conditions while the Golden Eagles were captured and removed to a remote location. The Channel Island Fox is making a come-back, but the Golden Eagles are apparently gone for good.

The eagle considered native to the Channel Island, the Bald Eagle, has been reintroduced. It apparently lives in peace with the Channel Island Fox because it eats fish.

Mule deer and elk are next up on the eradication agenda for fauna. Non-native plants are also doomed. Ice-plant and fennel are the top priorities for eradication by 2011. Herbicides and prescribed burns are used for this purpose.

Channel Islands — Prescribed burn, Santa Cruz Island, NPS photo

We were surprised to see notice of herbicide application for Garlon 4 Ultra during our visit to this fragile place. Someone dressed from head to toe in protective clothing was spraying this chemical on a steep hillside. We have reported the toxic effects of Garlon in our post about herbicides.

This is a complex ecosystem in which simplistic solutions—such as killing all the non-natives—can result in a big mistake. For example, do we know if there are native Anise Swallowtail Butterflies on the islands that are now dependent upon non-native fennel for their survival? Do we know how the application of Garlon will impact the survival of the rare, endemic Island Jay? The US Forest Service found in its risk assessment done for the EPA that the application of Garlon had a significant negative impact on the reproductive success of birds. Are those who decided to spray Garlon aware of this study?

Herbicide application notice, Santa Cruz Island

We went to the Channel Islands with open minds. We thought the strongest arguments could be made for restorations on islands. However, when we learned of the thousands of animals who were sacrificed to this effort and the dangerous and toxic methods used to accomplish the restorations, we were not convinced. We nearly lost the Channel Island Fox because of the unforeseen consequences of killing feral pigs. Man would like to believe that he is capable of managing nature. But can he do so without causing more harm than good?

They can destroy your trees

Million Trees was created to inform the public of the many projects that have destroyed or plan to destroy non-native trees on public lands at every level of government from the federal government to local jurisdictions such as the Alameda County Water District. However, private properties are not immune from such efforts to destroy non-native trees. The legal battle to destroy 28 of 45 trees on private property in Larkspur is a case in point.

We learned of this legal battle from the San Francisco Chronicle . The property owner, Dr. Anne Wolff, was sued by her neighbors who claimed that her trees are hazardous. When the judged ruled that her trees must be destroyed, she appealed that decision.

We attended the appeal hearing. It was disturbing to hear the case law cited by the attorney representing the neighbors. We learned that other property owners had been ordered by the court to destroy their trees for such frivolous reasons as “leaves in the rain gutters” of their neighbors. One court ruling said that the “sheer size [of the tree] is a menace.” In other words, neighbors have successfully forced the destruction of their neighbors’ trees without any evidence that the trees were dangerous. The mere theoretical existence of danger was sufficient for the court to require the destruction of trees.

As we have reported in our post KILLER TREES!!!, arborists are sometimes willing to declare trees as hazardous if they are hired to do so. Therefore we are not convinced by the assessment that Dr. Wolff’s trees are hazardous. If these trees are in fact hazardous, it is not visually apparent.

Dr. Wolff told us she has received many calls from other property owners who did not have the financial resources to challenge the legal demands of their neighbors to destroy their trees.

The California Supreme Court has refused to hear Dr. Wolff’s appeal.

Dr. Wolff is now hoping that the Larkspur City Council will invoke the city’s Heritage Tree ordinance to prevent the destruction of the largest trees. We attended the demonstration on June 13, 2010, organized to appeal to the city council to save the trees. About 50 people attended and the media reported on the demonstration.

IMG_5483-2 — Demonstration in Larkspur, June 13, 2010

If you would like to help Dr. Wolff save her trees, please send an email to the Larkspur City Council, asking them to invoke the city’s Heritage Tree ordinance on behalf of her trees: lrifkind@larkspurcityhall.org, lchu@larkspurcityhall.org, dhillmer@larkspurcityhall.org, jlundstrom@larkspurcityhall.org, lk_admin@larkspurcityhall.org, khartzell@larkspurcityhall.org

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

KILLER TREES!!! Scare Tactic #3

We have recently learned of another tree removal project in the Bay Area. In this case, the San Leandro Creek Tree Management Project by the Alameda County Flood Control & Water Conservation District proposes to destroy about 50 eucalypts in the short run and approximately 1,000 more in the long run. All eucalypts will be removed. All other species of trees will remain.

St. Mary’s Ave: Try to picture this neighborhood without any of the tall trees in the background.

In this case the apparent “cover story” for yet another native plant restoration is that the trees are hazardous. As we have said in other posts, native plant advocates have had difficulty convincing the public—and therefore their political representatives–of the need to destroy non-native trees and plants and so they have frequently resorted to scary cover stories. Particularly in the East Bay, the most powerful argument has been the claim that the trees are flammable. The argument heard more commonly in San Francisco, where there is no history of wildfire, is that the trees are invasive and are killing native plants. Fortunately, there is scientific evidence that these claims are not accurate.

Native plant advocates also claim that eucalypts are more dangerous than other trees. However, the public record indicates that every species of tree—both native and non-native—can fall. The most recent “death-by-tree” in San Francisco occurred on April 14, 2008, when a visitor to Stern Grove was killed by a huge branch from a Redwood tree that had been judged to be hazardous by a certified arborist 5 years earlier. Unfortunately, the arborist’s report was ignored, resulting in the needless death of a young woman in the prime of her life. The City of San Francisco paid her family $650,000 for their negligence…a waste of a life and the taxpayer’s money for a death that could have been easily prevented.

Tragic events such as this make it clear that we should not oppose the destruction of hazardous trees. Unfortunately, that is a judgment that is not clear-cut or irrefutable. When native plant advocates demand the destruction of non-native trees, we are deeply suspicious of the claim that the trees are hazardous. In the case of the San Leandro Creek project, it is simply not credible that every eucalyptus is hazardous, but not any other species of tree in the watershed.

After many years of being put in the awkward position of evaluating the truth of such claims, we have concluded that we trust only the judgment of certified arborists, but not those paid to destroy the trees. There are a handful of arborists whom we know not to be biased against non-native trees, especially eucalypts. If we are told by these arborists that a particular tree is hazardous, we accept that judgment.

The neighbors of the San Leandro Creek who were about to lose many of the trees they love, organized and fought back. They protested the removals not just because they love their trees, but also because the project was invisible to them until the Alameda County Flood Control & Water Conservation District granted itself a categorical exemption from California Environmental Quality Act (CEQA) requirements for an environmental review. Short of a legal suit there was little that could be done to stop the project except scream. So, that’s what they did.

What is unique about this project is that the neighbors have prevailed. For the moment, it appears that this project has been halted. The Flood Control District has apparently agreed to step back, start over, and involve the neighbors before implementing their plans. We should all learn from this experience. We must speak up for our trees when they are threatened with needless destruction.

Million Trees usually reports such projects directly from the public record. In this case, we have access to little of the public record. We have asked the Water District’s representative for answers to many questions about this project, but have not received answers. We are therefore reporting based on what little documentation is available on line, reports of the neighbors, and one media report . We invite any needed corrections to this report and we will correct any errors, based on verifiable documentation.

Update: We are pleased to tell you that this controversy was finally resolved to the satisfaction of the neighbors of San Leandro Creek. Neighbors forced the county to do another evaluation of the trees in the creek. As a result, plans to destroy as many as 1,000 eucalyptus trees were finally reduced to a total of 17 trees deemed hazardous.

Glen drive comparison — Glen Drive: What will this property be worth after the tall trees are removed? Significantly less.

ALIEN INVADERS!!! Another scary story about non-native trees

As we have said before in “FIRE!!! The Cover Story,” fear is a powerful motivator of public policy. The fear of fire is not the only tool in the toolbox of native plant advocates. They would also like the public to believe that non-native plants are invasive, that they will overwhelm the environment if they are not promptly eradicated. So, we will take a closer look at this claim and show that non-native trees are not invading Bay Area open spaces.

In “Vegetation Change and Fire Hazard in the San Francisco Bay Area Open Spaces,” William Russell (USGS) and Joe McBride (UC Berkeley) used aerial photos of Bay Area parks taken over a 60 year period from 1939 to 1997, to study changes in vegetation types. They studied photos of 3 parks in the East Bay (Chabot, Tilden, Redwood), 2 parks in the North Bay (Pt Reyes, Bolinas Ridge), and one on the Peninsula (Skyline).

These photos revealed that grasslands are succeeding to shrubland, dominated by native coyote brush and manzanita. Eucalyptus and Monterey pine forests actually decreased during the period of study. In those cases in which forests increased in size, they were native forests of oaks or Douglas fir. In other words, they found no evidence that non-native trees are invading native trees or shrubs.

They also studied the implications of these changes in vegetation types for fire hazard by measuring surface biomass for each vegetation type as an indicator of fuel load and by using a computer model (FARSITE) to simulate the speed of spread of a fire. They concluded,

“A significant increase in the cover of shrublands was apparent in the general analysis…The results from the fuel and fire hazard analysis suggest that the succession from grasslands to Baccharis [coyote brush] shrublands indicates dramatic increase in fire hazard for those areas. Fire line intensity, flame length, and total biomass were found to be significantly higher with the shrub dominated areas. In the context of the landscape matrix as a whole this increased hazard indicates a greater possibility of fire being spread into adjacent forested areas and residential communities.”

This is a view of one of the "recommended treatment areas" in the East Bay Regional Park District's "Wildfire Plan" in Anthony Chabot Park. In the foreground are many acres of coyote brush that are about six feet tall. The plan does not propose any "treatments" in these acres of highly flammable coyote brush. In the background is the eucalyptus forest that will be thinned in some places and removed in others. This is not a plan that will reduce fire risk.

This study, based on actual aerial photos, tells us that native shrublands are increasing in size while non-native forests are actually decreasing in size. It also tells us that this succession of vegetation types from grassland to native shrubland is increasing fire hazard. There is no evidence that non-native forest is invading the open spaces of the San Francisco Bay Area. The public has no reason to fear that non-native trees will overwhelm our environment.