Conservation Sense and Nonsense

Trees Withstand the Firestorm

Today, we visited the site of the fire in San Bruno that destroyed 37 homes, damaged many others and killed 8 people on September 8, 2010. The fire occurred because a 30 inch natural gas pipeline exploded, sending a 200 to 300 foot fireball into the sky, according to the San Francisco Chronicle. A federal investigation reported that it took the responsible utility company 1-1/2 hours to shut the supply valves to the burning gas line, so the fireball persisted for sometime, producing intense heat.

P1000615 — San Bruno blast destroyed this home, but the Monterey pines did not burn

Although trees in the immediate area of the blast burned, along with the homes, the fire did not spread into surrounding trees.

The area of the blast is a small valley. The ridgeline of that valley is lined with eucalypts. The fire did not spread into those trees. The eucalypts did not explode nor did they “loft embers” from one side of the ridge to the other, as we are often told they will by those who want us to believe that they are highly flammable and must be destroyed.

Trees adjacent to the blast did not burn

The San Bruno fire is therefore the most recent example of the fire resistance of trees. There are many other examples. An entire neighborhood of homes in San Diego burned in 2003, but the surrounding eucalypts just a few feet away did not ignite.

Scripps Ranch - nytimes — NY Times reported that 150 homes burned in this wind-driven fire in San Diego in 2003, but the eucalyptus did not burn. NY Times photo

The fire on Angel Island in 2008, twelve years after most eucalypts were destroyed, stopped at the edge of the remaining 6 acres of eucalypts. The eucalypts did not ignite during the fire in the Tamalpais Valley in 2006, according to the National Park Service, which continues to destroy eucalypts anyway, based on a bogus claim that they are highly flammable.

How much more evidence do we need to debunk the myth that eucalyptus and Monterey pine are highly flammable? Since those making this claim don’t seem to be influenced by actual experience, let’s subject their myth to some laboratory science.

The predominant species of eucalyptus in California, the Blue Gum eucalyptus (E. globulus) is native to Tasmania. Scientists at the University of Tasmania conducted laboratory experiments on the plants and trees in the Tasmanian forest to determine the relative flammability of their native species. The Blue Gum eucalyptus (E. globulus) is included in this study. The study reports that, “E. globulus leaves, both juvenile and adult, presented the greatest resistance [to ignition] of all the eucalypts studied. In this case, leaf thickness was important as well as the presence of a waxy cuticle.” Also, in a table entitled “Rate of flame front movement,” the comment for E. globulus leaves is “resistant to combustion.”* In other words, despite the oil content in the leaf, its physical properties protect the leaf from ignition.

Although local native plant advocates still maintain that non-native trees are highly flammable, we are encouraged by the comments of the Environmental Protection Agency (EPA) regarding the FEMA grant applications in the East Bay Hills. These and many other comments submitted to FEMA to identify the environmental issues are now available on FEMA’s website (scroll down to Appendix F). Although the projects propose to clear-cut non-native trees in most areas, the EPA does not consider this necessary for fire safety:

“Include a commitment to leave trees greater than a specific DBH [trunk diameter at breast height] in size, and identify how this should be implemented. Diameter and height are, in effect, measures of tree resistance to fire damage. Large diameter trees are generally more able to withstand wildfire, assuming that surface and ladder fuels have been reduced and the severity of the fire is not extreme. By leaving the largest trees and treating surface and ladder fuels, fire tolerant forest conditions can be created.”

This sensible fire safety policy is finally emerging from the highest levels of government. Surely it is only a matter of time before this common sense approach to fire safety penetrates local levels of government. We can only hope that it does so before our trees are destroyed.

* Dickinson, K.J.M. and Kirkpatrick, J.B., “The flammability and energy content of some important plant species and fuel components in the forests of southeastern Tasmania,” Journal of Biogeography, 1985, 12: 121-134.

Jared Diamond’s History Lesson for Us

In Collapse: How Societies Choose to Fail or Succeed, Jared Diamond reviews the histories of societies that have failed in climates as diverse as Polynesia and the Arctic North. He identifies a handful of factors that were instrumental in those failures, but only one of those factors is shared by all the examples he describes: deforestation.

In every case deforestation reduced agricultural productivity by causing soil erosion and reducing rainfall. The roots of trees hold soil in place and absorb rainfall which would otherwise wash over the surface of the soil, flushing it into watersheds where it increases turbidity and destroys fisheries. The rainfall that is absorbed by the roots of trees is transpired by the leaves into the air where it rejoins the water cycle to be returned to the land as rainfall. When the trees are destroyed, the water cycle is interrupted in that location and rainfall is reduced.

In some cases, the loss of trees had a more immediate, observable effect on the society. On Easter Island, for example, the loss of trees quickly meant the loss of their main source of food: fish. Easter Island was the most easterly of the islands inhabited by Polynesians. It was far from any other island. Therefore, when their trees were gone and their boats eventually fell apart and could not be replaced, they had no means of fishing from their rocky shores. (see video)

Likewise, the Norse population in Greenland eventually starved to death when they could no longer grow the hay needed to keep their cows alive. In this frigid climate, they had used all of their trees as fire wood for warmth and to pasteurize the milk that was their principle food source. As their fuel source diminished, they burned the peat that fed their cows.

In both cases, as well as in others, these societies made choices that eventually contributed to their demise. The failure of their societies was not inevitable. On Easter Island, for example, the Polynesians chose to cremate their dead, unlike other Polynesians who bury their dead. And they devoted much of their time, effort, and resources to building the gigantic stone tributes to their ancestors. These stone sculptures were carved in quarries and then transported many miles by rolling them on logs. These cultural uses of wood were not essential to the islanders’ physical survival.

: Easter Island, Wikimedia Commons

In Greenland, the Norse brought the cows from their homeland that were central to their culture. Their lives were devoted to keeping their cows alive by spending the brief summer growing the hay to feed the cows during the long winter in the huge stone barns in which the cows were protected from the extreme cold. The milk had to be boiled to prevent it from spoiling. As they depleted the wood needed to boil the milk, they simultaneously destroyed the land needed to grow the hay to feed the cows by burning the peat and causing erosion.

Meanwhile, the Inuit neighbors of the Norse made other choices that enabled them to survive in the harsh climate. They hunted whales and seals that were their principle food as well as the source of oil that heated their homes. The Norse considered the Inuit enemies with whom they did not interact or trade. Therefore, they were unable to learn these survival skills from them.

Diamond contrasts these histories with those of cultures that have made other choices. One of the most dramatic examples is the island of Hispaniola, shared by the nations of Haiti and the Dominican Republic. Haiti is almost entirely deforested and its ability to feed itself is destroyed by erosion. In contrast, the Dominican Republic is heavily forested because of a strong commitment to its forests made by its leadership. There are intervening factors, to be sure, but the deforestation of Haiti is a major factor in its impoverishment.

Diamond’s book intends to challenge us to look at the choices we are making for our own society. He asks and answers the rhetorical question, “Why did these societies make choices that contributed to their failure?” The short answer to that question is that long-term goals were sacrificed to short-term goals and that entrenched cultural practices were incapable of responding to changed conditions. When you are freezing cold today, you might choose to burn your last tree even if it means you don’t have any wood tomorrow. And when your entire diet is based on milk you can’t conceive that eating whale blubber may be a better choice for your long-term survival.

Million Trees sees these poor choices made by failed societies as similar to the poor choice that is now being made here in the Bay Area to destroy our non-native trees because we prefer native plants and trees.

We live in a place in which there were few trees prior to the arrival of Europeans. The landscape goal of native plant restorations is therefore grassland, scrub, and chaparral. Native trees are unlikely to survive in most of the places which are now forested by non-native trees. Native trees are being killed by Sudden Oak Death and bark beetle. Their historic ranges are changing in response to climate change. Releasing carbon sequestered in the trees and eliminating that source of carbon storage in the future will contribute to the greenhouse gases that result in climate change. Erosion is a likely consequence. Rainfall could be reduced by the absence of trees. Denuding our landscape of non-native trees is likely to result in a barren, weedy mess.

P1000017 — Grizzly Peak Blvd is being undermined by erosion resulting from clear-cutting of non-native trees

We urge native plant advocates to re-examine their demands for the destruction of non-native trees and plants in light of the changing climate which is exacerbated by deforestation. As Jared Diamond says as he concludes his book, “The other crucial choice illuminated by the past involves the courage to make painful decisions about values. Which of the values that formerly served a society well can continue to be maintained under new changed circumstances.”

We do not ask that native plant advocates abandon their preference for native plants. We encourage them to plant more native plants. We ask only that they quit destroying those that are not native.

Losing Battles to Save our Trees

In our posts “They can destroy your trees” and “KILLER TREES!! Scare Tactic #3” we told you about two efforts to save eucalyptus trees that were threatened with destruction. Today we must tell you that those battles have been lost.

In Larkspur, 25 trees that have been destroyed were on private property. The owner of that property was sued by her neighbors who demanded that the trees be destroyed because they believed them to be dangerous. The owner of the trees made every effort to save her trees, even appealing unsuccessfully to the California Supreme Court for reversal of the court order to destroy most of her trees. She organized demonstrations in a fruitless effort to interest local politicians to come to the defense of her trees. Finally, when she was cited for contempt of court, she had her beautiful trees cut down.

Yesterday we attended a memorial for her trees. We find it hard to believe that her neighbors would prefer the barren landscape that remains or the PG&E pole that was installed to hold the electrical wires that had previously been held by the trees.

In San Leandro, the neighbors worked equally hard to save the eucalyptus trees on the banks of the San Leandro Creek from being destroyed. They faithfully attended a series of community meetings which were theoretically an opportunity for them to defend the health, safety, and beauty of their trees. As is often the case when we advocate on behalf of our trees, we may be successful in demanding a public process, but that rarely seems to save our trees.

That was the case in San Leandro. Neighbors were informed at the last public meeting that 31 of the 47 trees originally in jeopardy will be removed and 2 will be “trimmed” to stumps, but allowed to regenerate (1). After months of effort, neighbors have saved only 14 of their trees and the assumption is that the remaining 1,000 eucalypts on the banks of the creek remain in jeopardy.

However, the county has made a commitment to an environmental review, which it had originally intended to avoid by destroying the trees piecemeal. This environmental review will give the neighbors another opportunity to document the negative environmental impacts of tree destruction, whether the trees are native or non-native.

As the needless destruction of non-native trees continues unabated, millions of native oaks are being killed by Sudden Oak Death, millions of native pines are being killed by bark-beetles, and the ranges of native plants and trees are shifting to higher elevations as the climate changes. Those who demand the destruction of non-native trees which are adapted to current climate, soil, and air quality conditions will doom us to a barren, treeless environment.

It is long past time for environmentalists to reorder their priorities to put climate change mitigation ahead of their commitment to native plants. Their crusade against non-native trees is contributing to climate change by releasing tons of sequestered carbon into the atmosphere. Ironically, as the climate changes, the native plants to which they are devoted are dying. In other words, they are shooting themselves and the plants they prefer in the proverbial foot.

(1) San Leandro Times, 9/2/10

SOD Update

The San Francisco Chronicle recently published an update about Sudden Oak Death (SOD) that was both misleading and inaccurate.

The article inaccurately claimed that “the mysterious pathogen…has killed tens of thousands of oak trees from Big Sur to southern Oregon.” This is a gross underestimate of the number of trees that have been killed by SOD. The California Oak Mortality Task Force reported in the announcement of their 2009 annual symposium that “Since the 1990s more than a million oak and tanoak trees have died from this pathogen and at least another million are infected.” Since there is no known cure for the disease, we must assume those trees will die.

Secondly, the article quotes Matteo Garbelotto of UC Berkeley—who is described as “the nation’s foremost expert on sudden oak death”—as recommending that “homeowners in infected areas can remove bay trees…[to] increase the survival rate of nearby oaks.” We doubt that this is an accurate quote because it is not consistent with the advice Garbelotto gave at one of his SOD workshops.

One of the many professional gardeners attending that workshop asked if he should remove the bays in the gardens in which there are also oaks to protect the oaks from infection. Mr. Gabelotto’s response was that the bays would resprout ten-fold and that the immature leaves of the resprouts would be more susceptible to infection than the mature leaves. The gardener asked if he could prevent resprouts with Roundup. Mr. Garbelotto replied that Roundup would not prevent resprouts.

In other words, removing bay trees is easier said than done. Attempts to do so can result in even more bay trees unless toxic chemicals such as Garlon are used repeatedly to prevent resprouts. Since the immature leaves of the resprouts are more susceptible to SOD infection, this is not a wise strategy.

Garbelotto may have told the Chronicle that removing bay trees already infected with SOD may prevent the spread of the pathogen to oaks. Although it seems to us a risky strategy, it is apparently being done in the Santa Cruz Mountains, according to the San Jose Mercury (“’Sorry baby, but you gotta go’,” December 17, 2009). This is an important distinction: removing healthy bay trees is likely to do more harm than good, while removing infected bay trees may make some sense, although we would prefer to avoid the use of toxic chemicals.

Journalism is a powerful tool that can strengthen democracy if used responsibly, reporting the facts faithfully and balancing competing opinions when necessary. The author of this article grossly underestimates the number of native trees killed by SOD and offers bad advice about killing healthy trees. Those who still subscribe to the dwindling San Francisco Chronicle will not be surprised by such sloppy journalism. It is an example of the death throes of the Bay Area’s local newspaper.

The Sierra Club instructs FEMA

Those who are still members of the Sierra Club, but are concerned about the Club’s endorsement of projects to destroy trees and use toxic poisons to kill their roots, might be interested in the Club’s public comment (scroll down to Appendix F “Written Comments) to Federal Emergency Management Agency (FEMA) in preparation for the Environmental Impact Study of four such projects in the East Bay hills.

The Chairman of the Bay Area Chapter of the Sierra Club begins by asking FEMA to ignore those who are critical of these projects: “1. We urge FEMA to discount the views of any individual or group that uses sophomoric name calling tactics in the press or in their FEMA scoping comments to categorize people or advocacy groups as ‘nativists’ (or other similar pejorative labels)…”

Apparently the author does not consider calling someone “sophomoric” an example of “name-calling.” Webster defines “sophomoric” as “intellectually pretentious and conceited but immature and ill-informed.” Hmmm…that sounds pretty insulting to us.

We don’t use the word “nativist” here on Million Trees, not because we consider it an inaccurate description, but rather because we have been told that it offends native plant advocates. Since our goal on Million Trees is to inform, rather than to offend, we stick with the clunky phrase, “native plant advocates.”

What about “other similar pejorative labels?” Does the Club also object to the phrase “native plant advocates?” We are at a loss to arrive at some phrase that would appease them. For the moment, we’ll stick with “native plant advocates” to describe those who advocate for the restoration of native plants to our public lands. After all, the Sierra Club freely admits its preference for native plants in their letter: “We obviously prefer our local native species and plant communities when compared to…introduced species.”

The Sierra Club also instructs FEMA to put the restoration of native plant communities on an equal footing with fire hazard mitigation: “We also urge FEMA to ensure that natural resource protection is given equal status with fire hazard reduction work when final projects are developed.” The letter provides a detailed description of the “natural resource protection” it has in mind. In this context, that phrase translates to “native plant restoration.”

Since the stated purpose of FEMA’s pre-disaster and hazard mitigation grants is to reduce fire hazard to the built environment and the humans who live in it, this doesn’t seem an appropriate request. FEMA’s legal and fiduciary responsibility is to respond to disasters when they occur and to reduce the potential for disasters in the future. FEMA seems to have its hands full doing just that. FEMA’s assigned mission does not include native plant restoration.

As we observed in our post “Open Letter to the Sierra Club,” the Club tends to ignore the fact that the tree destruction for which they advocate requires the use of toxic herbicides. However, in its public comment letter to FEMA, the Club acknowledges the use of such herbicides and endorses their use: “We are not currently opposed to the careful use of Garlon…” On our page about “Herbicides,” we report that the EPA classifies Garlon as “hazardous” and we cite the laboratory research on Garlon, indicating that it is harmful to many species of animals and is mobile in soil and water.

We hope that FEMA will maintain its mandated focus on hazard mitigation, its sole responsibility to the taxpayers. If the taxpayers wish to fund native plant restorations, they should do so by designating an appropriate fund source. FEMA is not an appropriate fund source for native plant restorations.

FEMA sees through the smokescreen

The Federal Emergency Management Agency (FEMA) has seen through the smokescreen that native plant advocates have created as a pretext for destroying non-native trees in the San Francisco Bay Area. Native plant advocates claim that destroying non-native trees will reduce fire hazard. As taxpayers, and as fans of all trees, we commend FEMA for preserving their limited resources for legitimate disaster mitigation.

In February 2010, UC San Francisco (UCSF) announced that it had withdrawn its application for FEMA funding to destroy most of the eucalypts on 14 acres of the Sutro Forest. When making that announcement UCSF explained that FEMA would require a comprehensive Environmental Impact Study before the grant would be awarded which would result in a two-year delay in the implementation of the project. UCSF preferred to pay for the project with its own funds rather than delay it during the environmental review. Therefore, UCSF withdrew its application for FEMA funding. Since then, UCSF has proceeded with its plans, expanding them to 40 acres, and continues to claim that there is extreme fire hazard in the Sutro Forest which it claims will be mitigated by the project.

Sutro Forest from savesutro — Sutro Forest on a typically foggy day in late summer. Courtesy SaveSutro.wordpress.com

We now know there is more to the story than is revealed by UCSF’s announcement. The neighbors of the Sutro Forest who have been trying to save their forest for over a year, have since obtained correspondence from FEMA regarding UCSF’s grant applications through a public records request. The correspondence with FEMA indicates that:

UCSF misrepresented and exaggerated the fire hazard on Mount Sutro by rating it as “extreme.” FEMA confirmed with the state’s fire authority that fire hazard on Mount Sutro is moderate, CAL Fire’s lowest rating of fire hazard. (1)
FEMA asked UCSF to explain how fire hazard would be reduced by eliminating most of the existing forest, given that: (2)
- Reducing moisture on the forest floor by eliminating the tall trees that condense the fog from the air could increase the potential for ignition, and
- Eliminating the windbreak that the tall trees provide has the potential to enable a wind-driven fire to sweep through the forest unobstructed.
FEMA asked UCSF to consider alternatives to its project, which would have the potential to mitigate fire hazard to the built environment by creating defensible space around buildings, structural retrofits, and vegetation management projects. (3)

UCSF has elected to ignore this advice from FEMA, choosing instead to proceed with its project as originally designed using its own funds at a time of extreme budgetary limitations. Clearly this is an indication that fire hazard mitigation is not the purpose of their project. UCSF chooses to increase fire hazard rather than reduce it, putting themselves and their neighbors at risk.

FEMA is now engaged in a comprehensive Environment Impact Study of four similar projects in the East Bay hills that propose to destroy hundreds of thousands of trees. The applicants are UC Berkeley, the City of Oakland, and East Bay Regional Park District. Fire hazard in the East Bay is greater than in San Francisco because the summer is hotter, the frequency of Diablo winds is greater, and there are rare deep freezes that cause some non-natives to die back, creating dead leaf litter on the forest floor. However, the remaining issues are the same as those on Mount Sutro:

The loss of tall trees will reduce moisture on the forest floor and eliminate the shade that maintains that moisture. The remaining native landscape will be predominantly grassland studded with scrub, chaparral, and short native trees in sheltered ravines. This will be a flammable landscape, not less flammable than the existing landscape.
The loss of the windbreak provided by the tall trees will enable a wind-driven fire to travel unhindered through the community.
The projects in the East Bay hills do not provide defensible space around homes, which would reduce fire hazard to homes and those who live in them, the stated purpose of FEMA grants.

We hope that FEMA will see the similarity between the East Bay projects and those in San Francisco and advise the applicants in the East Bay to revise their projects so that they are appropriately aimed at creating defensible space around homes. Destroying hundreds of thousands of trees will not make us safer. In fact, it is likely to increase the risk of wildfire.

———————————————————————————-

Sources:

(1) Excerpt from FEMA’s letter of October 1, 2009, regarding UCSF’s grant applications:

“In its response to provide a clarification of the wildfire hazard, UCSF inaccurately interprets a map, provides inadequate details regarding the history of wildfires in the Sutro Forest, and provides a simplistic and ineffective comparison of the wildfire hazard in the Sutro Forest to the hazard in other areas that have burned in the San Francisco Bay Area…The 2007 FHSZ [Fire Hazard Severity Zones] map shows the Sutro Forest to have a “Moderate” wildfire hazard in the 2007 FHSZ maps. “Moderate” is the lowest of the three fire hazard severity zones…”

(2) Excerpt from FEMA’s letter of October 1, 2009, regarding UCSF’s grant applications:

“Commenters argue that the proposed projects would increase wildfire hazard by removing some of the material that collects fog drip and keeps the forest moist and resistant to ignition and fire, thus allowing the forest to dry out more easily and increase the relative hazard for ignition. Can UCSF specifically address this comment and describe how overall forest moisture content will change after implementation of the proposed projects? Please provide scientific evidence to support any claims.”

“Additionally, several of these unsolicited public comments have stated that the proposed projects could result in changed wind patterns on Mount Sutro which could also increase the wildfire hazard in the forest. New wind patterns could reduce biomass moisture as well as reduce the effective windbreak created by the current forest. These comments argue that the effective windbreak created by the existing forest limits the potential for wildfire spread in the forest and the immediately surrounding area. As UCSF has stated, winds are a contributing factor in wildfires. Provide a citable and logical defense regarding how the proposed projects, and the resulting changes in wind patterns, would not result in an increase in the wildfire hazard in the Sutro Forest.”

(3) “Assuming that UCSF has been able to establish a clear need for wildfire mitigation activities, UCSF must conduct a more thorough analysis to identify alternatives to the proposed projects that could mitigate wildfire hazard in the Sutro Forest to the vulnerable built environment. These alternatives must be technically, economically, and legally practical and feasible and can include activities not eligible for FEMA grant funding. As described in FEMA’s Wildfire Mitigation Policy…wildfire mitigation grants are available for defensible space, structural retrofit, and vegetation reduction projects. It would seem reasonable that alternatives to the proposed projects could include defensible space or retrofit projects.” (emphasis added)

Eucalyptus and Poppies

Have you visited the Oakland Museum since it reopened this summer after extensive renovation? It looks pretty spiffy and continues to be a valuable resource for our community.

The museum’s collection of California art and design represents “the region’s creative output and its relationship to, and influences on, the nation and the world from the mid-1800 to the present,” according to its website. And so, as we would expect, the exhibit includes a fitting tribute to one of California’s iconic landscapes, “Eucalyptus and Poppies.”

The artworks in this exhibit were created from 1916 to 1940, a period when eucalypts were popular. They are out of fashion now, as are leisure suits and beehive hairdos. Will they make a comeback, as did bell bottoms and hip hugger jeans?

There was a time, not so long ago, when Californians thought eucalypts fit in just fine with our native poppies. Are they really the destructive intruders that native plant advocates make them out to be? We don’t think so. We believe that eucalypts are the victims of a “bad rap,” scapegoats for a fire they didn’t cause and a dwindling native landscape that is succumbing to climate change and other factors unrelated to the existence of eucalypts.

Creating Defensible Space for Fire Safety

Those who have a sincere desire to reduce fire hazards in the Bay Area would be wise to turn their attention away from the distracting and irrelevant debate about the flammability of native compared to non-native plants and trees. California native ecology is dependent upon and adapted to fire. The native landscape is not less flammable than non-native plants and trees. Most firestorms in California are wind-driven fires in which everything burns, including native and non-native trees and plants as well as any buildings in the path of the fire.

Rather, the creation of “defensible space” immediately around your home is your best defense against the loss of your home in a wildfire. Creating defensible space means reducing fire fuels around your home by appropriate pruning and maintenance, such as limbing up trees to remove the fire ladder to the tree canopy and removing leaf litter. Defensible space is intended to slow the progress of fire to your home.

In this post we will visit several reputable sources of information about fire safety that advise homeowners about how to protect themselves, particularly those who live in the Wildland-Urban Interface where fire hazards are greatest. We will see that all these sources of information have in common that they do not single-out specific species of plants or trees. Rather they emphasize that how vegetation is pruned and maintained is more important to reducing fire hazard and that materials we use in building our homes are equally important to our safety. These sources of information are not native plant advocates. Their advice is not based on a desire to destroy non-native plants and trees in the belief that their destruction will benefit native plants and trees.

Firewise Communities is an internet resource provided by the National Fire Protection Association and co-sponsored by the US Forest Service and the US Department of the Interior. This resource offers on-line courses in fire safety. In the course on “Firewise Landscaping” these criteria are listed as the characteristics of fire-resistant plants: low leaf litter, high water retention ability, high salt retention ability, lack of aromatic oils, low fuel volume, height and spread that fits well into the intended space. Some native and some non-native plants fit these criteria and some do not. For example, although the leaves of eucalyptus contain aromatic oils, so do the leaves of the native California bay laurel.

Homeowners in the Wildland-Urban Interface should focus on creating defensible space around their homes rather than on choosing particular plant or tree species. CALFire guidelines for creating defensible space do not advise for or against any particular species of plant or tree. Rather CALFire focuses on how to prune and maintain vegetation around your home and create a “defensible space” around your home with low fuel volume, as illustrated in this brochure on their website.

DefensibleSpaceFlyer - cropped copy — Creating defensible space around your home. CALFire

Likewise the UC Berkeley Fire Center in their brochure “Home Landscaping for Fire” says, “It is important to remember that given certain conditions, all plants can burn…how your plants are maintained and where they are placed is as important as the species of plants that you choose…landscape management (e.g., pruning, irrigation, and cleanup) have a greater impact on whether or not a plant ignites than does the species.” It is ironic that UC Berkeley is engaged in the destruction of every non-native tree and plant on its property, despite the advice on its own website about fire safety, which is obviously being ignored.

The August 2010 issue of Sunset Magazine includes a comprehensive “Wildfire Survival Guide,” including advice about planting a fire-safe garden.

The City of Oakland passed an ordinance in 2006 requiring homeowners to maintain defensible space around their homes and voters in Oakland agreed to tax themselves to pay for the enforcement of this requirement. Unfortunately, a drive in the Oakland hills informs us that these requirements are not being enforced.

This home is particularly vulnerable because fire tends to travel up hill. Firewise says that a 30% slope will accelerate the rate of spread of fire to twice the speed of fire on flat ground.

Wouldn’t the people of Oakland be better served by enforcement of requirements for defensible space around homes rather than paying shared costs of $662,280 for a FEMA grant to eradicate all non-native vegetation from 325 acres of wildland? (see “Our Mission, Projects in the East Bay”) Oakland is flat broke and one of the most violent cities in the country. Eighty policemen were recently laid off and 120 more are likely to be laid off if voters don’t vote to tax themselves further. Shouldn’t homeowners be required to create defensible space around their homes where their lives and property are most at risk before “vegetation management” is extended far beyond the perimeter of homes?

Invasion or Natural Succession?

In a recent post we considered the changes in our landscape that have occurred as a result of climate change. In this post we examine more historical sources of change in the landscape.

Native plant advocates in the Bay Area choose to replicate the “pre-settlement” landscape that existed in the late 18^th century. The arbitrary selection of this date does not take into account that Native Americans had lived in the Bay Area for approximately 10,000 years. Throughout that period Native Americans altered the landscape by setting fires to promote food production as well as to provide materials for cultural activities such as basket weaving. Fires were used to improve forage for the animals they hunted and visibility during the hunt, and to funnel animals into their hunts. Fires also promoted the growth of their food sources such as acorn production. (1)

Unlike some parts of California, fire ignition in the San Francisco Bay Area is rarely caused by lightening, making this anthropogenic (caused by man) source of fire the predominant cause of fire historically. (2)

After the arrival of the Spanish in the late eighteenth century, cattle and sheep grazing was the predominant economic activity in California and continued to be an important activity into the early 20^th century. These early ranchers also introduced non-native grasses which had greater nutritional value for their herds. The non-native annual grasses out-competed the native bunch grasses, resulting in California grassland that is 99% non-native today (3).

The fires set by Native Americans and the cattle grazing of the early Californians were both instrumental in preventing the natural succession of grassland to chaparral and scrub and subsequently to woodlands. Modern land use and management policies have suppressed fire and reduced grazing in the Bay Area. Consequently grasslands are succeeding to chaparral and scrub. Although managers of public lands often describe these changes in the landscape as “invasions,” Jon Keeley (Ph.D. biologist, USGS) considers them a natural succession:

“These changes are commonly referred to as shrub invasion or brush encroachment of grasslands. Alternatively, this is perhaps best viewed as a natural recolonization of grasslands that have been maintained by millennia of human disturbance.” (4)

Serpentine Prairie restoration. East Bay Regional Park District

So, if the succession of grassland to shrubland is natural, why do managers of public lands believe it is necessary to prevent—or even reverse– this succession?

Serpentine Prairie. 500 trees were destroyed, including many oaks.

For example, the “Wildfire Plan” of the East Bay Regional Park District is even more ambitious than halting natural progression of the landscape. In many instances it proposes to return the landscape to an earlier version of the native landscape. Here are a few examples of management actions in the “Wildfire Plan” that are intended to roll back biological time to sustain native landscapes from an earlier period:

“[Native] Grasslands and Herbaceous Vegetation…these widely-spaced trees will not cause an active crown fire because of the discontinuity of tree crowns. They could, however, provide a seed source for invasion of grassland habitats by woodland species and should be considered for removal to maintain desirable and declining grassland habitat.” (page 131)
“[Native] Maritime Chaparral…Favor chaparral community by removing oak, bay, madrone buckeye, and other trees under 8 inches diameter at breast height that are encroaching upon the maritime chaparral.” (page 136)
“[Native] North Coastal Scrub…Shift species composition towards native scrub species or consider conversion to grasslands, where appropriate on historic grassland sites…” (page 140)
“[Native] Coyote Brush Scrub…In most treatment areas, encourage conversion to grasslands by reseeding with native grasses…after brush removal.” (page 149)

Serpentine Prairie being weeded by hand. Mowing will be required during the restoration. Prescribed burns will be required to maintain it as prairie.

The return of the existing landscape to earlier, historical versions requires the removal of native trees and shrubs, as well as dangerous, polluting prescribed burns. In so doing, a permanent commitment to periodic prescribed burns is made to maintain the landscape as grassland. And what will this accomplish? If this strategy is successful the landscape would be returned to a version of the landscape in the late 18^th century, even though that landscape was actually created by the Native Americans and maintained by subsequent grazing by early European settlers.

As we often do on Million Trees, we ask the managers of our public lands to explain their strategy for artificially maintaining our landscape at an arbitrarily selected point in time. Should we run the risks of prescribed burns for the sole purpose of replicating an 18^th century landscape that was created by Native Americans? Since California grassland is now almost entirely non-native, what is the point of preventing its succession by destroying native plants? We don’t understand what would be accomplished by such artificial manipulation of the landscape.

(1) “The Use of Fire by Native Americans in California,” M. Kat Anderson in Sugihara, Fire in California’s Ecosystems, 2006.

(2) “Central Coast Bioregion,” Frank Davis & Mark Borchert in Sugihara, Fire in California’s Ecosystems, 2006.

(3) Natural History of California, Schoenherr, UC Press, 1992

(4) “Fire history of the San Francisco East Bay region and implications for landscape patterns,” Jon E. Keeley, International Journal of Fire, 2005.

Sudden Oak Death

Coast live oak, Mountain View Cemetery, Oakland

The coast live oak that is native to the Bay Area is one of our favorite trees and we would be happy to see more of them. However, the epidemic of Sudden Oak Death that is killing oaks in California and Oregon makes us question the wisdom of replacing non-native trees with oaks that may not survive that epidemic. Since any dead tree is more flammable than any living tree, we are also skeptical about claims that restoration of the oak-studded grassland will reduce fire hazard in the Bay Area.

SOD, Forest Service photo — Sudden Oak Death, US Forest Service photo

The pathogen (Phytophthora ramorum) that causes Sudden Oak Death (SOD) was reported on the UC Berkeley campus in 2002. At that time it also existed at the UC Botanical Garden and the researcher who identified the pathogen speculated that it probably existed throughout the East Bay. By 2008, the SF Chronicle reported that the infestation of SOD existed in several parks in the East Bay. The researcher estimated that about 20% of all coast live oaks in the East Bay are infected with the pathogen that will eventually kill them.

In February 2008, the California Oak Mortality Task Force estimated that ”millions of tanoak and coast live oak” have been killed by SOD in California. Thirty four other species of trees and shrubs are also infected with the pathogen, including bay laurels and redwoods. Although these species are not usually killed by the pathogen they are vectors of the disease. The bay laurel is singled out by the scientific literature as being particularly effective at transmitting the pathogen to the oaks that are then killed.

The “Wildfire Hazard Reduction and Resource Management Plan” of the East Bay Regional Park District proposes to destroy most non-native trees on over 1,500 acres of parkland. The “vegetation management goal” for most of these acres is the restoration of “oak-bay woodland.” And so we ask these rhetorical questions:

What is the probability that coast live oak will survive the deadly SOD pathogen in the Bay Area?
Does the proximity of bay laurel to the local oak population increase the probability of infection?
If the oaks are killed by SOD will the risk of wildfire in the East Bay hills increase?
If the non-native trees are destroyed and the oaks are killed by SOD will the resulting landscape be entirely treeless?

We believe these are legitimate questions and when we have asked them of native plant advocates we have not heard an adequate answer. We believe that eradicating non-native plants and trees without a clear understanding of the future of the natives, is irresponsible.