Eradicating non-native plants does NOT benefit insects

We briefly reactivate the Million Trees blog to publish an interesting and important debate between Jake Sigg and Professor Art Shapiro about the relationship between insects and native plants.  Their debate was initiated by this statement published in Jake Sigg’s Nature News on April 26, 2019:

“Did you know that 90 percent of insects can only eat the native plant species with which they’ve co-evolved?”

Jake Sigg has been the acknowledged leader of the native plant movement in the San Francisco Bay Area for 30 years.  He is a retired gardener for the Recreation and Parks Department in San Francisco. Art Shapiro is Distinguished Professor of Ecology and Evolution at UC Davis.  He has studied the butterflies of Central California for 50 years. 

Jake and Art are both passionately committed to the preservation of nature, but their divergent viewpoints reflect their different experiences.  Jake’s viewpoint is based on his personal interpretation of his observations.  As a gardener, his top priority is the preservation of plants rather than the animals that need plants.  As a scientist, Art’s viewpoint is based on empirical data, in particular, his records of plant and butterfly interactions over a period of 47 years as he walked his research transects about 250 days per year. The survival of butterflies is Art’s top priority.

Although their discussion is informative, it does not resolve the questions it raises because Jake and Art “agree to disagree.”  Therefore, Million Trees will step into the vacuum their discussion creates to state definitively that it is patently false to say that “90% of insects can only eat native plants.” That statement grossly exaggerates the degree of specialization of insects and underestimates the speed of adaptation and evolution.

There are several reasons why insects do not benefit from the eradication of non-native plants:

  • Insects use both native and non-native plants.
  • Pesticides used to eradicate non-native plants are harmful to both plants and insects as well as the entire environment.
  • There is no evidence that insects are being harmed by the existence of non-native plants.

Insects use both native and non-native plants

This statement was recently made in an article published by Bay Nature magazine about Jake Sigg:  “More than 90 percent of all insects sampled associate with just one or two plant families.”  (7,500 insect species were sampled by the cited study.  There are millions of insect species and their food preferences are largely unknown.)  This exaggerated description of specialization of insects seems the likely origin of the subsequent, inappropriate extrapolation to the statement that specialized insects require native plants.

Anise Swallowtail butterfly in non-native fennel. Courtesy urbanwildness.org

There are over 600 plant families and thousands of plant species within those families.  Most plant families include both native and non-native plant species.  An insect that uses one or two plant families, is therefore capable of using both native and non-native plant species.

We will use the Oxalidaceae plant family to illustrate that insects can and do use both native and non-native plants.  Oxalidaceae is a small family of about 5 genera and 600 plant species.  We choose that family as an example because Jake Sigg’s highest priority for eradication is a member of that plant family, Oxalis pes-caprae (Bermuda buttercup is the usual common name)In a recent Nature News (April 9, 2019), Jake explained why:  Oxalis is not just another weed; this bugger has a great impact on the present and it will determine the future of the landscapes it invades.” 

Five members of the Oxalis genus in the Oxalidaceae family are California natives. An insect that uses native oxalis can probably also use the hated Bermuda buttercup oxalis because they are chemically similar. 

Honeybee on oxalis flower, another non-native plant being eradicated with herbicide.

The consequences of eradicating non-native plants

Partly because of Jake’s commitment to eradicating non-native oxalis, San Francisco’s Recreation and Parks Department has been spraying it with herbicide for 20 years Garlon (triclopyr) is the herbicide that is used for that purpose because it is a selective herbicide that does not kill grasses in which oxalis usually grows.  Garlon is one of the most toxic herbicides available on the market.  More is known about Round Up (glyphosate) because it is the most widely used of all herbicides.  However, according to a survey of land managers conducted by California Invasive Plant Council in 2014, Garlon is the second-most commonly used herbicide to eradicate non-native plants. 

Garlon is toxic to bees, birds, and fish.  It is an endocrine-disrupter that poses reproductive and developmental risks to female applicators.  It damages the soil by killing mycorrhizal fungi that are essential to plant health by facilitating the transfer of nutrients and moisture from the soil to plant roots. 

A recent article in the quarterly newsletter of Beyond Pesticides explains that insecticides are not the only killers of insects: “Insecticides kill insects, often indiscriminately and with devastating consequences for biodiversity, ecosystem stability, and critical ecosystem services. Herbicides and chemical fertilizers extinguish invaluable habitat and forage critical to insect survival. Taken together, insecticides, fungicides, herbicides and chemical fertilizers make large and growing swaths of land unlivable for vast numbers of insect species and the plants and animals they sustain.” The loss of insects where herbicides are used to kill non-native plants are undoubtedly contributing to the failure of attempts to “restore” native plants which require pollinators and insect predator control as much as non-native plants.

In other words, eradicating non-native oxalis is damaging the environment and the animals that live in the environment.  Furthermore, after twenty years of trying to eradicate it, Jake Sigg admits that there is more of it now than there was when this crusade began:  “Maybe you’ve noticed that there’s more and more of it every year, and fewer and fewer other plants.  That is unlikely to reverse.”  (Nature News, April 9, 2019).

coyote in oxalis field. Copyright Janet Kessler

In fact, local failure of eradication efforts mirrors global failures of similar attempts:  “…despite international policies aimed at mitigating biological invasions, the implementation of national- and regional-scale measures to prevent or control alien species has done little to slow the increase in extent of invasions and the magnitude of impacts.” (1)

Update:  The California Invasive Plant Council has published “Land Manager’s Guide to Developing an Invasive Plant Management Plan.”  It says very little about the disadvantages of using herbicides to eradicate plants they consider “invasive” other than a vague reference to “unintended consequences,” without discussion of what they are or how to avoid them. 

However, it does give us another clue about why eradication efforts are often unsuccessful. When herbicides are used repeatedly, as they have been in the past 20 years, weeds develop resistance to them:   “The International Survey of Herbicide Resistant Weeds (2018) reports there are currently 496 unique cases (species x site of action) of herbicide-resistant weeds globally, with 255 species…Further, weeds have evolved resistance to 23 of the 26 known herbicide sites of action and to 163 different herbicides.”  The Guide therefore recommends that land managers rotate herbicides so that the “invasive” plants do not develop resistance to any particular herbicide.  The Guide gives only generic advice to use “herbicide X” initially and “herbicide Y or Z” for subsequent applications.

In other words, the California Invasive Plant Council continues to promote the use of herbicides to kill plants they consider “invasive.”  They give advice about ensuring the effectiveness of herbicides, but they do not give advice about how to avoid damaging the soil, killing insects, and harming the health of the public and the workers who apply the herbicides. 

Do insects benefit from eradicating non-native plants?

There is no question that insects are essential members of every ecosystem.  They are the primary food of birds and other members of wildland communities.  They perform many vital functions in the environment, such as consuming much of our waste that would otherwise accumulate. 

The Economist magazine has reported the considerable evidence of declining populations of insects in many places all over the world.  (However, the Economist points out that the evidence does not include large regions where insect populations have not been studied. The Economist is therefore unwilling to conclude that the “insect apocalypse” is a global phenomenon.) The report includes the meta-analysis of 73 individual studies that describe declines of 50% and more over decades. The meta-analysis concluded that there are four primary reasons for those declines, in order of their importance:  habitat loss, intensive farming, pesticide use, and spread of diseases and parasites.  The existence of non-native plants is conspicuously absent from this list of threats to insect populations.

In other words, although the preservation of insects is extremely important, there is no evidence that the eradication of non-native plants would benefit insects.  In fact, eradication efforts are detrimental to insects because of the toxic chemicals that are used and the loss of the food the plants are providing to insects.

Jake Sigg and Art Shapiro discuss insects and native plants

The discussion begins on April 26, 2019, with this statement published in Jake’s Nature News:

“Did you know that 90 percent of insects can only eat the native plant species with which they’ve co-evolved?”

On April 26, 2019, Arthur Shapiro wrote:

“No, I didn’t know 90% of insects can only eat the native plants with which they’ve co-evolved. I’ve only been studying insect-plant relationships and teaching about them for 50 years and that’s news to me, especially since on a global basis we don’t know what the vast majority of insects species eat, period! That’s even true for butterflies and moths, which are probably the best-studied group. And it’s even true here in California, one of the best-studied places on the planet (though way behind the U.K. and Japan). Where on earth did that bit of non-information come from?”

Jake Sigg responds:

“Art, I did my best to run down source for that statement.  As I suspected, it may lack academic precision.  That kind of precision is hard come by, and what exists is not entirely relevant.  Most of the information comes from Doug Tallamy.  But the statement is not accurate; it should have read “…90 percent of plant-eating insects eat only the native plants they evolved with”.  Whether that is true or not I don’t know, but it accords with my understanding and I am willing to go along with it, even if proof is lacking.  If you wait for scientific proof on everything you may wait a long time and lose a lot of biodiversity.  I have had too much field experience to think that exotic plants can provide the sustenance that natives do.

I expect you will be unhappy with this response.”

On May 2, 2019, Art Shapiro replies:

“If Tallamy said “90% of the plant-eating insects that I have studied…”  or “90% of the plant-eating insects that have been studied in Delaware…” or some such formulation I might take him more seriously. The phenomenon of “ecological fitting,” as described by Dan Janzen, is widespread if not ubiquitous. “Ecological fitting” occurs when two species with no history of coevolution or even sympatry (co-occurrence) are thrown together and “click.”  A.J.Thorsteinson summed up some 60 years ago what is needed for an insect to switch onto a new host plant: the new plant must be nutritionally adequate, possess the requisite chemical signals to trigger egg-laying and feeding, not possess any repellents or antifeedants and not be toxic. That set of circumstances is met very frequently. To those of us who study it, it seems to happen every other Tuesday.  As we showed, the urban-suburban California butterfly fauna is now overwhelmingly dependent on non-native plants. The weedy mallows (Malva) and annual vetches (Vicia) are fed upon by multiple native butterfly species and are overall the most important butterfly hosts in urban lowland California. . Within the past decade, our Variable Checkerspot has begun breeding spontaneously and successfully on Butterfly Bush (Buddleia davidii). The chemical bridge allowing this is iridoid glycosides. When I was still back East I published that the Wild Indigo Dusky Wing skipper, Erynnis baptisiae, had switched onto the naturalized European crown vetch (Coronilla varia) which had converted it from a scarce and local pine-barrens endemic to a widespread and common species breeding on freeway embankments. And the hitherto obscure skipper Poanes viator, the Broad-Winged Skipper, went from being a rare and local wetland species best collected from a boat to becoming the most abundant early-summer butterfly in the New York metropolitan area by switching from emergent aquatic grasses and sedges to the naturalized Mesopotamian strain of Common Reed, Phragmites australis. I can go on, and on, and on. If you find a sponsor for me to give a lecture about this in the Bay Area, I’ll gladly do it. If you promise to come!

I won’t snow you under with pdfs. Here’s just one, a serendipitous one that resulted from my walking near Ohlone Park in Berkeley. And one from the high Andes in Argentina. That paper cites one of mine in Spanish demonstrating that the southernmost butterfly fauna in the world, in Tierra del Fuego and on the mainland shore of the Straits of Magellan, is breeding successfully on exotic weeds.-! Copy on request.”

On May 2, 2019, Jake Sigg published his last reply:

“I believe many of your statements, Art, and many of these cases I am familiar with.  A conspicuous local example is the native Anise Swallowtail butterfly that still lays eggs on native members of the Umbelliferae, the parsley family, but which also breeds on the exotic fennel, which is an extremely aggressive weed that in only a few years can transform a healthy and diverse grassland supporting much wildlife into a plant monoculture—that, btw, won’t even support the butterfly, which shuns laying eggs where its larval food plant is too numerous and easy target for a predator, like yellow jackets.

What puzzles me is why you can keep your equanimity at the prospect of losing acres of very diverse habitat to a monoculture of fennel.  You live in the heart of the world’s breadbasket where for hundreds of miles both north and south there are almost no native plants except those planted by humans.  That would tend to distort one’s view.  I don’t mean to be flip, but it is not normal for even an academic to be indifferent about a loss of this magnitude.  I have worked hands-on on the land (I was raised on a ranch) all my life and still work every Wednesday maintaining our natural habitat in San Francisco—a task that hundreds of citizens pitch in on because they value the quality and diversity of the areas.  And why do you remain indifferent, are you just a contrarian?  You cite examples to bolster your view, but the examples are too small a percentage to be meaningful and wouldn’t stand up against a representative presentation.

I got my view from life.  I type this in my second-floor sunroom, which looks into a coast live oak growing from an acorn I planted in the late 1960s, about 50 years ago and which is immediately on the other side of the window.  It is alive with birds of many different species—flocks of bushtits, chickadees, juncos every day (plus individuals of other species), which species-number balloons in the migratory season.  What I can’t figure out is how the tree can be so productive as to stand up to this constant raiding.  I will take instances of this sort as my guide rather than the product of academic lucubrations.  And I will throw in Doug Tallamy; the world he portrays is one I recognize and love.

I think our battle lines are drawn.  This discussion could go on, as we have not even scratched the surface of a deep and complex subject.  But will either of us change our minds?  No.”

“Jake Sigg:  N.B.  Art responded with another long epistle, not for posting.  It clarified some of the points that were contentious and seemed to divide us.  We differ, but not as much as would appear from the above discussion.”


(1) “A four-component classification of uncertainties in biological invasions: implications for management,” G. LATOMBE , S. CANAVAN, H. HIRSCH,1 C. HUI, S. KUMSCHICK,1,3 M. M. NSIKANI, L. J. POTGIETER, T. B. ROBINSON, W.-C. SAUL, S. C. TURNER, J. R. U. WILSON,  F. A. YANNELLI, AND D. M. RICHARDSON, Ecosphere, April 2019.

Happy New Year and Farewell

The Million Trees blog is folding its tent and moving on because most of the projects in the San Francisco Bay Area that I have followed for 20 years have been approved, funded, and are being implemented.  Every public land manager in the Bay Area has made a commitment to destroying most non-native trees and using pesticides for that purpose.

If you wish to continue following the development of these projects, I recommend these websites:  San Francisco Forest Alliance Defend East Bay Forests, Save the East Bay Hills, and Hills Conservation Network.

For the record, this is a brief summary of my beliefs about the environment:

If I return to the blogosphere in the future, the title and mission of a new blog would change.  The focus would be the science that informs my commitment to the cosmopolitan landscape that exists, rather than the fantasized landscape of the past.  I will also continue to inform readers of new studies that find evidence of the damage that pesticides do to the environment and its inhabitants.  If you are a subscriber to the Million Trees blog, you will be informed if I publish a new blog.

Thank you for your readership.

Million Trees

Conference of the California Invasive Plant Council: Fallacies and Failures

The California Invasive Plant Council held their 27th annual conference in Monterey in November.  It was their biggest conference, with about 400 attendees and more sponsors than ever before.  Clearly the industry that promotes the eradication of non-native plants is alive and well.  However, a closer look at the conference presentations suggests otherwise.  Eradication efforts are growing, but eradication success is not and establishing a native landscape after eradication is proving elusive.

A few common themes emerged from the presentations:

  • Eradication cannot be accomplished without using pesticides.
  • When eradication is achieved with pesticides, non-natives are rarely replaced by native plants.
  • Planting natives after non-natives are eradicated reduces re-invasion, but secondary invasions of different non-native plants are common.
  • “Managing” forests with prescribed burns did not result in more biodiversity than leaving the forest alone.

Goals of these eradication projects have shifted in response to these failures to achieve original goals:

  • Replacement plantings after eradication are sometimes a mix of natives and non-natives.
  • Inability to establish native grassland has given way to different goals.
  • Language used to describe the projects are evolving to be more appealing to potential volunteers.

Here are a few examples of presentations that illustrate these themes:

Eradicating beach grass in Point Reyes National Seashore

About 60% of sand dunes in the Point Reyes National Seashore were covered in European beach grass when the eradication effort began in 2000.  The goal of the project was to restore native dune plants and increase the population of endangered snowy plovers that nest on bare sand.

The project began by manually pulling beach grass from 30 acres of dunes at Abbott’s Lagoon.  The grass grew back within one year, presumably because the roots of the beach grass are about 10 feet long.  Manually pulling the grass from the surface does not destroy the roots.

A new method was devised that was more successful with respect to eradicating the beach grass.  The grass and its roots were plowed up by bulldozers and buried deep in the sand.  The cost of that method was prohibitively expensive at $25,000 to $30,000 per acre and the barren sand caused other problems.

The barren dunes were mobile in the wind.  Sand blew into adjacent ranches and residential areas, causing neighbors of the park to object to the project.  The sand also encroached into areas where there were native plants, burying them.  The bare sand was eventually colonized by “secondary invaders.”  Different non-native plants replaced the beach grass because they were more competitive than the desired native plants.

In 2011, the National Park Services adopted a third strategy for converting beach grass to native dune plants.  They sprayed the beach grass with a mixture of glyphosate and imazapyr.  At $2,500 to $3,000 per acre, this eradication method was significantly cheaper than the mechanical method.

However, it resulted in different problems that prevented the establishment of native dune plants.  The poisoned thatch of dead beach grass was a physical barrier to successful seed germination and establishment of a new landscape.  Where secondary invaders were capable of penetrating the dead thatch, the resulting vegetation does not resemble native dunes.

Presentation at California Invasive Plant Council conference regarding attempt to eradicate European beach grass at Point Reyes National Seashore

The concluding slides of this presentation were stunning.  They said it is a “Restoration fallacy that killing an invader will result in native vegetation.”  My 20 years of watching these futile efforts confirm this reality.  However, I never expected to hear that said by someone actually engaged in this effort.  The presenter mused that such projects are like Sisyphus trying to roll a boulder up hill. 

Presentation at California Invasive Plant Council conference regarding attempt to eradicate European beach grass at Point Reyes National Seashore

Attempting to plant Douglas fir after eradication of broom

Over a period of 5.5 years, broom was eradicated in plots in Oregon by spraying glyphosate.  The plots were then planted with Douglas fir seedlings that soon died.  They were replanted the following year and died in the second year.

There were two theories about why the plantings failed, both broadly described as “legacy” effects in the soil left by the broom.  One theory is that nitrogen levels were too high for successful growth of Douglas fir.  That theory is consistent with the fact that broom is a nitrogen fixer.  That is, broom—like all legumes—have the ability to transfer nitrogen in the atmosphere to nitrogen in the soil with the help of bacteria that facilitate that transfer.  Nitrogen generally benefits plant growth, but there can also be too much nitrogen.

The second theory is that Douglas fir requires a specific suite of mycorrhizal fungi for successful growth.  Mycorrhizal fungi live in roots of plants and trees.  They transfer moisture and nutrients from the soil to the plants.  Plants with a healthy suite of mycorrhizal fungi are more drought tolerant because they extract more moisture from the soil.

Neither of these theories has been successfully proven by this project.  They remain unanswered questions.  We were struck that the researchers had not considered the possibility that the repeated use of glyphosate could have been a factor in the failure of the Douglas fir.  Glyphosate is known to kill bacteria in the soil.  Could it also kill mycorrhizal fungi?  (We know that triclopyr kills mycorrhizal fungi.) That possibility was not considered by this project. Did the project consider that glyphosate also changes the consistency of the soil by binding certain minerals together?  It is more difficult for roots and water to penetrate the hard soil.  Were soil samples taken before and after repeated applications of glyphosate to determine how the soil had been changed by pesticide applications?

The published abstract for this project made this observation:  “It is typically assumed that once an invasive species is successfully removed, the impact of that species on the community is also eliminated.  However, invasive species may change the environment in ways that persist, as legacy effects, long after the species itself is gone.”  In fact, it seems likely that the pesticides used to eradicate the “invasive” species could also be the source of the “legacy effects.”

Does “managing” a forest result in greater biodiversity in the understory?

California State Parks tested that hypothesis by conducting prescribed burns in some of their forests in the Sierra Nevada 20 years ago, while leaving other portions of the forest “unmanaged.”

The abstract for this presentation describes the goals and expectations for the prescribed burns:  “Prescribed fire is a tool used to reduce fuels in the forests in the Sierra Nevada and mimic the low and moderate severity wildfires that burned before the onset of fire suppression.  A manager’s hope is that prescribed fire will create the disturbance necessary to stimulate the development of species rich understory communities and increase species richness, compared to unburned forests, which are often viewed as species depauperate.”

Twenty years after the burns, abundance and species composition of the understory in the burned areas were compared to the unburned areas.  They found little difference in the biodiversity of the understory of burned areas compared to unmanaged forests:

  • “Species richness was highly variable within burned and passively managed areas but was not statistically different.”
  • “Passively managed areas did not appear to be depauperate in understory species diversity compared to areas managed with prescribed fire.”
  • “Fire did not appear to reduce or enhance species richness numbers in burned areas, as compared to passively managed areas.”

No fires occurred in either the burned areas or the unmanaged areas during the 20-year period.  Therefore, this study did not test the theory that prescribed burning reduces fire hazards in forests.  This study found no significant differences in diversity of forest understory resulting from prescribed burns.

There are significant risks associated with prescribed burns.  They cause air pollution and they frequently escape the controlled perimeter of the fire, becoming wildfires that destroy far more than intended.  This study does not provide evidence that would justify taking those risks.  In fact, available evidence supports the “leave-it-alone” approach to land management.

Moving the goal posts

If at first you don’t succeed, you have the option of redefining success.  Here are a few of the projects presented at the conference that seemed to take that approach.

Make projects so small that success can be achieved

Eric Wrubel introduced himself as the National Park Service staff who is responsible for prioritizing invasive plants for removal in the National Parks in the Bay Area (GGNRA, PRNS, Muir Woods, and Pinnacles).  His work is based on the premise that the most successful eradications are those that are small.  The bigger the infestation, the greater the investment of time and resources it takes to eradicate it and the smaller the likelihood of success.  This is illustrated by a graph showing this inverse relationship between the size of the invasive population and the success of eradication.

Source: Rejmanek and Pitcairn, “When is eradication of an exotic pest plant a realistic goal?,” 2002

The process of prioritizing eradication projects began over 10 years ago with a survey of over 100 species of plants considered invasive.  Cal-IPC’s “watch list” was used to identify the plants that are not yet widely spread in California, but considered a potential problem in the future.  Cal-IPC’s risk assessment was the third element in the analysis.  Plants with “High” risk ratings by Cal-IPC were put higher on the priority list than those with “Moderate” or “Limited” ratings.  Plants that did not exist elsewhere in the region or watershed were also given higher priority, based on the assumption that re-invasion was less likely.

This is the list of eradication projects in the National Parks in the Bay Area that was presented at the conference of the California Invasive Plant Council. The projects marked with the red symbol for crossing out are completed projects. Nearly half of the plants on this hit list are not considered invasive in California.

The priority list showed that the highest priority eradication projects were quite small.  Some were just a few acres.  Buddleia jumped out as the 7th highest priority on only 13 acres.  Buddleia was recently added to a new category of plants on Cal-IPC’s “invasive” inventory.  It is not considered invasive in California, although it is considered invasive elsewhere.

In placing buddleia on its “hit list,” Cal-IPC illustrates one of the fundamental weaknesses of its evaluation method.  Cal-IPC does not evaluate pros and cons of non-native plants.  Only traits considered negative are taken into consideration.

Monarch sanctuary in Monterey, California. November 2018

Buddleia is one of the most useful nectar plants for pollinators in California.  We took the time to visit the monarch butterfly sanctuary in Monterey while attending the conference.  The monarchs are arriving now to begin their winter roost in the eucalyptus, Monterey pine and cypress in this small grove.  At the entrance to the sanctuary a sign instructs visitors to plant only native milkweed as the monarch’s host plant and only native flowers for nectar.  Fortunately whoever planted the flowering shrubs in the sanctuary didn’t follow the advice of the sign-makers.  They planted buddleia and other flowering non-natives such as bottle-brush.  Several species of butterflies and hummingbirds were enjoying those plants in the Sanctuary. Strict adherence to the native plant agenda is not beneficial to wildlife because animals do not share our prejudices.

Monarch nectaring on butterfly bush. butterflybush.com

Acknowledging the difficulties of converting non-native annual grass to native perennial grass

Pinnacles National Park acquired 2000 acres of former ranchland in 2006.  The park wanted to convert the non-native annual grasses and yellow-star thistle on the former ranch to perennial bunch grasses and oak woodland.  They were able to reduce the amount of yellow-star thistle by burning and spraying with herbicide, but cover of native species remained low.  Conversion of grasses from non-native annuals to native perennial grass has been tried many times, in many places, and for long periods of time.  These projects were notoriously unsuccessful.

The project at Pinnacles has changed its goal to plant forbs (herbaceous flower plants) instead of grasses and they report that they are having some success.   They justify that shift in goal on soil analysis that suggests forbs were more prevalent than perennial grasses in inland valleys in California than previously thought.

This change in goal could be described as “adaptive management,” which adjusts methods and goals in response to observable outcomes of existing methods.  You could also call it “trial and error.”  We would like to see more land managers make such adjustments to their strategies, rather than doing the same thing over and over again and expecting a different outcome.

Recruiting volunteers with appealing messages

There were several presentations about effective methods of recruiting volunteers to participate in restoration projects.  Some of their messages seem to acknowledge that the language used in the past may have alienated some potential volunteers.  Speaking from personal experience, I can confirm that observation.  Here are just a few of the cringe-worthy native plant mottos that I hope have been abandoned in favor of a more positive message:

  • “That plant doesn’t belong here.”
  • “That is a good plant and the other is a bad plant.”
  • “The invasive landscape is sick and requires chemotherapy.” (to justify the use of pesticides)
  • “That’s a trash bird.” (said of common, introduced birds, such as starlings and house sparrows)

The speaker advised those who work with volunteers to focus on why an unwanted plant is a problem rather than where it comes from.  Unfortunately, the list of problems is heavily influenced by the preferences of native plant advocates.  If their criticisms are not accurate, or they don’t acknowledge the advantages of the plant, little has been achieved by using euphemisms.  Here are a few of the inaccurate criticisms made of eucalyptus:

What was missing?

Ecological restoration is a major industry. Thousands of people are employed by the industry, which is funded by many different sources of public money.  Whether individual projects are successful or not, the industry will survive and thrive as long as it is funded.  Greater care should be taken to design and implement projects that will be successful.

Stepping back from the conference presentations of specific restoration projects, here are a few issues that were conspicuously absent from the conference. 

  • Pesticides are being widely used by the restoration industry. When projects don’t achieve desired outcomes, pesticides should be considered as a factor.  Did pesticides alter the soil?  Were beneficial microbes and fungi killed? How persistent was the pesticide in the soil?  How mobile was the pesticide in the soil?  Was pesticide applied in the right manner?  Could aerial drift account for death of non-target plants?  There are many other useful questions that could be asked.

Update:  The California Invasive Plant Council has published “Land Manager’s Guide to Developing an Invasive Plant Management Plan.”  It says very little about the disadvantages of using herbicides to eradicate plants they consider “invasive” other than a vague reference to “unintended consequences,” without discussion of what they are or how to avoid them. 

However, it does give us another clue about why eradication efforts are often unsuccessful. When herbicides are used repeatedly, as they have been in the past 20 years, weeds develop resistance to them:   “The International Survey of Herbicide Resistant Weeds (2018) reports there are currently 496 unique cases (species x site of action) of herbicide-resistant weeds globally, with 255 species…Further, weeds have evolved resistance to 23 of the 26 known herbicide sites of action and to 163 different herbicides.”  The Guide therefore recommends that land managers rotate herbicides so that the “invasive” plants do not develop resistance to any particular herbicide.  The Guide gives only generic advice to use “herbicide X” initially and “herbicide Y or Z” for subsequent applications.

In other words, the California Invasive Plant Council continues to promote the use of herbicides to kill plants they consider “invasive.”  They give advice about ensuring the effectiveness of herbicides, but they do not give advice about how to avoid damaging the soil, killing insects, and harming the health of the public and the workers who apply the herbicides.  May 20, 2019

  • Are workers who apply pesticides being adequately trained and supervised by certified applicators? The safety of workers should be one of many goals of restoration projects.
  • When non-native plants are eradicated, serious thought should be given in advance to the probable outcome. Will native plants return?  Will wildlife be harmed?  Will the risks of failure outweigh the potential benefits of success?
  • Is climate change taken into consideration when planning the replacement landscape? Are the plants that grew in the project location 200 years ago still adapted to that location?  Is there enough available water?
  • If new plantings require irrigation to be established, what is the water source? Is it recycled water with high salt content that will kill many plants, including redwoods?
  • Are the new plantings vulnerable to new infectious diseases, such as phytopthera or infestations of new insects such as shot-hole borer?
  • Does the project team have sufficient horticultural knowledge to choose plants that can survive in current conditions? Does the project team know the horticultural needs of the plants they are planting?  Is there enough sunlight, water and wind protection for the trees they are planting?

The public is investing heavily in the “restoration” of ecosystems.  We can only hope that our investment is being used wisely and that projects will not do more harm than good.  Cal-IPC can play a role in raising the questions that have the potential to improve projects and enable them to succeed.  The long-term survival of the “restoration” industry depends on it.


Most quotes are from abstracts of presentations published in the conference program.

Trophic cascades are initiated by pesticide use

Although the Environmental Protection Agency requires that pesticides be tested before they can be sold in the US, we know that the required tests are inadequate to determine if the pesticide is dangerous to human health and the environment.  The tests are only as accurate as the test protocols and procedures.  There are many flaws in the testing methods required by federal law.  Here are a few of them:

  • Tests are conducted on laboratory animals in which the dose is limited to a single chemical. In the real world, humans and other animals are subjected to many chemicals simultaneously in doses that are unknown and unknowable, because little testing is done of contamination in the environment. Only the active ingredient in pesticide is tested, not the formulated product that is a cocktail of many chemicals.
  • Tests are done for relatively short periods of time, compared to the long lives of humans during which chemicals accumulate in our bodies.
  • The chemical threshold deemed “safe” is not the dose at which no adverse effect occurred. It is only the dose at which no adverse effect was observed:  “Subclinical affects—reduced fertility, compromised immune systems, and reduced intelligence, for example—are not observed not because they have not occurred but because they are seldom sought.” (1) In other words, the testing regimen does not test for many potential health problems.
  • The testing regimen is also limited to a few animal species at certain stages of development. For example, bees are the only species of insect on which pesticide tests are required and they are only tested at the adult stage.  Bee keepers will tell you that larvae stages of bee development are far more vulnerable to pesticides than adult bees, yet no tests are required on that stage of development.  Bees are probably less vulnerable to pesticides than caterpillars which eat vegetation, but caterpillars are not tested.  If caterpillars are killed, there are no moths and butterflies.

A proposal for a new testing standard of the impact on the entire ecosystem

Beyond Pesticides has published a review of many scientific studies about the impact of pesticides on the entire ecosystem in which they are applied.  The article reports substantial empirical evidence that pesticides are initiating trophic cascades in the entire ecosystem in which pesticides are used.  The article concludes that such studies of the entire food web are needed to identify and prevent such damage. (2)

What is a trophic cascade?

A change in the population of one member of an ecosystem can trigger a trophic cascade by altering the balance of the entire food web. 

The classic example of a “top-down” trophic cascade is the sequence of events in Yellowstone National Park when wolves were exterminated in the park.  In the absence of the top predator in the ecosystem, the population of elk that were their prey exploded.  The grazing animals ate trees and shrubs that were the food of the beavers.  The beaver population declined, which altered the hydrology of the ecosystem.  Wetlands maintained by beaver dams dried up and the community of plants and animals in the wetlands died off.  Although there were other predators of the grazing animals, such as bears and mountain lions, the packs of wolves subjected the herds of grazing animals to harassment that kept them moving, reducing damage to the vegetation.

Wolves have returned to Yellowstone National Park because of the Endangered Species Act that protected them and the ecosystem has been restored by the natural forces of predator and prey relationships.  The endangered status that protected wolves was recently rescinded in response to the demands of ranchers with domesticated animals.  Although wolves may not be killed inside Yellowstone, they may be killed when they leave the park.  We may eventually see a reversal of the improvements in an ecosystem ruled by wolves.


Update:  Emma Marris has critiqued the theory that the absence of wolves in Yellowstone National Park caused a trophic cascade that damaged the entire ecosystem in Yellowstone National Park and the reintroduction of wolves restored the ecosystem.  Her article, entitled “A good story:  Media bias in trophic cascade research in Yellowstone National Park,” was published in Peter Kareiva’s et al. new book, Effective Conservation Science, Data not Dogma.

Marris details the lack of data supporting the existence of a trophic cascade or its reversal when wolves were reintroduced.  She calls those claims speculative, an unproven hypothesis.  More importantly, Marris believes that proof of that hypothesis is unattainable:  “…even ecosystems as well studied as Yellowstone remain beyond our ken…lifetimes will be required to understand them and even then they may always remain, by virtue of changing faster than we are able to follow, essentially unknowable.”

More humility is needed to guide conservation.  If we are to avoid damaging the environment further, we need to keep in mind how little we know.  Nature may be far wiser in managing itself than humans presume to be. 


There are also examples of “bottom-up” trophic cascades when increases or decreases in the abundance of microscopic plants and animals disrupt the entire food web, ultimately impacting the top of the food chain.

Insects are also near the bottom of the food chain.  They are essential food for birds, particularly to young nestlings.  Scientists began noticing that insect populations were disappearing some time ago, but their anecdotal observations were not empirically tested until 2016 when an entomological society in Germany published a study about the decline:  “The German study found that, measured simply by weight, the overall abundance of flying insects in German nature reserves had decreased by 75 percent over just 27 years.” (3)  Although there are undoubtedly many reasons for this rapid disappearance of insects, including pesticides, there is almost no research being done to determine the causes:  “Rob Dunn, an entomologist at North Carolina State University…recently searched for studies showing the effect of pesticide spraying on the quantity of insects living in nearby forests.  He was surprised to find that no such studies existed.  ‘We ignored really basic questions,’ he said.  ‘It feels like we’ve dropped the ball in some giant collective way.’” (3)  Professor Dunn should not feel badly.  Almost no research is being done on the effects of pesticides on anyone, any animal or anything in the environment  Turning a blind eye to the possibility of such harm done by pesticides is one of the ways in which the industry is shielded from regulation.

Trophic cascades caused by pesticides

The review article published by Beyond Pesticides reports that many empirical studies have discovered trophic cascades initiated by pesticide applications.  Here is one example from agriculture:

“Mesleard et al. (2005) found that the insecticide fipronil, used to control midge pests in conventional rice fields, causes a trophic cascade that reduces the nutritional value of the area for waterfowl. Comparing a chemical intensive rice field to one managed organically, the trophic cascade ultimately neutralized the efficacy of synthetic pesticide use in the first place.

“Direct toxicity from fipronil reduced the number of invertebrate predators in chemical-intensive rice fields. This led to a trophic cascade that allowed herbivorous animals to flourish. On the surface, organic and chemically-managed rice fields both contained the same amount of invertebrate biomass. However, in chemical-intensive fields, this biomass was primarily in the form of gastropods (snails and slugs). When researchers surveyed the fields in late summer, only 12% of the invertebrate community were predators, while in organic fields that proportion was 70%. Slugs and snails are not a major food source for the most common waterfowl in the region studied, the heron, making organic plots a more valuable source of sustenance.” (2)

The review article also provides examples of trophic cascades initiated by pesticides in aquatic environments and in “invasive species” control projects.  Both herbicides and insecticides have initiated trophic cascades.  The effect on the food web of one pesticide is sometimes different from another.  The timing of a pesticide application sometimes has different impacts on the food web.  The effects of pesticides vary widely and are very complex.

A local example of a trophic cascade

There are many aquatic weeds in the Delta where the Sacramento and San Joaquin rivers slowly meander into the San Francisco Bay.  The weeds come from warmer climates and they are thriving here because of climate change.  Lower water levels are also a factor because shallower water is warmer.  The water level is lower because of drought and the diversion of water from the rivers and the Delta to irrigate agricultural crops.  Annual spring floods that cleansed the Delta system in the distant past have been stopped by upstream dams that keep water levels constant.

Instead of addressing the underlying reasons why the aquatic weeds have become a problem, the powers that be (State Parks Division of Boating and Waterways and approved by US Fish & Wildlife Service) have been spraying the aquatic weeds with pesticide and dumping pesticide pellets into the water.  These pesticide applications have been steadily increasing:  “Charts provided by the state show a 50 percent hike in the amount of pellets used from 2014 to 2017 and a 66 percent increase in the amount of spray that was administered during the same time period.” 

Fortunately, there are thousands of fishermen in the Delta who have noticed massive die-offs of fish, turtles, goats, ducks, muskrats, and otters since the spring. They have reported these deaths to California State Parks, who deny knowledge of such die-offs.

The fishermen have formed an organization, Norcal Delta Anglers Coalition.  They have organized to document this trophic cascade that was probably initiated by unnecessary pesticide applications.  We wish them luck.  We hope they have more success than we have had convincing public land managers that they are damaging the environment and its inhabitants with pesticides.

Testing and evaluation of pesticides must be improved

This important review article (1) concludes that pesticides can upset and imbalance ecosystem health and stability.  Studies find “increased risk of disease transmission, dangers to declining species, algae blooms, the loss of ecosystem services like nutrient cycling, and importantly, ineffective pest management.”  Therefore, there is a “critical need for EPA to consistently assess ecosystem level trophic effects as part of the pesticide registration process.” In the absence of a truly precautionary system where independent science is adequately considered by regulators, pesticides are likely to cause trophic cascades or other ecosystem disruption.

Such ecosystem evaluations of pesticides are not going to happen in the foreseeable future.  The 180-degree turn in American politics that would be required to improve pesticide regulation is unlikely.  Although most of the meager federal regulation we had in place prior to 2017 has been dismantled, regulation in the prior administration was also inadequate.

Courtesy Beyond Pesticides

Therefore, our fallback position should be DON’T USE ANY MORE PESTICIDE THAN ABSOLUTELY NECESSARY.  Buy organic food to protect your family and to put industrial agriculture using pesticides out of business.  Fight for rigorous pesticide regulation locally, in your city, your county and your state.

The end of another nativist myth

Native plant advocates promote the use of pesticides to eradicate non-native plants.  The myth they use to justify their use of pesticides is that damage is confined to the target plant or animal.  Clearly that is not true. Pesticides can be aimed at a specific plant, but non-target plants are often killed unintentionally because pesticides are mobile in the soil, they drift in the air and they are carried by the roots of the target plant to the intertwined roots of non-target plants.

Furthermore, killing one plant or animal in an ecosystem ultimately effects the entire community of plants and animals.  The collateral damage to the entire ecosystem caused by pesticides can be devastating to the entire food web.  Clearly the word “restoration” is a misnomer when used to describe eradication projects using pesticides.

Given the inevitable damage to entire ecosystems, the claim that native plant “restorations” benefit wildlife is clearly unlikely, if not patently false. 


  1. Joe Thornton, Pandora’s Poison, MIT Press, 2000
  2. Drew Toher, “Pesticide Use Harming Key Species Ripples through the Ecosystem,” Pesticides and You, Summer 2018.
  3. Brooks Jarvis, “The Insect Apocalypse Is Here,” New York Times, November 27, 2018

Action Opportunity: Speak up about Oakland’s Vegetation Management Plan

The stated purpose of Oakland’s Vegetation Management is to reduce fire hazards in Oakland.  Oakland’s Vegetation Management Plan will determine the fate of 2,000 acres of public parks and open spaces and 300 miles of roadside in Oakland.  It will also substantially increase the use of pesticides if approved in its present form.  Two public meetings will take place in November to discuss revisions of the draft plan:

Date: Thursday, November 15, 2018
Time: 5:30-7:30 PM
Location: Richard C. Trudeau Training Center, 11500 Skyline Blvd, Oakland, CA 94619

Date: Tuesday, November 20, 2018
Time: 5:30-7:30 PM
Location: Oakland City Hall, 1 Frank Ogawa Plaza, Hearing Room 2, Oakland, CA 94612

The agenda for these meetings has been carefully crafted to accommodate the wishes of native plant advocates, as expressed in their public comments on the draft plan.  This is the agenda for these public meetings:

  1. “The Plan should better incorporate the role of volunteers and stewardship groups that actively maintain vegetation at various City-managed parks/open space areas. The City should conduct additional outreach to such groups to continue to receive their input and feedback.”
  2. “The Plan should include more specificity regarding vegetation management recommendations at each City-managed parcel.”
  3. “The Plan should include cost estimates, or a range of potential costs, for the recommended treatments to assist the City for longer-term work budgeting and planning. The cost estimates and site-specific plans for City-managed parks would also help identify activities that volunteers can conduct.”

The first meeting on November 15th is “targeted towards the park steward/volunteer groups working on City-owned parcels.”  The second meeting on November 20th “will focus on the issue of plan specificity.  It is requested that participants come prepared to discuss their recommended edits/comments.  At each meeting we will briefly discuss each project site/area, and your feedback will be collected and considered for the revised draft Plan to be released in 2019.”

In other words, the public process that will result in a Vegetation Management Plan for Oakland is now entirely in the hands of native plant advocates (“park stewards/volunteer groups”), despite the fact that there were other important issues raised in the public comments.  Only the public comments of native plant advocates are being considered in the revision of the draft.  None of their requested revisions have anything to do with reducing fire hazards.  Their revisions are intended to greatly increase Oakland’s commitment to native plant “restorations.”

These are the issues being ignored

If you are an Oakland resident with a sincere interest in fire hazard mitigation, who does not believe the draft plan will reduce fire hazards, please attend one of these meetings.  These are the issues we believe are being ignored and must be addressed by the City of Oakland.

  • Pesticides are being used in the parks of the East Bay Regional Park District after completion of an Environmental Impact Report in 2009. The pesticide applications of the Park District are a preview of what will happen in Oakland city parks if the Vegetation Management Plan is approved as presently drafted.

    Pesticide use in Oakland city parks and open spaces is presently prohibited by Oakland’s city ordinance because no Environmental Impact Report has been completed for a revision of the ordinance that was proposed by the City Council in 2005. If the draft Vegetation Management Plan is approved and an Environmental Impact Report is completed as planned, pesticides will be permitted in Oakland’s parks, open spaces, and roadsides. 

  • Pesticide use will increase greatly because pesticides are required to prevent the tens of thousands of trees that the draft plan proposes to destroy from resprouting. Pesticides will also be needed to eradicate the flammable weeds that will colonize the unshaded ground.
  • Native plant advocates are opposed to goat grazing because goats eat both native and non-native plants. Goat grazing is a non-toxic alternative to pesticides.  Shade is the most benign method of weed control.
  • Native plant “restorations” do not mitigate fire hazards because native vegetation is as flammable as non-native vegetation. When non-native trees are destroyed, as proposed by the plan, no native trees will be planted to replace them.  Therefore, the moist forest will be replaced by grassland that ignites more easily than forests.
  • Every wildfire we have witnessed in California in the past 20 years has occurred exclusively in native vegetation. Wildfires in California have become more frequent and more intense because of climate change.  Deforestation is the second greatest cause of climate change because trees release the carbon they have stored throughout their lives, and in their absence carbon storage is reduced in the future.

The native plant movement has a death grip on our public lands in the San Francisco Bay Area.  Few would object to their advocacy if their projects were as constructive as they are destructive.  They are welcome to plant whatever they want, but they should not have the right to destroy everything that is non-native, particularly using pesticides, which is their preferred method.

I would like to believe that public policy is in our hands if we will participate in the political process.  It is becoming more difficult to believe in that ideal.  Please attend one of these meetings, if only to keep our democracy alive and well.

All life on Earth is related

Today we will take a deep dive into evolutionary history to talk about the origins of life on Earth.  Drawing from David Quammen’s new book, The Tangled Tree, we will tell you about “a radical new history of life,” as promised by the subtitle of his book. (1)

Categorizing Nature

Throughout written history, humans have demonstrated a compelling need to name and categorize everything in our world, including nature.  Naming and categorizing passes for understanding and enables us to talk about issues using commonly understood definitions.

Linnaean taxonomy was one of the first and most influential attempts to classify the natural world into three kingdoms:  plants, animals, and minerals.  Since Systema naturae was published by Carl Linnaeus in the 18th century, many other classification systems have been proposed by subsequent generations of scientists.

The conventional wisdom about classifying nature changed radically after the discovery of the molecular structure of DNA in the 1950s and the molecular analysis that it enabled in the 1960s.  Genetic analysis revealed the evolutionary relationships between organisms, enabling the development of phylogenetic “trees” depicting those relationships.

Haeckel’s Tree of Life, 1879

The revolutionary work of Charles Darwin was instrumental in initiating such speculation about evolutionary history.  Such theories about the history of life on Earth were often depicted as “trees of life,” showing the progression of evolution.  One of the earliest of such “trees” was published in the 1870s, shortly after the publication of Darwin’s Origin of Species in 1859.

In 1977, using molecular analysis, Carl Woese published his hypothesis of a new kingdom of life, Archaea.  He proposed a new categorization of all life on Earth, which he called domains:  Bacteria, Archaea, Eucarya.  Bacteria and Archaea are one-celled organisms without a nucleus.  Eucarya are every other living organism, including plants, animals, and fungi. Kingdoms of life were relegated to the second level of taxonomy (the classification of organisms).

The hypothesis of Woese was challenged, often contentiously, for decades, but is now conventional wisdom among scientists of phylogenetics, as the genetics of evolution is called.  However, as tidy as these new categories might appear, they aren’t.  As human intellectual constructs often are, many species of life defy neat categorization.  Around the edges of every domain there are many species of life that don’t entirely fit the criteria.  Likewise, around the edges of every genus and species, there are many gray areas.  Just as the distinction between “native” and “non-native” is often ambiguous, so is the categorization of many organisms.  This is a reminder that we must use such definitions with humility, always being prepared to consider a new hypothesis that improves our understanding.

Domains of life

Revising the mechanisms of evolution

Molecular analysis has also radically altered our understanding of how evolution proceeds.  Charles Darwin’s hypothesis about evolution was that change in organisms occurs through genetic variation from one generation to the next.  Occasional genetic mutations from one generation to the next was later added to what is called “vertical evolution.”  Each subsequent generation of a species is tested by the environment and that test is called natural selection.  The individual member of a species that is best adapted to the environment survives to reproduce, while less well-adapted individuals do not survive to reproduce.

Scientists have more recently observed that species in one domain of life also exchange genetic material with another domain of life, as well as exchanges between different species within domains.  This is called “horizontal gene transfer.”  The discovery of horizontal gene transfer (HGT) has revolutionized how we think about evolution.  Natural selection remains as the mechanism that confers success or failure on such changes in genes from one generation to another.

Significance of horizontal gene transfer

Horizontal gene transfers occurred in deep time, but are known to be a significant issue at the present time.  Horizontal gene transfer is the primary mechanism for the spread of antibiotic resistance in bacteria and plays an important role in the evolution of bacteria that can degrade synthetic compounds such as pesticides. Antibiotic resistance in one species of bacteria can be transferred to another species of bacteria, multiplying the incidence of antibiotic resistance. (2)

The introduction of chloroplasts into plant cells roughly 3.5 billion years ago was one of the most significant events in the evolution of life on Earth.  The introduction of chloroplasts into plant cells was an example of a horizontal gene transfer from a bacteria cell into eucarya cells.  Chloroplasts are the organelles (specialized structures inside eucarya cells that perform specific functions) that perform photosynthesis in plant cells.  Photosynthesis enables plants to convert the energy of the sun into carbohydrates that feed the plant and emit oxygen as its waste product.  Photosynthesis converts carbon dioxide into oxygen.  This neat trick of photosynthesis radically altered the atmosphere by reducing carbon dioxide and increasing oxygen.  Just as increased carbon dioxide in the atmosphere is now increasing temperatures on Earth, lower carbon dioxide levels in the atmosphere reduced temperatures.  This so-called “Great Oxidization Event” was the probable cause of one of the five great extinctions hundreds of millions of years ago. (3)

The horizontal gene transfer of mitochondria from bacteria cells to eucarya cells was equally significant to the evolution of life on Earth.  Mitochondria are organelles in eucarya cells that perform respiration and energy production functions in most eucarya species of both plants and animals. (2)

The list of such horizontal gene transfers is long.  Here are some examples to help you understand that HGT is an extremely important evolutionary mechanism, perhaps even more important than vertical evolution (2):

• From bacteria to fungi
• From bacteria to plants
• From organelle to organelle
• From plant to plant
• Fungi to insects
• From bacteria to insects
• From viruses to plants
• From bacteria to animals
• From plants to animals
• From plant to fungus

Implications of horizontal gene transfer

Our bodies contain more microbes, such as bacteria, than they do human cells.  Those microbes are interacting with our own cells.  Sometimes the microbes cause problems and sometimes they solve problems.  The microbes in our bodies cannot be called enemies or friends.  Sometimes their interactions with our cells permanently alter our genes and are inherited by our offspring.  Such permanent alterations of our genes are called horizontal gene transfer.  Such interactions between microbes and cells occurs in all life forms, altering plants, animals, etc. 

What are the implications of these interactions?

  • All life forms on Earth are related. No life form on Earth can be considered “alien.”  Every organism on Earth is constantly undergoing change, as it interacts with other organisms.  No “species” is immutable in the long term.
  • Critics of genetic engineering say it is “unnatural” and risky because it introduces genes into organisms in which they did not evolve naturally. But horizontal gene transfer does exactly the same thing and it is a “natural” process.  Genetic engineering is risky, just as HGT is, but it is mimicking a natural process.
  • Many pesticides are known to kill bacteria. Since bacteria are resident in our bodies in huge numbers and are known to sometimes be beneficial, it seems unnecessarily risky to kill them with pesticides.   As with genetic engineering, the risk should be weighed against potential benefits.  Are the risks worth taking?
  • Epidemiological studies report correlation between increased pesticide applications and increased birth defects in humans. Laboratory studies on rats report birth defects in rats exposed to low doses of glyphosate as well as birth defects in subsequent generations of the exposed rats: “A 2018 study of pregnant rats exposed to low doses of glyphosate-based herbicides revealed that the rats had difficulties in getting pregnant and surviving the pregnancy. The second generation offspring suffered from being smaller than normal. They were also afflicted with abnormalities developed before birth. This means the glyphosate-based weed killers inoculate their victims with monstrosities.” (4) These studies suggest that genes may have been altered by pesticide exposure.

  1. David Quammen, The Tangled Tree: A radical new history of life, Simon & Schuster, 2018
  2. Specific examples of these HGTs are available HERE.
  3. http://www.growingpassion.org/2010/04/evolution-of-chloroplasts-endosymbiosis.html
  4. https://sustainablepulse.com/2018/10/24/the-specter-of-genetic-catastrophe/?utm_source=newsletter&utm_medium=email&utm_campaign=gmos_and_pesticides_global_breaking_news&utm_term=2018-10-24#.W9B55ktKg2x

More opposition to Measure FF

As you make the important decision about voting on Measure FF, please take into consideration that Million Trees and the Forest Action Brigade are not the only East Bay residents who plan to vote against Measure FF.  Today we tell you more about why many East Bay voters have made that decision.

Post-election update:  Measure FF passed easily.  In Alameda County 85% of voters approved Measure FF.  In Contra Costa County 80% of voters approved Measure FF.  These were the vote tallies on the day after the election, on November 7th.  

A ’91 fire victim and survivor tells us why he will vote against Measure FF

The East Bay Times published the following op-ed about Measure FF on October 4th. It was written by Peter Scott. He states his opposition to Measure FF clearly and emphatically.  Emphasis and photo have been added.

“Save trees, ‘no’ on Alameda County’s Measure FF”

“Alameda County’s proposed Measure FF, East Bay Regional Park District Parcel Tax Renewal, appears innocent enough: improvements in area parks, safety, a 20-year continuation of a 2004 plan to enhance the public’s enjoyment of East Bay Regional Park District (EBRPD) properties.

And the tax — a dollar a month per single-family residence and $69 a month for multifamily units in Alameda County — seems affordable. But wait: Half of the money raised by this measure would fund destruction of thousands of healthy, mature trees in the East Bay hills.

This isn’t the first time this deforestation has been proposed. In 2013, FEMA offered a similar plan, to be implemented by UC Berkeley, the city of Oakland and the EBRPD. After the plan’s environmental impact was discussed in three public hearings, citizens responded with 13,000 written comments, which, by FEMA’s count, were 90 percent against the plan.

The reason, subsequently confirmed in litigation, was that the plan would involve significant, permanent negative impacts to the environment but would still fail to achieve its stated goal — to reduce risk of fire in the hills. The U.S. Forest Service commented that in terms of mitigating risk, it would be better to do nothing than to proceed with FEMA’s plan. The reason this type of proposal keeps popping up is because it is the object of long-term lobbying by a clique of nativists who want to rid the hills of species they don’t like. Their reasoning depends on myths such as these:

  • Once upon a time, before white people came and changed things, the hills were a stable environment of so-called native vegetation that was healthy and inherently fire-resistant;
  • “native” species tend to be less likely to ignite, and they have manageable flame lengths (the distance at the ground from the flame’s leading edge to its tip);
  • and trees are the culprit and were the primary reason that the 1991 fire burned out of control.

These statements are not only incorrect, they are the opposite of the truth. The old landscape burned regularly; the flame lengths of “native” brush and grasses are multiples of mature trees’ flame lengths and create conflagrations that fire personnel won’t fight because they spread and change direction so fast; the 1991 fire was a STRUCTURE fire, not a vegetation fire: houses set fire to trees, not the other way around.

Factually, the ’91 fire was human-caused. First, it was a contractor’s construction debris fire that escaped into the brush; secondly, it was a reignition from embers that the Oakland Fire Department had failed to extinguish. The official report examining the causes doesn’t mention trees but does criticize the OFD’s failures in its incident command’s preparation, training and management during the fire. Of the 16 major fires in the hills since 1905, there are basically two categories: human-caused (10 fires) and “unknown cause” — it’s a safe bet most of those “unknowns” were also human-caused.

If Measure FF is truly focused on fire risk mitigation, it would fund regular removal of fine fuels around the base of the trees — as EBMUD does so successfully — because it is the brush, grasses and debris on or near the ground that are most likely to ignite and are key to the fire’s spread and ferocity. Leave the tall trees alone, because they reduce wind, shade the ground, catch fog drip and discourage growth of flammable, weedy plants. If trees are not cut down, then repeated applications of herbicides to kill re-sprouts are unnecessary.

Measure FF proposes to fund some good things — maintenance and improvements in the parks — but they make FF a Trojan horse. They are sugar-coating on a foul and foolish enterprise: deforestation to create so-called “oak-bay savannahs,” which are actually grass- and brush-covered hills, dotted with occasional low trees — the type of landscape that has been burning so fast and ferociously in Lake and Sonoma counties and throughout the state. We must send the FF authors back to the drawing board, telling them to come back to us when they have plan that will actually reduce, not increase, the fire hazard.”

Peter Scott, Oakland, California

No one is more knowledgeable about East Bay fire history and fire hazard mitigation than Peter Scott.  He is a founding member of the Claremont Canyon Conservancy and the Hills Conservation Network.  He is passionate about fire safety in the East Bay partly because of his personal loss.  His home burned down in 1970 and 1991 and his mother was killed in the 1991 fire.  Since 1991, he has made fire hazard mitigation one of his personal priorities.  Peter Scott and his wife, Teresa Ferguson, instigated the Civil Grand Jury report about the ’91 fire.

Alameda County Green Party says “NO on Measure FF”

The Alameda County Green Party has recommended that “green” voters vote NO on Measure FF, with reservations. This was a difficult decision for the Green Party, as it was for us. We all love the parks and we know that some of the money raised by Measure FF will be used to make needed and appropriate park improvements. They explain their reservations and the reluctant conclusion they reached in their Green Voter Guide that is available on line. Here’s what they say about their decision (emphasis added):

“The Green Party of Alameda County recommends a NO vote, with reservations, on Measure FF (Alameda/Contra Costa Counties):

If approved by voters, Measure FF would simply continue existing Measure CC funding. Voters passed Measure CC in 2004 to provide local funding for park infrastructure, maintenance, safety, and services. Measure CC is a $12/year parcel tax that is set to expire in 2020. Measure FF is expected to raise approximately $3.3 million annually until it expires in 20 years.

Measure CC boasts a long list of successful improvement to East Bay Regional Parks in areas of public safety, wildfire mitigation, healthy forest management, shoreline protection, environmental stewardship, habitat preservation, park infrastructure and maintenance, recreational and educational programming, and visitor services.

While impacts of the Measure have been wide-ranging and largely celebrated, record California wildfires in 2018 have caused both opponents and proponents of the Measure to highlight the wildfire mitigation aspect of the program. Neither Measure CC nor Measure FF contains language that details how to approach reducing wildfires, however, Measure CC’s funds helped in developing the Wildfire Hazard Reduction and Resource Management Plan (“Plan”) that was approved in 2010 by the East Bay Regional Parks District (EBRPD) Board of Directors.

Proponents state that passing Measure FF is critical to continue to reduce risk of wildfires along the wildland-urban interface. They accept that thinning of certain tree species and controlled use of herbicides are tools outlined in the Plan to accomplish the task.

Opponents are against unnecessary removal of non-native species and use of herbicides (EBRPD has expanded use of herbicides and clear-cutting), arguing that extreme fires are driven by effects of climate change, not a particular tree species. Opponents agree with many fire experts that the key defense of homes against wildfire is defensible space, and argue that clear-cutting removes trees that sequester carbon (mitigating climate change) and removes the canopy that provides habitat for species and helps cool the environment. On pesticide use, they simply say: “If organic farmers can do it, so can EBRPD!”

We agree with the opponents: There are environmentally-sensitive alternate approaches to reducing wildfire risk that do not involve removing so many trees and applying poisons in East Bay parks, but the EBRPD Board must be willing to implement them. Vote “No” to send a message to the Board that we can do better. Our reservations are that we like the parks and want to protect them, and we appreciate most of the improvements that Measure FF funds.”

Alameda County Green Party

We are deeply grateful to the Green Party for their decision and we commend them for considering all sides of this complex issue, which is seldom done by political organizations.

Deliver the message to the Park District

Whatever the outcome of this election, votes against Measure FF will deliver a clear message to the Park District:  STOP destroying healthy trees and killing harmless plants and trees with dangerous pesticides!! 

This is the big, beautiful yard sign that you can put in your yard and neighborhood road medians in the East Bay.

Peter Scott and the Green Party have delivered this message and you have the opportunity to add your voice by placing a yard sign in your own yard and in the road medians in your neighborhood in the East Bay.  The Forest Action Brigade is offering yard signs at no cost to you.  Request your yard sign by contacting the Forest Action Brigade:  forestactionbrigade@gmail.com or call (510) 612-8566.

Vote NO on Measure FF!!

A vote against Measure FF on the ballot for the November 6, 2018 election is a vote against pesticide use in the East Bay.  If Measure FF passes, it will renew a parcel tax for 20 years.  For the past 15 years, the parcel tax has funded the destruction of thousands of trees on thousands of acres of public parks in the East Bay.  The renewal of the parcel tax will increase the percentage of available funds for tree removals and associated pesticide use from 30% to 40% of funds raised by the parcel tax.

Post-election update:  Measure FF passed easily.  In Alameda County 85% of voters approved Measure FF.  In Contra Costa County 80% of voters approved Measure FF.  These were the vote tallies on the day after the election, on November 7th.  

Tree removals increase pesticide use because herbicides are required to prevent the trees from resprouting.  Also, when the shade of trees is eliminated, the unshaded ground is soon colonized by weeds that are then sprayed with herbicide.  The destruction of trees has put public land managers on the pesticide treadmill.

The public tried hard to convince the East Bay Regional Park District to stop destroying healthy trees and quit using pesticides in our parks.  We attended public hearings and wrote letters to Park District leadership and its governing board.  We made many suggestions for useful park improvements that would be constructive, rather than destructive.  Our requests and suggestions were ignored.

After making every effort to avoid opposition to Measure FF, we reluctantly take a stand against it.  The parks are important to us and we would much prefer to support park improvements.  Unfortunately, Measure FF will not improve the parks.  Rather, it will continue down the destructive path the Park District has been on for the past 15 years. In fact, Measure FF would escalate the destruction and poisoning of our public lands.

On Friday, August 31st, the Forest Action Brigade participated in a press conference rally at Bayer headquarters in Berkeley. Bayer is the new owner of Monsanto, the manufacturer of glyphosate. The rally was sponsored by a labor organization that is concerned about exposing workers to glyphosate, which is probably a carcinogen.  The President of the Forest Action Brigade, Marg Hall, spoke at the rally.

The Voter Information Guides in Contra Costa and Alameda counties have published the following argument against Measure FF that was submitted by the Forest Action Brigade.  We hope you will read it and take this important opportunity to protect our public parks from being needlessly damaged.

Million Trees

Argument Against Measure FF

“We love public parks, and we support taxation which benefits the common good. Nevertheless, We urge a NO vote. East Bay Regional Parks District (EBRPD) has previously used this measure to destroy, unnecessarily, thousands of healthy trees under pretexts such as “hazardous tree” designations and “protection against wildfires”. But fire experts point out that tree shade retains moisture, thereby reducing fire danger. The measure has also funded so-called “restoration”—destruction of “non-native” plants, in a futile attempt to transform the landscape back to some idealized previous “native” era.

EBRPD’s restoration and tree-cutting projects often utilize pesticides, including glyphosate (Roundup), triclopyr, and imazapyr. We agree with the groundswell of public sentiment opposing the spending of tax dollars on pesticides applied to public lands. Not only do pesticides destroy the soil microbiome; they also migrate into air, water arid soil, severely harming plants, animals, and humans. Because EPA pesticide regulation, especially under the current administration, is inadequate, it is imperative that local jurisdictions exercise greater oversight. While EBRPD utilizes “Integrated Pest Management” which limits pesticide use, we strongly advocate a no pesticide policy, with a concomitant commitment of resources.

Given the terrifying pace of climate change, it is indefensible to target certain species of trees for eradication. All trees—not just “natives” —are the planet’s “lungs,” breathing in carbon dioxide and breathing out oxygen. When a tree is destroyed, its air-cleansing function is forever eliminated, and its stored carbon is released into the atmosphere, thus worsening climate change.

Throughout history, plants, animals, and humans have migrated when their given habitats became unlivable. Adaptation to new environments is at the heart of evolutionary resilience. To claim that some species “belong here” and others do not strikes us as unscientific xenophobia.

Until EBRPD modifies its approach, we urge a NO vote.”

Forest Action Brigade

Do not be misled

The arguments in favor of Measure FF are misleading.  East Bay Regional Parks District attempts to portray a destructive agenda as a constructive agenda.  Please look beneath these pretty-sounding euphemisms for the destructive projects of Measure FF:

·       EBRPD claims Measure FF will “protect against wildfires.”  Destroying harmless trees miles away from any residential structures and replacing the shaded, moist forest with dry grassland that easily ignites will NOT “protect against wildfires.”

·       EBRPD claims Measure FF will “enhance public safety” and “preserve water quality.”  Spraying thousands of acres of open space in our water shed with pesticides will endanger the public and contaminate our water supply.

·       EBRPD claims Measure FF will “protect redwoods and parklands in a changing climate.”  Destroying hundreds of thousands of healthy trees, storing millions of tons of carbon, will exacerbate climate change.  Our redwood forest in the East Bay was confined to less than 5 square miles prior to settlement because of the restrictive horticultural requirements of this treasured native tree.  Because redwoods require more water than most of our urban forest, it is a fantasy that they can be expanded beyond their native footprint.  Where they have been planted outside of that range, many are already dead.

·       EBRPD claims Measure FF will “restore natural areas.”  Our pre-settlement landscape in the East Bay was predominantly grassland in which fire hazards are greatest.  A landscape that has been sprayed with pesticide cannot be accurately described as “natural.”  Previous attempts to convert non-native annual grassland to native grassland have consistently failed, partly because the soil has been poisoned with herbicide.

You can help

The Forest Action Brigade is offering yard signs in opposition to Measure FF (shown below).  Request your yard sign by contacting the Forest Action Brigade: forestactionbrigade@gmail.com or call (510) 612-8566.  Please state how many signs you would like and the neighborhood where you plan to place them.  These are the East Bay cities in which Measure FF will be on the ballot:  Oakland, Alameda, Piedmont, Berkeley, Emeryville, Albany, Richmond, San Pablo, El Cerrito.  These cities are the top priority for yard sign placement.

Million Trees

Digging In: Nativists aggressively defend their use of herbicides

The trial of DeWayne Johnson vs. Monsanto began early in July.  This is the first trial of about 4,000 lawsuits against Monsanto for “product liability.”  Mr. Johnson is dying of non-Hodgkin lymphoma.  He believes that the glyphosate that he sprayed as an employee of the Benicia School District from 2012 to 2015 has caused his terminal cancer.  His lawyer will present evidence at the trial that Monsanto knew the health risks of the glyphosate they manufactured and hid that information from the public. 

This trial could be the turning point that will determine the future of glyphosate in America.  Therefore, this is a suitable opportunity to explain how we got here and why the fate of glyphosate may also determine the fate of the native plant movement.


Update August 10, 2018:  BREAKING NEWS!!!

”A San Francisco jury has found in favor of a school groundskeeper dying of cancer whose lawyers argued that a weed killer made by the agribusiness giant Monsanto likely caused his disease.

“Dewayne Johnson was awarded nearly $290 million in punitive damages and another $39 million in compensatory damages.

“Johnson’s lawsuit against Monsanto was the first case to go to trial in a string of legal complaints alleging the glyphosate-based Roundup herbicide caused non-Hodgkin’s lymphoma.

“He sprayed Roundup and another Monsanto product, Ranger Pro, as part of his job as a pest control manager at a San Francisco Bay Area school district, his attorneys have said.

“He was diagnosed with lymphoma in 2014, when he was 42.

“Monsanto, for its part, vehemently denies a link between Roundup and cancer.

“But jurors at San Francisco’s Superior Court of California, who deliberated for three days, found that the corporation failed to warn Johnson and other consumers about the risks posed by its weed-killing products.

“The outcome of the trial will not have a direct affect on the slew of other Roundup-related suits in state and federal courts. But it could serve as a bellwether for other cases in the queue.”  https://www.nbcnews.com/news/us-news/jury-orders-monsanto-pay-290m-roundup-trial-n899811

This could be the beginning of the end for glyphosate.  There will be many appeals of this decision, but there are also many other lawsuits in line by people who believe they were harmed by glyphosate.  This is a significant step forward.


The story begins

I have followed the native plant movement in California for over 20 years.  I knew that herbicides were used by land managers to eradicate plants they consider “invasive” only because I made the effort to inform myself of what they were doing.  It wasn’t easy to figure out that they were using herbicides because many land managers do not post notices of their pesticide applications and even fewer report their pesticide use to the public.  State law does not require posting of pesticide application notices if the manufacturer claims that the product dries within 24 hours, which exempts most of the herbicides used by land managers, including glyphosate (Roundup) and triclopyr (Garlon).

Pesticide use by land managers in California. Source California Invasive Plant Council

I didn’t know how extensive herbicide use is on our public lands until the California Invasive Plant Council conducted a survey in 2014 of 100 land managers about the methods they were using to kill “invasive” plants. Here’s what we learned from that survey:

  • Ninety-four percent of land managers are using herbicides to control plants they consider “invasive.”  Sixty-two percent are using herbicides frequently.
  • Ninety-nine percent of the land managers who use herbicides, use glyphosate products. Seventy-four percent use Garlon, which is one of the most hazardous herbicides available on the market.  The Pesticide Research Institute says that Garlon “poses reproductive and developmental risks to female applicators.”
  • Foliar spray is the method used most frequently by land managers to apply herbicides.  This method of application has the potential to drift into non-target areas and kill non-target plants.

Chapter Two:  World Health Organization takes a position

In 2015, one year after the Cal-IPC survey was done, the World Health Organization’s International Agency for Research on Cancer (IARC) classified glyphosate as a “probable human carcinogen.”  That decision suddenly and radically altered the playing field for the use of glyphosate, which is the most heavily used of all herbicides.

Since that decision was made, 25 countries have issued outright bans on glyphosate, imposed restrictions or have issued statements of intention to ban or restrict glyphosate-based herbicides, including Roundup.  Countless US states and cities have also adopted such restrictions. Locally, the Marin Municipal Water District made a commitment to not using pesticides—including glyphosate—in 2015.  MMWD had stopped using pesticides in 2005 in response to the public’s objections, but engaged in a long process of evaluating the risk of continuing use that resulted in a permanent ban in 2015.

Chapter Three:  Nativists dig in

The reaction of native plant advocates to this bad news of the dangers of glyphosate has been to dig in and aggressively defend their use of herbicides.

One of the first indications of this reaction was an article about the IARC decision in the Fall 2015 newsletter of the California Invasive Plant Council (Cal-IPC) that concludes:  “In the final analysis, this means that there’s no good reason to stop using glyphosate whether it’s a carcinogen or not.”  If the IARC decision isn’t a good reason, what is?  If the prospect of cancer isn’t a legitimate reason not to use glyphosate, what is?

In its Fall 2016 newsletter, Cal-IPC stepped up the volume.  The Executive Director’s introductory letter stated the highest priorities for Cal-IPC, including, “the increased need for Cal-IPC to publicly support the appropriate use of herbicides.”

That edition of the Cal-IPC newsletter also includes a review of Tao Orion’s book, Beyond the War on Invasive SpeciesTao Orion is a practicing permaculturalist who shares many of the objectives of native plant advocates. Permaculture is committed to conservation, preservation, and restoration, but practitioners achieve those objectives without using pesticides.  They focus on restoring ecological functions by identifying and correcting the underlying causes of change, such as loss of water resources.

Given Cal-IPC’s commitment to herbicide use, it was unable to find value in Orion’s book.  Much of their criticism seemed unfair.  They said that Orion’s recommendations for using restoration methods such as burning or grazing that don’t require the use of pesticides are preaching to the choir.  They claim that native plant restoration projects are, in fact, doing the same thing.  Yet, the survey Cal-IPC conducted in 2014 says otherwise.  Forty-seven percent of land managers said they “never” use grazing to control “invasive” plants, compared to 94% who said they use pesticides.  Burning was not mentioned by any land manager as a method they use.

The survey and accompanying risk assessment of the herbicides used by those who took the survey was presented at the annual Cal-IPC conference in fall 2014.  It was available on the Cal-IPC website until very recently, when it was scrubbed.  The risk assessment is still available on the website of the Pesticide Research Institute, which conducted that evaluation.

In October 2017, Cal-IPC published a position statement regarding glyphosate, “The Use of Glyphosate for Invasive Plant Management.”  Cal-IPC’s “position on the issue” is:  “Cal-IPC supports the use of glyphosate in invasive plant management as part of an Integrated Pest Management (IPM) approach. When using glyphosate according to the label, with appropriate personal protective equipment and best practices, glyphosate is low-risk for wildlife, applicators and the public.”  Their position is primarily based on their belief that doses of glyphosate used in wildland weed management are too low to be a health hazard.

Several new studies, published after the IARC decision, strengthen the case against glyphosate.  New research suggests that glyphosate is a health hazard at low doses considered “safe” by the EPA.  The Global Glyphosate Study is being conducted by six scientific institutions all over the world. This international consortium of scientific institutions recently published preliminary results of their study: “The results of the short-term pilot study showed that glyphosate-based herbicides (GBHs) were able to alter certain important biological parameters in rats, mainly relating to sexual development, genotoxicity and the alteration of the intestinal microbiome, at the ‘safe’ level of 1.75 mg/kg/day set by the U.S. Environmental Protection Agency (EPA).”  In other words, at doses deemed safe by the US EPA, significant negative health effects were found in animals used in testing.

Another recent study of glyphosate found that the formulated product is considerably more toxic than the active ingredient alone.  US National Toxicology Program recently conducted tests on formulated glyphosate products for the first time. In the past, tests were conducted only on the active ingredient…that is glyphosate alone. The formulated products that are actually applied as weed killers contain many other chemicals, some of which are not even known. The head of the National Toxicology Program Laboratory, told The Guardian newspaper the agency’s work is ongoing but its early findings are clear on one key point. “We see the formulations are much more toxic. The formulations were killing the cells. The glyphosate really didn’t do it,” DeVito said. A summary of the NTP analysis said that “glyphosate formulations decreased human cell ‘viability’, disrupting cell membranes. Cell viability was ‘significantly altered’ by the formulations, it stated.”

Two empirical studies found that low levels of exposure to the weed killer Roundup (glyphosate) over a long period of time can cause liver disease.

Is Cal-IPC aware of these recent studies?  Are the people who apply glyphosate aware of these studies?  Are the employers of these applicators aware of these studies?  Are these applicators the plaintiffs of future product liability lawsuits against Monsanto?

Chapter Four:  California Native Plant Society defends herbicides with fantasies

If you read the publications of the California Native Plant Society (CNPS) or attend their conferences, you know that little mention is made of herbicides by their followers and those who engage in “restoration” projects.  In the past, the best defense was to turn a blind eye to herbicide use.

More recently, the intense opposition to the use of herbicides on public lands seems to have forced CNPS to become actively engaged in the defense of herbicides.  The most recent edition of the Journal of the California Native Plant Society, Fremontia (Vol. 46 No. 1) is a “Special Issue on Urban Wildlands.” The introductory article is illustrated with a photo of Oyster Bay.  I nearly choked on this statement in that article:  “In order to control invasive plants, agencies and volunteers have sometimes resorted to using herbicides as a step in integrated pest control.  While use of herbicides is contentious, the use for spot treatments has enabled small groups of volunteers to successfully eliminate invasive weeds in some areas where future herbicide use will not be needed.” Oyster Bay is being doused with herbicides as we reported in a recent article that is available HERE.

Oyster Bay herbicide applications, May 2018

That same edition of Fremontia also includes several articles in which specific native plant “restorations” are described in detail.  All of the projects use herbicides, often repeatedly and often without successfully establishing native plants:

  • “Bull Creek Ecosystem Restoration Project: Not Quite a Success Story”:  This project began in 2008, after over 10 years of planning.  Bull Creek was reconfigured with bull dozers, eliminating the existing landscape.  Although natives were planted, weeds quickly took over the site.  It was weeded by hand initially and considered a success until the creek bank eroded significantly and the artificial oxbow filled with silt.  But “weeds continued to thrive” because the native plants were irrigated and they resorted to herbicide applications in 2010.  Subsequent failures of native plants were blamed on unauthorized public access and the state-wide drought.  Volunteer weeding has been abandoned.  The future of this project is very much in doubt.
  • “Weed Control Efforts in the Sepulveda Basin”: “Based on more than 20 years of experience with attempting to control various weeds in the Sepulveda Basin, and given the lack of support from the city due to budgetary priorities, it is apparent that without herbicide it will be impossible to control non-native weeds that threaten regional biodiversity.”
  • “Nature in the City: Restored Native Habitat Along the LA River…”:  The site was sprayed with Roundup (glyphosate) several times to remove as much of the non-native seed bank as possible.  Weeding continued throughout the habitat restoration and construction period.”

Did CNPS notice the contradiction between their first article and subsequent articles in the same publication?  Their introductory article claims they rarely use herbicides and when they do it is only temporary.  But subsequent articles about specific projects make it clear that herbicides are routinely and repeatedly used and even then, weeds persist.

Pesticides used in San Francisco’s “natural areas.” Courtesy San Francisco Forest Alliance

In the Bay Area, one of the oldest native plant “restorations” is in San Francisco, where the so-called Natural Areas Program (now called Natural Resources Division) started in 1998.  They have used pesticides consistently since the program began.  The San Francisco Forest Alliance began tracking their use of pesticides in 2008.  In their most recent report, the Forest Alliance informs us that pesticide use in the so-called “natural areas” has increased significantly in the first half of 2018.  This increase was anticipated because the program plan and its Environmental Impact Report were finally approved in spring 2017, after 20 years of being hotly contested.  The approval of the program enabled them to increase the staff of pesticide applicators from one to five.  Most of the increase in pesticide use in 2018 is of Garlon, one of the most toxic pesticides available on the market.  San Francisco’s native plant restorations are a specific example of the long term use of large quantities of herbicide.  You can visit those areas to see for yourself that 20 years of effort and herbicides have not successfully established native plant gardens.

Good luck to DeWayne Johnson

It is difficult to understand how nativists can continue to advocate for the use of herbicides.  It is even more difficult to understand how land managers can continue to use public money to spray herbicides on our public parks and open spaces.  Since they are apparently impervious to scientific assessment of the health hazards of herbicides and blind to the failures of their projects, we can only hope that DeWayne Johnson will prevail in his lawsuit against Monsanto.  We would like to see justice for Mr. Johnson and his family and the bonus will be the legal liabilities and associated economic costs of continuing to use a dangerous herbicide that damages the environment and everyone who lives in it.

Action Opportunity: Draft of Oakland’s Vegetation Management Plan

The City of Oakland applied for a FEMA pre-disaster mitigation grant in 2005 to clear-cut all non-native trees on 122 acres of city owned property in the East Bay hills, based on the claim that it would reduce fire hazards.  FEMA cancelled that grant in September 2016 in settlement of a lawsuit against the project. 

The City of Oakland began the process of writing a new plan to reduce fire hazards in the hills by hiring a consultant to develop a Vegetation Management Plan in November 2016.  The new plan will be much more comprehensive than the original plan, covering 1,925 acres of open space and 308 miles of roadside in Oakland.  Oakland also made a commitment to an open public process to develop the plan.  A survey of public opinion was conducted and two public meetings were held in 2017. 

A draft of Oakland’s Vegetation Management Plan is now available HERE.  There are detailed maps of the areas that will be covered by the plan.  We suggest you take a look at those maps to determine what effect the plan will have on your neighborhood and the parks and open spaces you visit.

 A public meeting about the draft was held on May 23, 2018 and written public comments will be accepted until June 11, 2018. Comments may be submitted in the following ways: Download comment card; Email VMPcomments@oaklandvegmanagement.org; Mail:  266 Grand Avenue, Suite 210, Attn: Ken Schwarz, Oakland, CA 94610.  We hope you will participate in this public process that will determine the future of much of the landscape in the Oakland hills.

We are publishing an excerpt of the written public comment of one of our readers, which we hope will help you understand the issues and to write a comment of your own.  Asterisks indicate where some detail has been omitted.  You can see the entire public comment HERE: Oakland Draft Vegetation Management Plan – public comment

 Million Trees


Ken Schwarz
Horizon Water & Environment
266 Grand Avenue, Suite 210
Oakland, CA 94610

I am broadly supportive of the Draft Vegetation Management Plan (DVMP) because:

  • It will create defensible space around structures in Very High Wildfire Hazard Severity Zones.
  • It will clear easily ignited vegetation on roadsides in places where fire hazards are greatest.
  • It sets priorities for implementation in places where fire hazards are greatest.

These three elements of the plan will reduce fire hazards while limiting destruction of trees and vegetation and being fiscally responsible.

My public comment will identify some weaknesses in the plan and make specific suggestions for improving the plan with the goal of minimizing fire hazards as well as collateral damage to the environment.

The 300-foot “buffer” zone is unnecessarily destructive.  California law requires 100-feet of defensible space around structures.  The DVMP proposes extending defensible space along roadsides and around structures to 300-feet, the length of a football field.  Such a wide clearance of vegetation greatly exceeds California fire code and is therefore unnecessarily destructive.  In a recently published op-ed in the Los Angeles Times, two academic scientists confirm our understanding of how to keep our communities safe:  “The science is clear that the most effective way to protect homes from wildfire is to make homes themselves more fire-safe, using fire-resistant roofing and siding, installing ember-proof vents and exterior sprinklers, and maintaining “defensible space” within 60 to 100 feet of individual homes by reducing grasses, shrubs and small trees immediately adjacent to houses. Vegetation management beyond 100 feet from homes provides no additional protection.”[1]

The buffer zone should be eliminated, reduced in size, or reduced to Priority 3 so that it is less destructive and costly. 

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The description of herbicide use in the draft is unnecessarily vague, because it provides no information about what herbicides will be used and the health and environmental hazards of specific herbicides.  Nor does it explain how, where, or why herbicides will be used.

Instead of providing that information, the plan describes the public’s opposition to herbicides as “social stigma,” which implies that our opposition is a baseless prejudice against herbicides.  In fact, our opposition is based on scientific information about the dangers of herbicides and those dangers must be acknowledged by the final version of this plan.

The dangers of herbicides are well documented and well known. ****** Here is a brief list of some of the most recent studies that conclude that glyphosate products are very dangerous to the health of animals and humans:

  • The International Agency for Research on Cancer classified glyphosate as a “probable human carcinogen” in 2015. The IARC is composed of an international team of scientists convened by the World Health Organization of the United Nations.
  • The State of California responded to that news by requiring all glyphosate products sold in the State to be labeled as carcinogens. The State was sued several times by the manufacturer of Round Up—Monsanto–to prevent the labeling requirement.  The State of California recently won in the state court of appeals[2].  Unless Monsanto appeals and wins in the State Supreme Court, all glyphosate products will be labeled as carcinogens in California.
  • US National Toxicology Program recently conducted tests on formulated glyphosate products for the first time. In the past, tests were conducted only on the active ingredient…that is glyphosate alone. The formulated products that are actually applied as weed killers contain many other chemicals, some of which are not even known. The head of the National Toxicology Program Laboratory, told The Guardian newspaper the agency’s work is ongoing but its early findings are clear on one key point. “We see the formulations are much more toxic. The formulations were killing the cells. The glyphosate really didn’t do it,” DeVito said. A summary of the NTP analysis said that “glyphosate formulations decreased human cell ‘viability’, disrupting cell membranes. Cell viability was ‘significantly altered’ by the formulations, it stated.”[3]
  • The Global Glyphosate Study is being conducted by six scientific institutions all over the world. ******* This international consortium of scientific institutions recently published preliminary resultsof their study: “The results of the short-term pilot study showed that glyphosate-based herbicides (GBHs) were able to alter certain important biological parameters in rats, mainly relating to sexual development, genotoxicity and the alteration of the intestinal microbiome, at the ‘safe’ level of 1.75 mg/kg/day set by the U.S. Environmental Protection Agency (EPA).”[4]  In other words, at doses deemed safe by the US EPA, significant negative health effects were found in animals used in testing.
  • The German Agriculture Minister announced on April 17, 2018 that she was finalizing a draft regulation to end use of the weed-killer glyphosate in household gardens, parks and sports facilities, and to set “massive” limits for its use in agriculture.[5] Germany is one of 25 countries that have issued outright bans on glyphosate, imposed restrictions or have issued statements of intention to ban or restrict glyphosate-based herbicides, including Roundup  Countless US states and cities have also adopted such restrictions. [6]
  • Marin Municipal Water District quit using all pesticides in 2015. In a letter to East Bay Municipal Utilities District, a member of the Board of MMWD explains why that decision was made.  (Attachment 2)  MMWD hired scientists at UC Davis to conduct a study of the biological persistence of glyphosate.  They found that glyphosate persisted for at least 84 days when applied to foliage, and perhaps longer after the study ended.

Garlon with the active ingredient triclopyr is more toxic than glyphosate.  Garlon is the herbicide that is used to prevent eucalyptus and acacia from resprouting when the trees are destroyed.  Its use was also specifically allowed for that purpose by Oakland City Council Resolution 79133.   Although the DVMP does not mention its use, we assume—unless specifically told otherwise by the final version of the VMP—that Garlon will be used to control resprouts.

  • Triclopyr is an organochlorine product, in the same family of pesticides as DDT, which was banned in the US in 1972. Organochlorine products bioaccumulate and are very persistent in the environment.  Nearly 50 years after it was banned, DDT is often found in the ground, in the water, and in people’s bodies.[7]
  • Organochlorine products are endocrine disrupters. The Pesticide Research Institute did a risk assessment of triclopyr for the California Invasive Plant Council.  They reported that triclopyr “poses reproductive and developmental risks to female applicators.” [8]
  • The Pesticide Research Institute did a risk assessment of triclopyr for Marin Municipal Water District in which they informed MMWD that birds and bees are both harmed by triclopyr and mycorrhizal fungi in the soil are damaged by triclopyr.[9]

More research has been done on Round Up than on Garlon because it is more widely used.  It is more widely used, partly because it is actually less dangerous than Garlon (it is also a non-selective plant-killer).  Because of the toxicity of Garlon, several public land managers in the Bay Area have made a commitment to controlling resprouts without using herbicides: ******** Marin Municipal Water District,  Marin County Parks and Open Space, UC San Francisco, and East Bay Municipal Utilities District (the supplier of our drinking water).

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There is no evidence that eucalyptus is inherently more flammable than native trees. ******** Eradicating non-native trees and shrubs will not reduce fire hazards because they are not inherently more flammable than the native vegetation that will remain.  Therefore, the reduction of fuel loads must be based on flammability, NOT the nativity of the flammable species.  The nativity of plant species is irrelevant to reducing fire hazards and must be abandoned as criterion for destroying plants and trees.

Vegetation that burned in the North Bay fires of October 2017 was almost exclusively native. Source: Bay Area Open Space Council

I support the thinning of eucalyptus, acacia, Monterey pine and cypress to reduce fuel loads, as long as the canopy is intact.  ******** When the canopy is intact, the forest floor is shaded which retains moisture that retards ignition and suppresses the growth of easily ignited weeds. The DVMP proposes to thin the targeted non-native trees to distances of 35 feet, creating gaps in the canopy of 10 feet within the 300-foot “buffer zone.”  The distance between the trees must be reduced to 25 feet to maintain the canopy.  In addition to reducing fire hazards, maintaining the canopy will also be less destructive and will reduce the amount of stored carbon released into the atmosphere.

Tilden Park, October 2016. East Bay Regional Park District has thinned this area to distances of 25 feet between remaining trees. The forest floor is still shaded because the canopy is intact.

My greatest disappointment in the DVMP is its proposal to remove all individual non-native trees where they presently exist in native vegetation outside the “buffer zone.” ******** Removing non-native trees in riparian areas and in redwood groves as proposed by the DVMP is not fire hazard mitigation because fire hazards in those areas are minimal.

*****************************

Furthermore, destroying healthy trees damages the trees that remain because the herbicide that is used to prevent eucalyptus and acacia from resprouting is mobile in the soil and it is known to damage mycorrhizal fungi in the soil that is essential to the health of the native trees.  ******* It is not possible to destroy isolated trees without damaging neighboring trees in close proximity. ****** Studies show that eucalyptus trees in native forests are not doing any damage to neighboring trees. ********

If individual non-native trees within native vegetation are not doing any environmental damage and do not increase risk of fire they should not be destroyed because destroying them WILL damage native vegetation.  Please leave them alone!

 Putting the DVMP into the long-term big picture

Finally, I suggest that we all take a step back from the details of the DVMP and consider the proposal in the context of the entire environment.  The final VMP must minimize damage to the environment while mitigating fire hazards because:

  • The climate has changed and it will continue to change. When the climate changes, the vegetation changes.  That is one of the axioms of ecology and it will continue to be.  If non-native plants and trees are better adapted to the current and anticipated climate, we should abandon futile attempts to force plants to live where we want them to live.
  • If we want trees in California, we must look to the future, not the past. 130 million native conifers have died in California since 2010. 5-10 million oaks in California have been killed by Sudden Oak Death. The future of redwoods in California is in jeopardy because they require a lot of water and they don’t tolerate wind.

********************

A climate change specialist at the US Forest Service tells us in a recent study that native tree species are the most vulnerable to climate change. USFS found that native trees are more vulnerable to the changes in temperature, precipitation, growing season, and other effects of accumulating greenhouse gases. The assessment found that 88 percent of invasive tree species are expected to prove resilient in the changing climate, ranked with low vulnerability, compared to 20 percent of natives.[10]

  • We are contributing to climate change by destroying healthy trees that are storing tons of carbon that will be released into the atmosphere as the destroyed trees decay. The primary reason why wildfires are more frequent and more intense is because of the warmer, drier climate.  Therefore destroying more trees than necessary increases fire hazards because we are exacerbating climate change by destroying more trees than necessary.
  • It is a fiction that destroying trees will release less carbon than the wildfires imagined by those who demand their destruction. According to a recently completed study at Oregon State University, “wildfire is not the biggest source of climate-warming carbon dioxide in Oregon forests—logging and wood products are.”[11]

*******************

The trees that will be destroyed in Oakland will not be used as lumber, which means they will contribute even more carbon to the atmosphere.  Timber that is used for building retains its stored carbon until the building deteriorates or is destroyed.

  • The herbicides that are used to destroy vegetation and prevent trees from resprouting damage the soil and pose serious health risks to animals and humans. The more vegetation and trees the VMP destroys, the greater the damage caused by herbicides.  Therefore, we must minimize the amount of vegetation that is destroyed as much as possible if herbicides are used.

We achieve nothing if the damage we do to the environment and to ourselves is greater than real or imagined reduction in fire hazards.

Thank you for your consideration.

Resident of
Oakland, California
June 2018


[1] http://www.latimes.com/opinion/op-ed/la-oe-hanson-miller-governor-fire-orders-20180525-story.html

[2] https://www.sfgate.com/news/article/State-can-label-widely-used-herbicide-as-possible-12849147.php

[3] https://www.theguardian.com/us-news/2018/may/08/weedkiller-tests-monsanto-health-dangers-active-ingredient

[4]https://sustainablepulse.com/2018/05/22/monsanto-in-epic-fail-with-attempted-attack-on-global-glyphosate-study/?utm_source=newsletter&utm_medium=email&utm_campaign=gmos_and_pesticides_global_breaking_news&utm_term=2018-05-23#.WwhUfkgvyUl

[5] https://sustainablepulse.com/2018/04/17/germany-moving-ahead-with-plans-to-restrict-weed-killer-glyphosate/?utm_source=newsletter&utm_medium=email&utm_campaign=gmos_and_pesticides_global_breaking_news&utm_term=2018-04-18#.WwhWWUgvyUl

[6] https://www.baumhedlundlaw.com/toxic-tort-law/monsanto-roundup-lawsuit/where-is-glyphosate-banned/

[7] https://www.sciencealert.com/ddt-consistently-found-in-humans-study

[8] https://www.pesticideresearch.com/site/pri-resource-centers/weed-management-resource-center/herbicide-risk-comparisons/workers/

[9]http://www.marinwater.org/DocumentCenter/View/254/HRA_Chap4_Triclopyr_1_1_2010

[10] https://www.forbes.com/sites/jeffmcmahon/2018/04/15/hug-your-native-trees-goodbye-thanks-to-climate-change/#4ad4a4176abd

[11] https://www.hcn.org/articles/climate-change-timber-is-oregons-biggest-carbon-polluter