Spartina eradication is now a zombie project

Over 20 years ago the governors of California, Oregon, and Washington made a commitment to eradicate non-native spartina marsh grass on the entire West Coast of the country.  Intensive aerial spraying of herbicide killed over 95% of non-native spartina about 10 years ago, but the project continues in the San Francisco Bay.  The goal is now the eradication of hybrid spartina that grows at the same marsh elevations as native spartina and is so visually similar that it requires 500 genetic tests every year to determine that it is a hybrid before it is sprayed with herbicide (1). This article will explain why the Invasive Spartina Project in the San Francisco Bay Estuary is now a zombie project, a project that is dead, but is not being allowed to rest in peace.

Click on the picture to see the presentation of the Invasive Spartina Project to the California Invasive Plant Council on June 11, 2021. This is the source of some of the information in this article. Answers to questions at the end of the presentation are particularly important.

Hybridization is the boogey man of plant nativism

Hybrid spartina is being hunted because it outcompetes native spartina.  Nativists fear the loss of native spartina as a distinct species.  Rather than seeing the potential for a new, improved species of spartina, they see it as a loss of biodiversity, rather than an increase in biodiversity. 

Non-native spartina is also accused of “invading” mudflats where some animal species require that type of environment. However, that accusation is contradicted by these photos where native spartina has been planted on mudflats at Eden Landing. The source of these photos is the June 2021 presentation of the Invasive Spartina Project.

Hybridization is an important evolutionary tool that frequently increases biodiversity by creating new species on the margins of ranges where closely related species encounter one another.  For example, hybridization is credited with creating over 500 species of oaks all over the world that are well-adapted to their respective microclimates.  The rapidly changing climate and the globalization of trade have created more opportunities for hybridization and resulting speciation. 

Advances in molecular analysis has informed us of the frequency of hybridization and its benefits to biodiversity:

“With the growing availability of genomic tools and advancements in genomic analyses, it is becoming increasingly clear that gene flow between divergent taxa can generate new phenotypic diversity, allow for adaptation to novel environments, and contribute to speciation. Hybridization can have immediate phenotypic consequences through the expression of hybrid vigor. On longer evolutionary time scales, hybridization can lead to local adaption through the introgression of novel alleles and transgressive segregation and, in some cases, result in the formation of new hybrid species.” 

Restoration and expansion of wetlands is extremely important as we prepare for anticipated rising sea levels.  If hardier, denser, stronger hybrid species of marsh grass are available why would we reject that opportunity?  Nativist ideology should not deprive us of this opportunity. 

Native species are not inherently superior to species that are better adapted to present environmental conditions.  The rapidly changing climate requires corresponding changes in vegetation to adapt to present conditions.  Extreme weather events are natural selection events that kill species that are no longer adapted to the climate.  We cannot stop evolutionary change, nor should we try.

Why does this matter?

If herbicides were not required to eradicate hybrid spartina perhaps I could shrug and move on.  Hundreds of gallons of imazapyr herbicide were used by East Bay Regional Park District to aerial spray non-native spartina for the first few years of the eradication project.  In 2020, EBRPD used 43 gallons of imazapyr for “ecological function,” a nebulous category that includes spartina eradication. 

When the Invasive Spartina Project (ISP) made a presentation to the California Invasive Plant Council in June 2021, the public asked several questions about the toxicity of the herbicide (imazapyr) that is used to eradicate spartina (1). The ISP mistakenly claimed that imazapyr is not harmful to humans and wildlife because it uses a different metabolic pathway to kill plants that does not exist in animals.  They probably believe that claim, but they are wrong.

 A similar claim was made for glyphosate for 40 years.  We now know that the claim about a “unique pathway” for glyphosate existing only in plants is not true.  In 2020, plaintiffs in a class-action suit against Monsanto alleging that it falsely advertised that the active ingredient in Roundup only affects plants were awarded $39.5 million.  The settlement also requires that the inaccurate claim be removed from the labels of all glyphosate products: “…[plaintiff] says Monsanto falsely claimed through its labeling that glyphosate, the active ingredient in Roundup, targets an enzyme that is only found in plants and would therefore not affect people or pets. According to the suit, that enzyme is in fact found in people and pets and is critical to maintaining the immune system, digestion and brain function.”

I asked Beyond Pesticides for help to determine if the exclusive pathway claim was true of imazapyr.  Beyond Pesticides informs me that both imazapyr and glyphosate use metabolic pathways that exist in animals. I summarize their response:  “You asked about the ALS pathway that is the target of imazapyr—is there a comparison to glyphosate?  [According to] the research I found, I think the comparison is valid.  This early paper appears to clearly state that ALS is a pathway found in yeast and bacteria as well as plants (2). Another early paper which identified ALS as coming from bacteria, fungi, and plants (3).”  These pathways exist in bacteria that reside in our bodies and perform important functions, particularly in our digestive and immune systems.  When we damage those bacteria, we are damaging our health.

Please note that both of these studies of imazapyr are nearly 40 years old.  If pesticides were being evaluated and regulated, the public and the users of imazapyr might know that it is harmful to animals.  I provided this information to the Invasive Spartina Project.  They responded that their use of imazapyr is legal.  Unfortunately, they are right.  Because there is no regulation of pesticide use in the United States, the Invasive Spartina Project has the legal right to use it.  But is it ethical?  I asked the Invasive Spartina Project to quit making the inaccurate claim that imazapyr kills plants, but cannot harm animals.  They did not respond to that request.

Unfortunately the judicial system is our only recourse to take dangerous chemicals off the market.  For example, chlorpyrifos that is known to damage children’s brains was finally banned as the result of a court order.  The EPA refused to ban chlorpyrifos, but a lawsuit finally resulted in a judge requiring that the EPA either provide studies proving its safety or ban its sale.  The EPA could not prove its safety, so it had no choice but to finally ban it. 

What about the animals?

Ridgway rail. Source: Cornell Ornithology Laboratory

The only issue that temporarily brought the spartina eradication project to a halt was the impact it has had on endangered Ridgway rail. Ridgway rail is a close relative to the Clapper rail on the East and Gulf coasts where the spartina species considered non-native here (S. alterniflora) is native.  Clapper rails are abundant where S. alterniflora resides.

“Fig. 2.  In marshes where invasive Spartina was present in large densities, populations declined rapidly commensurate with the amount of Spartina removed [from 2005 to 2011].” (4)

The eradication of Ridgway rail breeding habitat in the San Francisco Bay reduced the rail population significantly by 2011, according to the US Geological Service and the US Fish and Wildlife Service (4). The loss of rails was greatest where the most non-native spartina was killed with herbicide.  In response, USFWS mandated a moratorium on eradication in areas where rails were nesting (5). According to the ISP 2020 survey of rails in the project areas, the rail population rebounded where eradication was stopped.  When treatment resumed in 2018, the number of Ridgway rails in the previously restricted areas declined by 9% in the following year.  That outcome was predicted by the USFWS Biological Opinion: “In the 2018 Biological Opinion, the Service estimated that rails inhabiting the nine previously-restricted sub-areas may be lost due to mortality or exhibit decreased reproductive success due to loss of hybrid Spartina cover when treatment of these sub-areas resumed.”

Clearly, the endangered Ridgway rail has been harmed by spartina eradication, as USGS and USFWS concluded in their analysis that was published in 2016 (4):

“California [now known as Ridgway rail] rail survival was higher prior to invasive Spartina eradication than after eradication or compared to survival in a native marsh. The combined indication of these studies is that tall vegetation structure provides California rails with both higher quality nesting substrate and refuge cover from predation, particularly during high tides. Thus, habitat structure provided by invasive Spartina in heavily infested marshes may facilitate California rail survival, and continued efforts to remove invasive Spartina from tidal salt marshes could lead to further California rail population declines….” (4)

Given that Ridgway rail is protected by the Endangered Species Act, it is difficult to understand why this project is allowed to continue.  Much like the unregulated use of pesticides, it will probably take a lawsuit to enforce the Endangered Species Act on behalf of endangered Ridgway rail. When government is not functional, the judicial system can sometimes compensate.

Let’s bury this zombie project

The US Geological Service and the US Fish and Wildlife Service have put their finger on the failure of the Invasive Spartina Project.  The same could be said of many other pointless eradication projects:

“Removing the source of that novel habitat without addressing pre-existing native habitat quality limitations threatens to re-create an ailing landscape for California rails by dogmatically adhering to specific management approaches. In essence, the conservation community is choosing the winners and losers in this ecosystem by failing to solve the underlying problems that will support a healthy species community with all constituent members.” (4)

The spartina eradication project serves no useful purpose.  In fact, it damages the environment and the animals that live in it.  We cannot stop evolution, nor should we try.  Let natural selection determine the plant species that are best adapted to our environment and the animals that live in it.  Not only would we benefit from better protection for our coastline from rising sea levels, we could reduce our exposure to dangerous pesticides that are harmful to our health, as well as improve habitat for wildlife.  This project is doing more harm than good. 


  1. Presentation of Invasive Spartina Project to California Invasive Plant Council, June 2021 
  2. Falco, S.C., Dumas, K.S. and Livak, K.J., 1985Nucleotide sequence of the yeast ILV2 gene which encodes acetolactate synthase
  3. LaRossa, R.A. and Smulski, D.R., 1984. ilvB-encoded acetolactate synthase is resistant to the herbicide sulfometuron methylJournal of bacteriology160(1), pp.391-394.
  4. M.L. Casazza, et.al., “Endangered species management and ecosystem restoration: finding the common ground,” Ecology and Society, 2016, 21(1):19. http://dx.doi.org/10.5751/ES-08134-210119
  5. Adam Lambert et.al., “Optimal approaches for balancing invasive species eradication and endangered species management,” Science, May 30, 2014, vol. 344 Issue 6187

“A history of food, from sustainable to suicidal”

“A brilliant and insightful explanation of the food system. Bittman’s writing is succinct and entertaining, and his recommendations are spot on.” –David Kessler, MD, former FDA commissioner

Mark Bittman’s new book, Animal, Vegetable, Junk, is best described by its subtitle, A history of food, from sustainable to suicidal.  Bittman starts the story at the beginning, nearly 300,000 years ago when humans were hunter/gatherers.  The transition from a hunter/gatherer to an agricultural society began only 10,000 years ago.  It was a long, slow transition that happened unevenly all over the world.  Hunter gatherer societies still exist in the Amazon and perhaps elsewhere.  Where nature was generous, hunting/gathering persisted longer.  For example, indigenous people in California were still hunters/gatherers when Europeans arrived and indigenous people on the East coast had developed agricultural societies.

The conventional wisdom has been until recently that sedentary agriculture is superior to hunting/gathering as a lifestyle and a producer of food.  Bittman and Yuval Harari in Sapiens—the sweeping history of human civilization—disagree.  The diets of hunters/gatherers are more diverse, which makes them healthier and less vulnerable to famine.  If you can’t find what you need in one place, you move to another.  Families of hunter/gatherer societies are small because mothers can’t carry more than one child at a time, so there is no advantage to the large families required by farming.  Women’s role as gatherer is as important as man’s role as hunter, making the family less patriarchal than agriculture societies.  A mobile society has less impact on the land and is less likely to deplete resources, such as water and soil.  Communities were smaller, making them less vulnerable to communicable diseases.

The invention of the plow more than 2,000 years ago was one of the first significant turning points in the development of agriculture.  The plow requires the strength of men to operate, making the participation of women in food production less important.  A division of labor between the genders developed, along with the gender power hierarchy that persists today.  This division of labor was consistent with the need for families to have more children and therefore more farm hands. 

As the population of humans in agricultural society increased, so did the pressure on the land to be more productive.  Farmers knew and still know that the soil requires regeneration if it is to remain fertile.  Such practices as planting cover crops between cash crops to return vegetation to the soil, are not new.  Farmers also knew that leaving land fallow for a season or two enables the soil to recover from the loss of nutrients required to grow crops.  Rotating crops helps to control pests and diseases that are usually associated with one type of crop, but not another.  But the pressure to produce more food as the population increases puts pressure on farmers to squeeze more from the soil than it has to give in the long term.

Mechanization of agriculture

Mechanization was the most significant incremental step on the long road to the dead end that we now face in agriculture.  John Deere introduced his steel-bladed plow in the middle of the 19th century that was capable of breaking the tough sod of the Mid-Western prairie.  Deere mass-produced the steel plow using the assembly-line methods of the industrial revolution.  By 1859 John Deere was making 10,000 plows in a year. 

Although the Deere plow was a significant invention, the advent of the steam and then gas-powered tractor shortly thereafter were the true game changers that started the transition from family farms to the corporate agriculture of today:  “In 1830 it took a farmer and a horse at least seventy-five hours to produce a hundred bushels of corn.  BY 1930 that same task took as little as fifteen hours.  Production grew in parallel, from 173 million bushels of wheat in 1859 to 287 million by the century’s end.  The big difference was the tractor.”

The tractor was only the beginning of mechanization of agriculture.  There are now enormous machines, such as harvesters that cost half a million dollars and more.  Family farmers can’t afford to buy these machines.  They aren’t useful to small land-holders because huge farms are needed to pay for the cost of these machines.  Farmers who tried to stay in the game took huge loans to buy them.  Agriculture is risky business because the climate is changeable and unpredictable.  In drought years, many farmers with small holdings lost their land because they couldn’t repay their loans. 

Cornfield

Corporate interests are in a position to obtain the necessary loans and buy out the small land-holders.  Family farms are a thing of the past.  The romanticized notion of family farms is a fiction. Family farmers understand that destroying their soil is not in the interests of their family. Corporate interests have a short-term perspective when making business decisions.  Therefore, regenerative agricultural methods such as cover crops, rotating crops, and leaving land fallow are also a thing of the past.   

The Green Revolution

The so-called “green revolution” was the response to the destruction of agricultural land.  By the 1930s, the soil in agricultural America was exhausted.  The result of a century of short-term perspective agriculture that didn’t give back to the soil what was taken from it was the Dust Bowl of the 1930s. 

The Dust Bowl

Instead of returning to regenerative agricultural methods, the response was the introduction of chemical fertilizers and pesticides. Sixty years of pesticide use has bred many weed and insect species that are resistant to pesticides because no amount of chemistry can outwit evolution. In addition to introducing toxic chemicals into the environment, these chemicals exacerbated the trend toward bigger, corporate-owned agricultural lands because chemicals are expensive.  They must be purchased in advance of realizing the income of selling a crop, requiring bigger loans. According to Bittman, John Deere company makes four times as much money from financing these loans as from selling farm equipment. More family farms failed and their land was consolidated into huge acreages owned by corporate interests with short-term goals for higher profits.

The chemical warfare waged by industrial agriculture escalated greatly when Monsanto’s Roundup Ready seeds were introduced in 1996.  These genetically modified seeds enabled the indiscriminate spraying of the non-selective herbicide, glyphosate on commodity crops.  The seeds are expensive and their patents require that they only be used once.  They greatly increased farmer’s dependence on loans to finance the planting of their crops.  This indiscriminate spraying of glyphosate on commodity crops used in all processed food and animal feed means that we are now eating and drinking food laced with glyphosate, a probable carcinogen.

Chemical fertilizers deliver phosphorous to the soil, needed for plant growth.  Run off from agricultural land pollutes our lakes and rivers, killing fish and making water unsafe to drink or swim in.  Pesticides are indiscriminately killing insects, many of which are beneficial, such as our pollinators.  Pesticides are found in our water, our soil, and our food.  Little is known about the effects of these chemicals on our health or on wildlife, but what we know suggests they are probably more dangerous than we realize.  For example, recent research suggests that chemicals that disrupt our endocrine systems are probably reducing fertility, causing birth defects and contributing to gender dysphoria. 

Consequences of agricultural surpluses

Bigger is not better in agriculture because bigger also means that only a handful of crops are grown on huge corporate farms.  It is more expensive to grow diverse crops, requiring different cultivation methods and inputs.  Huge machines are operated more efficiently on huge plots of land.  Most agricultural land in America is devoted to growing crops of corn, soy beans, and wheat.  So much of America’s farm land is devoted to these commodity crops that they produce huge surpluses that require a global market to sell them to.

The global marketplace for commodity agricultural crops has fundamentally changed many countries.  The North American Free Trade Agreement (NAFTA) forced farmers in Mexico to abandon their small farms and move to cities to take low-paying manufacturing jobs because they could not compete against cheaper American corn.  The diet and health of the Mexican people has deteriorated significantly because they no longer have access to the variety of fruit and vegetables their small properties produced.  Their healthy fruit juices have been replaced by sodas made from corn syrup, resulting in high rates of obesity and diabetes.

Children’s cereals. Glyphosate residues are found in most cereal.

The diet of Americans has also been changed radically by the marketing campaigns designed to sell surplus commodities.  A surplus of milk produced the “Got milk?” advertising campaign that sold milk to adults for whom milk is rarely healthy.  Bittman says that 65% of adults are lactose intolerant, which he knows from personal experience.  He was forced to drink milk until he left home.  He was plagued by indigestion until he was able to quit drinking milk as an adult. 

Far more pernicious, is the advertising campaign that convinced mothers to quit breast feeding in favor of feeding formula.  This insidious campaign used guilt to pressure mothers by making the inaccurate claim that formula is healthier for their babies.  Breast feeding is the primary means that a baby’s immune system develops.  Formula contains higher levels of sugar that sets the stage for life-long eating habits that are not healthy.  High levels of obesity and diabetes begin at childhood and are very difficult to change later in life.  The advertising campaign was global and it did more damage in undeveloped countries where the water needed to dilute formula is often not safe.  Although the health consequences of using formula are well known, the advertising campaign continues to this day.  The New York Times ran a full-page advertisement for formula recently, using convenience as its approach, suggesting that modern mothers should not be guilt-tripped into breast feeding. 

Not the end of the story

We landed in this dietary and environmental disaster zone over thousands of years of small, incremental changes that were imperceptible at the time.  We could not foresee the consequences of the cumulative effect of each small step along the road to this dead end.  And Bittman says we can back out of this dead end in the same way, by making small steps back to regenerative farming.  Bittman’s final chapters are devoted to the many projects all over the world devoted to restoring our agricultural land, our diets, and our health. 

This brief summary of Bittman’s book does not do it justice.  There are a multitude of other important factors to consider, such as the huge contribution that industrial agriculture is making to climate change and the changes in raising animals that are just as unhealthy as how we are growing our plant-based food.  I can’t say that Bittman’s book is a pleasant read, but I assure you that it is important. 

Update on California’s 30X30 initiative: The good, the bad, and the ugly

In May 2021, Conservation Sense and Nonsense introduced California’s $11 billion investment in addressing climate change and protecting biodiversity by protecting 30% of land and coastal waters by 2030 (30X30). Since then, the California Natural Resources Agency (CNRA) held a series of workshops to explain the initiative and give the public an opportunity to provide feedback to CNRA.  Sixteen hundred Californians participated in those workshops, including me. Today I am reporting what I learned about the initiative and tell you my opinion of what I learned.

Update: The final California budget commits $15 billion for climate change and protecting biodiversity.

Good news always comes first

The Land Conservation Panel identified the opportunity to remediate degraded spaces that will address many of the objectives of the 30X30 initiative.  Many degraded spaces are found in poor communities that are exposed to toxic waste and pollution.  Eliminating public health hazards in these communities will not only improve their health, it will make those spaces available for recreational and other purposes.  Here are just a few of many such opportunities in California:

Superfund sites in California as of 2013. Source: Environmental Protection Agency
  • There are 94 toxic waste Superfund sites in California.  Where these sites are threatening the health and safety of the public they should be high priorities for remediation.  For example, nearly 30,000 corroding barrels of DDT were recently found on the ocean floor near Catalina Island.  The extent of that particular toxic dump was not known at the time the LA Times reported it, but investigating scientists speculated that as many as half a million barrels may have been dumped by the manufacturer of DDT.
  • There are 47,000 abandoned mine sites in California, according to the Bureau of Land management.  84% of those sites present physical safety hazards and 11% of the sites present environmental safety hazards.  Abandoned mine sites that are potential recreational areas in underserved communities should be considered high priorities for remediation.
  • The California Clean Water Act identifies “impaired waters.”  The list of impaired waters is long and it is alarming.  It identifies pollution with toxic substances such as mercury, diazinon, sewage from leaking septic tanks, sedimentation from erosion, run off of agricultural chemicals, etc.  Addressing these issues will reduce public health hazards and improve fish and wildlife habitat.  Most rivers in California are ultimately watersheds into the ocean, therefore cleaning up these “impaired waters” will also improve ocean health.  At this time of extreme drought and the expectation of continuing drought, water quality should be a high priority for the 30X30 initiative.
  • There are over 5,000 orphan oil wells in California with no known responsible operator.  Capping and retiring these oil wells would reduce health hazards and make the land available for recreational and other uses.  These abandoned oil wells are frequently found in economically disadvantaged areas such as Bakersfield and poor areas in the Los Angeles basin, which is all the more reason to remediate this blight on the landscape. 

The remediation of hazardous pollution would benefit Californians, reducing health hazards for humans and wildlife and potentially making land available for other useful purposes.  Remediating polluted, dangerous land must be a higher priority than funding the horticultural preferences of hobbyists with romantic notions about recreating a landscape that is long gone and cannot be replicated.  If we are to achieve durable objectives, we must have realistic expectations and goals that are consistent with current and anticipated climate conditions.  Thriving landscapes that do not require irrigation should not be replaced with fragile landscapes that require irrigation and access restrictions.  No land that requires pesticides to accomplish “conservation” goals can legitimately be called “conserved.”

Not so good indicators of destructive projects

Although the Summary Document of the Panel for Coastal Waters made vague references to the importance of “Linking protection of land and coastal ecosystems through adjacent terrestrial and marine protected areas,” the words “watershed” and “wetlands” do not appear in the Summary Document.  No specific suggestions were made to address the close relationship between coastal land and coastal waters.

The preservation and expansion of wetlands will reduce the flow of pollution from land to ocean by acting as a filter of runoff from the land.  Wetlands are also one of our chief defenses against rising sea levels if they are expanded to perform that function.  Wetlands are the nurseries of our fisheries and they provide essential habitat for wildlife.  Wetlands are also significant carbon sinks.  Yet the Summary Document makes no mention of these essential functions that contribute to healthy oceans.

Cleaning up the watersheds that are now draining toxic pollutants into the ocean is a more worthwhile endeavor than anything suggested by the Coastal Waters Summary Document. Most rivers in California are ultimately watersheds into the ocean, therefore cleaning up these “impaired waters” will also improve ocean health.  Many important fish species that migrate from ocean to rivers are killed or harmed by these hazardous contaminants.  The ocean is only as healthy as its watersheds.

Instead of addressing the opportunities to expand wetlands and cleaning up watersheds, the Coastal Waters Panel is proposing an outdated “restoration” approach that begins with killing plants and animals. The attempt to “restore” kelp forests is one of the few specific examples of possible projects that is mentioned in the Panel’s Summary Document.  Like most of these futile projects, that project begins by killing thousands (millions?) of the chosen scapegoat, purple urchins, predators of kelp.  Where urchins are killed kelp is being replanted.  Like most of these projects, the chosen method does not address the underlying causes for declining kelp forests that were killed by ocean heat waves.  Ocean heat waves are a consequence of inexorable climate change.  It is delusional to assume that the heat waves that killed the kelp will not occur again.  Furthermore, the massive die-off of sea stars from a mysterious “wasting syndrome” is an important factor in the explosion of urchin populations that are prey of sea stars.  As you might know, sea stars are making a comeback.  Sea Otters are also predators of urchins.  If their populations weren’t repeatedly suppressed by commercial fishing interests, urchins would have more predators.  In other words, present methods of “restoring” kelp forests are based on inadequate understanding of the food web and the underlying causes of the loss of kelp forests.  Is anyone trying to breed a more heat-tolerant variety of kelp?  Is anyone looking for a functional equivalent in warmer waters?  In other words, the loss of kelp forests is a serious problem, but the methods being used to address it are amateurish and futile.

The Ugly:  Composition of 30X30 panels is deeply flawed

There are representatives of organizations on two 30X30 panels that promote and participate in island eradication projects such as the Farallon Islands project that proposes to kill mice by aerial bombing 1.5 tons of rodenticide on the islands.  One representative on the Biodiversity Panel identifies himself as a “conservation entrepreneur” and the founder of Island Conservation, the organization that has conducted more than 350 island eradications in 65 countries around the world and is participating in the Farallons project.  One member of the Coastal Waters Panel represents Point Blue, an organization that has participated in many deadly projects.  Point Blue actively promotes the Farallons project and has participated in its development. 

The Farallon Islands project is another example of a project that has selected an animal scapegoat for eradication without addressing the underlying cause of the perceived problem, which is a dwindling population of ashy storm petrels.  Mice are the chosen scapegoat despite the fact that they do not harm any birds or their chicks.  The mice are blamed because they are the preferred prey of a small number (8-10) of burrowing owls that prey on the petrel chicks when mice are not available.  The burrowing owls could easily be non-lethally removed from the island (Try walking up to a burrowing owl.  Chances are it won’t flinch.)  The National Park Service removed 44 Golden Eagles from the Channel Islands because they were preying on Channel Island Foxes (after NPS eradicated sheep and goats from the islands that were the Eagles’ preferred prey).  USFWS proposes to kill the mice by aerial bombing 1.5 tons of rodenticides on the Farallons and they acknowledge that hundreds (thousands?) of non-target birds are likely to be collateral damage, as they have been in hundreds of similar projects all over the world.  USFWS claims that the burrowing owls will “go away” if their preferred prey is eliminated.  It seems more likely that the burrowing owls will either be killed by the rodenticide or will eat more birds if that’s all there is to eat.  Second-generation rodenticides were recently banned in California because they are killing non-target birds and mammals.  Unfortunately an exemption for projects considered ecological “restorations” was carved out of that ban. Why the proposed Farallons project is considered a “restoration” is a mystery to me. 

We saw burrowing owls in Argentina in 2010. We walked up to them to test the claim that they are easily disturbed by people. We got even closer than this before the owl reacted.

Similar island eradications have been completed all over the world.  Rats are the usual target of those projects and unlike the mice on the Farallons, there is evidence that rats are capable of harming birds.  However, a significant portion of those projects were unsuccessful because rats are resourceful creatures capable of reproducing quickly after their population is reduced.  More importantly, those projects have killed thousands of non-target birds who ate the poison (or poisoned rats) and contaminated the water around the islands, harming fish and marine mammals that live around the islands.

Island eradications done by Island Conservation

As I told California Natural Resources Agency in my written public comments, Point Blue and Island Conservation should not be represented on 30X30 panels because they are likely applicants for projects that will be funded by the state.  This is a serious conflict of interest.  Point Blue is involved in hundreds of destructive projects all over California, including surveying barred owls in preparation for shooting them. Island Conservation has published a study that identified other islands off the coast of California for potential island eradications.  If these organizations are in a position to influence the types of projects that are funded by the 30X30 initiative, they will be in a position to profit from creating projects they can perform. 

Several of the public commenters at the Coastal Waters workshop on August 17th mentioned that there is no representation on the Coastal Waters Panel of recreational and commercial fishermen.  Other panels include representation of recreational interests because increasing recreational opportunities is one of the primary goals of the 30X30 initiative.  Point Blue should be replaced on the Coastal Waters Panel by representation of recreational and commercial fishermen. 

Where do we go from here?

You can view the 30X30 workshops on CNRA’s You Tube Channel. You can read the recommendations of the 30X30 panels on CNRA’s website.  And you can respond to CNRA’s invitation to send them pictures of successful restoration projects:

“If you or your organization has images of before and after climate smart land management projects, successful nature-based solutions; or iconic California landscapes we would love to feature them!…If your organization is interested in sharing pictures, please email them to Heather Williams at the California Natural Resources Agency (CNRA) by September 17. Please include a description/caption of the image, the organization’s name, and the image date(s). Send only high-resolution images (1200×800 or larger). By emailing these pictures, you give CNRA the right to use these images in our nature-based solutions and climate-smart land efforts.”

Organizations that will compete for $11 billion of grant funds will undoubtedly provide many beautiful pictures of their projects.  If you have pictures of projects that were not successful, you may send them as well. 

There will be another round of workshops to review draft plans in Fall 2021.  You can ask to be notified of those workshops and register to attend them by sending an email to californianature@ca.gov.  Plans will be finalized for implementation in January 2022. 

The 30X30 initiative has the potential to be constructive by addressing important issues with viable projects.  It also has the potential to be destructive by destroying harmless plants and animals, poisoning our land, and installing replacement landscapes that are not adapted to current and anticipated environmental conditions.  Our participation in the development of the plans is our only means of influencing the outcome.  California taxpayers will pay for these projects, whether we like them or not.  It is in our hands.

Collaboration triumphs over competition in the forest

“Ecosystems are so similar to human societies—they’re built on relationships. The stronger those are, the more resilient the system.” Suzanne Simard, Finding the Mother Tree

Suzanne Simard is an academic scientist of forestry of some renown because her research has revealed that the forest is a community of plants and trees that share resources to their mutual and communal benefit.  Her recently published memoir, Finding the Mother Tree, about her 40-year career in forestry is deeply personal and informative. 

Simard grew up in the forests of British Columbia in an extended family of traditional loggers who used manual methods to selectively remove individual trees, leaving forests intact.  This is physically demanding and dangerous work, making it a predominantly male occupation. 

After her education as a forester, Simard joined the Canadian Forest Service and a profession dominated by men and committed to maximizing profit by clear cutting patches of forest with mechanized methods.  This policy requires the destruction of all vegetation in clear cuts considered potential competition for the next crop of timber.  After mechanical removal, the ground is sprayed with herbicide from helicopters before being replanted with tree seedlings.  This policy is called “free to grow,” a misnomer that was eventually revealed by Simard’s research.  The plant and tree neighbors of the seedlings are their collaborators in the enterprise of the entire forest, functioning as an ecosystem that creates a home for every life form in the community.

Suzanne Simard’s lonely professional journey in forestry

One of Simard’s first assignments as a forester was to assess the health of seedlings planted in a clear cut.  The seedlings were not doing well.  It became her mission to find out why.  A lifetime of observing healthy forests had taught her that the soil is occupied by vast networks of fungi that connect the plants and trees.  These mycorrhizal fungi transfer moisture and nutrients from the soil to the trees and plants, to their benefit.  She speculated that the destruction of all vegetation in clear cuts was eliminating that support structure and she designed experiments to test her hypothesis. 

Douglas fir forest, MacMillan Provincial Forest, Vancouver, British Columbia

Her experimental plots were divided into areas with varying degrees of vegetation clearance.  At one extreme, seedlings were isolated by sheets of metal buried deep into the soil that prevented development of mycorrhizal networks to support the seedlings.  Decades later, these isolated seedlings were the most likely to have died.  The seedlings that survived most often were on the perimeter of clear cuts, with access to the surrounding intact forest.

The relationships between tree and plant species and their mycorrhizal networks vary by plant and fungi species.  There are thousands of mycorrhizal fungi species associated with trees and about half are generalists that associate with most tree species.  Specialist species of fungi are confined to a narrower range of tree species, genera, or families.  There are fewer species of mycorrhizae associated with plants and most are generalists. 

The specifics of fungal associations between trees also varies, which requires that we describe a specific relationship.  Simard’s original studies focused on the fungal associations between Douglas fir and birch trees.  Birch trees were destroyed in the clear cuts that were then planted with Douglas fir seedlings that were not doing well.  Simard’s experiments eventually revealed that birch trees and firs mutually benefit one another through their fungal networks.  Carbon stored and the sugar produced by photosynthesis by firs are shared with deciduous birch during winter months while they are leafless.  In summer months when birch are foliated, they store more carbon that is shared with firs.  Birch is resistant to a root pathogen to which firs are susceptible.  In a sharing fungal relationship between birch and firs, birch confers some of that resistance to the root pathogen onto their fir neighbors.

Nitrogen is essential to plant and tree health, but not all species are capable of converting atmospheric nitrogen to soil nitrogen available to plants.  When a nitrogen-fixing plant is associated with a plant without that capability, it can share its nitrogen with its neighbor through their fungal network. 

A mature tree can store more moisture than its young seedlings without extensive root structure.  The mature tree can share its stored moisture with struggling seedlings through its fungal network.  Seedlings with access to that network are more likely to survive while establishing their own root structures.  Research of Simard’s graduate students and collaborators eventually found that such sharing of resources between mature and young trees occurs more frequently within the same species, but sharing also occurs with unrelated tree species.  The mature trees nurture their offspring, enabling their survival and the survival of the species.  They are, in effect, Mother Trees.

MacMillan Provincial Forest, Vancouver, British Columbia

Herbicides used to kill vegetation in clear cuts

Another early assignment by the forest service required that Simard determine the most effective herbicide regimen to kill plants in clear cuts perceived to be potential competitors of the seedlings of the next timber crop.  Simard and her sister applied several different concentrations of herbicide to vegetation and predictably determined that the most concentrated formulation of herbicide was the most deadly.  Glyphosate is the most commonly used herbicide for this purpose.

This particular episode in Simard’s early career was disturbing in view of the fact that she eventually developed breast cancer that nearly killed her.  Simard and her sister were uncomfortable about their assignment and they suited up cautiously as best they knew how while applying herbicide.  The Simard sisters felt ill after an application and they sought medical help from whom they learned that their masks did not contain the necessary filters.  Required safety measures for herbicide applicators are only as good as the knowledge on which they are based.  That knowledge moves slowly forward and becomes more alarming as we learn more.

What has the timber industry learned from Simard’s research?

The short answer to that question is very little.  The strategy of the timber industry in both Canada and the US remains clear cuts that destroy all trees and vegetation followed by herbicide application by helicopter to kill all herbaceous vegetation before seedlings are planted.  Simard reports that concentrations of herbicide have been reduced recently.  She also says that a few large, mature trees are sometimes spared by clear cuts. 

Recent knowledge of the health effects of glyphosate is causing some concern, but few changes in policy or practice have been made.  Declining moose populations in a region of Canada led to decreased herbicide applications.  Legislators in the State of Maine recently passed a law to ban herbicide applications in timber clear cuts.  That legislation was then vetoed by the Governor of Maine.

Strangely, none of these reports of reduced herbicide use by the timber industry mention that herbicides are known to damage mycorrhizae.  Health concerns are cited as the sole reason for reducing herbicide use despite the fact that we now know the importance of mycorrhizal networks to the health and survival of forests.  While Simard opposes the use of herbicides in forests, she does not explicitly connect herbicides with the destruction of mycorrhizal networks that enable the survival of tree seedlings. 

Are these studies relevant to our urban forest?

Those who are looking for support for our urban forest in Simard’s work will be disappointed.  Her focus is on the health and preservation of native forests. In fact, she has harsh words for “exotic weed invasions:” She says they are accelerating the decline of native grassland “possibly by sending the native grasses some poisons or an infection to finish the murder.  Or starving them, taking over their energy, degrading the native prairie. Like the invasion of the body snatchers.  Or the colonization of the Americas by Europeans.”  Note that her indictment is speculative and not the conclusion of an empirical study.   

But the principles of Simard’s findings are relevant to our concerns for the destruction of our urban forests and the herbicides used for that purpose.  Mycorrhizal fungi are as essential to urban forests as they are to native forests.  Herbicides used in our urban forests are as damaging to fungal networks as they are to clear cuts of native forests. 

Trees, Truffles, and Beasts (1) was written by academic foresters in Oregon and Australia who are primarily concerned about the destructive consequences of destroying native forests and replacing them with timber plantations, often of another, faster growing species.  Ironically, in the case of old growth eucalyptus forests in Australia, the choice of replacement species is often Monterey pines.  Since some species of mycorrhizal fungi are specific to certain species or types of trees, this change of species is not successful without the inoculation of appropriate species of fungi.  For example, some of the mycorrhizal fungi that grow on the roots of conifers are not found on eucalyptus species.

I corresponded with the authors of Trees, Truffles, and Beasts to confirm that fungi are found in the eucalyptus forests of California.  Since eucalyptus was brought to California as seeds, rather than potted plants, I needed confirmation that our eucalyptus forests are also enjoying the benefits of mycorrhizal fungi.  We are grateful that the authors replied.  They report that eucalyptus forests in California are indeed populated with generalist fungi, including some species that are native to Australia.  Therefore, we can assure our readers that our description of how the forest functions as a community applies to the eucalyptus forest in California, as well as in Australia.

When eucalyptus is destroyed in California their stumps are immediately sprayed with herbicide (usually Garlon) so the tree does not resprout.  The herbicide is carried into the roots of the tree through the cambium layer that is briefly functional after the tree is destroyed.  Garlon is known to damage mycorrhizal fungi.

Herbicide is also used to destroy the non-native vegetation that thrives in the full sun after trees are destroyed.  Glyposate that is commonly used for that purpose is known to kill microbes that are essential to soil health, handicapping any replacement planting. 

Suzanne Simard’s mission

Before leaving the Canadian Forest Service, Suzanne Simard made every effort to inform her colleagues of the damage being done by the timber industry and the potential for more successful planting of a new generation of timber if policy and practice were revised to preserve soil health.  In a male-dominated profession that was committed to the methods being used, her message fell on deaf ears.  In fact, her colleagues were openly hostile to her message, making the offer of an academic position welcome relief that gave her more freedom to conduct research and deliver her message.

After recovering from a nearly fatal bout of breast cancer, Simard became more committed to bringing her research to the attention of the public.  She has delivered inspiring and wildly successful TED talks and she was immortalized as the heroine of The Overstory (2), the barely fictional account of defenders of the forest that made Simard’s research accessible to the general public.

Finding the Mother Tree, Suzanne Simard’s memoir, is a sad reminder of the difficulty of bucking conventional wisdom that is deeply rooted in the profit motive.  In the case of the timber industry, competition remains the dominant narrative that drives policy and the consequences of that approach are unnecessarily destructive.    


  1. Chris Maser, Andrew W. Claridge, James M. Trappe, Trees, Truffles, and Beasts, Rutgers University Press, 2008
  2. The Overstory, Richard Powers, W.W. Norton and Company, 2019.

Nativism turns a blind eye to climate change

“Reflexive demonization of alien species ignores the beautiful but complex truth that nature fights to find a way—and for a planet navigating the pressures of climate change and overpopulation, that just might be our saving grace.” – Marianne Willburn, Garden Rant

Margaret Renkl writes an opinion column for the New York Times that I usually enjoy because she frequently writes about nature, often based on observations of wildlife in her own garden.  She lives in her childhood home in Nashville, Tennessee.  Much of her garden was planted with non-native plants and trees decades ago by her deceased mother.  Yet, in a recent column, Ms. Renkl blames non-native plants for a variety of crimes against nature. 

  • She suggests that non-native trees are blooming earlier than native trees, which she says has “skewed our experience of spring.”  She is apparently unaware that spring does indeed arrive earlier than it has in the past because of climate change.  Warmer weather arrives earlier, triggering the blooms of spring, not vice versa.  Both native and non-native plants are blooming earlier than they did in the past. 
  • She suggests that gardens planted with non-native plants are “blooming wastelands where the flowers feed nobody at all,” yet her columns are usually filled with the wildlife that lives in her own garden, with introduced plant species.
  • Although she does not use pesticides in her own garden, she believes that her neighbors’ non-native gardens require them to use pesticides that kill wildlife.  She says, “The typical suburban yard is actually worse than a wasteland. It’s a death trap.” She does not seem to know that most herbicide is used to kill non-native plants, not native plants nor does she seem to realize the contradiction in her indictment of gardening with non-native plants.  If there are more insects living in native gardens than non-native gardens, why would more pesticide be needed in non-native gardens?  If people could learn to love the clover, dandelions, and English daisies in their lawns as much as I do, they would use less “weed killers” on their lawns.

Ms. Renkl’s misperceptions about non-native plants seem to be based on a mistaken belief in their origins.  She says, “Ambulatory and omnivorous, human beings are a migratory species. That’s not true for the vast majority of plants.”  In fact, plants are just as mobile as animals, including humans.  Plants are carried by birds, animals, wind, ocean currents, etc.  They come and go as the climate changes, as it has many times in the past 500 million years that plants have existed on Earth.  Plants now considered non-native existed here in the distant past, in a different climate.  Here are a few examples of such dispersals; most occurred before humans even existed:

The ability to migrate is essential to the survival of plant and animal species.  As the climate changes, this survival strategy is quickly becoming even more important.  When we demand that plants be restricted to their historical “native” ranges, we doom them to extinction because when the climate changes, the vegetation must change.

Where did Ms. Renkl learn these myths?

Ms. Renkl’s cites Doug Tallamy’s Nature’s Best Hope as one of the sources of her mistaken beliefs.  Tallamy considers the existence of non-native plants the root of all evil in nature.  He calls them “ecological tumors.” He blames non-native plants for declining populations of both native plants and insects, and by extension to declining populations of birds that eat insects. 

In Nature’s Best Hope, Tallamy says, “…we must not use climate change as an excuse to do nothing.  Most species of plants and animals are far more resilient to climate variability than we give them credit for.  Besides, increasing the number and biomass of the plantings in our yards and public spaces is one of our most accessible and convenient tools to fight climate change.”  The problem with Tallamy’s dogma is that it inspires the public and land managers to eradicate established landscapes that are not native based on Tallamy’s claims that non-natives are “crowding out” native species and depriving wildlife of food. All native plant “restorations” begin by eradicating non-native plants, usually with herbicides that retard new growth.  In other words, the native plant ideology is causing the loss of vegetation and therefore the loss of stored carbon and the reduced capacity for carbon sequestration in the future.  The native plant ideology is not increasing biodiversity, nor is it “fighting climate change.”  It is more destructive than constructive. 

I’m not looking for “an excuse to do nothing.”  On the contrary, I believe every effort must be made to stop or at least slow down the inexorable advance of climate change.  The most basic effort we can make is to stop destroying functional vegetation, especially trees.  Then, there is a lengthy list of what we should be doing to reduce greenhouse gas emissions, which is another, equally important topic. 

Native plant advocates consider climate change irrelevant because they believe the existence of non-native plants is the sole culprit of all problems in the environment.  They see every environmental issue through the narrow lens of their dogma.  This comment on an article about the value of non-native plants by Marlene Condon published in [Chesapeake] Bay Journal is an example of such a misinterpretation of an environmental issue:

“English ivy is an evergreen, non-native, invasive groundcover that has demolished undisturbed natural areas…In salmon country that’s the difference between clean, cold streams and warmer streams filled with sediment.”

Eradicating ivy on stream banks is likely to produce more sediment because it will take some time for replacement vegetation to cover the ground, especially if herbicides are used to eradicate the ivy. Water is warmer in streams because of climate change and because there is less water due to water diversion and droughts. There are many other reasons for declining populations of salmon, particularly dams that prevent salmon from reaching their spawning grounds upstream.

Treat the cause, not the symptom

The native plant ideology ignores the underlying causes of changing ecosystems. Most changes are caused by the activities of humans, such as agriculture, development, water diversion, and pesticides.  Climate change is the underlying cause of some changes in nature and it will steadily become a more important factor.  Eradicating non-native plants will not reverse any of those changes nor will it prevent changes in the climate.    


  1. Alan de Queiroz, “The resurrection of oceanic dispersal in historical biogeography,” Trends in Ecology and Evolution, 20 No. 2, February 2005

Photo credit for featured photo: Garden Rant, Marianne Willburn

Science meets the “restoration” industry

I was encouraged to hear a presentation by an academic scientist at the recent Beyond Pesticides Forum that was another indication of the paradigm shift in invasive species management toward a less destructive approach.  Dr. Bernd Blossey is a Professor at Cornell University, where he directs the Ecology and Management of Invasive Plants Program in the Department of Natural Resources.  His many years of studying invasive plants, such as purple loosestrife, garlic mustard, water chestnut, Japanese knotweed, and phragmites have convinced him that there are often “multiple stressors” that contribute to such invasions.  Some factors such as the presence of earthworms and deer can be more important factors in the Northeast than the non-native plants themselves. 

Based on his research experience, Dr. Blossey delivered wise advice to land managers at the Beyond Pesticide Forum.  The featured photo at the top of this article was his introductory slide. 

Before a restoration project begins, these questions should be asked and answered:

Source: Dr. Blossey’s presentation to Beyond Pesticides Forum on June 8, 2021

If the project seems worthwhile after such analysis is done, this is Dr. Blossey’s advice about monitoring the project and measuring its success:

Source: Dr. Blossey’s presentation to Beyond Pesticides Forum on June 8, 2021

Practicing what he preaches

Dr. Blossey used these principles in his study of garlic mustard in the forests of the northeast. (1) Over a period of more than 10 years, Dr. Blossey and his collaborators measured the abundance of garlic mustard in 16 plots from New Jersey to Illinois where no attempt had been made to control or eradicate it.  They found that growth rates initially increased, but decreased over time and eventually the population started to decline.  Dr. Blossey explained their findings in a recent webinar that is available HERE:

Garlic mustard was first recorded in North America in 1868 on Long Island, New York.  It spread west from there and is now found from southern Canada to Georgia and from New York and Quebec to Oregon, British Columbia and Alaska.  Because land managers believed that garlic mustard suppresses populations of native plants, they have been trying to eradicate garlic mustard in northern forests for decades, with little long term success.  Dr. Blossey addressed that concern in his webinar. 

Source: Dr. Blossey’s webinar about garlic mustard

Earthworms are the prerequisite for garlic mustard invasion.  Earthworms in northern forests are also considered alien invaders because they were killed, along with forests, by advancing glaciers during the Ice Age.  When forests returned after the Ice Age over 10,000 years ago, they evolved without earthworms that were reintroduced by European settlers less than 500 years ago. 

When deer are excluded from areas by fencing plots with garlic mustard populations, abundance of native vegetation does not decline.  Deer have a strong preference for native vegetation.  Absent deer, garlic mustard does not seem to suppress the growth of native plants in northern forests.

In other words, garlic mustard is not guilty as charged.  Dr. Blossey explains the disadvantages of attempting to eradicate it.  The decline of garlic mustard abundance over time is attributed to negative soil feedback that builds over time as the soil microbial community responds to the new plant. Removing garlic mustard episodically prolongs the process of building that negative soil feedback.  When groups of well-meaning young people are sent into the forest to pull garlic mustard, they trample the very native plants they are trying to save. 

Are there lessons for land managers in the Bay Area?

Because garlic mustard doesn’t exist in California and our native earthworms are considered beneficial to soil health, you might wonder if this study is relevant here.  California was not glaciated during the Ice Age.  Our earthworms survived the Ice Age and they evolved with our forests. 

So, what can we learn from this study?  The pattern of initial growth and eventual decline of populations of introduced plants is not unique to garlic mustard“A phenomenon that has received increased attention is whether introduced species go through boom and bust cycles, ultimately becoming non-threatening members of local communities.” (1)  One recently published study was based on nearly 5,000 vegetation inventories collected in 49 National Parks in the eastern United States.  It reported that non-native plants appeared to decline after 100-200 years: 

Residence time appears a core part of invasion that interacts with other mechanisms, such as climate matching, propagule pressure and empty niche. Initially, time appears to benefit non-native species as they establish in a novel range. They likely face low enemy loads, and any successful dispersal increases their populations and invaded range. As they spread, initial barriers, such as distance or suboptimal habitat, were overcome, as was resistance from native relatives. However, their biggest challenge appeared to be time, as they all declined after ~1 to 2 centuries, suggesting that pathogens and herbivores caught up with them.” (2)

The message for land managers everywhere is that patience is needed to judge the impact of introduced species.  Most will fit into ecosystems eventually and attempts to speed up that process often do more harm than good.  We can’t judge changes in nature by the short-term perspective of human lifetimes because the evolution of nature is a continual process that began long before humans existed and is likely to persist long after we are gone. 

Applying Dr. Blossey’s “Core Knowledge” to local projects

What if Dr. Blossey’s “Core Knowledge” had been applied to projects in the San Francisco Bay Area?  Here are examples of local eradication projects that might have benefitted:

  • San Francisco has been trying to eradicate oxalis in its parks for over 20 years by spraying a selective herbicide (Garlon).  There seems to be more oxalis now than there was 20 years ago.  Oxalis is visible only about 2 months of the year.  When it dies back in the spring it leaves behind the native plants with which it co-exists.  If a control plot had been set aside before they started eradicating oxalis perhaps we would know the answer to these important questions:  Does oxalis suppress the growth of native plants?  Does attempting to eradicate oxalis produce more or less oxalis?
  • California, Oregon, and Washington have been trying to eradicate non-native spartina marsh grass along the entire West Coast for over 20 years.  Here in the Bay Area, non-native species of spartina have been 99% eradicated, but a hybrid of the native and the non-native remains and is poisoned with imazapyr annually.  According to a recent presentation by the Invasive Spartina Project, the hybrid is visually indistinguishable from the native and it occupies the same elevation of the marsh.  Over 500 genetic tests are needed every year to distinguish the hybrid from the native in order to poison the hybrid.  Dr. Blossey’s approach might ask these important questions:  What harm is hybrid spartina doing?  Do more or fewer animals live in hybrid spartina?  What effect has 20 years of spraying imazapyr had on the soil and the microbes that live in it?  Is the eradication project doing more harm than good? 
oxalis bloom, February 2021

We don’t know the answers to these important questions because projects were initiated and implemented without the analysis and monitoring metrics needed to answer the questions.  The projects continue without being accountable for the damage they are doing.  Public money is funding these projects without requiring the projects to be accountable for the consequences. 

California has made a commitment to spend billions of dollars on “nature based solutions” and achieving “biodiversity goals.”  This is an opportunity to start new projects off on the right foot by:

  • Requiring the analysis needed to determine the impacts and causes of perceived problems in the environment.
  • Requiring control plots so that the effects of the project can be compared with the option of not doing the project.
  • Requiring that projects be monitored, using established metrics so that the success of the project can be measured.

  1. Bernd Blossey, et. al., “Residence time determines invasiveness and performance of garlic mustard (Alliaria petiolota) in North America, Ecology Letters, February 2021.  
  2. Robert Warren, et. al., “Multiple mechanisms in woodland plant species invasion,”  Plant Ecology, April 2019.

Improvements in pesticide use by supplier of water in the East Bay

Four years ago, a small group of activists brought their concerns about the use of pesticides to the attention of the Board of East Bay Municipal Utilities Department (EBMUD), the supplier of our water in the East Bay. 

In particular, we showed EBMUD officials photos of inappropriate applications of herbicide, specifically RoundUp (glyphosate).  The photos showed that District employees were spraying RoundUp in residential neighborhoods without posting pesticide application notices.  They weren’t wearing protective gear.  They were spraying RoundUp on bare ground, which is not how RoundUp should be applied because it is not a pre-emergent that is effective on seeds or roots.  It must be sprayed on green vegetation during the growing season.  In one case, the District employee was spraying RoundUp from an ordinary garden hose, which means far more herbicide was being applied than necessary, even if anything were growing there.  In other words, the manner in which RoundUp was being applied suggested that District employees didn’t understand what they were doing.

EBMUD officials were responsive to our report.  They hired a Pesticide Control Advisor as a consultant to evaluate their program who identified several significant deficiencies in the District’s IPM program.  The District responded by making many improvements in their use of pesticides, such as:

  • There is now a comprehensive, annual training program for all employees who apply pesticides.
  • There are now more accurate and complete records of EBMUD’s pesticide use.
  • The PCA consultant was retained on a contractual basis to monitor some pesticide applications for compliance with product labels and District policies.
  • An annual report of the District’s pesticide use, including quantities and products, is presented to the Board at an annual meeting and posted to the District’s website. (1)
  • The District’s IPM Program guidelines were updated and posted to the website in April 2021. (2)
  • The revised guidelines are more comprehensive and detailed.  Requirements for posting notices of pesticide applications are clearer. (2)

Some of these improvements have probably contributed to the decrease in pesticide use in the past five years from over 600 gallons per year to over 400 gallons per year.  Most pesticide used by EBMUD is herbicide and most herbicide used by EBMUD is glyphosate products. 

EBMUD is still using a lot of herbicide, but their practices are safer for their employees and the public.  Their pesticide applications are more visible to the public and the public now has access to information about their pesticide applications. 

EBMUD uses pesticides primarily to maintain their facilities.  Little pesticide is used on EBMUD’s watershed property.  EBMUD does not use herbicide to prevent eucalyptus and bay laurel resprouts when those tree species are destroyed.  Most trees destroyed by EBMUD are intended to reduce fire hazards and many of the tree removals are requested by Cal Fire.   

Lessons Learned

It pays for the public to pay attention to what is happening on our public lands and to speak up if you see something that doesn’t make sense to you.  There are usually mechanisms for figuring out what is happening, asking questions, and making your concerns known. 

Changing public policy isn’t easy, but it can be done.  It’s often frustratingly slow and it takes persistence. Personally, I have found it more effective to be consistently polite and as patient as needed to get your message through. In the case of EBMUD’s pesticide use practices, there is more they can do to reduce their use of pesticides, so the public should continue to pay attention because the quality of our water is extremely important to our health.


  1. Annual IPM Report is available HERE. Scroll down to to “Integrated Pest Management” and lick on “Annual IPM Report.”
  2. IPM Guidelines are available HERE.  Scroll down to “Integrated Pest Management” and click on “IPM Guidelines 2021.”

Looking for Godot: Finding achievable restoration goals

There are chemical and non-chemical approaches to native plant restoration. Neither succeeds.  Non-chemical methods are labor-intensive, which makes them prohibitively expensive.  Chemicals are cheaper and they kill non-native plants, but they don’t restore native plants because they kill them and damage the soil. Either strategy must be repeated continuously to be maintained. This article is the 25-year story of reaching the conclusion that neither chemical nor non-chemical approaches are capable of restoring native plants on a landscape scale.  Where do we go from here?

In 2014, the California Invasive Plant Council (Cal-IPC) conducted a survey of land managers to learn what methods they were using to control plants they considered “invasive.”  The Cal-IPC survey reported that herbicides are used by 94% of land managers and 62% use them frequently.  Glyphosate was the most frequently used herbicide by far. In 2014, no other eradication method was used more frequently than herbicides.

Frequency of herbicide use by land managers in California to kill “invasive” plants. Source California Invasive Plant Council, 2014

We have learned a great deal about the dangers of herbicides since 2014. 

  • The World Health Organization has categorized the most frequently used herbicide—glyphosate—as a probable carcinogen.
  • The manufacturer of glyphosate, Monsanto-Bayer, was successfully sued by terminally ill users of glyphosate.  These product liability lawsuits resulted in multi-million dollar awards for damages. The awards were reduced on appeal but ultimately upheld.  Monsanto has agreed to pay more than $10 billion to settle close to 100,000 product liability claims. 
  • The US Environmental Protection Agency has finally published its Biological Evaluation (BE) of the impact of glyphosate products (all registered formulations of glyphosate products were studied) on endangered animals (mammals, birds, amphibians, reptiles, fish, invertebrates) and plants. The BE reports that 1,676 endangered species are “likely adversely affected” by glyphosate products. That is93% of the total of 1,795 endangered species evaluated by the study. Both agricultural and non-agricultural uses of glyphosate products were evaluated by the BE. Although only endangered plants and animals were evaluated by the BE, we should assume that all other plants and animals are likewise harmed by glyphosate because the botanical and physiological functions of plants and animals are the same, whether or not they are endangered. 

How have land managers responded to the dangers of herbicides?

San Francisco’s Recreation and Park Department has increased the use of herbicides in public parks every year since 2016.  In 2020, herbicide use increased significantly from 243 applications in 2019 to 295 applications in 2020.  SF RPD has been spraying herbicides on non-native plants for over 20 years.  They have been using hazardous herbicides on some 50 target plant species year after year. The longer they use them, the more resistance to the herbicides the plant develops.

Herbicides used by Natural Resource Division of San Francisco Recreation and Parks Department. Source San Francisco Forest Alliance based on public records of pesticide use

Chris Geiger, director of the integrated pest management program at the San Francisco Department of the Environment, told San Francisco Public Press that although the city has reduced its use of glyphosate outside parks, it won’t ban glyphosate because it hasn’t found a more efficient or safer alternative for controlling some weeds. He said, “In habitat management, there are certain plants you cannot remove from a natural area by hand.”

San Francisco’s IPM program recently published  “Pest Prevention by Design Guide” that illustrates the bind they are in with respect to promoting native plants while trying to reduce pesticide use.  On the one hand, the Guide promotes the use of native plants in landscape design plans by making the usual claim that “Native species are generally best suited to supporting local insect populations and ecosystems.”  On the other hand, the Guide recommends the use of “pest resistant” species that are not eaten by insects and grazing animals and are capable of outcompeting weeds.  Can’t have it both ways, folks!!  

East Bay Regional Park District has made a commitment to phase out the use of glyphosate in developed areas such as parking lots, playgrounds and picnic areas.  However, EBRPD remains committed to using glyphosate and other herbicides to eradicate non-native plants on undeveloped park land. In 2020, no glyphosate was used in developed areas, but about 23 gallons of glyphosate were used to eradicate non-native plants on undeveloped park land. Twenty-one gallons of triclopyr were also used to eradicate non-native shrubs and to prevent non-native trees from resprouting after they were cut down. They continued the 15-year effort to eradicate spartina marsh grass with imazapyr. A few other selective herbicides were used on other eradication projects. (2)

In the San Francisco Bay Area, most land managers are still committed to using herbicides, particularly in so-called “natural areas,” regardless of the damage herbicides do to human health, wildlife, and native plants.  In fact, the City of Oakland is planning to begin using herbicides on 2,000 acres of public parks and open spaces for the first time to implement its vegetation management plan.  The vegetation management plan is both a fuels reduction program and a “resource protection” program, which is a euphemism for native plant “restoration.”

Given what we now know about the dangers of herbicides, why are public land managers still committed to using herbicides?  The City of Oakland explains in the EIR for its vegetation management plan why it is proposing the use of herbicides where they were prohibited in the past:

“It is estimated that if the City were to rely on hand removal and mechanical treatments in place of herbicide, it would cost the City up to 40 times more to treat these areas than under the VMP. The cost for herbicide treatments, not including any associated physical treatments, is approximately $250-$500 per acre. This reflects a range of potential vegetation conditions, vegetation types, and densities. The cost for hand removal and mechanical treatments is estimated at approximately $1,000-$4,000 per acre, using the same range of site-specific conditions.” (page 5-9)

In other words, herbicides are the preferred method of killing non-native plants because it is the cheapest method.  However, there is another reason why herbicides are preferred to non-chemical methods.  There isn’t a non-chemical method that is more effective than using herbicides.

Looking for an alternative to herbicides

As we should expect, new information about glyphosate has increased the public’s awareness of the dangers of pesticides.  California Invasive Plant Council has responded to the public’s growing awareness and concern about the herbicides to which they are exposed in our public parks and open spaces.  They recently published a comprehensive 300-page brochure entitled “Best Management Practices for Non-Chemical Weed Control.”  (1) Many highly qualified land managers participated in the preparation of this credible publication.  The Cal-IPC brochure is credible because it frankly admits that no method of eradication is without problems.  Irrigation and intensive planting are required for good results, but without continuing regular maintenance the results are only temporary.  Few land managers have the resources needed for success.

If you wonder why herbicides are the preferred method of eradicating non-native plants, reading Cal-IPC’s brochure about non-chemical methods will tell you why.  There is no non-chemical method that achieves better results than using herbicide. 

Herbicides are not a magic bullet

Herbicides are the most frequently used method of killing non-native plants, but using herbicides does NOT result in a native landscape.  “Lessons learned from invasive plant control experiments:  a systematic review and meta-analysis,” analyzed 355 studies published from 1960 to 2009 to determine which control efforts were most effective at eradicating the target plants and which method was most successful in restoring native plants. The analysis found that “More than 55% of the studies applied herbicide for invasive plant control.” Herbicides were most effective at reducing invasive plant cover, “but this was not accompanied by a substantial increase in native species,” because, “Impacts to native species can be greatest when programs involve herbicide application.”  It’s not possible to kill non-native plants without simultaneously killing native plants and damaging the soil.

Reaching a dead—and deadly—end

Public land managers in the San Francisco Bay Area have been trying to restore native landscapes for over 25 years.  Every project begins by eradicating non-native plants, usually with herbicides.  Our public parks have been poisoned repeatedly, but native landscapes have not replaced the plants that were killed.  Meanwhile, we have learned that herbicides are dangerous to our health and animals who live in our parks. 

Oyster Bay is a park in San Leandro that was built on a former garbage dump on landfill in the San Francisco Bay.  The garbage was capped with barren soil and many acres were planted with native bunch grass, as shown in these photos.  This “restoration” method is called competitive planting. The bunch grasses did not survive and the ground was quickly colonized by weeds that were then sprayed with herbicides. 

The only viable alternative to using herbicides to “restore” native plants is to change the goals for native plant restorations such that herbicides won’t be required: 

  • An exclusively native landscape cannot be achieved where native plants have never existed, such as the many parks along the bay waterfront that were built on landfill.  It is an unrealistic goal.
  • Given that no effective method of achieving this unrealistic goal has been found after 25 years and the most popular method is poisoning our environment, it is time to stop trying.
  • Smaller, achievable goals must be set.  Landscape scale projects should be abandoned and replaced with small scale projects where native plants already exist. 
  • Smaller areas can be managed without using herbicides because they will be affordable to manage with labor-intensive methods that are more expensive.
  • If smaller projects are more successful, they will be less controversial.  The projects are unpopular partly because they aren’t successful. 

The native plant movement in the San Francisco Bay Area has bitten off more than it can chew.  Native plant advocates need to back out of their dead end and regroup with plans that are less destructive and more realistic.  As the Economist magazine said in 2015, “you can garden in a garden, but you can’t garden nature.”


(1) California Invasive Plant Council is offering free video training for non-chemical methods of killing “invasive” plants on May 4, 2021, 1-5 pm.  Sign up HERE. 

(2) 2020 IPM Report, East Bay Regional Park District available HERE.   

Nobody cares where a pretty wildflower is from

The feel-good ending of the local news broadcast on Channel 7 (ABC) on February 17, 2021, featured this video of a huge field of oxalis (Bermuda buttercup, Oxalis pes-caprae) blooming on the roadside of Highway 1 in Santa Cruz County.  People were stopping along the road to admire the bright yellow blooms of spring and photograph them.  No one said anything about where the plant “belongs,” and no bad words were spoken about this useful plant that native plant advocates love to hate.

Click on the picture to activate the video

Despite its beauty and utility, oxalis is sprayed with one of the most toxic herbicides on the market in public parks and open spaces in the Bay Area.  San Francisco’s Recreation and Parks Department has been spraying oxalis in several public parks for over 15 years.  San Francisco Forest Alliance (SFFA) published a brilliant article about this pointless and destructive crusade that was republished by Conservation Sense and Nonsense in 2015.  That article about the many benefits of oxalis is one of the most popular articles on this blog; it has been viewed by over 10,000 readers and many more on the SFFA website.  We invite you to visit it and we summarize it briefly here:

  • Oxalis blooms briefly in early spring and dies back before summer begins, leaving the ground to other plants. It does not kill other plants, rather it co-exists briefly during its annual bloom.
  • Oxalis is very useful to pollinators and its tuberous roots (bulbils) are eaten by ground dwelling animals such as gophers.
  • Oxalis is called sour-grass because of its pleasant-tasting tang and it is often eaten by children.
  • Triclopyr is the active ingredient in the herbicide that is used on oxalis during its blooming season. It damages the soil by killing beneficial fungi and microbes, and it is toxic to many animals.

The annual poisoning of oxalis on Mount Davidson was recently videotaped by Ron Proctor and published by the San Francisco Forest Alliance. A crew of 5 men was hired to do the deed.  Ironically, this spraying of oxalis on Mount Davidson in San Francisco was taking place at the same time that tourists were admiring oxalis in a neighboring county.

Click on picture to activate the video.

Oxalis is not an isolated example of a non-native plant that is admired by the public, but hated by native plant advocates and public land managers who do their bidding.  As a member of the Sierra Club, I receive emails alerting me to opportunities to advocate for the protection of the environment.  The most recent email featured a picture of a yellow wildflower in the foreground of a photograph of a Bay Area landscape:

The yellow wildflower in the foreground is Black Mustard (Brassica nigra).  I responded to the Sierra Club’s email:

“The plant in the foreground of your photograph appears to be Brassica nigra:  ‘Brassica nigra, or black mustard, is an annual plant cultivated for its black or dark brown seeds, which are commonly used as a spice. It is native to tropical regions of North Africa, temperate regions of Europe, and parts of Asia.’ Wikipedia

“I hope the use of this photo in this Sierra Club email to its members means that the Sierra Club is finally prepared to accept the reality of the presence of non-native plants in our public parks and open spaces.  The Sierra Club’s support for unnecessary and destructive eradication projects has been regrettable, particularly because they require the use of harmful herbicides.  I hope this email is an indication that the Sierra Club is finally ready to reconsider this futile crusade.”

I received this disappointing reply from the Sierra Club:  The staffer who puts together our newsletter isn’t a plant buff and wouldn’t have known the difference. But I am a plant buff and review the newsletter and know the difference between a mustard and a native plant. I somehow just overlooked that photo entirely. Thanks for bringing it to my attention. I’ll be more careful in my review of the newsletter in the future (look more carefully at the photos). And we’ll change the online version.”

The beauty and resilience of weeds

Dandelion by Mona Caron. Click on the picture to see more murals by Mona Caron.  Mona is a Swiss artist who became a muralist in her adoptive hometown San Francisco, California.  She is best known for her multi-story murals celebrating the rebellious resilience of weeds.

 The Bottom Line

The general public doesn’t care where plants came from.  The public recognizes and values beauty wherever it is found.  Unfortunately, our public lands are in the death grip of the native plant movement and environmental organizations that should be objecting to the use of herbicides in our public parks and not promoting that destructive agenda.  The crusade against non-native plants has been responsible for spraying our public lands with dangerous pesticides for over 20 years.  They have little to show for their toxic crusade, perhaps because the herbicides damage the soil and make the survival of native plants even less likely.


The featured photo at the top of this article was taken in Glen Canyon, another public park in San Francisco where oxalis has been sprayed annually for many years.  The copyright photo of a coyote in a field of oxalis was taken by Janet Kessler and is shown with her permission.

Migration: Life on the move

Sonia Shah’s recently published book, The Next Great Migration: The Beauty and Terror of Life on the Move, takes a deep dive into the past to trace the ancient history of migrating life on Earth. For as long as life has existed on Earth, life has been on the move, as needed to survive the constantly changing environment in which all plants and animals live.

1 Homo sapiens
2 Neanderthals
3 Homo erectus

Shah’s is an ambitious attempt to tell this story, not confined to human migration, but encompassing plants and animals as well because all of these migrations are connected. Scientists speculate the earliest migrations of human ancestors, some 100,000 years ago out of Africa, were in pursuit of the migrating animals that humans hunted.  On balance, the movements of plants and animals are beneficial to life on Earth because they are necessary to survive. When they aren’t beneficial, the problems are usually short-lived and humans are usually unable to stop them because nature is more powerful than we are.

Click on map for animated movement of animals in response to changing climate conditions.

Migrations are even more frequent at a time of rapid and extreme climate change. As crops fail in the withering heat and drought caused by global warming, farmers are abandoning their farms to find the food they need to survive. Hence, Shah’s prediction that we are about to witness the “next great migration” because of the challenges of climate change. When the climate changes, the vegetation changes. When the vegetation changes, animals must move to find the food they need. Humans wish to put ourselves in a special category that denies our kinship with animals. But we are as dependent upon our food as any animal and the changing climate will challenge our existence as much as other forms of life.

Shah also traces the brief history of human knowledge of migrations about which little was known before the development of the scientific tools to study it.  Paleontology could dig up fossils that would raise more questions than answers about the residents of deep time, but it wasn’t until the development of molecular analysis that fossils could inform scientists of the evolutionary history of and close relationships among plants and animals that reflect migrations in the distant past.  New technology is capable of tracing the movements of animals that were unknown in the distant past, when animals seemed to mysteriously disappear at the end of one season and returned at the beginning of another season.

Invasion Biology is based on ignorance of migration

The fact that animal migration was largely unknown led to some fundamental misunderstandings about nature, including the unfortunate rise of nativism in the natural world that was spawned by the mistaken hypotheses of invasion biology. Shah explained the consequences of inadequate knowledge of migration in a recently published article in New York Times Magazine:

“When scientists considered movements across barriers and borders, they characterized them as disruptive and outside the norm, even in the absence of direct evidence of either the movements themselves or the negative consequences they purportedly triggered…Influential subdisciplines of biological inquiry focused on the negative impact of long-distance translocations of wild species, presuming that the most significant of these occurred not through the agency of animals on the move but when human trade and travel inadvertently deposited creatures into novel places.  The result, experts in invasion biology and restoration biology said, could be so catastrophic for already-resident species that the interlopers should be repelled or, if already present, eradicated, even before they could cause any detectable damage.”

In turn, Invasion Biology spawned pointless and destructive eradication projects

Conservation Sense and Nonsense has followed the destructive and futile attempts to eradicate plants and animals that nativists say “don’t belong here:”

  • Hawaii is an extreme case of attempts to eradicate non-native plants and animals: frogs, owls, egrets, seals, fruit trees, mangroves, parrots, etc.  These eradication projects often do more harm than good.  The “logic” for these projects is muddled, partly because the Hawaiian Islands emerged from the sea as barren volcanoes.  The question of “what belongs there” is a matter of opinion and debate in Hawaii and elsewhere.

Bird migration routes

Migration enables survival

I hope that improved knowledge of migration will help people understand that migration is a natural phenomenon that is essential to the survival of all life on Earth.  Migration enables life to adapt to changes in the environment, facilitating evolution and reducing frequency of extinction.