Spartina Eradication – Conservation Sense and Nonsense

Money and Fire: 2022 Conference of California Native Plant Society

The California Native Plant Society (CNPS) held a conference in October for the first time since 2018. There were two main themes of the conference:

Money: The State of California is making a huge investment in the environment with many interrelated goals:

“30 X 30” is shorthand for the goal of protecting 30% of California’s land and coastal waters by 2030.
Developing “nature-based solutions” to address the threats of climate change.
Vegetation and forest management to reduce wildfire hazards.
Protecting and enhancing California’s biodiversity.

Fire: The frequency and intensity of wildfire is of concern to all Californians, but the California Native Society has a particular interest in fire because it is viewed as a tool to enhance native plant abundance and control the spread of non-native plants that outcompete native plants.

Money

If attendance were the sole measure of success, the conference was a resounding success. The conference was sold out with record-breaking attendance of 1,200 people. That’s a 50% increase in attendance since 2018, when 800 people attended. People came to learn about the many opportunities for public funding of their “restoration” projects and they were not disappointed.

Jennifer Norris, Deputy Secretary for Biodiversity and Habitat for the California Natural Resources Agency (CNRA) was one of the keynote speakers. She and many other staff of CNRA made presentations at the conference to inform the community of native plant advocates about the many new opportunities to obtain grants for their projects. This slide (below) shown at the conference, itemized by state agencies the $1.631 Billion budget for just the 30 X 30 portion of the CNRA’s environmental grant programs. It does not include Cal-Fire funding for forestry projects to reduce wildfire hazards and address climate change. Nor does it include $10 million of new funding for Weed Management Areas, which funds projects that attempt to eradicate non-native plants and $10 million of new funding for the state council for invasive species. State funding is also supplemented by new federal funding in support of a national goal of achieving 30 X 30.

But money isn’t the only element of this state program that native plant advocates are excited about. They have also been gifted a three-year moratorium on requirements for Environmental Impact Reports for their projects. There will therefore be no requirements for a public process to review plans and comment on them.

An anxious applicant for state grant funding asked a speaker representing the Wildlife Conservation Board about a rumor that projects using herbicides would not be funded. The speaker’s reassuring answer was, “We are not rejecting projects using herbicides.” Applicants are being asked to complete a questionnaire about herbicides they plan to use, but the speaker was quick to add, “We have not rejected any [such applications] so far.” She assured the audience that “You are all careful” in your use of herbicides.

Huge buckets of money are being distributed with no restrictions on the use of herbicides and no vetting process such as an environmental impact review with opportunities for the public to comment. It seems inevitable that some of the projects will unintentionally do more harm than good, and the public will have nothing to say about which projects are funded.

Fire

Alexii Sigona was the first keynote speaker for the conference. He is a member of the Amah Mutsun-Ohlone Tribal Band (not a federally recognized tribe) and a Ph.D. candidate at UC Berkeley in the Department of Environmental Science. He explained that there are 600 recognized members of the Amah Mutsun Band in a wide region around Pescadero, Hollister, and San Juan Bautista. They collaborate with organizations such as CNPS because they don’t have the resources to manage their ancestral tribal lands. He described some of the projects they engage in:

Landscape scale removal of “invasive” plants.
Plug planting of 120,000 native grass plants.
Creating “native hedgerows” for food sources.
Removal of native Douglas Firs “encroaching” on grassland. They have removed 5,000 native Douglas fir trees. He acknowledged that this project caused some concern about erosion and aesthetics. Removal of native Douglas fir was mentioned by several other speakers during the conference. It is an example of the preference of native plant advocates for grassland because it is the pre-settlement vegetation. Native coyote brush is another target of eradication projects that attempt to prevent natural succession of grassland to other vegetation types.

There is great interest among native plant advocates in the land management practices of Native Americans because controlled burns were Native Americans’ most important tool to maintain grassland species needed for food and for their prey. Controlled burns are important to native plant advocates because they believe they are beneficial to native plants and help to control non-native plants. Prescribed burns are also currently popular with many public land managers and they are the current fad among many fire scientists.

Two presentations at the conference suggest that prescribed burns are not compatible with the preservation of native chaparral, nor are they capable of converting non-native grassland to native grassland.

This (above) is the concluding slide of Jon E. Keeley’s presentation. Dr. Keeley is a respected fire scientist with US Geological Service with expertise in chaparral species. He explained that 60% of native chaparral species (notably manzanita and ceanothus) are obligate seeders that do not resprout after fire and therefore depend on the existence of their dormant seed bank for regeneration. In recent decades the fire interval in chaparral has decreased due to climate change and associated drought. In many places, the fire interval has become too short to establish the seed bank needed for regeneration. In those places Dr. Keeley has observed vegetation type conversion to non-native annual grasses.

Dr. Keeley Is concerned that vegetation type conversion from forests in some cases and shrublands in others to non-native annual grassland may be the result of shortening fire intervals further “because of the upsurge in state and federal programs to utilize prescription burning to reduce fire hazard.” (1) This concern extends to some conifer species that do not resprout. Some are serotinous conifers whose cones are sealed shut and do not release their seeds in the absence of fire.

This is a familiar theme for much of Dr. Keeley’s research. He asks that land managers balance the conflicting goals of resource management and fire hazard reduction.

This (above) is the concluding slide (sorry for the poor quality of my photo) of a presentation about a 20-year effort at the Santa Rosa Plateau Ecological Reserve to convert non-native annual grassland to native grassland, using annual (sometimes bi-annual) prescribed burns. Many different methods were used, varying timing, intensity, etc. The abstract for this presentation reports failure of the 20-year effort: “Non-native grass cover significantly decreased after prescribed fire but recovered to pre-fire cover or higher one year after fire. Native grass cover decreased after prescribed fire then recovered to pre-burn levels within five years, but never increased over time. The response of native grass to fire (wild and prescribed) was different across time and within management units, but overall native grass declined.” (1)

The audience was audibly unhappy with this presentation. One person asked if the speaker was aware of other places where non-native grass was successfully converted to native grass. The speaker chuckled and emphatically said, “NO. I am not aware of any place where native grasses were successfully reintroduced.”

Another questioner prefaced her question with the admission that “I’m new here and all this is new to me.” Then she suggested that Native Americans are having some success using prescribed fire and that they should be consulted. The speaker graciously replied that she planned to do so.

Keep in mind that Native Americans weren’t historically using prescribed fire to convert annual grasses to native grasses. Their burns were intended to maintain native grassland in the absence of competing non-native annual grassland. Their objectives were different and they were operating in a very different climate and environment.

Estimates of the pre-settlement population of Native Americans in California range from 138,000 to 750,000. The population of Native Americans is estimated to have been reduced to as few as 25,000 after the arrival of Europeans due to disease and violence. There are now over 39 million Californians and only 630,000 of them were Native Americans in the 2020 census. Land management practices that are suitable for a population of less than 1 million seasonally migrating Californians are not necessarily suitable for a population of over 39 million sedentary Californians.

The futility of trying to eradicate non-native plants

The Invasive Spartina Project (ISP) is another 20-year eradication project that is doomed to failure. The presentation about the ISP was bravely made by Dr. Debra Ayres, one of the creators of the ISP in 1998. With intensive effort and hundreds of gallons of herbicide (imazapyr), non-native spartina marsh grass has been greatly reduced in the San Francisco Bay, but the hybrid of non-native S. alterniflora and native S. foliosa persists. Dr. Ayres explained why:

The spartina hybrid is reproductively stronger in every way than either of its parent species. Dr. Ayres predicts that the hybrid will eventually replace both of its parent species:

If the goal of this project was to eradicate non-native spartina, hybrid spartina will accomplish that goal. You might think that this prediction would end the futile attempt to eradicate the hybrid, but you would be wrong. There is no intention of abandoning this 20-year project. More funding is assured by the California Coastal Conservancy and the project continues to provide well-paid jobs.

Dr. Ayres ended her presentation with this enigmatic statement: “Evolution doesn’t stop just because we think it has to.” She seems to acknowledge that humans cannot stop evolution, yet she seems to recommend that we continue to try doing so. If those positions seem contradictory, that’s because they are. The bottom line is that as long as public funding continues to be available, this project will continue.

A central theme of the nativist agenda is the futile desire to prevent hybridization because it has the potential to replace a species considered “native.” They fail to understand that hybridization is an important evolutionary tool that helps plant and animal species adapt to changes in environmental conditions by favoring traits that are better adapted to new conditions. Humans cannot stop evolution, nor should we try.

San Francisco

I have a special interest in San Francisco because I lived there for nearly 30 years. The native plant movement is very strong in San Francisco and there were several presentations about the success of the movement at the conference.

Sunset Blvd being built on barren sand in 1931

One of the projects is trying to turn Sunset Blvd on the western side of San Francisco into a native plant garden. I lived in that district and am therefore familiar with Sunset Blvd as the major north-south traffic artery through the district. It is important as the only wind break in the windiest district of the city, which is only 13 short blocks from the ocean. The district is virtually treeless because of wind conditions and the pre-settlement landscape of barren sand. Sunset Blvd is therefore the oasis of the Sunset District. In the past, it was the only place to take a long walk in the shelter of the tall Monterey pines and cypress and tall-shrub understory. The lawn beneath the trees was the only place for children to play close to their homes.

San Francisco’s Department of Public Works (DPW) is responsible for maintaining the medians in San Francisco. It was therefore DPW’s responsibility to replace the wind break on Sunset Blvd that is dying of old age. That’s not what they chose to do. They are replacing the lawn with native shrubs and the tall trees with small native trees that won’t provide shelter from the wind.

The spokesperson for DPW acknowledged that the project is controversial. Neighbors of Sunset Blvd valued the sheltered recreational space provided by the 2.5 mile-long and wide median. Native plant advocates and their allies want to create a wildlife corridor through the western edge of the city. The spokesperson for DPW said that their plans are a compromise between these different viewpoints. I don’t know if the neighbors agree, but I can say that native plant advocates are thrilled with the new native plant gardens on Sunset Blvd based on their presentation at the CNPS conference.

Planting Sunset Blvd. with native plants, December 2020

Native plant advocates prevailed on Sunset Blvd because CNPS bought or raised all the native plants and provided volunteers to plant them and maintain them for 3 years. DPW couldn’t look their gift horse in the mouth. DPW hired 6 new gardeners to support maintenance of Sunset Blvd. This is an example of how the money that is flowing into such projects will transform many places into native plant gardens.

So, let’s look at the result of these projects. Presenters of these projects showed many beautiful pictures of newly planted native gardens on Sunset Blvd (above). The pictures were taken in spring, when native plants briefly flower. But that’s not what these places look like most of the year. They will look better if they are irrigated year-round, but that would defeat the purpose of replacing the lawn to reduce water usage. Unlike native plants, lawn turns brown during the dry season if it isn’t watered, but it is still functional as walkable ground.

Here’s what that garden at Sunset Blvd and Taraval looks like most of the year:

There was also a presentation by a spokesperson from San Francisco’s Public Utilities Commission (PUC) about the creation of rain gardens in San Francisco. San Francisco’s sewer system was built long ago when regulations did not require the separation of street run off from residential sewage. When it rains, the sewage treatment plant is overwhelmed by street run off. The sewage treatment plant releases untreated sewage and run off into the ocean, in violation of federal standards for water treatment.

Rain garden on Sunset Blvd as shown at the CNPS Conference

Rain Garden on Sunset Blvd in August 2022. They aren’t pretty year around.

The PUC is developing rain gardens to redirect street run off away from sewage treatment plants into the ground so that treatment plants are not overwhelmed during heavy rain. The San Francisco Chronicle recently reported that 151 rain gardens have been installed so far. It seems a very good idea, but native plant advocates are not happy with the rain gardens because the PUC has not made a commitment to plant exclusively native plants in the rain gardens. The audience pressured the speaker about this issue. He advised them to lobby the PUC to make a commitment to plant only native plants in the rain gardens. I have no doubt that they will take his advice. Given their influence and their access to public funding, I would be surprised if the PUC continues to resist their demands.

Conclusion

I have undoubtedly exhausted your patience, although there is much more I could tell you about, including several projects that look promising because they are exploring the importance of soil health to achieve successful results.

The conference themes in 2022 were consistent with the previous two conferences I have attended since 2015. This is my summary of the fundamental errors of the nativist agenda in the natural world. They are as apparent in 2022 as they were in 2015:

The futility of trying to eradicate non-native plants that are better adapted to current environmental conditions.
The futile and harmful attempts to prevent natural succession and hybridization.
The contradictory goals of fuels management and resource management.
The lack of understanding that vegetation changes when the climate changes. The ranges of native plants have changed and will continue to change. The pre-settlement landscape of the 18^th century cannot be recreated.
The lack of understanding of the importance of soil health to ecological restoration and associated ignorance (or denial) of the damage that pesticides do to the soil.

(1) Abstracts for all presentations are available on the CNPS website.

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:

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?

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.

Eradication of marsh grass on East and West Coasts doesn’t make sense

New York State agencies have been trying to destroy the Piermont Marsh since 2013, because most of the marsh grass is not native. Piermont Marsh is adjacent to the small village of Piermont on the west side of the Hudson River, less than 30 miles north of New York City.

The community of Piermont organized to prevent the destruction of their marsh for two reasons:

They believed that the marsh had protected them from the devastating storm surge caused by Hurricane Sandy in 2011. The village sustained damages of $11.8 million in that storm, but villagers believed it would have been much worse without the protection of the marsh.
The initial plan to eradicate 200 acres of non-native phragmites proposed the use of herbicides to kill the marsh grass. The villagers were concerned about large quantities of herbicides being sprayed into their waterways.

The Piermont Marsh is also very beautiful.

I have followed the attempt to save the Piermont Marsh because it is nearly identical to our West Coast version of the same issue. Non-native spartina grass has been nearly eradicated on the entire West Coast using herbicides over the past 15 years. After witnessing the unintended consequences of the eradication of spartina, I was sympathetic to the community of Piermont and hopeful that their organized resistance might be successful.

Opposition to the proposed project to destroy the Piermont Marsh has accomplished a great deal. The first round of public comment and negotiation resulted in a reduction in the size of the project from 200 acres to 40 acres. The Piermont community was also given a commitment to conduct an analysis of the damage done to the village by the destructive storm surge in the 2011 hurricane Sandy to determine the role the marsh played in protecting the village from even greater damage.

The scientist who conducted that study reported the results of the study in July 2020. He concluded that “the presence of the Marsh is estimated to have avoided $902,000 worth of property damage and loss.” (1) He made other significant observations:

The native marsh grass that the project wishes to restore does not provide as much storm protection in the spring: “Typha [the native species of marsh grass] shows far more seasonal variation than phragmites. Unlike phragmites, which maintains its height and density year-round, Typha is shorter and sparser in the spring.” (1)
The scientist predicted that by 2100 the Piermont Marsh will likely be overwhelmed by sea level rise. Whatever vegetation is at the Piermont Marsh, it will be gone within 80 years.

For the moment, the Piermont Marsh project is on hold: “[The plan] will be redrafted and the new draft should be presented to the public in 2021.” (1) Meanwhile, herbicides will not be used in the marsh and experiments will be conducted to kill marsh grass by covering it with a geotextile that deprives the vegetation of light. However, project managers have not made a commitment to avoid herbicides in the future.

Based on my experience with opposition to such destructive projects, delays are often ultimately victories. Funding priorities often change and more scientific information becomes available to inform a better decision. For example, the current draft plan contains outdated information about glyphosate. It claims that “Glyphosate is a non-selective, systemic herbicide that controls weeds by inhibiting a specific pathway for amino acid synthesis that is unique to plants and not present in animals.”

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.”

In defense of phragmites

According to a study conducted in 2017, phragmites is playing the same ecological roles as their native predecessors:

“An invasive species of marsh grass that spreads, kudzu-like, throughout North American wetlands, may provide similar benefits to protected wetlands as native marsh grasses. According to new research from North Carolina State University, the invasive marsh grass’s effects on carbon storage, erosion prevention and plant diversity in protected wetlands are neutral… studies have shown that Phragmites may help reduce shoreline erosion in marshlands and store carbon at faster rates than native grasses…The team found no significant differences between ecosystem services of the marshes they studied, indicating that Phragmites’ effect was largely neutral.”

Land managers and contractors have been trying to eradicate phragmites in the Delaware River and its estuary for nearly 40 years. Although the contractors are still committed to that project, critics are getting louder and scientists are finding more evidence of the benefits of phragmites. It is no longer clear that eradicating phragmites is possible, nor is it clear that it would be beneficial.

Rising sea levels as ice melts in warmer temperatures are bringing the benefits of phragmites into focus: “Some scientists have been arguing that phragmites…could be a key line of defense against rising sea level, particularly in areas like the Mid-Atlantic where land is sinking while water continues to rise… Research from 20 years ago found that phragmites help marshes elevate faster than some other plants…”

The herbicides used to kill phragmites are aerial sprayed from helicopters, killing both native and non-native plants, resulting in barren mudflats that are more vulnerable to erosion: “The herbicide treatment of phragmites can also mean other native plants become casualties in the process, leaving an unvegetated landscape behind. With no plants to hold sediment in place, an open mudflat can be extremely vulnerable to flooding in the face of storms or unsuccessful regrowth… ‘You know, the Phrag marsh is certainly a whole lot better than no marsh,’ [a Rutgers scientist] said.”

Trying to eradicate phragmites no longer makes sense. So why is it continuing to happen? A Rutgers marine biologist explains: “Well, might I say…there’s a whole army of environmental consultants that get paid to remove phragmites and don’t get paid to leave it alone.” That is really the heart of the matter. The projects are designed to create jobs and apply for government funds, not to protect the environment.

The West Coast version of marsh grass eradication

If the word “spartina” is substituted for the word “phragmites” the Piermont Marsh project and the questions it raises apply to similar projects on the West Coast. For over 15 years, non-native spartina marsh grass has been eradicated using herbicides along the entire West Coast. The result of spartina eradication projects on the West Coast is also barren mud shoreline that is poisoned with herbicide and miles of coastline that is vulnerable to rising sea levels and erosion.

The Ridgway Rail was collateral damage of the spartina eradication project. The population of this endangered bird plummeted because its nesting habitat was destroyed.

There is another similarity between the East Coast and West Coast versions of eradicating marsh grass. Like the native typho (cattail) that is the goal of the East Coast project, native spartina that was the goal of the West Coast project is inferior protection of the coastline against storm surges. The native species of spartina on the West Coast that was the theoretical goal of the eradication project is shorter and less dense than the non-native species. It also dies back in the winter, unlike the non-native species that persists throughout the year. In other words, the native species does not provide the same protection for the shoreline that is provided by the non-native species. In any case, plantings of the native species failed in the poisoned ground, so its benefits claimed by the project are entirely irrelevant.

These eradication projects don’t make any more sense on the West Coast than their mirror image on the East Coast.

The Piermont Marsh Alliance Report on July 16 Webinar regarding Piermont Marsh

“San Francisco’s Natural History”: A mixed bag of fact and fiction

Million Trees breaks its self-imposed silence to bring you this book review of San Francisco’s Natural History: Sand Dunes to Streetcars, by Harry G Fuller. It was frustrating to read this book because I had high expectations that I would like it and learn from it. And to some extent, I did. However, the book also repeats old myths about eucalyptus that have long ago been debunked and fabricates a new myth. It also supports deadly and dangerous “restoration” projects in the Bay Area without acknowledging the loss of wildlife they cause. On the other hand, historical records of San Francisco’s natural history seem to be accurately reported by Fuller and he paints the picture of pre-settlement San Francisco as drifting sand dunes and treeless grass and chaparral.

Persistent myths about eucalyptus

Fuller says, “There is evidence…that eucalyptus trees may be deadly to both wintering birds and monarch butterflies…At the same time the trees provide necessary shelter, their chemical make-up and their sticky leaves may prove deadly.”

Hummingbird in eucalyptus flower. Courtesy Melanie Hoffman

Fuller does not provide the “evidence” for this statement, so we must speculate about what he means. It seems likely that he is repeating the 23-year old claim that eucalyptus kills birds by suffocating them with their sticky nectar when eucalyptus blooms in winter months. (Neither the nectar, nor the leaves of eucalyptus is sticky.) A local birder reported seeing two dead birds in eucalyptus forest over the course of his long career as a serious birder and parlayed those isolated observations into the generalization that birds are killed by eucalyptus trees. Decades of research was required to put that accusation to rest. (1, 2) Officially, the myth died when the California Invasive Plant Council updated the classification of eucalyptus in 2015. The claim that eucalyptus kills birds was deleted from Cal-IPC’s revised classification. It was aggravating to see this claim repeated by Mr. Fuller in his book, which was published in 2017.

Fuller’s claim that eucalyptus is also deadly to monarch butterflies is unprecedented. I have heard innumerable stories about the bad habits of eucalyptus, but I have never heard that eucalyptus kills monarch butterflies. You won’t find that accusation anywhere on the internet and you won’t find it anywhere in the scientific literature. I confirmed with Art Shapiro, Distinguished Professor of Ecology and Evolution at UC Davis and author of Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions, that he had never heard that claim either.

In fact, available empirical evidence contradicts that claim. Eucalypts are the preferred trees for over-wintering monarchs in California: “Three types of trees were used most frequently by roosting monarchs: eucalyptus (75% of the habitats primarily Eucalyptus globulus), pine (20% of the habitats primarily Pinus radiata), and cypress (16% of the habitats Cupressus macrocarpa). Twelve other tree species were identified…with a combined prevalence of only 10%.” (3) Monarchs migrate down the coast of California during the winter months, when eucalyptus is flowering at a time when there is little else blooming in California. They are an essential source of nectar during the monarch migration.

Fuller says, “The eucalyptus’s natural herbicides prevent many other plants from growing beneath their canopy.”

This is another accusation that has been repeatedly disproven by empirical research. The eucalyptus forest is as biodiverse as native oak woodland (4). The 2015 revision of the California Invasive Plant Council assessment of eucalyptus deleted previous mention of the allelopathic (the scientific term for “natural herbicide”) properties of eucalyptus. A rigorous study at Cal Poly concluded, “In these experiments, we found that germination and seedling growth of the species tested were not inhibited by chemical extracts of blue gum foliage, either at naturally-occurring or artificially concentrated levels.” (5) This study was presented by its author at the most recent conference of the California Native Plant Society, which should establish its credibility with native plant advocates.

Presentation at conference of California Native Plant Society

Fuller says in support of his “natural herbicide” theory, “You never see moss or lichen on a healthy eucalyptus trees.”

We don’t see moss or lichen on eucalyptus tree trunks because the thin, papery bark on the trunk sloughs off annually, leaving the trunk bare. Moss and lichen grow slowly on tree trunks in the bark that remains on the tree throughout the tree’s life.

Spartina (aka cordgrass) eradication

Ironically, Mr. Fuller prefaces his strong support for cordgrass eradication with this admonition: “Do not forgive ignorance, please.” Then, he displays profound ignorance of the consequences of cordgrass eradication in the San Francisco Bay Area. Fuller is a professional birder, yet he is seemingly unaware of the fact that the eradication of cordgrass has nearly wiped out the population of endangered Ridgway Rail (formerly Clapper Rail) in the Bay Area. He is also unaware of the huge quantities of herbicide that have been used to eradicate cordgrass. Elsewhere in his book, he expresses concern about pesticides and other forms of pollution, yet in the case of cordgrass eradication he turns a blind eye. (6)

Pesticide Application Notice, Heron’s Head, 2012

Eradication of mice on Farallon Islands

Mr. Fuller also supports plans to eradicate mice on the Farallon Islands: “The latest effort to return the Farallones to a more natural preserve is an attempt to remove all the house mice.” He is either unaware of plans to aerial bomb rodenticides on the Farallons to kill the mice or he chooses to use the euphemism “remove” to avoid the issue. Elsewhere in the book, he mentions that rodenticides used in Golden Gate Park to kill rats also killed Great Horned Owls that ate the dead or dying rats. He seems to understand that non-target birds are killed by rodenticides, yet he apparently supports the use of rodenticides on the Farallons, a national marine sanctuary. (7)

A Cautionary Tale

Mr. Fuller displays a sincere concern for the wildlife of San Francisco throughout his book. He also acknowledges the very real threats of climate change and pollution for the future of the environment in the Bay Area. I do not doubt his sincerity and I believe he has written a valuable book that is unfortunately damaged by his uncritical acceptance of inaccurate versions of several important environmental issues in the Bay Area. I believe Mr. Fuller has been a victim of “incestuous amplification” in his acceptance of these myths. Let that be a lesson to all of us to look deeply at every issue and to verify any tale you are told by an amateur or someone with a vested interest in those issues, such as employment.

I cannot recommend this book to anyone who is not prepared to read it critically. If you don’t already have a basic knowledge of the natural history of San Francisco you could easily be led astray by baseless rumors.

https://milliontrees.me/2013/11/05/eucalyptus-trees-do-not-kill-birds/
https://milliontrees.me/2014/07/26/birds-and-butterflies-in-the-eucalyptus-forest/
Dennis Frey and Andrew Schaffner, “Spatial and Temporal Pattern of Monarch Overwintering Abundance in Western North America,” in The Monarch Butterfly Biology and Conservation, Cornell University Press, 2004.
https://milliontrees.me/2011/02/04/biodiversity-another-myth-busted-2/
htt ps://milliontrees.me/2018/02/06/highs-and-lows-of-the-2018-conference-of-the-california-native-plant-society/
https://millio ntrees.me/2014/06/02/spartina-eradication-herbicides-are-their-dirty-little-secret/
https://milliontrees .me/2014/01/10/the-mouse-eradication-project-on-the-farallon-islands-the-con-in-conservation/