Herbicides/Pesticides – Conservation Sense and Nonsense

Life on Earth has saved itself many times without help from humans. It must do so again.

“What exists now can only ever come from what came before.” –Thomas Halliday, Otherlands

The consequences of climate change were more severe this summer than ever before:

Many places around the globe experienced extreme and prolonged heat waves.
Extreme heat caused wildfires in many places around the world.
There were also many severe floods all over the world.
The collapse of a glacier and the bedrock under it killed thousands of people in Nepal and warned of similar cataclysmic events elsewhere in the future.
NOAA is predicting the strongest El Niño on record in 2026-2027. It is expected to cause heavy rain in some places (such as California) and extreme droughts in other places around the world.

America is unwilling to do anything to reduce greenhouse gases causing climate change. In fact, we are developing more sources of fossil fuels and preventing the development of renewable sources of energy that do not contribute to greenhouse gases causing climate change.

Today, I would like to put these radical changes in our planet into some perspective, by revisiting some of the many catastrophic changes on Earth in the 4.6 billion years of its existence. In the 3.7 billion years that life has existed on Earth, 98% of all living species have become extinct. The species that survived those events were best adapted to the changed environment and many more evolved as conditions allowed. There are more species of plants and animals now than ever before, but many are threatened by climate change.

Homo sapiens have lived on Earth for only about 300,000 years. Clearly, humans have had little to do with the appearance of new species or the disappearance of extinct species over 3.7 million years until humans initiated the current round of climate change by burning fossil fuels to power our economy.

We must look to nature to save itself. Humans are not capable of doing so. In fact, we are standing in the way. Today, I am republishing an article that explains how nature has survived for billions of years without the “help” of humans and will do so again if we let it.

Conservation Sense and Nonsense

Let Evolution Lead the Way to Adaptation and Survival of Life

Otherlands, A Journey Through Earth’s Extinct Worlds was written by a paleontologist using the latest scientific techniques available. (1) Paleontology has advanced far beyond digging up fossils. Computer and DNA analysis enables paleontologists to reconstruct models of whole animals from bone fragments as well as describe the lifestyle of extinct animals such as what they ate and what ate them.

Geologic periods described by *Otherlands*. Source: Wikipedia

Thomas Halliday puts this knowledge of some of the 5 billion species that have gone extinct in the 4.6 billion years that Earth has existed into the context of geological and biological changes that caused their extinction. He describes vivid scenes of specific places at specific times, starting 500 million years ago (mya), a geological period when we can recognize most of the phyla (major groups of animals sharing characteristics) that exist today. These snapshots of deep time illustrate that “Environments shape their inhabitants as much as their inhabitants shape them.” (1)

In this article, we will visit a few of these scenes that demonstrate the biological innovations resulting from evolution and the associated geological and atmospheric events. And we will tell you about how modern conservation methods are often working at cross purposes against evolution and adaptation of life as it copes with catastrophic challenges.

Biological Innovation

Primitive life is said to have existed on Earth 3.7 billion years ago (bya). All life that presently exists on Earth is said to have evolved from the first life forms, although the common ancestor is yet to be identified. No life on Earth is truly alien.

The diversification of life on Earth began to accelerate when cyanobacteria developed the ability to photosynthesize about 3 bya. Photosynthesis converts sunlight to energy by consuming carbon dioxide, creating carbohydrates that feed plants and storing carbon in plants and the soil, while emitting oxygen into the atmosphere as a by-product.

This evolutionary innovation is responsible for the abundance and diversity of plants today. It is an important factor in the balance of carbon dioxide and oxygen in the atmosphere, which is one of the most important factors in the Earth’s climate. More plants also mean more food for animals that evolve alongside plants, often forming relationships with one another.

The first mass extinction, roughly 445 million years ago (mya), is the only mass extinction caused by a rapid change in the Earth’s climate from tropical to glacial, which is equivalent to saying the atmosphere changed from predominantly carbon dioxide to predominantly oxygen, the opposite of our currently changing atmosphere and climate.

Carbon dioxide levels are said to have dropped from 7,000 parts per million (ppm) to 4,400 ppm during the Ordovician extinction event that killed about 85% of plant and animal species. Currently our carbon dioxide level is about 420 ppm, just a fraction of what it was during the Ordovician period. In the context of the history of Earth, the climate we are experiencing is mild, a reminder of the potential for a much more extreme climate in the near future.

This graph of global mean surface temperature on Earth in the past 485 million years tells us the Earth’s climate has been mild since humans evolved. The graph should help us understand the potential for the Earth’s climate to increase beyond the tolerance for human life.

Comparing contemporary sea levels with those in deep time is another way to appreciate the potential for devastating changes in the future. 20,000 years ago, at the height of the last ice age, sea levels were 120 meters lower than they are now. Conversely, sea levels were highest during the mid-Silurian period, 430 mya, when sea levels were between 100-200 meters higher than they are now and atmospheric carbon dioxide concentrations were high.

Although the causes of the drastic change in the atmosphere and therefore the climate during the Ordovician period are still debated, the advent of photosynthesis is considered a factor. The development of fungi enabled plants to move from water to land by delivering moisture from soil to roots of plants, greatly increasing abundance and diversity of plants. About 80% of plants today receive much of their nutrients and moisture through mycorrhizal fungi.

The photosynthesizing capabilities of plants is one of the ways greenhouse gas emissions, currently causing global warming, can be reduced. Yet, we are using pesticides to kill plants that native plant advocates have arbitrarily decided “don’t belong.” Pesticides also kill fungi in the soil that enable plants to survive during drought conditions created by global warming. This is one of many examples of how management strategies used by humans are counteracting the accomplishments of evolution that occurred long before humans existed or began to think they were competent to “manage” nature.

Plant Evolution Timeline

To make a long, complicated story short, we’ll focus on the major plant groups we recognize today by starting with seedless land plants that reproduce by dispersing spores, such as mosses and ferns that evolved from algae about 460 mya.

Gymnosperms, which we recognize today as conifers, cycads, and Gingkos, are seed-producing plants that evolved about 300 mya. Early species of gymnosperms formed huge forests. The carbon they stored became the coal fields of today when they died during the Carboniferous period (360-300 mya). Today, we draw our fossil fuels from these coal and oil basins. They provide most of our energy, while releasing greenhouse gases causing climate change.

Continents were close together during the Cretaceous geologic period when angiosperms evolved. Source: Australian Museum

Angiosperms evolved from gymnosperms about 130 mya. They are flowering plants whose seeds are often encased in fruit. They are by far the most diverse group of land plants. The evolution of bees around the same time is an example of co-evolution: the flowers feed the bees and the bees pollinate the flowers, delivering pollen from the male anther to the female stigma. This sexual method of reproduction creates greater genetic diversity than self-pollination. Greater genetic diversity creates more opportunities for natural selection to operate on plant variations, which may result in species that are better adapted to existing conditions.

A recent study (2) found that the decline in the population of bees has increased the frequency of self-pollination of some plant species that are capable of both methods of pollination. This is an example of evolution at work today. Plants are responding to the existential need to reproduce in the absence of bees by self-pollinating.

What evolution has accomplished in the past can be undone. In this case, our indiscriminate use of pesticides such as neonicotinoids has decimated bee populations. Some plants will adapt to the loss of bees by self-pollinating, but not without some loss of genetic diversity provided by sexual reproduction and consequently the long term fitness of plants to face challenges in the future.

There’s another trade-off for both plants and bees. Producing nectar and attracting bees with colorful flowers is a big energy expense for plants. Plants therefore save energy by reducing flower size and color, when they can rely solely on self-pollination for reproduction. Obviously, self-pollination ultimately results in a loss of food for bees and may accelerate the decline in bee populations, a negative feed-back loop, if you will.

This example is a reminder that evolution is neither positive nor negative. It is simultaneously both positive and negative. It is what it is: an inexorable force for change.

Evolution of grasses

Grasses and grasslands are late comers to the Earth’s plant kingdom. Grasses evolved from angiosperms about 70 mya, during the Age of Dinosaurs that abruptly ended 66 mya when an enormous asteroid collided with Earth. Grasses are wind pollinated and their seeds are dispersed by the wind, which enables them to spread rapidly and widely.

Grasslands became dominant ecosystems about 30 mya, replacing many forest ecosystems. With the optimal combination of fuel, heat, and oxygen, wildfires were a factor in the transition from forests to grasslands in many places. Once again, wildfires in conifer forests are presently playing a role in converting forests to grasslands, suitable to a warmer and drier climate.

The development of enhanced photosynthesis by C4 grasses gave them a competitive advantage in hot, dry places where photosynthesis is suppressed. C4 grasses are more drought tolerant and they store more carbon than their predecessors, C3 grasses. There are only about 60 groups of C4 grasses, including several important food crops, such as maize, sugarcane, and sorghum. They are found in tropical and sub-tropical regions of Africa and South America and some deserts. California’s native grasses as well as introduced grasses considered “invasive” are not C4 grasses, according to a list of C4 grasses available on Wikipedia. (3)

Because of their potential to improve drought tolerance and increase productivity and carbon storage, there is great scientific interest in converting C3 grasses to C4 grasses. Despite decades of effort, agricultural science has not been able to duplicate what the natural forces of evolution have accomplished, reminding us that evolution is more powerful than we are.

The transition from forests to grasslands had a corresponding impact on the evolution of animals. Some browsers of woody plants learned to be grazers, if they could, while others went hungry, and the diversity and abundance of grazers increased.

Native plant advocates in California have selected grassland as their preferred ecosystem because it was the dominant ecosystem prior to the arrival of Europeans at the end of the 18th century. They have consistently failed to convert non-native grassland to native grassland in California. Nor is it clear that there would be any benefit to the environment or to its inhabitants to return to the treeless landscapes of California that existed prior to settlement in the late 18^th century.

Where populations of native grazers of grassland were reduced by the activities of humans, many grasslands in California naturally succeeded to shrubs and trees. “Restoration” projects attempt to prevent succession of grasslands. Some of these projects destroy native trees and shrubs (e.g. Douglas fir, coyote brush, juniper, etc.) mechanically and with pesticides to maintain ecosystems as grassland.

Nativists also want to reintroduce the grazing animals of the pre-colonial period to replace domesticated animals humans introduced because nativists see them as competitors of native animals they consider superior. Where top predators have been killed, these herds of grazing animals outgrow available vegetation unless their numbers are controlled as domesticated animals are.

A recent meta-analysis of 221 studies of the impact of megafauna on plant abundance found, “no evidence that megafauna impacts were shaped by nativeness, “invasiveness,” “feralness,” coevolutionary history, or functional and phylogenetic novelty. Nor was there evidence that introduced megafauna facilitate introduced plants more than native megafauna. Instead, we found strong evidence that functional traits shaped megafauna impacts, with larger-bodied and bulk-feeding megafauna promoting plant diversity. Our work suggests that trait-based ecology provides better insight into interactions between megafauna and plants than do concepts of nativeness.” (4)

The author of Otherlands agrees that the concept of nativeness is not a useful way to understand the environment or conduct conservation because: “Where an animal or a plant from one part of the world appears in another, some might use the language of invasion, of a native ecosystem despoiled and rendered lesser by newcomers…In reality, species do move, and the notion of ‘native’ species is inevitably arbitrary, often tied to national identity…There is no such thing as a fixed ideal for an environment…To look into deep time is to see only an ever-changing list of inhabitants of one ecosystem or another…The concept of native that we so easily tie to a sense of place also applies to time…We must avoid putting our own ahistorical spin on what was, although certainly dangerous and unlikely, a journey guided entirely by chance.” (1)

Migration

The history of evolution is also a history of migration. The oscillation of the Earth’s climate between freezing cold and blistering heat created and destroyed land bridges that enabled or blocked migration as sea levels rose and fell. When North America and South America were connected by Central America as a result of lower sea levels and geological events about 3 mya, the plants and animals of those continents were mixed by migration. Likewise, aquatic life of the Pacific Ocean was separated from the Atlantic Ocean by the Central American land bridge until the Panama Canal was built in 1914.

Geological events also created or destroyed the same opportunities for migration. The opening and closing of the Strait of Gibraltar is a case in point. The Mediterranean Sea exists because the Strait of Gibraltar exists. When the narrow Strait is open, the Atlantic Ocean flows into the Mediterranean Basin, creating the Mediterranean Sea, which is an obstacle for migration of plants and animals between Europe and Africa.

About 6 mya the Strait of Gibraltar closed because the African tectonic plate moved north, colliding with the European tectonic plate. The Mediterranean Sea slowly evaporated, concentrating ocean salt from the Atlantic Ocean, laying down a sea bed of salt in the Mediterranean Basin and ultimately creating a migration corridor between Africa and Europe. There is every reason to believe that the Strait could close again. The Earth’s tectonic plates are in constant motion and there is no reason to believe they will stop moving.

The obsession with “where plants belong” seems to be based on ignorance of the history of dispersal and migration. Much of China and North America have been in the same latitude since the evolution of angiosperms. As a result, many of our plant species considered native in Eastern North America are also considered native in China. These paired species in the same genus are called disjuncts. There are many woody disjuncts in China and North America (magnolias, persimmons, hickory, catalpa, dogwood, sweetgum, tuliptree, tupelo, sassafras, Virginia creeper, etc) as well as many herbaceous disjuncts (ginseng, lopseed, mayapple, skunk cabbage, etc.). (5) They are different species because they have been separated long enough to change as a result of genetic drift, but are in the same plant lineage, therefore chemically similar and presumably used by the same insects. The study of these disjuncts says, “Most scientists do not consider long-distance dispersal to have played much of a role. The prevailing view is that most disjuncts are remnants of genera that were once widely distributed in the northern temperate zone during the Tertiary period [66 mya to 2.6 mya per Wikipedia]. These broad distributions in the northern hemisphere were made possible by recurring land bridges.” (5)

Lateral migration patterns of the past are changing in response to contemporary patterns of climate change. The temperatures at different latitudes are becoming more similar because Polar Regions are warming at a much faster pace than temperate and tropical latitudes. Plants and animals escaping extreme heat and associated changes in vegetation are moving to higher latitudes in the Northern Hemisphere and lower latitudes in the Southern Hemisphere. The increasing similarity of the Earth’s climate is changing wind and ocean currents and contributing to the extreme weather events of our changing climate. Although there are lessons in the events of deep time, we cannot assume that events in the past are entirely predictive of future events because of the complexity of natural processes and our limited understanding of them.

Of all the nonsensical conservation strategies humans are presently using, perhaps one of the most damaging is the futile attempt to stop migration. It is one of few survival strategies of plants and animals needed in a rapidly changing climate and it cannot be stopped.

The project that proposes to shoot barred owls in the Pacific Northwest is an example of a “conservation” project that does not deserve that honorific. Barred owls have migrated from the East to the West Coasts of North America via the boreal forests of Canada. This is another instance in which large contiguous stretches of land at the same latitude facilitate the migration of life because there is less variation in climate at the same latitude.

Specialists vs. Generalists

Barred owls are more adaptable than their closely related relative in the same genus, spotted owls. Barred owls have a more varied diet, they are willing to nest in less dense, second-growth forest, and they have greater reproductive success. They are therefore perceived as competitors of endangered spotted owls. Instead of letting natural selection identify the winner of that competition, the US Fish & Wildlife Service intends to shoot 500,000 barred owls in the next 30 years based on their belief that spotted owls will benefit. They do not expect to eradicate barred owls and they made a commitment to continue shooting barred owls in perpetuity. While we continue to log old-growth forests in which spotted owls live, we will kill barred owls with no expectation that they can be eradicated.

This project is typical of American “conservation” projects that attempt to save a specialist species by killing a generalist species. This strategy was enshrined in American law by the Endangered Species Act, which is now 50 years old. Like many 50-year-old public policies, we now know that this conservation strategy is not working because it is inconsistent with evolutionary principles. Change in nature is inexorable. Legal mandates are not capable of stopping evolution. If we had a functional political system, we could stop the greenhouse gas emissions causing climate change, but we don’t. Therefore, we must rely on evolution to cope with the changes in the environment that we have caused.

The most recent mass extinction occurred 66 mya when an asteroid hit the Earth, ending the Age of Dinosaurs. About 80% of all plant and animal species became extinct. The species that survived were the most versatile and the most mobile. Flying dinosaurs were the only dinosaurs that survived, as birds, perhaps because they were the most mobile. “Of the specialized insects, 85% were lost and it was the generalists that survived.” (1)

Mass extinctions have created many vacant ecological niches that are opportunities for experimentation, creating new species. Some were better adapted than others. Natural selection determined the winners of competition within ecological niches. The end of the Age of Dinosaurs created the opportunity for the Age of Mammals, as well as bony fish, marsupials, and lizards.

In other words, our outdated conservation strategy is wasting our limited resources to save specialized species that are probably doomed to extinction. And we are doing so at the expense of generalist species that might survive if we would quit killing them. Keep in mind that 99% of all life forms that have existed on Earth have gone extinct. At a time when the climate is changing rapidly, the goal of saving every endangered species seems both unrealistic and wasteful of limited conservation resources.

Hybridization

Hybridization is one of the tools of evolution. Closely related species, usually in the same genus and even family often mate and their offspring often survive to eventually give rise to new species. Successful hybridization is a means of increasing biodiversity. Hybridization is sometimes a means of improving adaptability and therefore survival.

Unfortunately, nativists see hybridization as a loss of biodiversity rather than an opportunity to improve adaptability and increase biodiversity. Their “conservation” projects often attempt to prevent hybridization by killing hybrids. For example, the plan to kill 500,000 barred owls includes all hybrids of barred and spotted owls. Because barred owls are more versatile, hybridization with spotted owls could even the playing field with barred owls by expanding food sources and nesting habitats of spotted owls.

The Spartina eradication project is another example of the pointless eradication of hybrids. In the case of Spartina, the non-native species grows more densely and it doesn’t die back in winter. Non-native Spartina provides better storm protection and better habitat for nesting birds. The Invasive Spartina Project has been spraying hybrid Spartina with herbicides for over 20 years, without total success. The hybrid looks so similar to native Spartina that 600 genetic tests are required every year to confirm their identification as hybrids before they are sprayed. The Invasive Spartina Project is a waste of limited conservation resources and it serves no useful purpose.

Evolution vs. Conservation

Otherlands should be required reading for those who are engaged in the “restoration” industry. Some of the methods and goals of conservation are at odds with the mechanisms of evolution that have ensured the survival of life on Earth for nearly 4 billion years.

The use of pesticides by “restoration” projects is antithetical to the goal of conservation because they do more harm than good.
Migration is a means of species survival. Natural migration of plants and animals cannot and should not be stopped.
Humans cannot duplicate the forces of evolution. Natural selection is the most powerful, efficient, and effective method of determining the winners of competition.
Hybridization has the potential to improve adaptability of closely related plants and animals. Hybridization cannot and should not be stopped.
Resources being wasted in the attempt to stop the natural forces of evolution should be redirected to reducing greenhouse gas emissions causing climate change. Such efforts are appropriately called “conservation.”

Thomas Halliday, Otherlands, A Journey Through Earth’s Extinct Worlds, Random House, 2023
https://www.nytimes.com/2024/01/04/science/flower-sex-evolution-bees.html?searchResultPosition=1
https://en.wikipedia.org/wiki/List_of_C4_plants
Erik Lundgren et.al., “Functional traits—not nativeness-shape the effects of large mammalian herbivores on plant communities,” Science, February 2, 2024
David Yih, “Land Bridge Travels of the Tertiary: The Eastern Asian-Eastern North American Floristic Disjunction, Arnoldia, 2012

Originally published March 1, 2024

“Nature’s Best Hope” is Evolution, Not Native Plants

Six months ago, an ecologist friend and mentor alerted me that Ferris Jabr was writing an article about Doug Tallamy for The New York Times Magazine. They spoke by phone for about an hour, during which my friend recommended that Jabr also speak with me. I was hopeful that the Times would publish an even-handed assessment of Doug Tallamy’s nativist ideology. I’m a subscriber who trusts NYT to report fairly on controversial issues. I’m sorry to say that in this case, NYT let its readers down. (1)

In contrast to that brief phone interview, Jabr reports spending several days visiting Doug Tallamy at his home in Delaware, months before he spoke with dissenting voices. That disproportionate time shows in the resulting article, which lands firmly in Tallamy’s camp. Jabr also spoke by phone with several other academic ecologists whom I know, but quoted none of them.

Preparation

I began preparing for an interview I hoped to be granted by Ferris Jabr. I read his book, Becoming Earth: How Our Planet Came to Life, about how life and Earth coevolved. It examines the concept that our world is a single, interconnected, self-regulating living system, and argues that all living things are not just inhabitants, but active participants in the planet’s evolution.

Jabr’s life-long interest in gardening contributed to his understanding of the intertwined fates of life and Earth. He describes how he transformed the barren lawn of his new home into diverse wildlife habitat, with the help of contractors and tons of soil amendments, shown in before, transition, and after photos (see below). He says he and his partner planted native species and a vegetable garden, but he also mentions planting traditional ornamentals such as peonies and dahlias.

Ferris Jabr’s garden. Source: *Becomiing Earth*

The book demonstrates a solid grasp of evolution and events in deep time that illustrate how life changes as the environment changes. I was hopeful that knowledge would enable him to write a balanced article about Tallamy’s nativist ideology in which evolution plays no role. The public’s poor understanding of evolution is the main obstacle to grasping a simple truth: when the climate changes, vegetation must move, adapt, or die.

Plants that lived in pre-European America 500 years ago are unlikely to be the best adapted to our changed and changing climate. I encourage home gardeners to plant whatever they want, but be prepared to watch plants die if you insist on exclusively species native to your region. I wince when Tallamy rails against hybrid plants, which he insists must be eradicated. Hybridization is one of the most powerful evolutionary tools that enables life to adapt to environmental change.

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. Intensive aerial spraying of herbicide killed more than 95% of non-native spartina over 10 years ago, but the project continues in the San Francisco Bay. The project killed 600 endangered Ridgway rails, because non-native spartina was denser and did not die back in winter. 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. Funding for the project was recently renewed. Source: https://milliontrees.me/2021/10/15/spartina-eradication-is-now-a-zombie-project/

I watched a video of Jabr presenting his book at Yale Law School. When he gave the same talk at a Bioneers Conference at UC Berkeley in March, I asked to speak with him there. It became clear he wouldn’t speak with me. He implied I lacked the required “credentials.” I changed tactics.

Bringing the Mountain to Mohammed

I asked a collaborator with unimpeachable credentials — a horticultural professional and university instructor — to reach out to Jabr. She did, but he did not interview her.

I also recruited an academic botanist to write a guest post for my website about data manipulation he’d found in one of Tallamy’s studies, manipulation that effectively hid the many contributions non-native plants make to lepidoptera (butterflies and moths). Nathan Lambstrom is a busy university lecturer and designer of ecological gardens, but he wrote the piece, published here. Jabr interviewed Lambstrom after that article ran, but didn’t quote him, nor did he mention the data manipulation underlying Tallamy’s ideology in his article.

Where Does Jabr Land?

Jabr’s article centers on Tallamy’s thirty-year transformation of his 10-acre Pennsylvania farm into a native garden. To his credit, Jabr offers some mild qualifiers to Tallamy’s version of nativism:

Despite applying herbicides, Tallamy was unable to eliminate all introduced species: multiflora rose still forms a few thickets, and Japanese stiltgrass carpets the forest floor. As a witness to such attempts to eradicate non-native plants on public land, I can confirm that they are rarely successful.

Coyote in Oxalis pes-caprae in a San Francisco public park. Herbicides have been used on *Oxalis pes-caprae* in San Francisco’s parks for over 25 years. Over 20% of all herbicide spraying by the Natural Resources Division (NRD) of the Recreation and Park Department was applied to kill oxalis in “natural areas” in 2022. NRD sprayed oxalis 35 times in 2021 and 38 times in 2022. Bees love oxalis. *Oxalis pes-caprae* is native to South Africa, but there are 4 species of oxalis native to Northern California. Source: https://milliontrees.me/2023/02/28/the-oxalis-obsession/

Tallamy concedes that “on average just 14% of the natives in a given region feed more than 90% of local butterflies and moths.” That’s a striking admission: it means a small set of keystone natives is doing nearly all the ecological work, while the remaining 86% of native species contribute comparatively little. That’s hard to square with the blanket claim that gardeners must plant natives indiscriminately. The data suggest that keystone status, not native origin itself, is what matters.
Jabr takes issue with some of Tallamy’s “grandiose claims” and notes that “polarized attitudes toward native and introduced species” are controversial. He says that “introduced species have few noticeable effects or provide ecological benefits” and names a few examples.
He quotes Professor Emeritus Art Shapiro as saying that more than 30% of California’s butterfly species use introduced plants as hosts for their larvae, because those plants have leaf chemistry similar to their native hosts, and that “some North American butterflies have even expanded their geographic ranges and reproductive seasons by adapting to foreign plants.”
Jabr also quotes Professor Emily Meineke (UC Davis) about a project seeking the most suitable street trees from warmer regions to tolerate the warming, drier climate in Davis, California.
Jabr acknowledges that “all life is equally Earthly” because all “extant species are branches of a single ancient trunk.” That’s the fundamental truth missing from Tallamy’s ideology: all life on Earth is related. Jabr also advises ecologically minded gardeners to focus on what plants do rather than where they’re from.

Ultimately, Jabr lands firmly in Tallamy’s camp. His concluding paragraphs describe how, after visiting Tallamy, he began replacing introduced plants in his own garden with natives and he believes the swap has brought more wildlife to his yard.

An Alternative Perspective

Two days after the Times published Jabr’s article, Garden Rant published a piece by Nathan Lambstrom, the same academic botanist who reported data manipulation in a Tallamy study. “The War on Invasive Species” offers a contrasting view of nativist purism. It is grounded in extensive, cited documentation and provides numerous examples of non-native plants’ contributions to wildlife. It also documents the harmful consequences — especially from herbicide use — of attempts to eradicate non-native plants.

Lambstrom concludes, in his usual even-handed way: “I do not dispute that invasive plants and animals, especially predators, are associated with ecological change, sometimes quite significant. Though we often must intervene to mitigate that change, my hope is that we can move past a dichotomous framing of natives versus non-natives and invasives, and move towards recognizing ecological value wherever it occurs, responding carefully and appropriately while our ecosystems adapt to the presence of these new residents. I believe this is the soundest and only realistic way forward.”

Jabr interviewed Lambstrom for his Times article, but didn’t quote him or mention the data manipulation in Tallamy’s study. Times readers were denied the chance to learn more about a genuinely controversial issue.

Public Reaction

Comments on Jabr’s article are overwhelmingly favorable. Most are from gardeners thrilled with the results of replacing their lawns with native plants. It stands to reason that more plants bring more life to a garden. It’s less obvious that a purely native garden brings more life than a diverse garden that prolongs blooming and provides a bigger menu for wildlife. Native vegetation looks dead during our long California summer dry season. A few all-native gardens in my neighborhood look more like vacant lots than intentional gardens from May to November. Many of my neighbors have made a transition to drought and heat tolerant succulents and cactus, not native to our region.

Many commenters are angry about Jabr’s few mild misgivings about Tallamy’s version of nativism. Their comments display the kind of bullying that less purist gardeners find intimidating.

What’s Missing

Here’s what I think is missing from Jabr’s article. I offer what I believe are the strongest arguments against Tallamy’s version of nativism in the natural world.

Global warming is a far greater threat to life on Earth than any single plant species, native or not. All plants — native and non-native alike — remove carbon dioxide from the atmosphere, store carbon in the soil, and emit oxygen. Tallamy’s ideology encourages gardeners, and the public land managers who’ve adopted his approach, to eradicate non-native plants in favor of natives. But public land managers rarely have the resources to replace what they remove, and eradication on public land is typically done with herbicides. Herbicides kill the fungi and microbes in the soil that facilitate carbon storage and plant growth. In that sense, Tallamy’s ideology, as currently practiced on public land, contributes to the very climate change that threatens plant and animal life with extinction.

This is one of many tree graveyards in San Francisco’s public parks. Nearly 30 years ago, San Francisco’s park department designated one-third of their parkland as “natural areas,” about 1,100 acres. Because pre-settlement San Francisco was mostly treeless, the creation of the so-called Natural Areas Program obligated San Francisco to destroy much of its urban forest, which is predominantly non-native. In the case shown, the trees were mostly Monterey pines, which are native in Monterey, California, less than 150 miles away. There is also fossil evidence that Monterey pines lived in the San Francisco Bay Area in the distant past. Source: https://milliontrees.me/2022/08/01/creating-tree-graveyards-in-san-francisco/

I encourage home gardeners to plant whatever they want. If they prefer an exclusively native garden, that’s their prerogative. The native plant movement becomes controversial only when it drives destructive eradication projects on public land — parks, in particular — that rely on herbicides because herbicides require less labor and cost less. Such projects expose the public to toxic chemicals and damage the soil by killing beneficial fungi and microbes. Non-selective herbicides such as RoundUp are as likely to kill natives as non-natives.

“Nature’s Best Hope” is evolution, not native plants. For roughly 3.5 billion years — since not long after Earth itself formed, 4.6 billion years ago — life has survived by evolving adaptations to changing climate and environmental conditions, including cataclysmic events like the asteroid that struck Earth 66 million years ago, wiping out the dinosaurs and accelerating the evolution of mammals. It is not the strongest or most intelligent species that survives, but the one most able to adapt to change. Ninety-eight percent of all plant and animal species that have ever existed on Earth have gone extinct as the Earth continuously changes. What exists here now is adapted to present conditions that are now undergoing rapid, accelerating change.

In a rapidly changing climate, it’s unlikely that plants native to pre-European, pre-industrial North America 500 years ago are best adapted to current conditions. That fiction is sustained by American ignorance of evolution. In 2024, a Gallup poll found that only 24% of Americans believe humans evolved without God’s involvement, a share that has risen steadily since 2000. Thirty-seven percent of the public still believes that God created humans in their present form. That ignorance of evolution also obscures how closely related plants are: entire plant families, most containing both native and non-native species, share similar chemistry, enabling insects to use both natives and non-natives within the same family.

Humans cannot stop evolution, nor should we try. Doug Tallamy has won this round. The ultimate victor will be climate change, because we’ve decided to do nothing about it. Unless we get a grip on climate change, it’s senseless to quibble about native plants.

(1) “I Wanted an Ecologically Responsible Garden. It Was Harder Than I Thought,” Ferris Jabr, New York Times Magazine, July 7, 2026

Revising the Eradication Goals of Invasion Biology

It is my pleasure to publish (with permission) Arthur M. Shapiro’s (Professor of Ecology & Evolution Emeritus, UC Davis) review of Ecological Explosions: The History of Biological Invasion and Invasion Science, by Daniel Simberloff (Professor of Environmental Science, University of Tennessee).

Professor Simberloff is a prolific and vociferous adherent to the hypotheses of invasion biology, as well as to the related commitment to eradicating non-native plants. I heard Simberloff speak at the conference of the National Park Service, “Science for Parks, Parks for Science,” at UC Berkeley in 2015. It was a time when critics of invasion biology were emerging and becoming more vocal and visible. Simberloff called out by name Emma Marris, Peter Kareiva and others for their criticism of invasion biology.

In 2020, I heard Simberloff speak at the annual forum of the California Invasive Plant Council. His presentation was similar to his presentation in 2015 in that it was primarily focused on critics of invasion biology whom Simberloff calls “deniers.” Simberloff categorized the criticisms of invasion biology then flipped them off, one by one.

Then, Simberloff’s presentation took an unexpected turn when he was asked this question by the moderator: “Dan, you mention the “futility” argument, but what about the notion that the cost in environmental damage (e.g, pesticide use and nontarget impacts) is too high for some well-established invaders?” Simberloff’s answer to this question was surprising and encouraging to critics of pesticide use to kill non-native species:

“Absolutely, it’s a huge problem, not only on non-target species, but also the fact that evolution of resistance leads to greater use of pesticides before they are useful and leads to greater impact on non-target species. I didn’t talk about this, but yes, of course the cost both economically and ecologically might be too great even if management eradication is feasible. But that’s not what denialism is about. Denialism willfully denies that there are impacts or they confound arguments about values as if it is an argument about science.” Daniel Simberloff

Simberloff’s concern about the costs “both economically and ecologically” of eradicating non-native plants was as much a shock to the Executive Director of the California Invasive Plant Council–which actively champions the use of herbicides to eradicate non-native plants–as it was to me.

Based on that experience, I had a premonition that Simberloff’s recent publication might be another surprise and so it is, as Professor Shapiro explains in his review. Simberloff publishes this exhaustive tome at the age of 84. Perhaps it is his last word. It is a significant revision to the long crusade to eradicate every non-native plant.

One hopes Simberloff’s book will influence the “restoration” industry to be more circumspect when choosing their eradication targets and their methods. If so, it comes at a good time because every effort to reduce pesticide use in the US has been tried and failed.

Last week, the US Supreme Court overturned product liability lawsuits brought by users of glyphosate with cancer, because the Environmental Protection Agency does not consider glyphosate carcinogenic, though it indisputably is. EPA’s determination now over-rides any state determination to the contrary. Earlier, President Trump also signed an Executive Order, promoting the use of glyphosate and Robert F. Kennedy, Jr., Secretary of Health and Human Services, endorsed the Executive Order.

I am deeply grateful to Professor Shapiro for giving me this opportunity to publish his review of Professor Simberloff’s book about invasion biology. I am also grateful to Professor Simberloff for taking a closer look at the consequences of eradicating non-native plants.

Conservation Sense and Nonsense

REVIEW: ECOLOGICAL EXPLOSIONS: THE HISTORY OF BIOLOGICAL INVASIONS AND INVASION SCIENCE. Daniel Simberloff. University of Chicago Press. 2025. 729 pp.

I was fully prepared to detest this book—until I read it.

Dan Simberloff, as E.O. Wilson’s star graduate student at Harvard, was present at the creation of the theory of island biogeography, which used simple mathematical and graphical models to bring order to a vast heap of anecdotal information and in so doing radically transformed ecology—from natural history to analytical science (not everyone was thrilled). Simberloff’s subsequent career can be seen as the application of that approach to the implications of human-mediated changes in the geographic ranges of species generally. Now in his 80s, he has written this doorstop of a book as the envoi to his career. Why, I wondered, would anyone want to read it?

Simberloff and I are contemporaries. My undergrad adviser at Penn, Robert MacArthur, was Wilson’s collaborator on “The Theory of Island Biogeography,” and very much wanted me to do my Ph.D. with Wilson. MacArthur was under the illusion that I had mathematical talent, despite my best efforts to convince him otherwise. I knew it would be a bad fit, and to his frustration never even applied to Harvard. I went to Cornell for my degree, a place more in tune with a natural historian like me. I have often joked that had I gone to Harvard I would have become Dan Simberloff! Both Simberloff and I read Charles Elton’s “The Ecology of Invasions by Animals and Plants” (1958), the book that established invasion biology as a field and gave it its name. In Dan’s case reading that book shaped his entire career. It had many impacts on mine as well; I began observing and studying the adoption of naturalized host plants by native insects, mainly Lepidoptera, and it profoundly affected my teaching (community ecology, biogeography) for the next 50+ years. So it was natural that I, at least, would want to read it.

At the same time I had become disaffected with what I perceived as both the ideological and the faddish turn of invasion biology, and I was apprehensive about what I might find. I needn’t have been.

The first part of the book is a more-or-less chronological history of the development of invasion science, from the earliest observations of European weeds in New England by John Josselyn down to our own time. This is not a catalogue of case histories, but the ones selected are judiciously chosen to be representative of aspects of the field. Most were already familiar to me, but quite a few were not, even after more than five decades.

But the most important chapters for me were at the end. Chapter 18 (“Controversies Abound”) confronts head-on the conflation and entanglement of invasion biology on the one hand and xenophobia and racism on the other—exemplified by the term “native plant Nazis,” referring to those who advocate eradication of non-native species. The use of political and military metaphors (including the word “invasion” itself!) has contributed to such conflation and its undesirable resonances. The conflation has deep roots, which Simberloff explores—consider the New York socialite Madison Grant, a prominent lay conservationist, who authored the scurrilous racist tract “The Passing of the Great Race: or the racial basis of European history” (1916), by no means an isolated case. Simberloff has no patience for the blanket rejection of species solely on the basis of their “native” vs. “non-native” status. He recognizes that each case must be approached contextually and that there is no justification for eradication campaigns except in the most exigent circumstances (pathogens, parasites—the current alarm over the screwworm comes immediately to mind; invaders that pose grave risks to agriculture or to the survival of prized native species and ecosystems). Chapter 19, on the future of invasion science, elaborates on these themes in the context of a world that is changing at an ever-accelerating pace.

Do age and experience confer wisdom on us? Perhaps not inevitably. But this book convincingly demonstrates that they have done so for Dan Simberloff. If you are seriously interested in invasion biology, get and read this doorstop of an envoi: all 729 pages of it.

ARTHUR M. SHAPIRO

University of California, Davis

Seeking Peace in Our Gardens

Garden Rant recently published an article by garden-writer, Marianne Willburn, defending gardeners who prefer a diverse garden over an exclusively native garden. This issue has been hotly debated for several decades, generating conflict in gardens and garden societies. These are places where people seek refuge from life’s many challenges. Some mourn the loss of peace in the garden and wish for a return to peaceful co-existence between gardeners regardless of which plants they prefer. As American politics have become increasingly polarized, all the more reason to foster peace in our gardens.

Conflicting Goals in the Garden

The primary goal of home gardeners was beauty prior to the advent of the native plant movement. As the saying goes, beauty is in the eye of the beholder, which is a way of saying everyone has their personal definition of beauty. In the garden, some prefer order and symmetry while others prefer naturalistic chaos and abundance.

The native plant movement brought an entirely different goal to the garden about 30 years ago. Native plant advocates want a garden that they believe will best serve the wildlife that lives in it, from the insects at the bottom of the food web, to the birds that eat insects and beyond, to the top of the food web. Beauty is not their goal. In fact, a beautiful garden is considered by some the antithesis of a native garden, judging by the gardens of some of my neighbors whose gardens look dead half the year in our Mediterranean climate that is without rain half the year.

Dictators in the Garden

Such different viewpoints about the purpose of our gardens could have lived peacefully side-by-side if native plant advocates had respected the opinions of cosmopolitan gardeners, but they didn’t.

To quote the Garden Rant article, the native plant movement “saddles everyman gardeners (whether they wished to grow Hemerocallis [daylilies] or fill a raised bed with herbs) with the burdens of past and present ecological damage to our planet, the saving of species from extinction, and the reversal of climate change.”

Source: Garden Rant image of media article

If you haven’t been on the receiving end of such a moralistic lecture from a native plant advocate, you may think that’s an exaggeration. Here are a few examples of such condescending lectures from native plant advocates about the obligations of gardeners to save the planet:

Gardens planted with non-native plants are “blooming wastelands where the flowers feed nobody at all.”
“The typical suburban yard is actually worse than a wasteland. It’s a death trap.”
Margaret Renkle, NY Times, March 28, 2021

“It turns out I’ve been filling my yard with a mix of ecological junk food and horticultural terrorists.”
“I’m sorry to say that if you have a typical urban or suburban landscape, your lawn and garden are also dooming the Earth.”
Dana Milbank becomes a native plant gardener, Washington Post, April 7, 2023

“’I think of it as chemotherapy,’ said Doug Tallamy, a University of Delaware entomologist and guru of the native-plant movement. ‘We have ecological tumors out there. If we don’t control them, we have ecological collapse. We have the collapse of the food web.’”
Doug Tallamy, Washington Post, June 30, 2023

“…no other “don’t” has been shouted more loudly lately than the list of plants to avoid, the various nonnative, longtime nursery-industry standards that are now understood to cause environmental harm.”
Margaret Roach, NY Times, March 17, 2026

Such dire predictions of ecological collapse are overheard among neighbors, over garden fences, in garden society meetings, and in conferences of the California Invasive Plant Council and the California Native Plant Society. Articles with similar themes are found in garden magazines and in the publications of environmental organizations such as the Sierra Club and the Xerces Society.

If the extravagant claims of advocates about the superiority of native plants received the scrutiny and analysis they need, the native plant movement would not have the power and influence that it presently has. Now let’s turn a bright light on the claims of nativism in the natural world.

Debunking Nativist Myths

Nathan Lambstrom is a botanist and professional landscape designer who has given us an example of how nativist myths persist. He reports that Doug Tallamy supports his claim that insects require native plants by obscuring the many contributions non-native plants make to moths and butterflies. He manipulates his data set to hide the documented contributions of non-native plants, including plants considered “invasive.”

I was introduced to the nativist myth that native plants store more carbon than non-native plants nearly 20 years ago in an undergraduate ecology class at UC Berkeley. The University’s land manager who was responsible for destroying non-native trees on the University’s open space told the class that “carbon storage in non-native trees doesn’t count.” I was horrified that the class as well as the professor teaching the class accepted this nonsensical statement without comment. The truth is that both native and non-native plants and trees store carbon while they are alive that would otherwise be released into the atmosphere, contributing to climate change. As long as native plant advocates continue to demand the destruction of non-native plants and trees, they cannot claim that their projects reduce greenhouse gases that cause climate change.

Academic Ecologists Retreat from Invasion Biology

Recently, Thomas Christopher (one of Doug Tallamy’s co-authors and allies) interviewed James Hitchmough, a British ecologist on his Growing Greener podcast. The title of the podcast suggests that Mr. Hitchmough’s viewpoint “challenges the US Consensus” regarding the relative value to insects of natives compared to non-natives. Mr. Hitchmough’s response was that the claimed preference of insects for native plants was conventional wisdom among ecologists in the past, but that “when they did the [field] work, they changed their view.” He also said that the singular focus on the needs of lepidoptera skews the issues because lepidoptera are only 15% of all insects. Other taxa of insects have less restricted host plant preferences than lepidoptera.

That change in viewpoint has occurred among academic ecologists in the US, but continues to be resisted by many gardeners, such as Thomas Christopher. Professor Emeritus Juliet Stromberg recently published a book about her journey from her graduate education, which was deeply steeped in invasion biology, to her present viewpoint, based on decades of fieldwork and as expressed by the title of her book: The Unruly Wild: Embracing Ecological Change in the Southwest.

Stromberg’s book is representative of the opinions of many academic ecologists today. Change in nature is inevitable and it is usually both good and bad, from the perspective of other members of the ecological community and no matter the geographic origins of plants and animals. When judging the impact of new members of an ecological community, the most likely answer is “it depends.”

Endorsements of Stromberg’s book suggest that she is not alone in her realization of the value of introduced plants, which are adapted to the conditions humans have imposed on them:

“An erudite love story of nature in the American Southwest.”
Fred Pearce, author of The New Wild

“Stromberg has written a masterful treatise on why a knee-jerk response to eradicating nonnative plants is not just misguided but counterproductive.”
Dov F. Sax, co-editor of Species Invasions

“Julie Stromberg articulates, with personal knowledge and deep love, a new way to understand and care for a changing world.”
Erick Lundgren, University of Alberta, Canada

Climate change, human activities, and evolution force us to embrace ecological change. Juliet Stromberg helps us to face this reality without fear, but with hope that nature can continue to cope with the demands that humans have made of it. Our efforts to prevent change are futile and they often cause more damage than the environmental changes themselves.

Restoring Peace to Our Gardens

We encourage gardeners to restore peace to our gardens by respecting our cosmopolitan preferences in our gardens, as we respect the preference of others for native plants.

Environmentalism in the Rear-View Mirror

One year ago, less than a month after Donald Trump was re-elected President, I announced on Conservation Sense and Nonsense my intention to “hunker down and watch the changes [in the federal government] play out.” Although I predicted major changes in federal public policies, I did not foresee the scale and speed of changes in environmental policies that we have witnessed in the past year. The uncomfortable reality is that some of what is being destroyed deserved to be destroyed, but at the expense of some valuable environmental protections.

In describing the changes we have witnessed, I will focus primarily on environmental issues in the following main categories. Please keep in mind that changes in environmental policies are but a small fraction of the changes that have occurred in all aspects of American life and global geopolitics, e.g., education, public health, arts and entertainment, architecture, science, economics, immigration, media sources, judicial system, disaster relief, social safety net, foreign aid, tariffs, etc.

Policy intended to protect endangered plants and animals, included “loss of habitat” as one of the harms that recovery plans must mitigate. “Harm” is now defined by the Endangered Species Act narrowly as only harm directly to the endangered plant or animal. The Trump administration has also proposed significant new limitations on the application of the Endangered Species Act that will remove obstacles to resource extraction that will have a negative impact on endangered wildlife.
Federal agencies that were responsible for protecting the environment in the past have been defunded and their staff drastically reduced. The President calls them “Democrat agencies.” National parks, wildlife refuges and marine sanctuaries have lost both their funding and much of their staff. Places that were protected from unfettered resource extraction, no longer are.
Manufacturers of pesticides are lobbying Congress to prevent product liability lawsuits filed by people who have been harmed by pesticides. Congress is trying to prevent states from regulating the use of pesticides. Supporters of Robert F. Kennedy, Jr. are disappointed that Health and Human Services will not attempt to limit the use of pesticides in the US.
Laws and agency regulations that enabled the protection of the environment, the proverbial teeth in environmental policies, are being repealed:
- USFWS is in the process or rescinding the Roadless Rule, which prohibited new road construction in 60 million acres of national forests since 2001, enabling the expansion of timber operations.
- Bureau of Land Management is rescinding a policy that included conservation as one of many official uses of BLM land.
- Policy intended to protect endangered plants and animals, included “loss of habitat” as one of the harms that recovery plans must mitigate. “Harm” is now defined by the Endangered Species Act narrowly as only harm directly to the endangered plant or animal. The Trump administration has also proposed significant new limitations on the application of the Endangered Species Act that will remove obstacles to resource extraction that will have a negative impact on endangered wildlife.
- The Trump administration has proposed a significant limit on the EPA’s authority to limit pollution in wetlands, rivers and other bodies of water across the country: “These changes could strip federal protections from up to 55 million acres of wetlands, or about 85 percent of all wetlands nationwide, according to the Natural Resources Defense Council…”
- All efforts to reduce greenhouse gas emissions causing climate change have been abandoned. The President made good on his campaign promise to “drill, baby drill.” New commitments have been made to increase oil and gas extraction, as well as coal mining, off-shore drilling, and seabed mining. Corresponding new policies have eliminated commitments to develop renewable energy sources, such as wind and solar. The Environmental Protection Agency is promising to erase the endangerment finding that underpins climate regulations nationwide. The endangerment finding established that greenhouse gases endanger public health and must therefore be regulated to protect the public.

The Trump administration has left the international Paris Agreement, the legally binding treaty adopted in 2015 to limit global warming to below 2 degrees Celsius. The US was not represented at the November 2025 meeting of the UN Conference of the Parties (COP30) to the agreement in Brazil, but the US actively campaigned against the new commitment on the agenda to limit pollution from cargo ships by using fines. According to the New York Times, “…the United States launched a pressure campaign that officials around the world have called extraordinary, even by the standards of the Trump administration’s combativeness, according to nine diplomats on its receiving end.” US diplomats and officials were successful in threatening countries with loss of US port access and other onerous penalties if they voted for the proposal. The Trump administration hasn’t just dropped out of the Paris Agreement. It is also actively engaged in preventing other countries from reducing greenhouse gas emissions that cause climate change. COP30 ended without any new commitments to reduce the sources of greenhouse gas emissions, or even explicit mention of fossil fuels as the primary greenhouse gas.

America Accommodates

Many of these changes have been delayed by legal challenges, but until appeals reach the Supreme Court, the final verdict on most issues is not known at this time. However, the Supreme Court has signaled their intentions with many emergency orders, also known as the shadow docket. These decisions have upheld most of the federal government’s actions, without providing any legal reasoning for doing so. These preliminary decisions foretell the ultimate victory of the actions of the Trump administration.

Other segments of American society are contributing to the control the President has over the implementation of his agenda. At his request, Congress has completely defunded National Public Radio and the Public Broadcasting Service. They are scrambling to find other sources of revenue, while cutting programs and staff as well as closing stations. Associated Press was banned from White House press briefings when they refused to call the Gulf of Mexico the Gulf of America, as renamed by President Trump. Legal challenges have not restored AP’s access to White House press briefings.

Mainstream media has paid multi-million dollar settlements to resolve defamation lawsuits (ABC and CBS) brought by President Trump over perceived slights. One major network (CBS) has changed ownership and is now owned by Trump supporters (Larry & David Ellison). The Department of Defense (now calling itself the Department of War) has restricted access of the press to department staff and now requires department approval of press releases prior to publication. Most members of the Pentagon press corps refused to agree to these restrictions and have left their offices in the Pentagon. Self-censorship is a more insidious threat because the public no longer knows when the media is pulling its punches to avoid retribution, which is the President’s modus operandi.

The legal profession has also been brought to its knees by the President’s threats of punishment if they participate in lawsuits that try to prevent the implementation of the administration’s policies. Many major law practices have been forced to provide pro bono legal services for President Trump after being threatened with access restrictions to the judicial system. Major law practices are refusing to represent plaintiffs who are trying to protect themselves from government prosecution, hoping to stay out of the line of fire.

California Responds

The same day that Americans re-elected Donald Trump in November 2024, California voters passed Proposition 4 , the $10 billion bond that funds climate change mitigation and ecological restoration in California. California’s bond funding will help to compensate for the loss of federal funding of ecological and climate mitigation projects in California. California Natural Resources Agency reported the cancellation of federal funding for these projects in California:

Source: California Natural Resources Agency, July 2025

Does California have enough money to compensate for the loss of federal funding of climate change mitigation and ecological restoration in California? I don’t know, but I do know that federal funding is also being lost for many other purposes that are important to Californians, such as subsidies for health insurance and food assistance needed by many Californians. Some municipalities are responding by raising sales and property taxes to backfill the loss of federal funding in many sectors of the economy. While federal taxes are being cut, California’s taxes may rise.

Meanwhile, California is challenged by related issues such as the need to build more housing in order to reduce the cost and house our growing homeless population. In July 2025, California responded to that issue by revising the California Environmental Quality Act (CEQA), which will remove many obstacles to building new housing and allow more aggressive fire hazard mitigation.

The cost of gas in California has been consistently higher than in most states because of voters’ desire for clean air. Regulations have made drilling for and refining oil in California costlier than in other states, which makes gas more expensive for consumers. Refineries have responded to California’s restrictive regulations by leaving the state, which reduces supply, raises prices further and is expected to restrict availability of fuel. California’s Senate Bill 237, signed into law in September 2025, addressed these concerns by streamlining approval of drilling permits, including idle pipelines, in an “environmentally responsible and safe manner.”

In other words, California has been forced to adapt to new economic and environmental realities. At the same time, California is aggressively fighting back. As of October 1^st, California has filed 46 lawsuits against the 2^nd Trump administration, “contesting the Trump administration’s executive orders, agency decisions and even recent laws that Trump himself signed.”

Americans Shrug

Composite opinion polls reported a persistent negative approval rating of 11% for the Trump presidency until the government shutdown in October, when the approval rating dropped to negative 15% before returning to negative 11% when the government re-opened. Over 40% of American voters still approve of the Trump presidency. Many voters have made up their mind and are not responsive to the daily onslaught of alarming information. I understand and am sympathetic to the public’s dilemma, summarized in a recent social media post: “My desire to be well informed is presently at odds with my desire to remain sane.”

For perspective, consider that President Biden’s composite approval poll on July 6, 2024 was negative 19.3%, just 15 days before Biden dropped out of the presidential race on July 21, 2024.

The demonstrations I have attended are another window into the mood of the American public. The NO Kings demonstration on June 14, 2025 is said to have drawn 5 million people. The second NO Kings demonstration on October 18^th claims to have drawn 7 million people. Although these seem impressive numbers, they don’t add up to a change-making revolt. The lack of young people participating in these demonstrations is dispiriting. The future is in their hands, yet their commitment to democracy is lukewarm compared to my generation, the boomer generation that still feels a strong commitment to the peace and prosperity that democracy has delivered to us.

On the other hand, Democrats aren’t dead yet. In November 2025, moderate Democrats won governorships in New Jersey and Virginia and a Democratic Socialist won the mayoral election in New York City. In response to Republican gerrymandering of congressional districts in Texas, 64% of Californians voted to gerrymander congressional districts in favor of Democratic candidates. A recent Marist poll indicated that registered voters in the US plan to vote for Democratic candidates for congressional seats in 2026 by a margin of 14%.

Changes in the elected leadership of the Bay Area chapters of the Sierra Club are an indication of a change in the public’s commitment to the environment. The San Francisco Bay Area Chapter is now led by activists who want more housing and more active recreational opportunities. The old guard, who were committed to restricting recreational access in favor of native plant restorations in public parks, has been replaced. The Lomo Prieta Chapter, which represents the South Bay, is now undergoing a similar transition to new leadership with new priorities.

Changes in the leadership of the San Francisco Bay Area chapters of the Sierra Club are symptomatic of the Club’s much broader decline on a national scale. According to the New York Times, the Club has lost 60% of the 4 million members it had in 2019. The Times attributes this loss of support to the change of the Club’s advocacy focus from environmental issues, most prominently climate change, to progressive social justice issues such as racial justice, gay rights, labor rights, and immigration rights. In 2019, one of the Board Directors objected to the proposed budget, but was voted down: “I said, ‘We have two F.T.E.s devoted to Trump’s war on the Arctic refuge, and we have 108 going to D.E.I., and I don’t think we have our priorities straight,’” Mr. Dougherty said.

Finally, wealthy American philanthropists are providing clues of a fundamental change in the political climate in America. Bill Gates, former owner of Microsoft and supporter of global health initiatives, recently announced that it is time for a “strategic pivot” in the global climate fight from focusing on limiting rising temperatures to fighting poverty and preventing disease. Gates still believes climate change is a serious problem, but it won’t be the end of civilization because he thinks scientific innovation will contain it. Unfortunately, federal support for finding such scientific innovations has been withdrawn. Gates’ message seems to be that we aren’t able to stop climate change, so we must cope with it. It’s another way of accommodating the environmental policies of the Trump administration.

Looking Ahead

I am deeply troubled by the many threats to America’s treasured democracy. However, many of the changes in environmental policies in the past year are aligned with the mission of Conservation Sense and Nonsense. Since its inception in 2010, the mission of Conservation Sense and Nonsense has been the preservation of our predominantly non-native urban forest, opposition to the use of pesticides on public lands and advocacy for mitigating the causes of climate change. Some of the changes in environmental policy in the past year are consistent with those goals:

Many projects that use pesticides and kill harmless animals and vegetation have been defunded by the federal government. The State of California is trying to compensate for the loss with state funding, but its ability to do so will be challenged by many other new demands on state resources, such as subsidies for health care and food.

When wildlife refuges and marine sanctuaries lost much of their funding and staff, many of their projects were abandoned. Many of those projects may have been beneficial, but the plans to aerially drop rodenticides on the Farallon Islands to kill harmless mice is an example of a project that is better off dead.

Prevailing public opinion that native plants and animals are superior and the corresponding belief that non-natives are a threat to them is unlikely to change in the near-term. I do not begrudge the horticultural preferences of home gardeners. However, native plant advocates will have limited ability to demand that public land managers eradicate non-native plants if there is no public money available to fund landscape-scale “restorations.”
As public money for ecological “restorations” on public land dries up, the “restoration” industry and the jobs it creates will probably dwindle over time. As economic interests in “restoration” evaporate, the advocacy that supports it is likely to as well. College students are likely to make other educational choices with more promising career prospects, which will further reduce the labor force engaged in “restorations.”
When forest “restoration” projects that involve clear-cutting or removing healthy trees are defunded, existing carbon storage is preserved. Every mature tree—native or non-native—sequesters carbon at a time when we need every available carbon sink to compensate for the loss of limits on greenhouse gas emissions causing climate change.
Climate change will accelerate as we abandon our efforts to reduce greenhouse gas emissions that cause climate change. The landscape that survives the changed climate will be best adapted to the changed environment. When the climate changes, vegetation changes or dies. No amount of human intervention can alter that ultimate reality because nature always bats last.

In 2026, Conservation Sense and Nonsense will continue to report major developments relevant to my mission. In other words, I will continue to “hunker down and watch it play out.” Guest posts consistent with my mission and civil comments, both pro and con, are always welcome here. Thank you for your readership.

Happy Holidays and best wishes for a more peaceful year in 2026.

“Instead of ‘controlling’ non-native plants, perhaps we should practice more ‘self-control’”

Julian Burgoff wrote a guest post for Conservation Sense and Nonsense about the undervalued functions of non-native aquatic plants in 2023. Necessary Nuisance explained that non-native aquatic plants perform valuable ecological functions. Attempts to eradicate aquatic plants deprive aquatic animals of valuable habitat. The herbicides used to kill aquatic plants also pollute the water, harming aquatic animals and killing non-target aquatic plants.

Julian Burgoff is an avid bass angler and aspiring fisheries ecologist from western Massachusetts. He recently received a master’s degree with the Massachusetts Cooperative Fish and Wildlife Research Unit at UMass- Amherst where he studied juvenile river herring growth, diets and habitat use in coastal Massachusetts lakes and estuaries. He is passionate about lake ecology and the management of aquatic vegetation in lakes and hopes to work in a field related to lake conservation and warmwater fisheries management in the future.

I am grateful to Julian for giving us another opportunity to publish an article about a specific project that is trying to kill valuable aquatic plants with herbicides. Thank you, Julian.

Conservation Sense and Nonsense

Hydrilla and the Connecticut River: Falling into the “Invasive” Trap

If you spend time on the tidal Connecticut River in summer, you will likely see thick green mats covering its shorelines, coves and backwaters. This is hydrilla — a non-native aquatic plant that’s long been demonized by state agencies and lake managers across the country.

One morning during a summer internship performing fisheries related fieldwork on the river, I saw a young doe on the bank nibbling on a clump of hydrilla exposed at low tide. I laughed to myself — I knew it was good fish habitat, but even deer like the stuff!

The “official” position was that it was choking the river, outcompeting native species, and impeding recreational use of the river. But as a passionate angler and ecologist who studies aquatic ecosystems, I’ve learned that what we (as western scientists) think about non-native species and their impacts — especially in the world of aquatic plants — often turns out to be driven more by ideology than by scientific evidence.

The War on Hydrilla

Hydrilla arrived in the Connecticut River around 2016 and has since spread through the lower mainstem and its tributaries. In response, the Connecticut Agricultural Experiment Station (CAES) and the U.S. Army Corps of Engineers (USACE) have launched an aggressive herbicide campaign that seeks to “restore” native aquatic plant communities and study the efficacy of using a cocktail of various herbicides to treat the areas of the river where the growth of hydrilla is most prolific. Over the past few summers and into next year, private contractors plan to treat hundreds of acres of river coves with a mix of chemicals, including diquat and florpyrauxifen-benzyl.

On paper, this might sound like responsible ecological stewardship — reducing non-native plant stands such that their native counterparts can flourish. But in my view, it’s another example of what resource managers in Minnesota have referred to as “the invasive trap”: the belief that any non-native species must be “harmful”, and that launching management campaigns to kill them must be ecologically and economically beneficial.

The problem is that this assumption is not based on data, but on the dogmatic assumptions of invasion biology that underpin the world view of many western scientists and management agencies.

Unexpected Ecosystem Services: What the Evidence Shows

Across the country, hydrilla has often played the opposite role of what managers might expect. In the Chesapeake Bay and its tributaries, researchers found that hydrilla helped stabilize sediments, clear up murky water, and create habitat for fish and invertebrates — even helping native aquatic plant stands return. In Florida lakes, scientists compared lakes with and without hydrilla and found no major differences in fish, bird, or aquatic plant diversity.

In other words, hydrilla didn’t destroy these ecosystems where it was introduced. It filled open niche space, performed valuable ecosystem services, and is now integrated into the food web, for better or for worse.

That’s not to say hydrilla should be introduced to new water bodies or can’t impact ecosystems in ways that are perceived as harmful. Like many aquatic plants (native and non-native), hydrilla can grow in thick stands that interfere with swimming or boating, alter water chemistry and change physical habitat suitability for aquatic organisms. But many of these impacts are human nuisances, not ecological disasters, and should be managed as such. In large, dynamic systems like the Connecticut River, hydrilla’s role is likely far more complex — and possibly beneficial — than its label as “one of the world’s most invasive aquatic plants” suggests.

The Risks of Herbicide Use to “Restore” Native Plant Communities

Despite the lack of evidence that hydrilla is causing ecological “harm” to the Connecticut River, the proposed management intervention — widespread herbicide use — carries significant ecological risk.

Diquat, one of the main herbicides being applied, is what’s called a contact herbicide: it kills whatever plant tissue it touches (including native plant taxa). Florpyrauxifen-benzyl is a systemic herbicide, meaning it’s absorbed into plants and disrupts their growth. When a large quantity of aquatic plants rapidly die, they decay and release nutrients into the water, which can fuel algal blooms that reduce water clarity. If water clarity is significantly reduced, the very native plants managers aim to “restore” can’t regrow.

Ironically, hydrilla often bounces back first because it’s more tolerant of poor water quality than many native species. This can lock managers into a costly, never-ending cycle: herbicide use → temporary die-off → algal bloom → hydrilla regrowth → more herbicides.

Similar outcomes have been observed in Florida, where researchers found a large-scale florpyrauxifen-benzyl treatment sharply reduced hydrilla abundance in a Florida lake, but the plant regained dominance within a year as reduced water clarity from the treatment hindered native plant recovery.

Cascading Food Web Effects

As primary producers, aquatic plants are essential to the foundation of food webs — sheltering young fish, providing surfaces for invertebrates to live, and supporting wildlife like waterfowl. When herbicides are used to kill aquatic plants, there are often complex indirect impacts to the integrity of aquatic food webs.

Diquat is known to be toxic to not just plants (native and non-native) but invertebrates (the tiny animals that feed fish), such as amphipods. Even at concentrations lower than what’s used in field applications, diquat has the potential to impact these organisms which in turn may reduce available habitat for organisms higher up the food web like fishes.

Diquat also contains bromide, a compound that researchers have linked to a neurological disease killing bald eagles in the southeastern U.S. The disease develops when a particular cyanobacteria grows on hydrilla plants and interacts with bromide — forming a toxin that bio-magnifies as it moves up the food web. Ducks eat the hydrilla, eagles eat the ducks, and the toxin accumulates, damaging the eagles’ brains.

While this phenomenon hasn’t yet been documented in the Connecticut River, applying bromide-based herbicides in a manner that is likely to contribute to algal blooms (including cyanobacteria blooms) is not an ecologically sound management practice.

What We Don’t Know

Despite the confidence behind these large-scale management interventions, there’s little data showing how hydrilla has actually affected biodiversity or water quality in the Connecticut River. To prove that hydrilla is causing ecological “harm”, we’d need long-term monitoring — decades of data on aquatic plants, fish, wildlife, and water quality — collected before and after hydrilla became established. These data likely don’t exist at the scale needed to make an informed, unbiased assessment. Yet herbicide applications in the name of ecological “restoration” are moving forward anyway. The “post-monitoring” required by the project plan mostly focuses on the “efficacy” of the treatment (e.g. how much hydrilla biomass is reduced) not on whether algae blooms occur or how invertebrate and fish communities are affected.

This is a common phenomenon with herbicide treatments: the indirect effects of the management intervention are simply too complex and too costly to quantify. Based on the current “post-monitoring” protocol, if it’s found that hydrilla biomass is reduced and that native aquatic plant communities continue to exist following treatment, the project will be considered a success.

Less is More: Observation Based Management

Sometimes, the most ecologically mindful (and most cost effective) management decision is to pause to let species interactions occur unmolested and find their own equilibrium rather than impose an imaginary concept of what a given ecological community “should” be.

Where hydrilla interferes directly with human activities — say, blocking a boat ramp or clogging a marina — mechanical removal or small, targeted herbicide treatments could be reasonable management interventions. But broad, river-wide herbicide use is neither justified by science nor a long-term sustainable solution to non-native aquatic plant management.

With non-native species introductions, the truth is that there is no going back. Climate change, nutrient loading, and decades of physical habitat alteration via damming etc. have already changed this river beyond what it was a few centuries ago. Plants and animals are constantly being introduced and adapting to a new reality — one where species origins and “native” vs. “non-native” status matter far less than their role in maintaining ecosystem functions.

Rather than pouring more chemicals into the water, perhaps we should pour our efforts into observing, monitoring, and trying to understand why certain plants succeed and how ecosystems adjust to change over time. Instead of “controlling” non-native plants, perhaps we should practice more “self-control” and let nature heal itself without the imposition of the human ego and its desire to constantly fight the expressions of the natural world in the Anthropocene.

Julian Burgoff
Amherst, MA
jburgoff@umass.edu

California’s Wildlife Conservation Board needs to hear from you!

Although I have stopped writing original articles for Conservation Sense and Nonsense, I am still actively engaged in local environmental issues. When there are opportunities to influence public policies that affect the environment, I often participate.

Today, I am sharing my public comment on the update of the strategic plan of California’s Wildlife Conservation Board (WCB) in the hope that it might inspire you to write your own comment on the draft plan, which is available HERE. The deadline for submitting comments is May 16, 2025. Comments may be sent to this email address: wcb@wildlife.ca.gov

The mission of the Wildlife Conservation Board is to “protect, restore and enhance California’s spectacular natural resources for wildlife and for the public’s use and enjoyment…” In service of that mission, WCB awards grants of millions of dollars every year for “restoration” projects. According to WCB’s annual report for 2024, WCB awarded $93.5 million for “habitat restoration and enhancement of 5,000 acres” of land in California in 2024.

Over the life of the updated strategic plan, from 2025 to 2030, the Wildlife Conservation Board will distribute grants of $1.02 billion ($204 million per year) from funding made available by Proposition 4, the $10 billion “California Climate Bond,” which was approved by voters in November 2024. Because most federal funding of climate and ecological restoration has been cancelled by the Trump administration (and being litigated, as we speak), the “California Climate Bond” will be one of the few sources of funding for these projects.

This is my public comment on the strategic plan update for California’s Wildlife Conservation Board:

WCB Strategic Plan Update

Thank you for this opportunity to comment on the draft of WCB’s update of its strategic plan (SP). I am writing to suggest that WCB consider the addition of a few over-arching principles that would apply to all of its programs. These principles would enhance the plan’s stated goals of climate resilience and biodiversity protection by ensuring projects are evaluated based on their actual ecological outcomes rather than adherence to historical conditions.

All projects funded by WCB should be more constructive than they are destructive. For example, a project that proposes to destroy more habitat than it creates should be less competitive than a project that will create more habitat than it destroys. A project that reduces carbon storage by destroying vegetation does not “reduce and remove carbon pollution,” as the SP proposes.
Projects that do not propose to use pesticides to destroy habitat should be more competitive than those that use pesticides because pesticides damage the soil and are harmful to wildlife and human life. The success of projects is jeopardized by pesticide use.
Projects that apply for additional funding for a continuing project must address the fundamental question of the viability of the project. In other words, if a project has been funded for 20 years, WCB should consider if the goals of the project are still realistic in a rapidly changing climate and environment (e.g., Invasive Spartina Project).
Projects should be consistent with the basic principles of science, such as:
- The scientific definition of biodiversity includes both native and non-native plants and animals.
- Hybridization is one of the tools of evolution that enables adaptation and speciation in response to changes in the climate and the environment.
- The flammability of vegetation varies, but the variation is unrelated to the nativity of the plant. Native plants are not inherently less flammable than non-native species.
- The native ranges of California’s native plants have changed in response to the changing climate and they must continue to change if they are to survive.
- Our changing environment dictates that historical landscapes cannot be replicated. Humans cannot stop evolution, nor should we try.

I recommend that the WCB consider incorporating these principles into its project evaluation criteria to ensure that funded projects align with current ecological knowledge and maximize benefits for California’s biodiversity in a changing climate. Incorporating these principles into the SP would strengthen the plan’s objectives related to climate resilience (C2.1, C2.2), biodiversity protection (B1.1, B2.1), and program evaluation (D2.1, D2.2).

In support of these principles, I offer the following scientific studies for your consideration:

On pesticides damaging soil and harming wildlife and human health

Wan et al. (2025): Pesticides affect a diverse range of non-target species and may be linked to global biodiversity loss. This study presents a synthesis of pesticide (insecticide, herbicide and fungicide) impacts on multiple non-target organisms across trophic levels based on 20,212 effect sizes from 1,705 studies. For non-target plants, animals (invertebrate and vertebrates) and microorganisms (bacteria and fungi), we show negative responses of the growth, reproduction, behavior and other physiological biomarkers within terrestrial and aquatic systems. Negative effects were more pronounced in temperate than tropical regions but were consistent between aquatic and terrestrial environments. Results question the sustainability of current pesticide use and support the need for enhanced risk assessments to reduce risks to biodiversity and ecosystems.
Klein et al. (2024): New Roundup formulations are 45 times more toxic to human health,on average, following long-term, chronic exposures. The study identified eight Roundup products in which Bayer has replaced glyphosate with combinations of four different chemicals: diquat dibromide, fluazifop-P-butyl, triclopyr, and imazapic. All four chemicals pose greater risk of long-term and/or reproductive health problems than glyphosate, based on the EPA’s evaluation of safety studies. Diquat dibromide and imazapic are banned in the EU. Diquat dibromide – present in all the new formulations – is 200 times more toxic than glyphosate in terms of chronic exposure and is classified as a highly hazardous pesticide. New Roundup formulations pose significantly more harm to the environment. The chemicals replacing glyphosate in Roundup are significantly more likely to harm bees, birds, fish, earthworms, and aquatic organisms, on average. They are also significantly more persistent in the environment and more likely to leach down into groundwater, increasing the risk of contaminating waterways and drinking water.

On biodiversity including non-native species:

Schlaepfer et al. (2011): This pivotal paper challenges the automatic negative classification of non-native species by documenting their potential conservation benefits. The authors present evidence that some non-native species provide ecosystem services, habitat, and resources for native species, particularly in human-modified landscapes where native species may struggle. They advocate for conservation approaches that evaluate species based on their ecological functions rather than origin alone.
Mascaro et al. (2012): This study examines novel forests in Puerto Rico dominated by the non-native Castilla elastica tree. The research demonstrates that these novel ecosystems maintain key ecological processes such as productivity, nutrient cycling, and carbon storage at levels comparable to native forests. The findings suggest that novel ecosystems composed of non-native species can maintain essential ecosystem functions even after native tree species decline.

On hybridization as an adaptive mechanism:

Hamilton & Miller (2016): This paper reframes hybridization as a potential adaptive resource rather than a conservation threat. The authors present evidence that hybridization can introduce genetic variation that helps species adapt to changing environmental conditions, particularly relevant in the context of climate change. They suggest that conservation strategies should sometimes protect hybrid zones as sources of evolutionary potential rather than trying to eliminate them.
Fitzpatrick et al. (2015): This study examines how hybridization challenges traditional conservation approaches based on species preservation. The authors argue that hybridization is a natural evolutionary process that can generate biodiversity and adaptive potential. They present a framework for evaluating conservation value that considers genetic, ecological, and evolutionary factors rather than focusing solely on taxonomic “purity.”

On flammability unrelated to nativity:

Zouhar et al. (2008): This comprehensive technical report examines relationships between non-native plants and fire regimes. While acknowledging that some non-native plants can alter fire behavior, the report emphasizes that flammability is determined by plant structure, chemistry, and arrangement rather than nativity status. It provides detailed case studies showing both native and non-native plants can increase or decrease fire risk depending on specific traits.
Pausas & Keeley (2014): This study documents abrupt changes in fire regimes that occur independently of climate changes. The authors demonstrate that shifts in vegetation structure and fuel characteristics—which can be caused by both native and non-native species—are often more important determinants of fire behavior than plant origin. The research challenges simplistic assumptions about the relationship between native plants and fire resilience.

On changing native ranges:

Pecl et al. (2017): This influential paper documents how species are naturally shifting their ranges in response to climate change. The authors present global evidence of species redistributions across latitudinal, longitudinal, and elevational gradients. The study emphasizes that these range shifts are necessary adaptations to changing conditions and argues that conservation strategies need to accommodate these natural movements rather than trying to maintain historical distributions.
Bonebrake et al. (2018): This paper synthesizes research on climate-driven species redistribution and its implications for conservation. The authors highlight how traditional conservation approaches focused on preserving species in their historical ranges are becoming increasingly unviable under climate change. They advocate for more dynamic approaches that facilitate range shifts and species movements as adaptive responses to changing conditions.

On novel ecosystems and historical conditions:

Hobbs et al. (2014): This seminal paper introduces a framework for categorizing landscapes as historical, hybrid, or novel ecosystems. The authors argue that many ecosystems have been irreversibly altered by human influences and climate change, making restoration to historical conditions impossible in many cases. They advocate for pragmatic management approaches that focus on ecosystem functions and services rather than historical composition.
Stralberg et al. (2020): This study examines climate refugia in North America’s boreal forests. The research demonstrates that even supposedly pristine ecosystems will undergo significant changes due to climate change, with some areas serving as temporary refugia. The authors emphasize that conservation strategies need to recognize the transient nature of these refugia and plan for ongoing ecological transitions rather than static preservation.

In Conclusion

As you know, the mission of the Wildlife Conservation Board is to “protect, restore and enhance California’s spectacular natural resources for wildlife and for the public’s use and enjoyment…” In addition, the Wildlife Conservation Board “envisions a future in which California’s wildlife, biodiversity and wild places are effectively conserved for the benefit of present and future generations.” My suggestions for improvements in the draft strategic plan are consistent with the mission of the WCB.

There was a time when academic scientists believed that the goal of conservation was to replicate historical landscapes by destroying plants and animals that were not here prior to European settlement. Although many of these plants and animals found their way to California by natural means, without human assistance, they were perceived as “alien invaders” that didn’t belong here. The assumption was that ecosystems can achieve an equilibrium state that represents an ideal that can be sustained by preventing change. Science has long ago abandoned that notion in favor of acknowledging that nature is constantly changing in response to constant change in the environment.

The belief that destroying such “alien invaders” would restore the landscape persisted for decades. In many cases, no replanting was done after introduced plants were destroyed. After poisoning our public land for decades, it has become clear to those who are not ideologically committed to historical landscapes that the original goal is not attainable because the plants and animals that survive are those that are best adapted to current environmental conditions, particularly the rapidly changing climate that is expected to continue to change. In most cases, the newcomers are performing the same ecological functions of their predecessors and the harm that was presumed is usually balanced by benefits of their existence.

Most academic scientists acknowledge this reality, but cultural lag has left the public behind as science has moved on. Non-profit organizations that survive by the grace of their donors, have contributed to the pressure on public land managers such as the Wildlife Conservation Board. Academic scientists are unwilling to participate in such grass-roots policy politics and their publications are often incomprehensible and inaccessible to the public and public land managers, leaving public land managers at the mercy of those with the least amount of information and the most amount of passionate belief.

The Wildlife Conservation Board has a responsibility to the public to inform itself of the consequences of conservation practices that are damaging the environment and are no longer realistic. I respectfully ask that the WCB read the scientific studies I have provided and take them into consideration as it distributes over a billion taxpayer dollars made available by the passage of Proposition 4.

Conservation Sense and Nonsense
May 1, 2025

References for cited studies

On pesticides harming soil and damaging wildlife and human health:

Wan, NF., Fu, L., Dainese, M. et al. Pesticides have negative effects on non-target organisms. Nat Commun 16, 1360 (2025). https://doi.org/10.1038/s41467-025-56732-xK
Klein, K, Starman, S, “New RoundUp, New Risks: Bayer’s new weedkiller more toxic than ever,” Friends of the Earth, October 2024 https://foe.org/wp-content/uploads/2024/10/Roundup_Report_2025_final.pdf

On biodiversity including non-native species:

Schlaepfer, M.A., Sax, D.F., & Olden, J.D. (2011). The potential conservation value of non-native species. Conservation Biology, 25(3), 428-437.
Mascaro, J., Hughes, R.F., & Schnitzer, S.A. (2012). Novel forests maintain ecosystem processes after the decline of native tree species. Ecological Monographs, 82(2), 221-228.

 On hybridization as an adaptive mechanism:

Hamilton, J.A., & Miller, J.M. (2016). Adaptive introgression as a resource for management and genetic conservation in a changing climate. Conservation Biology, 30(1), 33-41.
Fitzpatrick, B.M., Ryan, M.E., Johnson, J.R., Corush, J., & Carter, E.T. (2015). Hybridization and the species problem in conservation. Current Zoology, 61(1), 206-216.

 On flammability unrelated to nativity:

Zouhar, K., Smith, J.K., Sutherland, S., & Brooks, M.L. (2008). Wildland fire in ecosystems: fire and nonnative invasive plants. General Technical Report RMRS-GTR-42-vol. 6. USDA Forest Service.
Pausas, J.G., & Keeley, J.E. (2014). Abrupt climate-independent fire regime changes. Ecosystems, 17(6), 1109-1120.

 On changing native ranges:

Pecl, G.T., et al. (2017). Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being. Science, 355(6332).
Bonebrake, T.C., et al. (2018). Managing consequences of climate-driven species redistribution requires integration of ecology, conservation and social science. Biological Reviews, 93(1), 284-305.

 On novel ecosystems and the impossibility of recreating historical conditions:

Hobbs, R.J., et al. (2014). Managing the whole landscape: historical, hybrid, and novel ecosystems. Frontiers in Ecology and the Environment, 12(10), 557-564.
Stralberg, D., et al. (2020). Climate-change refugia in boreal North America: what, where, and for how long? Frontiers in Ecology and the Environment, 18(5), 261-270.

Deforestation in San Francisco

I am publishing an article today that was published by the San Francisco Forest Alliance, with permission. Many thanks to SFFA for reporting about the continuing assault on San Francisco’s urban forest. You can express your opinion about these tree removals by calling 800-801-2661 Ext 4.

Conservation Sense and Nonsense

Deforestation on Clarendon Avenue

Posted on March 31, 2025 by SF Forest Alliance

There’s a lot of deforestation on both sides of Clarendon Avenue, above the Laguna Honda, and on the slope below Laguna Honda Hospital. This time it’s courtesy of SFPUC – San Francisco Public Utilities Commission (which our followers would recall is managed in the same way as SFRPD – San Francisco Recreation and Parks Department’s “Natural Resources Division.”)

Indeed, Lisa Wayne, who for many years spearheaded the SFRPD effort, moved to SFPUC in 2021.

Note: All pictures in this post copyright Anastasia Glikshtern

SAN FRANCISCO FOREST ALLIANCE WROTE TO SFPUC

San Francisco Forest Alliance is following up with SFPUC for evidence that the trees have indeed been evaluated as hazardous. We also pointed out that the bird nesting season has started on February 1 (it runs through August 31, 2025). It appears that the work continued through mid-February.

This forest added much to the beauty, privacy, and air quality of the neighborhoods around it. It’s historic: This charming article by Rex Bell described it in 2011 and compared it to the same places in 1896, where it was described as “A Genuine Old-Fashioned Country Road Within the Limits of the City of San Francisco.”

RISKS AND ISSUES

Quite aside from the historic beauty of this urban forest, and the many benefits of urban trees , there are issues of risk. One is slope stability – and we wonder if SFPUC actually assessed the risk of that steep slope above Clarendon Avenue being destabilized by this deforestation. The second is flammability. This is an area of the city that gets summer fog, and the fog moisture harvested by these trees kept the area below damp and cool. Now it will be dry and covered in fine fuels; we can only hope we do not face a hot dry summer any time soon.

Finally, since SFPUC uses herbicides as freely as does SFRPD’s Natural Resources Division, we can expect a lot more pesticides flowing into the groundwater.

San Francisco seems to have moved forward quickly with its war on trees. They have been felled everywhere where the urban forest exists in the city: Mount Sutro, McLaren Park, and now Clarendon Avenue. Ironically, they call it “Restoration.”

Malibu, California: A model for grassroots opposition to pesticides

“How could intelligent beings seek to control a few unwanted species by a method that contaminated the entire environment and brings the threat of disease and death even to their own kind?” – Rachel Carson

I am pleased to publish a guest article about a grassroots effort to reduce the use of pesticides in Malibu, California, a community of about 10,000 on the coast of Southern California. Malibu is famous as the residence of Hollywood celebrities and executives and surfers attracted by 21 miles of beaches with world-class surfing conditions.

City of Mallibu. Wikipedia – Creative Commons

The author, Kian Schulman, and her husband, Joel Schulman, are founding members of the Malibu-based nonprofit Poison Free Malibu, a group that has had much success protecting local wildlife, children and pets in the Santa Monica Mountains and throughout California by educating the public and policy makers about the dangers associated with pesticides.

I hope the impressive accomplishments of Poison Free Malibu will inspire readers to participate in such efforts in your community in 2025.

Happy New Year! Best wishes for a more peaceful 2025.

Conservation Sense and Nonsense

Grassroots Power is a Strong Voice!

In the fight against harmful pesticides, the coastal community of Malibu, California is a model for the power of grassroots activism and persistent community engagement, which has significantly reduced the use of pesticides in Malibu.

Chemical companies like Bayer (Monsanto), Dow, Syngenta, and others have expanded beyond agricultural markets, targeting “invasive” and “non-native” species in nature preserves with toxic pesticides. The Santa Monica Mountains surrounding Malibu are replete with “invasive species,” targets for eradication with herbicides, downplayed by claims of so-called Integrated Pest Management policies.

The Santa Monica Mountains are wildfire prone. In December 2024, the Franklin Fire threatened the campus of Pepperdine University in Malibu, burned over 4,000 acres, multiple homes, and displaced many residents. Various methods of fuels management are available, but herbicide is the primary tool because it is the cheapest method. I ask, “What is the price tag to our health and the entire ecosystem?”

The Pesticide Problem

The impacts of pesticide exposure on our health are profound. Pesticide exposure has been linked to a rising tide of serious health problems, including cancer, Parkinson’s disease, diabetes, reproductive failures, developmental disorders, and autism. (1)

Pesticides and other chemicals can persist in soil for decades, contaminating soil and watersheds with toxic breakdown products. In 2021, Scientific American published an article about a meta-analysis of nearly 400 studies that examined 275 soil organisms and 294 different pesticides. In 70% of those experiments, pesticides were found to harm the organisms that are critical to maintaining healthy soils. Tens of thousands of subterranean species of invertebrates, nematodes, bacteria and fungi are filtering our water, recycling nutrients, and helping to regulate the planet’s temperature. The EPA, which is responsible for approving chemicals for the market, is not presently required by law to test the effects of chemicals on the soil.

The widespread use of these poisons are also harming wildlife. Rodent poisons used to kill small rodents don’t stop there. Other non-target animals are often killed as well, either by eating the bait directly or eating the poisoned rodents. Many top predators, such as mountain lions and bald eagles, have been killed by rodent poisons that work their way up the food chain.

Market size of rodenticides in the US, 2014 to 2025 (in million US dollars)

Malibu’s Transformative Journey

In 2012, local activists began investigating the city’s pesticide use, discovering a shocking reality. Malibu’s parks and public spaces were being treated with a cocktail of toxic chemicals, including glyphosate (RoundUp), 2,4-D, triclopyr (Garlon), pre-emergents and others, often applied in areas where children and pets play.

RoundUp being sprayed in a Malibu public park while child cycles nearby.

Protecting Wildlife

Poison Free Malibu was activated in 2012, after a mountain lion was found dead in a local park with rodent poison detected in the autopsy. Reducing rodent poison exposure has always been one of our primary objectives. All top predators of rodents are at risk of rodent poisoning: “The vast majority of bald and golden eagles in the United States are contaminated with toxic anticoagulant rodenticides…” (2)

Poison Free Malibu addressed this issue in a variety of ways:

We asked local businesses selling rodent poisons to quit selling them. No stores in Malibu now sell rodent poisons.
We asked businesses and organizations to remove bait boxes from their premises.
We approached 10 neighboring cities to suggest that they pass resolutions banning the use of rodent poisons in their communities. Animals are on the move, so broader protections are needed for them.
We helped pass three state bills to prohibit the use of 3 specific rodent poisons in California. Unfortunately, these laws have exceptions, including one for using rodent poisons on off-shore islands to kill rodents. The pesticide industry was quick to respond to the new restrictions by promoting other, still allowed but extremely dangerous rodent poisons such as bromethalin and cholecalciferol. Both of these have NO antidote, endangering wildlife and pets. According to the National Park Service, bromethalin was detected in 10 out of 16 mountain lions tested in the Santa Monica Mountains from July 2020 to August 2022.
We helped to pass a Dumpster Lid Lock Ordinance in Malibu. In both commercial and residential areas, this ordinance was key to eliminating rodent issues.

Changing Public Policy

As we learned about the extensive use of a wide range of pesticides in Malibu it became clear that a broader effort was needed. We petitioned our city for an Earth Friendly Management Policy, which bans the use of all toxic chemical pesticides in EPA 1, 2, and 3 categories of toxicity. The city now relies on organic solutions, environmental enrichment, and “Expel, Deter, and Repel” tactics.

There is a National Park and a State Park in Malibu that also use pesticides on our public lands. We had to negotiate directly with those organizations that are not subject to our city policies. Following numerous meetings with State and National officials, we reached an agreement to establish hand weed-pulling events. This initiative has proven highly successful.

Public Education

The support of the public is needed to achieve changes in public policy. Educating the public about the dangers of pesticides is therefore an important part of our strategy:

We reached out to school systems, other local cities, and counties, to bring these issues to their attention. Many have adopted pesticide-free policies, most recently Ojai just on December 10, 2024.
We received grants from our city and county to help us with our outreach efforts, such as developing coloring books, distributing hundreds of yard signs, and putting up billboards throughout Los Angeles.

Not the end of the story

Despite these many important accomplishments, our work is never done. Legislative hurdles to our progress exist because of opposition from various government agencies, such as the Wildlife Conservation Board, the Department of Pesticide Regulation, the Environmental Protection Agency, CalTrans, and the California Department of Food and Agriculture. There is regrettable opposition from many non-profit organizations that champion the use of pesticides to kill so-called “invasive” species, such as the California Invasive Plant Council and the American Chemistry Council, a trade association representing manufacturers of chemicals.

Our work is never done, but the grassroots movement in Malibu proves that collective action can transform seemingly insurmountable challenges into opportunities for positive change.

Kian Schulman, RN, MSN
Director, Poison Free Malibu
Contact: PoisonFreeMalibu@gmail.com | 310-456-0654
Website: PoisonFreeMalibu.org

(1) “Wide Range of Diseases Linked with Pesticides,” Pesticides and You, Summer 2010

(2) https://beyondpesticides.org/dailynewsblog/2021/04/study-finds-eagle-populations-experiencing-widespread-rodenticide-exposure/

My transition from activist to observer

This is my last article of 2024, and the last for the foreseeable future. However, I still welcome guest posts that are consistent with the mission of my website. If you have a story to tell, please contact me at mildredtrees@gmail.com.

Clarification: I published this article prematurely on November 28^th in error. I republish the article today to clarify my intentions.

Although I have accomplished little in 25 years of environmental activism, I can point to a few achievements that I am proud of.

I was successful in getting the “invasiveness” of eucalyptus downgraded from “Moderate” to “Limited” by the California Invasive Plant Council. There were a few specific issues that were deleted from Cal-IPC’s assessment of eucalyptus. The assessment no longer claims that eucalyptus kills birds. Cal-IPC also removed the claim that eucalyptus leaves are allelopathic, i.e., they do not emit a chemical that suppresses the growth of an understory. However, these improvements in Cal-IPC’s assessment of eucalyptus had no apparent effect on the demands of native plant advocates to destroy all eucalyptus in California.
I am proudest of our achievements to improve pesticide applications by the supplier of our drinking water in the East Bay, EBMUD. With the help of a video and a photo, a small team of collaborators convinced the leadership of EBMUD that their staff did not know how to apply herbicides. The leadership of EBMUD deserves equal credit for this accomplishment because they listened and they acted. EBMUD is now conducting annual training of its staff about proper application of pesticides, herbicide application notices are being posted, and an annual report of pesticide use is presented to the Board and posted on-line for the public to see. As a result of these efforts, herbicide applications were reduced by one-third, but have since plateaued.
When the SelecTree website published by CalPoly San Louis Obispo claimed that blue gum eucalyptus lives only 50 years, it became another tool nativists used to support their demands to destroy blue gums in California. I was able to give CalPoly the evidence needed to disprove this inaccurate claim. Blue gums have lived in California since the 1860s and many of the original plantations are still alive. Eucalypts are known to live in Australia from 200-400 years. It’s difficult to determine the age of eucalyptus because trees growing in mild climates such as ours do not have clear growth rings used to determine age. SelecTree initially changed the lifespan estimate to 150 years, which was the maximum lifespan for the entire SelecTree database of trees in California. Since then, SelecTree has deleted all lifespan estimates because they weren’t able to find reliable sources of this information. The correction of blue gum lifespan on SelecTree relieved some of the pressure to destroy them.
I also claim small credit for the final version of Oakland’s Vegetation Management Plan, which is a compromise with native plant advocates who wanted all non-native trees on public land in Oakland to be destroyed and replaced with native trees. The consultant who wrote the plan also deserves credit for listening and reading studies I sent to him about the flammability of trees. Non-native plants and trees are not inherently more flammable than native trees. We live in a Mediterranean climate in which vegetation is fire adapted and fire dependent. It took 7 years and 4 revisions to reach a compromise that satisfied the nativists. The plan will destroy all eucalyptus less than 31” in circumference on 2,000 acres of public land and 300 miles of roadside. The plan will also use herbicides on public land where it has been prohibited since 1998, when herbicide spraying was confined to road medians. Although the plan is destructive, its approval after 7 years of pointless delay will finally enable Oakland to mitigate fire hazards with fuels reduction without destroying all non-native trees on public land.

These were small victories and they were difficult to accomplish. I won’t bore you with a list of hundreds of my failed efforts to protect public lands from needless destruction. My most recent failure was an appeal to California’s Wildlife Conservation Board, which is theoretically responsible for protecting California’s wildlife. Despite the effort of a small team of collaborators, the WCB granted another 10 years of funding for an eradication project that has killed over 50% of an endangered bird species in the San Francisco Bay after 20 years of spraying herbicides, destroying the bird’s habitat and its food.

I hope these few achievements and multitudes of failures will help to convey why I am pulling back from my 25-year effort to defend our urban forest and our public lands. In a word, it is unrewarding work.

Good sources of information about invasion biology and the “restoration” industry

I have 535 subscribers on Conservation Sense and Nonsense and over 1,000 followers on Meta (Facebook). In addition, my articles on Conservation Sense and Nonsense have been read by over 500,000 people who found them with internet searches over the 15 years that Conservation Sense and Nonsense has existed.

I intend to keep posting occasional news items to Facebook and I welcome my readers to follow me there. I also encourage my readers to follow other sources of reliable information about the issues I have covered. I leave the field in the good hands of those who still have the courage to fight what seems like a losing battle:

Beyond Pesticides is a reliable source of information about pesticides. I recommend that you subscribe to BP’s Action Alerts that inform us of opportunities to engage with decision makers about new policy decisions regarding pesticides.
For home gardeners looking for advice about creating gardens that are beautiful as well as respectful of the environment and the animals that live in our gardens, I recommend that you subscribe to Garden Rant.
For readers who love all plants, both native and non-native, I recommend the Substack of Kollibri terre Sonnenblume . His articles are deeply researched, informative, and beautifully written. His knowledge of plants far exceeds anything I have learned about plants because he works directly with them as an integral part of his life and he is an astute observer.

Right turn at the crossroads

After a long, bumpy trip to the crossroads of the 2024 presidential election, the American people made a hard right turn on Election Day. Voters have re-elected President-elect Donald Trump and given him control of all branches of government with which to implement his agenda.

As Trump approached the crossroads he also acquired some allies who will be influential in crafting his agenda. Wunderkind Elon Musk, who is already a major government contractor in space exploration and telecommunications, is likely to influence and benefit from policies in those—and other—areas. Billionaire “tech-bros” have convinced Trump to promote crypto currency. Robert F. Kennedy, Jr. is likely to influence the future of our policies regarding health, such as the availability of drugs and vaccines.

This is to say that although we can’t predict specific policy decisions, we can predict that there will be significant changes in the functioning of the federal government. We know that Republicans have been trying for years to defund, if not eliminate, many federal agencies.

The Environmental Protection Agency and the Department of the Interior have long been Republican targets for budget cuts. And the US Supreme Court has collaborated with this effort by reducing the power of federal agencies to implement policies that aren’t specifically authorized by federal laws.

We should probably expect that federal funding for many so-called “restoration” projects will evaporate, such as the USFWS plan to shoot 500,000 barred owls in Western Forests or the USFWS plan to dump rodenticides on hundreds of off-shore islands to kill non-native animals. Likewise, the theoretical ability of the EPA to evaluate new pesticides for access to the market is likely to end altogether, to the extent that regulation exists at all.

On the other hand, State funding of “restoration” projects is unlikely to decrease. California voters have approved Proposition 4, which will provide $10 billion of bonds for water, wildfire, and land protection in California. The federal government is expected to withdraw funding for ecological “restoration” while California state government is likely to replace the lost federal funding.

Becoming an observer

We are headed into a long period of radical change. It is an opportunity to hunker down and watch the changes play out. That is my plan for the foreseeable future.

Although environmentalism had little explicit role in the rightward shift in American politics, it probably played a role on the margins. The electorate’s rejection of environmentalism as a priority policy goal requires some deep reflection.

Does environmentalism contribute to the political divide between urban and rural voters?

For example, urban environmentalists support the reintroduction of top predators, such as wolves, into rural communities, where they become predators of domesticated animals. Rural communities resent that their livelihoods are threatened by decisions made by urban policy makers who are not impacted by the decisions they make.
Proposition J in Sonoma County would have shut down many agricultural operations that raise animals. Most of these agricultural operations are certified organic and they are central to the economy of Sonoma’s rural community. Proposition J was easily defeated by an agricultural community that could have been destroyed by an extremist version of environmentalism. However, a similar Proposition DD in Berkeley passed narrowly in a community with a more diverse economy.

Has environmentalism contributed to the high cost of housing and the growing homeless population?

The San Francisco Bay Area Chapter of the Sierra Club has a track record of suing to prevent the building of new housing. The Chapter’s support for this agenda reflected the opinions of entrenched elected leaders who were recently displaced by a coalition of housing advocates. One of the displaced leaders explained how this coup has changed the Chapter’s approach to new housing. The changed leadership is now reflected in the Chapter’s political endorsements of housing advocates, such as State Senator Scott Wiener.
The insurance industry in California is in trouble. Major insurance companies have left California. Some have quit insuring homes. The companies that remain have cancelled thousands of policies insuring homes. Premiums of the policies that remain have increased significantly and are expected to increase further. California’s wildfires have increased the costs of the insurance industry and California has not allowed the insurance industry to anticipate increased risks of wildlife in setting premium prices for home insurance. Insurance is required to finance new building and home buyers cannot get a mortgage without property insurance. The 7-year delay of Oakland’s Vegetation Management Plan is an example of how extreme versions of environmentalism have handicapped fire hazard mitigation.

Statement of Purpose

I am a moderate Democrat who voted for the Democratic candidate for president in 2024. I am disturbed by the sudden and extreme lurch to the political right. I also see it as an opportunity for all Americans to think deeply about how we reached this point. I intend to do more listening and less talking. I hope to find something more rewarding to do.

I leave the field knowing that nativism in the natural world will be defeated eventually by evolution, as natural selection “chooses” the plants and animals capable of surviving in a radically altered climate. Nativism in the natural world is ultimately a dead end. Nature moves forward, not backward. Activism, such as mine, will not successfully deliver that message to the ideologues who continue to destroy the plants and animals most likely to survive, but nature will, because nature always bats last.

Thank you for your readership. Best wishes for happy holidays and a more peaceful new year in 2025.