native plant movement – Page 2 – Conservation Sense and Nonsense

Going Toe to Toe with Doug Tallamy

In June 2023, Washington P ost p ublished an opinion piece advocating for the use of herbicides to kill non-native plants, in which Doug Tallamy was quoted as saying that spraying herbicide on non-native plants is “chemotherapy,” equating non-native plants with cancer and pesticides with medical therapy. Tallamy. and more broadly his viewpoint, received some blowback from Conservation Sense and Nonsense and others.

Thomas Christopher and Doug Tallam y collaborate on their shared mission of promoting the use of native plants and the closely related goal of eradicating non-native plants they consider a threat to native plants and insects. In October 2023, Tom Christopher (TC) gave Doug Tallamy (DT) an opportunity to respond to criticism of native plant dogma on his Growing Greener podcast that is available HERE. Christopher also invited listeners to send him feedback on the podcast. Professor Art Shapiro, whose work was central to the interview, has responded separately and his response is available as a footnote. Conservation Sense and Nonsense (CSN) sent Christopher an email, which I hope he shared with Tallamy. The following is an excerpt from that email.

Hi Tom, Thanks for the air time for opposition to eradicating non-native plants in your interview with Doug Tallamy and for this opportunity to respond. I’m flattered that criticism of native plant dogma has attracted some attention on the East Coast. I’ve transcribed most of your interview with Doug Tallamy as best I can and provided some feedback to Tallamy’s viewpoint. I sent Art Shapiro the podcast and he has responded separately.

TC: Some people say that non-native plants are just as effective as natives in supporting food webs. For example, buddleia that is spreading throughout the East and West is used by butterflies.

CSN: Buddleia davidii is on California’s list of invasive plants, but it is not considered invasive in California. It was put on California’s list because it is considered invasive elsewhere, making the point that invasive plant behavior varies depending on local conditions, such as climate. Sweeping generalizations about invasiveness are rarely accurate. If gardeners are concerned about the potential for invasive behavior, they can plant a cultivar of buddleia that does not reproduce.

DT: We shouldn’t call all insects pollinators. Just because an insect visits a flower for nectar doesn’t mean it’s pollinating that flower. There are more visitors to flowers than there are pollinators. Butterflies visiting buddleia are just there to sip nectar.

Euphydryas chalcedona — Variable checkerspot. Photo by Roger Hall

CSN: Buddleia davidii is native to Central China. Non-native buddleia is used by a butterfly species that is native to California and other states in the Western US.

The first actual observation of checkerspot butterflies breeding spontaneously and successfully on buddleia was in Mariposa County, California in the Sierra Nevada foothills. Checkerspot bred there successfully on buddleia in 2005 and in subsequent years. This colony of checkerspot on buddleia was reported in 2009: “We conclude that buddleia davidii [and other species of buddleia] represents yet another exotic plant adopted as a larval host by a native California butterfly and that other members of the genus may also be used as the opportunity arises.” (1)

In 2017, a gardener in Mendocino County, California also reported the use of buddleia as the host plant of checkerspot: “By now I am questioning how it was that butterfly larvae were using my butterfly bush as a host plant, completely against everything I’d ever heard. How was this possible? I emailed Art Shapiro, a very well-known butterfly expert and author, sending him a pic. He wrote back to confirm they were butterfly larvae, but added, ‘These are not mourning cloak butterflies. They are checkerspots. And the only time I’m aware this has happened [like, ever, except one in a lab in 1940…] is in Mariposa County.’” (2)

Buddleia is available as the host plant of checkerspot butterflies with a native range from Alaska south along the Pacific Coast through California and Arizona to Baja California and Mexico; east to Montana, the Dakotas, Wyoming, Colorado, New Mexico. This is a clear case of a widespread native butterfly choosing a non-native plant as its host.

Arthur M. Shapiro and Katie Hertfelder, “Use of Buddleia as Host Plant by Euphydryas chalcedona in the Sierra Nevada foothills, California,” News of the Lepidopterists’ Society, Spring 2009
http://plantwhateverbringsyoujoy.com/never-pull-up-and-discard-what-you-cannot-identify/

DT: Most bees that people see in their gardens are honeybees that are there to get pollen and sometimes nectar. These are generalist bees but specialist bees that require pollen from particular plants (always native plants) can’t be supported by those at all.

CSN: Specialization of insects is exaggerated by Tallamy. For example, he would probably call a squash bee a specialist. As its name implies, its host plant is squash plants in the squash family, with 98 genera and 975 species. The squash bee is considered an excellent pollinator of zucchini and butternut squash, both native to Central and South America. However, they do not usually visit melon plants, according to Wikipedia. Again, we are reminded to avoid broad generalizations when describing the complex and diverse natural world.

Likewise, the native alkali bee is a particularly effective pollinator of alfalfa, which is native to the Mediterranean region. Alkali bees also pollinate members of the large legume family with over 16,000 species that are native all over the world. If you are interested in such associations, you can find an exhaustive list of native butterflies and their many non-native host plants in Art Shapiro’s butterfly guide for Central California and the Bay Area. It is not true that bees Tallamy considers “specialists” require pollen from only native plants.

DT: Sometimes butterflies adopt a new host plant as a caterpillar host. For example, black swallowtail butterflies caterpillars eat carrots or parsley or dill. What’s going on? There are two different kind of hosts: 1) The caterpillar has not adopted a new host at all because it was already adapted to that particular host. 2) Actual host switching from one plant to another is very rare. It happens on a time-scale of thousands of years. It requires a mutation or an adaptation to chemical defenses of new host plants.

CSN: Tallamy tries to make a distinction to avoid acknowledging that insects make use of introduced plants because they are chemically similar to the native plants they have used in the past, which in some cases are no longer available. The butterfly has, in fact, adopted a new host, a plant that wasn’t there before and is now hosting the caterpillar. There are many cases of rapid evolution that enable such transitions, but both cases are clearly transitions from native to non-native plants. If the original native host is still available, it isn’t necessarily abandoned in favor of a non-native. Such transitions are useful because they increase the population of available insect hosts and are essential if the original native host is no longer available.

TC: Pushback from California cites research of Professor Art Shapiro reporting that spontaneous spread of non-native plants has benefited native butterflies. He reports that 82 of 236 California native butterfly species (34%) are laying their eggs on introduced plant taxa, so caterpillars feed on them and many more butterflies use introduced plants as nectary sources.

DT: Great! These are host range expansions. Agriculture in California has eliminated the host plants of a lot of butterflies and it’s a good thing we had close relatives of natives so butterflies could expand their host range and use them. But if 34% of native butterflies are using introduced plants that means 66% are not. If all plants were introduced, we would lose 66% of butterflies in California. This is not the direction I want to go. I would choose 60% rather than 34%.

CSN: Christopher and Tallamy seem to have read one sentence in the abstract of Shapiro’s study without reading subsequent sentences: “Interactions with introduced plant taxa are not distributed evenly among butterfly species. Alpine and desert butterflies interact with relatively few introduced plants because few exotic plant species have reached and successfully colonized these habitats. Other California butterfly species are specialists on particular plant families or genera with no exotic representatives in California and have thus far failed to recognize any introduced plants as potential foodplants. Some California butterflies have expanded their geographic ranges and/or extended their flight seasons by feeding on exotic plants.” In other words, where there are more introduced plants and some are closely related to native plant hosts, more native butterflies use introduced plants.

TC: What do you say to the claims that introduced plants stay greener longer than native plants adapted to wet or dry seasons so that introduced plants give rise to extra generations of caterpillars?

DT: This is only true if caterpillars can use those plants and in host range expansions they can. Shapiro is also right about extending availability of nectar. For example, monarchs that migrate need forage along the way. The minus is that we’ve been so hard on native flora. These insects were doing just fine before we brought in non-native plants. It’s a Band-Aid we’re putting on an environment that has been ravaged by taking out native species that were here before. Let’s put native species back too.

CSN: The claim that non-native plants are driving native plants to extirpation or extinction goes to the heart of the controversy. Native plant advocates believe that accusation, although there is little evidence to support it. The greatest threat to native plants and insects is habitat loss, particularly converting wildlands to agricultural fields. The second greatest threat is the pesticides that are used by agriculture. Remember that Tallamy is an enthusiastic promoter of herbicides to eradicate non-native plants. He calls it “chemotherapy” in a recent opinion column in the Washington Post. Pesticides kill both plants and the animals that feed on them, they are anathema to biodiversity and the food web that Tallamy believes he is supporting.

Marcel Rejmanek (UC Davis) is the author of the most recent report on plant extinctions in California, published in 2017. At that time there were 13 plant species and 17 sub-species native to California known to be globally extinct and another 30 species and sub-species extirpated in California but still found in other states. Over half the globally extinct taxa were reported as extinct over 100 years ago. Although grassland in California had been converted to Mediterranean annual grasses by grazing domesticated animals decades before then, most of the plants now designated as “invasive” in California were not widespread over 100 years ago.

Most of the globally extinct plant species had very small ranges and small populations. The smaller the population, the greater the chances of extinction. Most of the globally extinct plants were originally present in lowlands where most of the human population and habitat destruction are concentrated. Although there are many rare plants at higher altitudes, few are extinct. Plants limited to special habitats, like wetlands, seem to be more vulnerable to extinction. The primary drivers of plant extinction in California are agriculture, urbanization and development in general. Non-native plants are the innocent bystanders to disturbance.

“Invasive species” are mentioned only once in the inventory of extinct plants published by California Native Plant Society and only in combination with several other factors. However, the identity of this “invasive species” is not clear. Rejmanek suggests that the “invasive species” rating refers to animal “invasions” by predators and grazers. He says, “Indeed, one needs quite a bit of imagination to predict that any native plant species may be driven to extinction by invasive plants per se.” (Marcel Rejmanek, “Vascular plant extinctions in California: A critical assessment,” Diversity and Distributions, Journal of Conservation Biogeography, 2017)

TC: 90% of all insect species are specialists that have evolved in concert with only one or a few plant lineages. How can they cope with the loss of native plants?

DT: Native plants are adapting in evolutionary time. Specialization is a continuum. Few insects are confined to a single plant species, some are confined to one or two genera, and others are confined to one or two families of plants. But if you are looking at the number of plants available to them, only about 7% of plants they are adapted to are available to them. 93% of available plants are not viable hosts for insects. Everything is a specialist on one level of another.

CSN: That sounds like an argument for a diverse garden, with many plant species that offer more food sources for insects. That doesn’t seem a sound argument for eradicating non-native plants.

TC: I understand that some native plants are more useful to insects than others?

DT: These are the keystone species. Many native plants don’t support insects because plants are well-defended against them. Keystone species are making most of the food for the food web. Just 14% of native plants across the country are making 90% of food that drive the food web. 86% of the native plants are not driving the food web. Insect food comes from the big producers, like oaks, black cherries, hickories, and birches.

CSN: That is a mind-boggling admission!! Earlier Tallamy complained that non-native plants are hosting only 34% of butterflies in California. Now he says that only 14% of native plants are useful to insects. He asks home gardeners to plant only native plants as well as limit our plantings to a small subset of native plants.

Tallamy’s ideology is antithetical to the goal of biodiversity, which could be the salvation of ecosystems in a changing climate. Since we can’t predict the climate of the future, biodiversity provides more evolutionary options, which increases the chances that some species will survive. Tallamy asks us to put a few eggs in the huge basket of our ecosystems, reducing their ability to survive the challenges of our changing climate.

For example, in Oakland, California, where I live, there were approximately 10 species of native trees prior to settlement. In 1993, there were 350 tree species in Oakland. (David Nowak, “Historical vegetation change in Oakland and its implications for urban forest management,” Journal of Arboriculture, September 1993) The recently published draft o f Oakland’s Urban Forest Plan reports that there are now over 500 tree species in Oakland. I can’t fathom why Oakland would want to limit the planting of trees to only 10 native species.

I agree with Tallamy that many native plants are not useful to insects. I attend the annual conference of California Invasive Plant Council to give native plant advocates every opportunity to convince me of their viewpoint. At the most recent conference at the end of October, Corey Shake of Point Blue Conservation made a presentation about his project to “Evaluate native bee preference for common native and exotic plants.”

He designed 16 hedgerows around agricultural fields in Yolo County to determine if native bees have a preference for native plants or exotic plants, by controlling for availability of native plants compared to exotic plants. Here is his abstract:

“Farm edge restoration monitoring in Sacramento Valley highlights native bee use of some exotic plant floral resources. Corey Shake. Point Blue Conservation Science. cshake@pointblue.org

“Research of native bee preference for native versus exotic plant floral resources in California’s Sacramento Valley has shown mixed results. No studies have demonstrated a preference for exotic plants by native bees there, but some have highlighted the importance of exotic plant floral resources in plant-pollinator networks and expressed concern that rapid removal of exotic plants without restoring native plant populations could have negative impacts on native bees. We have been collecting native bee flower visitation, plant species, and floral abundance data on 16 farm edge restoration projects in Yolo County, California since 2019, which will allow us to assess bee preferences for some key native and exotic plants relative to their floral abundance. In our preliminary analysis, we see some important trends: (1) relative to their floral abundance in our plots, some native plant species are more frequently visited by native bees than other native plants that are infrequently or rarely visited, and (2) there is significant native bee visitation to some exotic plants relative to their floral abundance. We will further evaluate these data as well as our butterfly diversity and abundance data to provide plant-species specific insights to restoration practitioners and weed management specialists to help them reduce harmful impacts to native pollinators when executing restoration projects and managing weeds.”

In other words, not all species of native plants are useful to native bees and some species of non-native plant species are useful to native bees. Tallamy’s sweeping generalizations about the usefulness of native plants to insects are not supported by empirical or field studies. Although the characteristics of plants vary widely, the variation is unrelated to the national origins of plants.

From Micro to Macro Perspective

I recognize my voice in the questions Tom Christopher asked of Doug Tallamy, as well as Art Shapiro’s. Speaking for myself, not for Art, this interview misses the point of my criticism of native plant ideology. I like native plants as much as I like any plant and I encourage everyone to plant whatever they prefer. I only object to the pointless destruction of harmless non-native plants that thrive because they are best adapted to the conditions where they have naturalized. Non-native plants do particularly well in the wake of disturbance. Where they have replaced native plants, the natives were destroyed by disturbance, not by the hardy non-native plants that can tolerate disturbance. Non-native plants are a symptom of change, not the cause.

I object to destructive eradication projects because they poison the soil with herbicides, making it even less likely that non-native plants will be replaced by fragile native plants. I object to the loss of biodiversity which is a hedge against extinction in a rapidly changing climate. We don’t know which plants will be capable of surviving in the changed climate. We should not be taking cards out of the deck while we gamble with the future of the environment and everything that lives in it.

Unfortunately, native plant advocates take offense when anything positive is said about introduced plants. A positive statement about a non-native is routinely interpreted as a negative statement about native plants. It shouldn’t be. The emphasis on the negative assessment of introduced plants results in harmful land management decisions. The pros and cons of all plants should be considered before we condemn non-natives with a death sentence. Like our justice system for human society, all plants should be presumed innocent until proven guilty.

Thanks again for airing this debate on your podcast. I hope you will forward my email to Doug Tallamy

Webmaster, Conservation Sense and Nonsense

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Oakland’s revised Vegetation Management Plan is the compromise I hoped for

On September 1^st, I told readers that Oakland would soon publish a revised Vegetation Management Plan to reduce fire hazards in Oakland by managing vegetation on 2,000 acres of city-owned property and 300 miles of roadside. I also shared with readers my anxiety that the revised plan would be more destructive than the previous version of the plan in response to criticism of that version.

The 4^th revision of Oakland’s Vegetation Management Plan and its revised Draft Environmental Impact Report was published on September 20^th. These documents are available HERE. There will be a public hearing about the plan by Oakland’s Planning Commission on November 1^st. The deadline for submitting written comments on the plan is November 4^th. Comments can be submitted by email DEIR-comments@oaklandvegmanagement.org or by mail to Montrose Environmental, attention Ken Schwarz, 1 Kaiser Plaza, Suite 340, Oakland CA 94612.

Update: The deadline for commenting on the Vegetation Management Plan has been extended to Monday, November 6, 2023, at 5 PM.

The Oakland Planning Commission held a public hearing about the VMP on Wednesday, November 1, 2023. There was no expressed opposition to the VMP at the hearing. Representatives of Claremont Canyon Conservancy, North Hills Community Association, and Oakland Fire Safe Council spoke in support of the plan.

One speaker said that Oakland Fire Department and the consultant who wrote the plan successfully “threaded the needle” that made agreement possible. She also said that “of course, we wish all the eucalyptus were gone, but we understand that is expensive.”

All members of the Planning Commission expressed their admiration and support for the VMP.

Below is a map of the VMP project areas. Figure 2.2 in the revised plan also shows detailed maps of roads in VMP project areas, with property ownership adjacent to roads indicated, which require different vegetation management standards.

The authors of the plan have made it easy for you to read the revised version by underlining additions and striking out deletions. If you have read earlier versions of the plan, you won’t need to read it all again, because revisions are minimal. They are briefly summarized on page 1-2 of the plan:

“Expanded the Revised Draft VMP area to encompass the area from 30 feet to 100 feet of the edge of roadsides in the City’s VHFHSZ [Very High Fire Hazard Severity Zone] where dead and dying trees (as determined by a Certified Arborist, Licensed Forester, or Fire Safety Expert) are present on City owned property and could strike the road if they fell.

“Updated the vegetation management standards as follows:

Expanded the zone recommended for 3-inch maximum height of grasslands after treatment from 30 feet to 75 feet from habitable structures.
Clarified that, where feasible, horizontal crown spacing should adhere to the California Department of Forestry and Fire Protection’s (CAL FIRE’s) most recent defensible space standards (presently codified in Pub. Res. Code Section 4291).

“Updated treatment standards for eucalyptus stands to increase the trunk diameter of single-stem eucalyptus recommended for removal from 8 inches to 10 inches, and to recommend removal of trees that pose an unreasonable fire and/or life safety risk, based on the determination of a Certified Arborist, Licensed Forester, or Fire Safety Expert.

“Updated treatment standards for closed-cone pine-cypress stands to include removal of trees that pose an unreasonable fire and/or life safety risk, based on the determination of a Certified Arborist, Licensed Forester, or Fire Safety Expert.”

If you need a reminder of vegetation management standards in the previous version, you can find them on Table 2-4. Basically, the VMP will thin trees and vegetation and remove dead trees and fire ladders to canopies in management areas. The most significant revision of those vegetation management standards is the expansion of clearance of dead and dying trees from 30-100 feet from the edge of 300 miles of roadsides on city-owned property. The management standards defined by the previous version were acceptable to me and the proposed revision of those standards are also acceptable to me.

However, I am sorry to see that more eucalyptus will be removed because the diameter size standard for removal has been increased from 8 to 10 inches (circumference is greater than 31 inches). The flammability of eucalyptus has been exaggerated by native plant advocates who want all non-native trees to be destroyed. California’s native vegetation is fire adapted and fire dependent. Many of our most prominent native plants—such as ceanothus and manzanita–will not germinate in the absence of fire. The planned removal of isolated non-native trees within stands of native trees is unnecessary because it will not reduce fire hazards. The VMP should be a fire hazard reduction plan, NOT a native plant restoration.

Although I recognize that dead trees are important for the long-term health of forests because they provide food and habitat for insects and birds as well as recycle nutrients into the soil, we can’t indulge that preference in very high fire hazard zones in high-density population areas that are being treated by Oakland’s Vegetation Management Plan. As always, we must set priorities and the public’s safety must be a high priority.

Like most public policy, the revised Vegetation Management Plan is a compromise between two extremes. One extreme wanted all non-native trees to be destroyed in the management areas as well as within 100 feet from the edge of 300 miles of roadside. They also wanted Oakland to make a commitment to replace those trees with native vegetation. The opposite extreme wanted no trees to be destroyed and no herbicides to be used to control vegetation or prevent destroyed trees from resprouting.

The revised Vegetation Management Plan is the compromise I had hoped for. Specifically, I had hoped that fire hazards could be reduced in Oakland without destroying more trees than necessary to mitigate fire hazards. The thinning strategy that the VMP proposes has been used successfully by the East Bay Regional Park District for over 10 years. It leaves the canopy intact so the forest floor is shaded, which suppresses the growth of weeds and keeps the forest floor moist, which retards ignition.

I had hoped that herbicides would not be used in public parks, but did not achieve that goal. However, I am grateful that the revised plan makes many efforts to protect the public, their pets, wildlife and goats grazing in project areas from exposure to the herbicides that will be used. (Improvements in these protections are described on pages 2-81, 3.3-29, 3.3-32) There are also extensive new protections for monarch butterflies and a rare species of bee (see page 3.4-86).

If your interests in the Vegetation Management Plan are different from mine, I urge you to read the plan and form your own opinion. I hope you will be able to support the revision because it is going to be attacked by the same extreme interests that have prevented Oakland from adopting and implementing a fire hazard mitigation plan for over 7 years. Expressing our support might help to get the VMP over the finish line after years of delay caused by gridlock. I would welcome you to the middle ground that I occupy. It’s lonely here in the middle. We don’t have much of an audience above the noise made by the extremes, but we have the capacity to enable public policy to be made if we speak up in defense of compromise. If we want to reduce wildfire hazards in Oakland, we must compromise.

An Attempt to Legally Mandate Native Plants Throughout California Has Failed

This is a story of the influence of interest groups on the process of making new laws. When Assembly Bill 1573 was introduced in February 2023, it seemed to be primarily a water-saving measure that would “eliminate the use of irrigation of nonfunctional turf” (turf that is not a recreational area or community space with foot traffic). AB1573 also mandated that all new or renovated nonresidential areas install not less than 25% local native plants by 2026, 50% local native plants by 2030, and 75% local native plants by 2035. It defined local native plants as “California indigenous plants to an area that have evolved and occur naturally in the Jepson Region associated with a specific California location.”

As AB1573 passed through legislative committees in the Assembly and the Senate it was amended six times (legislative history of AB1573 is available HERE.). California Native Plant Society and its many allies pulled out all the stops to influence the legislation and ensure its passage. Members of these advocacy organizations were asked at each juncture to contact their elected representative to urge them to pass this legal mandate requiring public and commercial properties to plant native plants.

The final revision of AB1573 occurred on September 1^st, after consideration by the Senate Appropriations Committee. The final revision made two significant changes:

The requirement for native plants in new and renovated landscapes on non-residential properties was lowered to 10%.
However, the definition of native plant was revised to include: “a plant that is nonnative and noninvasive that provides pollinator benefits, and that is a low-water use plant, as determined by the Department of Water Resources and the Natural Resources Agency” In other words, the final revision considers many non-native plants the functional equivalent of native plants.

On September 7, 2023, the authors of AB1573 asked that the bill be moved to the “inactive file.” They have given up. Their bill has been so emasculated that they don’t see the point of continuing to try to pass it.

Why did this attempt to legally mandate native plants fail?

There are probably many aspects of this story that I don’t know. There were probably many private meetings and written communications that I’m not aware of. I could probably learn about some of them by making a public records request, but I think I know enough of the story to relate it to my readers. If you know more about the process than I do, please share it with us.

The first visible sign that AB1573 was in trouble was in June 2023, when the Associate Director of Plant California Alliance published an editorial about AB1573 in an agricultural newsletter, available HERE. Plant California Alliance represents “California’s nursery industry. Our membership includes farmers, growers, urban agriculturists, wholesalers, retail garden centers, landscapers, garden suppliers, horticulturalists, as well as educators and researchers.” This is an organization with horticultural knowledge and practical experience growing plants in California. The editorial explained why the goals of AB1573 are unrealistic and based on mistaken assumptions about California native plants:

There aren’t enough native plants available for sale to meet such a requirement. California Native Plant Society claims nursery sales are about 6% native, but two large wholesale nurseries estimate their stock is not more than 1% native.
“…there is also the fundamental question of why a native plant mandate is included in a water conservation bill at all. Not all native plants are low water plants…Sometimes a non-native plant is a better choice when designing a drought resilient, low water garden.” California Water Service recommends: “Plants that are adapted to long, dry summers and short, rainy winters are called “Mediterranean-zone” plants. These include plants that are native to California, as well as those that originated in southern Europe, South America, and other “Mediterranean” climates. These plants don’t need much water in the summer and have thrived in water-scarce conditions for thousands of years.”
“And, what about native plants’ impacts on fire? Unfortunately, some California native plants are not considered fire-resistant, and some are even considered fire prone. For example, FireSafe Marin has several California native plants on their list of fire-prone plants, including manzanita (Arctostaphylos), coyote brush (Baccharis spp.), California buckwheat (Erigonum fasciculatum), and California bay (Umbellularia californica).” Most wildfires in California occur in native chaparral and native conifer forests. When wildfires occur in residential neighborhoods, the homes themselves are the primary fuel for the fire. Everything burns in wind-driven fires, regardless of the native origins of plants.

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

In August, tree advocacy organizations finally woke up to the implications of AB1573 for California’s urban forests when they realized that the definition of “native plant” also included native trees. California Releaf and California Urban Forests Council asked their members to contact the Senate Appropriations Committee to ask that trees be explicitly exempted from the requirement for native plants on non-residential properties in California.

Composition of California’s Urban Forest. Source: Californian’s Guide to the Trees Among Us

Only 9% of California’s urban forests are native to California. (1) Pre-settlement San Francisco was virtually treeless. One-third of San Francisco was barren sand dunes on its western edge. San Francisco’s urban forest is now predominantly non-native and much of it is being destroyed to accommodate native plant restorations that require full sun.

Non-native trees were planted in Oakland in the 19th century because there were few native trees: “Vegetation before urbanization in Oakland was dominated by grass, shrub, and marshlands that occupied approximately 98% of the area.” (2) Non-native tree species in the East Bay are adapted to soil and microclimate conditions that are not suitable for native species. Non-native annual grasses will replace Oakland’s urban forest in the hills, not native trees, if native plant advocates get the Vegetation Management Plan they have been fighting for for nearly 8 years.

A Learning Experience?

I would like to think that California’s policy makers learned something from the process of considering AB1573. Do they have a better understanding of what grew in California in the past and therefore what is capable of growing in the future?

Probably not

Ironically, on the same day that AB1573 was withdrawn by its authors, the San Francisco Examiner published this article about a new initiative to plant more greenery in San Francisco, led by the California Academy of Sciences. It’s an excellent idea, except that the leaders of this initiative equate greenery with native plants: “He’s looking to introduce more native plants in The City, which will in turn attract more native insects and more native birds throughout San Francisco.” Nature is not synonymous with native plants. The scientific definition of biodiversity includes both native and non-native plants. In fact, San Francisco’s Open Space Element of the General Plan also defines biodiversity as including both native and non-native plants.

As much as I would like to hope that Californians have a more realistic goal for the future of California’s landscapes after watching the failure of AB1573, I don’t think I can.

Matt Ritter, A Californian’s Guide to the Trees Among Us, Heydey Books, 2016.
David Nowak, “Historical vegetation change in Oakland and its implications for urban forest management,” Journal of Arboriculture, September 1993

Oakland’s Vegetation Management Plan Is Headed in a Destructive Direction

Oakland has been trying to adopt a vegetation management plan (VMP) to mitigate fire hazards since November 2016. The plan has been drafted three times in 2018, 2019, and 2020 and a draft Environmental Impact Report was also published in 2020. All three versions of the plan were acceptable to me and many others. Every version would have removed dead trees and thinned non-native trees on 2,000 acres of public land and 300 miles of roadsides in Oakland, leaving the tree canopy intact so that the forest floor would be shaded, suppressing the growth of weedy vegetation that ignites easily and keeping the forest floor moist, which retards fire ignition.

Unfortunately, none of the proposed vegetation management plans were acceptable to native plant advocates who want all non-native trees in project areas in Oakland to be destroyed and the land replanted with native plants and trees. The plan they are demanding is a native plant restoration, not a wildfire hazard mitigation plan. Since they have successfully prevented Oakland from addressing wildfire hazards for eight years, we might assume they aren’t concerned about wildfire.

A fourth version of the plan and a new Environmental Impact Report are expected to be published in September 2023 and there will be a new public comment period in October. Based on written and oral public comments at public hearings, we predict that the revised plan is likely to be far more destructive than previous drafts of the plan. Based on that prediction, I am alerting you to the need to read the revision and write a public comment. Please ask to be notified of the publication of the plan by sending an email to info@oaklandvegmanagement.org .

Update: The revised Oakland Vegetation Management Plan and revised Draft Environmental Impact Report were published on September 20, 2023. These documents are available HERE. There will be a public hearing by the Oakland Planning Commission on November 1, 2023. The deadline for public comment will be November 4, 2023. Comments can be submitted by email DEIR-comments@oaklandvegmanagement.org or by mail to Montrose Environmental, attention Ken Schwarz, 1 Kaiser Plaza, Suite 340, Oakland CA 94612.

When I have read the revised plan and its revised EIR, I will post a draft of my public comment on the draft by October 1^st.

– Webmaster, Conservation Sense and Nonsense, September 20, 2023

What do opponents of previous plans want?

There is a wide range of opinions about a vegetation management plan for Oakland. I will use the public comment of the California Society of American Foresters (SAF) on the third version of the VMP as a representative opinion and the best available predictor of where the fourth revision is likely headed. The entire comment of the Society of American Foresters (SAF) is available HERE and here are some of the revisions SAF is asking for:

“Ecological restoration should be a goal of the VMP, including the establishment of native plant species where nonnative species dominate…Thinning of dense stands of nonnative tree species should only be done as part of an overall strategy of restoration, i.e., the goal of any tree removals should always be to eventually convert these stands to native tree or vegetation cover in order to build greater ecological resiliency.”
“In concert with the goal of ecological restoration, adaptive management in light of climate change should guide management practices and restoration plans. Adaptive management strategies that incorporate new information and changing conditions will be critical to ecosystem restoration. Annual grasslands may become more dominant, oak woodlands less so in the planning area in the future as climate changes. Management targets in many cases will have to be based on anticipated future conditions.”
“However, if thinning is kept as the desired practice, we ask that you design each entry to be sufficiently intensive to assure that tree crowns will not close before the next thinning entry (10 years from now?) and indeed is sufficiently thinned to allow work towards establishing native vegetation in these stands.”
“The use of prescribed fire as a vegetation maintenance tool should have been considered and included in the VMP especially on ridges where fire moving from adjacent jurisdictions might occur, or along power-line transmission corridors.”
“The vegetation management zones along roadsides, especially along routes of egress, should be modified to extend 100 feet from roadside edges and should include any trees with underlying structural or health conditions that are tall enough to fall onto streets and roads. This may in some cases require looking outside of the 100-foot roadside clearance.”
“It is important that the use of triclopyr herbicides is included to treat cut stumps in eucalyptus to prevent sprouting. Glyphosate herbicides will not be effective in treating eucalyptus stumps and will result in resprouts.”
“There should be an Ecological Restoration Guide added to the appendices…This new appendix would outline the City of Oakland’s current ecological restoration efforts, identify stakeholders (e.g., city departments, Oakland Wildlands Stewards, etc.) and their roles…”

Native plant restoration, NOT wildfire hazard mitigation

The Society of American Foresters (SAF) is asking the City of Oakland to make a commitment to eradicating all non-native trees in project areas and replacing them with native plants. Such a plan would not reduce wildfire hazards in Oakland because native vegetation is not inherently less flammable than non-native vegetation. Most wildfires in California occur in native chaparral and native conifer forests.

The plan proposed by the Society of American Foresters (SAF) is a native plant restoration plan, NOT a wildfire hazard mitigation plan. Their proposal would destroy much of Oakland’s urban forest, which would not be replaced by native trees:

Non-native trees were planted in Oakland in the 19th century because there were few native trees: “Vegetation before urbanization in Oakland was dominated by grass, shrub, and marshlands that occupied approximately 98% of the area.” (1) Non-native tree species in the East Bay are adapted to soil and microclimate conditions that are not suitable for native species.
Grassland was the dominant vegetation type of pre-settlement Oakland partly because of the land management practices of Native Americans and the stock grazing of early settlers: “Native Americans played a major role in creation of grasslands through repeated burning and these disturbance-dependent grasslands were maintained by early European settlers through overstocking of these range lands with cattle and sheep. Twentieth century reduction in grazing, coupled with a lack of natural fires and effective suppression of anthropogenic fires, have acted in concert to favor shrubland expansion.” (2)
Grassland in California is not native to California. Mediterranean annual grasses were brought to California in the early 19^th century by the grazing herds of Spanish-Mexicans. California’s native bunch grasses are not adapted to heavy grazing by herds of domesticated animals. The grassland of California is about 99% non-native (Allan Schoenherr, A Natural History of California, UC Press, 1992). Attempts to convert annual grasslands to native bunch grass have not been successful. A team of scientists at UC Davis spent $450,000 and 8 years trying to convert 2 acres of grassland to native bunch grasses without success. Grassland that will replace our urban forest will not be native.
Grass is easily ignited and fires move quickly through grassland, particularly in a wind-driven fire. The deadly, destructive fires in Maui, Hawaii are a case in point. When agricultural fields of sugar cane, pineapple and other tropical fruit left Maui they were quickly succeeded by non-native grass that was considered a factor in the spread of fire. (3) Dormant, dry annual grassland in the East Bay Hills will be more flammable than the living vegetation that native plant advocates want to destroy.
A small redwood grove was the only pre-settlement exception to the otherwise treeless Oakland hills: “…for thousands of years [the Oakland hills] were treeless meadows, visited seasonally under Indigenous management…The one exception was the redwood groves of the southern Oakland Hills, a restricted forest that extended a few miles eastward from upper Dimond Canyon over the ridgetop to the outskirts of Moraga.” (4) Much of this grove still exists today because coastal redwoods are vigorous resprouters when they are burned or cut down.
SAF also predicts a vegetation type-conversion from forest to grassland: “Annual grasslands may become more dominant, oak woodlands less so in the planning area in the future as climate changes.” Grassland will naturally succeed to shrubland without regular burning, which SAF recommends to reduce fuel loads.
Prescribed burns in densely populated urban areas are rarely approved by Bay Area Air Quality Management District because they pollute the air and often cause uncontrolled wildfires. California law regarding liability for damage caused by prescribed burns was revised in 2022 to provide legal protections for those who manage prescribed burns. The revised law lowers the standard for liability to gross negligence from a previous standard of simple negligence. (5)

Consequences of landscape conversion to grass and shrubs

Destroying thousands of trees will increase air pollution and reduce air quality. Destroying thousands of trees will increase greenhouse gas emissions causing climate change by releasing the carbon stored by the trees that are destroyed and reducing carbon sequestration going forward because the destroyed forest will not be replaced by a forest of native trees.

There was little biodiversity in Oakland’s pre-settlement forest: “Oakland’s original species composition has increased from approximately 10 tree species to more than 350…Today [1993], only 31% of existing trees are native to Oakland, the plurality of trees (38%) are native to Australia/New Zealand.” (1) Destroying thousands of non-native trees in Oakland will reduce the biodiversity of our forest. A more diverse forest is more resilient, particularly in a changing climate, with extreme and variable weather conditions.

Increasing 300 miles of roadside clearance from 30 feet (as proposed by the 3^rd version of the VMP) to 100 feet (as proposed for the 4^th version of the VMP) will produce wood debris on a scale that cannot be disposed of. We know what the outcome will be because of a similar project on Claremont Ave, where eucalyptus was clear cut 100 feet from the north side of 1.1 miles of the road in fall 2020. Below are pictures of the piles of wood chips and logs that remained along that stretch of road for about 9 months while project managers tried to figure out what to do with the wood debris, which was eventually dispersed throughout the hills. UC Berkeley implemented the project with funding from Cal-Fire.

The north side of Claremont Ave. was clear cut 100 feet from the road. The south side of the road was not cut because the trees are native. There is a creek flowing at the bottom of the canyon that creates the moist conditions needed for native trees, which will not grow where non-native trees now grow. Photo by Doug Prose, courtesy Hills Conservation Network.

One of many piles of logs, Claremont Ave, November 2020. It took about 9 months for the logs to be dispersed along roads in the hills. Photo by Doug Prose, courtesy Hills Conservation Network.

One of many piles of wood chips, Claremont Ave, November 2020

The roads in the East Bay hills are now lined with logs, preventing people from pulling off the road. No native plants or trees were planted after the trees were destroyed. Three years later, the clear cut roadside is vegetated with non-native annual grasses and coyote brush, a pioneer native shrub.

The project on the property of UC Berkeley was very small in comparison to the Oakland vegetation management plan that will clear cut 300 miles of roads, producing at least 300 times the amount of wood debris. What will Oakland do with the wood debris that is produced from the destructive VMP that native plant advocates demand? Tons of wood debris lying on the ground is far more flammable than living trees, which is another indication that the VMP that native plant advocates demand is not about mitigating fire hazards. It’s about their preference for a native landscape that is not less flammable than the landscape they demand be destroyed. Like all Mediterranean climates, our native vegetation is fire adapted and fire dependent. A significant number of our native species will not regenerate in the absence of fire. Most wildfires in California in the past 5-10 years have occurred in native chaparral and native conifer forests.

The more trees that are destroyed, the more herbicide will be required to prevent the trees from resprouting. SAF is correct in saying that tricopyr will be needed to kill the roots of the trees to prevent them from repsouting. Glyphosate will not accomplish that task. Triclopyr is more toxic than glyphosate. Triclopyr has a signal word of “warning” and glyphosate has a less toxic signal word of “caution.” Triclopyr kills the roots of woody plants by traveling from the cut stump to the roots of the plant in the soil. Triclopyr is known to kill mycorrhizal fungi in the soil, which are essential to the health of plants growing in the soil. The more herbicide that is used to kill the roots of destroyed trees, the less likely a newly planted native landscape is to survive. All the more reason to assume that the destroyed forest will not be replaced by a native landscape.

In Summary

The landscape that native plant advocates demand for Oakland will be predominantly non-native annual grasses.
Native trees will not replace the trees that are destroyed because they are not adapted to most places where non-native trees now live and because there is no available funding to purchase native plants, plant them on thousands of acres of public land, and irrigate them until they are established. Similar fuels management projects done by East Bay Regional Parks District, East Bay Municipal Utilities District, and UC Berkeley have not planted a native landscape to replace trees that have been destroyed.
Non-native annual grasses will naturally succeed to shrubs in the absence of frequent fire. Shrublands are more flammable than the existing urban forest because fire travels on the ground, unless wind-driven fire ignites tree canopies. In that case everything burns, both native and non-native trees. The wind-driven fire in Oakland in 1991 spared no trees in burned areas, whether native or non-native.
The project would produce many tons of flammable wood debris that has no commercial value and no place to be safely disposed of.
The loss of our urban forest will increase air pollution in Oakland, contribute to greenhouse gas emissions causing climate change, and raise temperatures in a city that is already a heat-island.
Herbicides needed to prevent the urban forest from resprouting will poison the soil and suppress the growth of a new landscape.

If you live in Oakland City Council District 4 or 6, you are likely to be directly affected by Oakland’s vegetation management plan. The most effective way to influence the VMP is to express your opinion to your representative on the City Council, as well as our at-large representative on the Council. Contact information for members of the Oakland City Council is available HERE.

(1) David Nowak, “Historical vegetation change in Oakland and its implications for urban forest management,” Journal of Arboriculture, September 1993
(2) Jon E. Keeley, “Fire history of San Francisco East Bay Region and implications for landscape patterns,” International Journal of Wildland Fire, September 2005.
(3) https://www.nytimes.com/2023/08/13/us/hawaii-wildfire-factors.html
(4) Andrew Alden, Deep Oakland: How geology shaped a city, Heyday, 2023.
(5) https://kion546.com/news/2022/01/04/new-california-law-changes-liability-for-out-of-control-prescribed-burns/

Dana Milbank: “How I learned to love toxic chemicals”

Dana Milbank is a political commentator for the Washington Post. Like many city dwellers, Milbank moved his family from Washington DC to the Virginia countryside during the Covid pandemic.

His new home inspired him to become a native plant advocate with the usual corresponding hatred of non-native plants. He announced his new hobby of killing non-native plants in April 2023, as described in thi s response to his article by several defenders of the natural world as it exists, rather than as some might wish it to be.

In a more recent articl e, Milbank expressed his frustration at the failure of his early efforts to destroy non-native plants on his property without using herbicides: “When last I wrote about my battle of the brush, I was losing, badly, to the invasive vines and noxious weeds that had turned forest and field at my Virginia home into an impassable jungle. I’d cut them back, but they would return in even greater numbers.”

And he explained how he “learned to stop worrying and love chemicals.” He is now both a native plant advocate and a promoter of herbicides (specifically glyphosate) which is typical of most native plant advocates.

He justifies poisoning both his property and the Shenandoah National Park near his home by turning to advisors who tell him what he wants to hear, people who make their living using herbicides to eradicate non-native plants.

Of course, renowned native plant guru, Doug Tallamy, is one of his advisors. Although Tallamy advised residential gardeners against using herbicides in his book, Nature’s Best Hope, published in 2020, he has now changed his mind about herbicides. In Milbank’s article, Tallamy says that herbicides are an “essential tool:” “‘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.’”

Poisoning the soil

Milbank admits that glyphosate (Roundup) is toxic and he wears protective gear when applying it, including a respirator (which is not required for glyphosate applications by California’s pesticides regulations). He describes his application technique: “My preferred technique is ‘hack and squirt.’ With my hatchet, I cut gouges around the circumference of the invading tree, then spray the poison inside. For smaller invaders, I can chop the whole thing down and apply the chemical as a ‘cut stump’ treatment.

I read most of the over one thousand comments on Milbank’s article to determine the public’s reaction. Although many commenters express reservations about the use of herbicides, the majority of commenters are supportive of the use of herbicides. The manufacturers of pesticides are definitely winning the public relations battle regarding chemical safety. When supporters reply to doubters of herbicide use, they defend Milbank’s application technique as “surgical.”

Cut stump and hack and squirt application methods are less likely to disperse chemicals in the air, but they increase soil contamination. These application methods work by applying herbicide shortly after the woody plant is cut, while the cambium layer (between the bark and the heart wood) is still functional. The cambium layer delivers the herbicide to the roots of the plant to kill the roots. The application may appear to be “surgical” from the standpoint of above-ground contamination, but the damage is being done in the soil, the plants growing in the soil, and the animals that eat those plants.

Source: https://www.acompletetreecare.com/blog/what-are-the-layers-of-a-tree-trunk/

There are many consequences of poisoning the soil:

Because the roots of plants are intertwined as well as connected to one another by fungal networks in the soil, non-target plants are harmed and often killed. It is not possible to poison one plant without poisoning others. HERE is an example of a forest of native trees that was damaged by spraying herbicide under the trees.
Herbicides kill beneficial microbes and fungi in the soil that contribute to plant health. (1) For example, fungal networks that are killed by herbicides transport moisture and nutrients from the soil to the plants. Whatever vegetation remains or is planted in the future is handicapped by the loss of this living support system.
Glyphosate binds minerals in the soil, preventing essential nutritional minerals such as iron and manganese in the soil from being taken up by plants. (2) Glyphosate is so widely used that it is found in the blood and urine of most of the population, including children. Could glyphosate be a factor in widespread iron-deficiency anemia in adolescent girls and young women? (3)
Glyphosate is a well-known anti-microbial agent. These effects raise concerns regarding glyphosate’s influence on human health and behavior through secondary means, such as our gastrointestinal microbiome, given what is now known regarding the gut microbiome and its influence on human health and disease. (4,5)

Source: https://symsoil.com/soil-food-web-soil-cities/

Who are the climate change deniers?

Milbank repeats his accusation that those who believe the threat of non-native plants is exaggerated, are climate change deniers. He turns to the Executive Director of the federal Invasive Species Council for confirmation, who calls the threats of non-native plants “settled science.” Science is, by definition, never settled. Science is a process, not a conclusion. Every scientific hypothesis is constantly tested and usually refined or overturned as new knowledge and methods are available. Many scientists are testing the hypotheses of invasion biology and questioning their validity in a changing climate.

The only issue about invasion biology that is “settled” is that it has created a multi-billion dollar “restoration” industry that relies on and benefits the manufacturers of pesticides, as well as creating vested interests that perpetuate the industry.

Milbank also quotes one of his advisors who claims that native plants are better adapted to the changed climate than non-native plants: “The natives have the best ability to adapt — they’ve been adapting for tens of thousands of years in these areas — so they’ve got the ability to change as the climates and the landscapes have been changing.” This statement seems comical, given that the topic is the extreme difficulty of eradicating non-native plants and the fact that they are out-competing native plants. There is zero evidence that native plants are better adapted to the changed climate than the non-native plants that have replaced them. 500 million years of geologic history on Earth has informed us that when the climate changes—as it has many times–the vegetation changes.

All plants, whether native or non-native, convert carbon dioxide to oxygen and store carbon. Destroying them contributes to greenhouse gases causing climate change by releasing their stored carbon into the atmosphere and reducing the capacity of the landscape to absorb more carbon in the future. To deny that fact, is to be a climate change denier.

Reality trumps unrealistic hopes

Milbank describes the landscape he hopes to achieve with the help of herbicides. It is the landscape that existed in the distant past, in a different climate, before the environment was altered by the activities of humans. I am reminded of one of the presentations at the most recen t conference of the California Native Plant Society, an event where the audience hopes and the speakers douse the audience’s hope with the reality of their unsuccessful efforts. The presenter described a 20-year effort at the Santa Rosa Plateau Ecological Reserve to convert non-native annual grassland to native grassland, using annual (sometimes bi-annual) prescribed burns. Many different methods were used, varying timing, intensity, etc. The abstract for this presentation reports failure of the 20-year effort: “Non-native grass cover significantly decreased after prescribed fire but recovered to pre-fire cover or higher one year after fire. Native grass cover decreased after prescribed fire then recovered to pre-burn levels within five years, but never increased over time. The response of native grass to fire (wild and prescribed) was different across time and within management units, but overall native grass declined.” The audience was audibly unhappy with this presentation. One person asked if the speaker was aware of other places where non-native grass was successfully converted to native grass. The speaker chuckled and emphatically said, “NO. I am not aware of any place where native grasses were successfully reintroduced.”

(1) “Glyphosate kills microorganisms beneficial to plants, animals, and humans,” Beyond Pesticides, October 2021.
(2) “Glyphosate, a chelating agent—relevant for ecological risk assessment?” Environmental Science and Pollution Research International, 2018
(3) “Prevalence of Iron Deficiency and Iron-Deficiency Anemia in US Females Aged 12-21 Years, 2003-2020,” Journal of American Medical Association, 2023
(4) “Is the Use of Glyphosate in Modern Agriculture Resulting in Increased Neuropsychiatric Conditions Through Modulation of the Gut-brain-microbiome Axis?” Frontiers in Nutrition, 2022
(5) “Toxic Effects of Glyphosate on the Nervous System: A Systematic Review” International Journal Molecular Science, 2022

Talking back to nativism

Dana Milbank is a political columnist for the Washington Post. He broke out of his political mold on April 7, 2023 to write an article about gardening published by the Post, which repeats every myth of the nativist ideology.

A team of dismayed critics of invasion biology has responded to excerpts of Milbank’s column:

Marlene A. Condon is a garden writer based in Virginia and the author of The Nature Friendly Garden. She has a degree in physics. Her entire critique of Milbank’s column is available on her website. Her comments address the reader.
Carol Reese is a retired Extension Horticulture Specialist who conducted her 27 year career from the University of Tennessee’s West Tennessee AgResearch and Education Center in Jackson, where a large and diverse display garden gave her the opportunity to observe biodiversity in action on an enormous range of plant species from other parts of the world. She describes herself as a farm raised country girl tomboy who has looked at the natural world in hundreds of settings and landscapes, natural and manmade, and read countless books and articles. She has written for several magazines, newspapers, articles for Garden Rant as well as university publications. Her speaking engagements around the country have allowed her to engage with many other green industry professionals. Dana Milbank’s column prompted her to email him directly with her concerns, directly addressing some of his assertions. I publish some excerpts here from her emails sent directly to Milbank.
Conservation Sense and Nonsense is the webmaster of this website. I have studied invasion biology and the native plant movement it spawned for over 25 years. I’ve watched forests of healthy, non-native trees in California be destroyed and replaced by weedy grassland. I have used what I have learned to advocate for a less destructive approach to restoration, a word I am reluctant to use to describe projects that use herbicides to eradicate harmless plants and trees. My comments are addressed to the reader.

What follows are excerpts from Dana Milbank’s column with responses from Marlene Condon, Carol Reese, and Conservation Sense and Nonsense, just three of many skeptics of invasion biology. To summarize the point of our criticism:

Insects are not dependent on native plants. They are just as likely to use related non-native plants in the same genus or even plant family with similar chemical properties and nutritional value.
While some non-native plants have potential to be harmful, many are beneficial. There are pros and cons to both native and non-native plants and that judgment varies from one animal species to another, including humans. For example, we don’t like mosquitoes, but they are important food for bats and birds.
All plants, whether native or non-native convert carbon dioxide to oxygen and store carbon. Destroying them contributes to greenhouse gases causing climate change.
When the climate changes, vegetation must also change. Many non-native plants are better adapted to current climate and environmental conditions in disturbed ecosystems.

Conservation Sense and Nonsense

“I’m no genius about genuses, but your garden is killing the Earth”
By Dana Milbank
Washington Post, April 7, 2023

Milbank: I did almost everything wrong.

Reese: I’m so sorry you thought this!

Milbank: For 20 years, I found the latest, greatest horticultural marvels at garden centers and planted them in my yard: sunny knock-out roses, encore azaleas, merlot redbud, summer snowflake viburnum, genie magnolia, firepower nandina

In between them flowed my lush, deep-green lawn. I hauled sod directly from the farm and rolled it out in neat rows. I core-aerated, I conditioned, I thatched, I overseeded, I fertilized. I weeded by hand, protecting each prized blade of tall fescue from crabgrass and clover.

In this season, a symphony of color performs in my yard. The fading daffodils, cherry blossoms, saucer magnolias, hyacinths and camellias meet the arriving tulips, lilacs, creeping phlox and azaleas, with the promise of rhododendrons, peonies, hydrangeas, day lilies and roses to debut in the coming weeks.

But this year, the bloom is off the rose. And the hydrangea. And the rhododendron. And all the rest. It turns out I’ve been filling my yard with a mix of ecological junk food and horticultural terrorists.

Condon: When Mr. Milbank posits that he’s “been filling his yard with a mix of ecological junk food and horticultural terrorists,” he’s channeling the kind of words Bringing Nature Home author Doug Tallamy loves to employ: Biased expressions that implant negative images in the reader’s mind so he will become yet another minion of this scientist. Nowadays you can’t read a garden or environmental column without being accosted with the same words or variations thereof, as if everyone has become a mouthpiece for Doug Tallamy, which I’ve never seen done more obviously than in this column by Dana Milbank.

Conservation Sense and Nonsense: Milbank’s lengthy list of “bad” plants in his garden paints with too broad a brush. For example, instead of identifying a particular species of hydrangea and rhododendron, Milbank condemns an entire genus. Both hydrangea and rhododendron genera have several native species within the genus. Most (all?) species of phlox are also native to North America.

Milbank: When it comes to the world’s biodiversity crisis — as many as 1 million plant and animal species face near-term extinction because of habitat loss ― I am part of the problem. I’m sorry to say that if you have a typical urban or suburban landscape, your lawn and garden are also dooming the Earth.

Reese: YIKES! This is pretty extreme, and dare I say inaccurate? No, home gardeners are part of the solution, no matter the plants in their garden. Doom will come from lack of diverse green space. Doom will come from climate warming as a result, as well as from pollution, tillage, factory farming and development.

Milbank: I came to understand the magnitude of my offenses after enlisting in nature boot camp this spring. I’m in “basic training” with the state-sponsored Virginia Master Naturalist program. While others sleep in on rainy weekend mornings, my unit, the Arlington Regional Master Naturalists, has us plebes out in the wetlands distinguishing a yellow-bellied sap sucker from a pileated woodpecker.

I’m no genius with genuses, but I know a quercus from a kalmia, and because of my gardening experience, I began the program with confidence. Instead, I’ve discovered that all the backbreaking work I’ve done in my yard over the years has produced virtually nothing of ecological value — and some things that do actual harm.

A few of the shrubs I planted were invasive and known to escape into the wild. They crowd out native plants and threaten the entire ecosystem. Our local insects, which evolved to eat native plants, starve because they can’t eat the invasive plants or don’t recognize the invaders as food.

Anise swallowtail on non-native fennel. Courtesy urbanwildness.org “Papilio zelicaon, the anise swallowtail, typically has one to two generations in the mountains and foothills of California where it feeds on native apiaceous hosts. However, along the coast, in the San Francisco Bay Area and the urbanized south coastal plains and in the Central Valley, P. zelicaon feeds on introduced sweet fennel, Foeniculum vulgare, and produces four to six or more generations each year… the use of exotics has greatly extended the range of P. zelicaon in lowland California.” SD Graves and A Shapiro, “Exotics as host plants of the California butterfly fauna,” Biological Conservation, 2003.

Reese: It sounds so logical, but is sooo inaccurate. Ask any entomologist that has spent their careers “fighting pests” on valued crop or ornamental plants. Remember Pange a [when all continents were fused into one]? More recently, have you thought about the exchange of plants and animals across Berengia when we were still connected to Asia? We can trace those relationships/kinships of our plants to Asian/Eurasian plants now through DNA. They eventually differentiated into species (a continuum of change caused by climate and geologic pressures until we [Man] declare it as a different species, though biologically it is still basically the same nutritional makeup)

Condon also dissects Milbank’s statement:

“They crowd out native plants and threaten the entire ecosystem.” Read virtually any description of where you find so-called invasive plant species and you will find the word “disturbed.” This tells you the soil profile has been negatively impacted by people, animals, or weather, and usually means the topsoil is gone. Only very tough plants—known as colonizers—can grow in disturbed areas because the soil is nutrient-poor and is typically compacted. Consequently, these areas may fill with a mix of native and nonnative plants, or mainly one or the other—but every single plant is a colonizer that is working to rehabilitate the land for the benefit of the native plants that require topsoil in which to grow. “Invasiveness” is nothing more than a derogatory word used by people with contempt for alien-plant colonization. Conclusions: Alien plants can’t “crowd out” native plants because once the soil is disturbed and thus degraded, most of our native plants can’t grow there and thus are not there to be crowded out. As for “threatening the entire ecosystem,” to the contrary, alien colonizers are helping to restore it.
“Our local insects, which evolved to eat native plants, starve because they can’t eat the invasive plants or don’t recognize the invaders as food.” This oft-repeated distorted premise comes straight out of Bringing Nature Home, in which Doug Tallamy deceptively writes about “an excellent demonstration of how restricted a specialist’s [an insect with particular food preference] diet is.” Tallamy tells the story of Eastern Tent caterpillars on a cherry tree denuded of its own leaves but hosting a Japanese Honeysuckle vine. He writes that the caterpillars didn’t recognize the honeysuckle as food (sound familiar?) But, of course, they didn’t because this species of insect can only eat plants in the Rose Family, which does not include honeysuckle. What Doug Tallamy doesn’t tell the reader is that the tent caterpillars could certainly have eaten the so-called invasive Multiflora Rose, which I’ve documented in the photo below. Conclusion: Native insects did not evolve to eat only local (native) plants, but rather can typically feed upon dozens, if not hundreds or thousands, of plants related to each other by family classification, even though they grow in other countries.

Tent caterpillar on multiflora rose. Photo by Marlene Condon.

Milbank: This in turn threatens our birds, amphibians, reptiles, rodents and others all the way up the food chain. Incredibly, nurseries still sell these nasties — without so much as a warning label.

Reese: As I read, I also watch the many birds on my lawn, the fence lizards on my decks, the insects humming among the flowers in my diverse collection of native cultivars and introduced plants.

Hummingbird in eucalyptus flower. Eucalyptus blooms from November to May. It is one of the few sources of nectar and pollen for birds and bees during the winter months when little else is blooming. Courtesy Melanie Hoffman

Eucalyptus leaf litter makes excellent camouflage for this garter snake. Courtesy Urban Wildness

Milbank: Most of my other plants, including my beloved lawn, are ecological junk food.

Reese: Now, now! Many (most) natives do not supply useful forage either. All plants supply some benefit. They provide shelter, create, improve and anchor soil, cleanse air and water, make oxygen and cool the planet. The plant must be judged on benefits versus detriments in each situation. If a nonnative plant is the only thing that will flourish in bombed out rubble, or contaminated soil, if it is providing many benefits, shall we rip it out because caterpillars won’t eat it? If we let it get established, will it ready the site for other species with more benefits to become established? Shall we get out of the way and let nature do what she does, which is heal herself?

Milbank: The trees, shrubs and perennials are mostly “naturalized” plants from Asia or Europe or “cultivars,” human-made varieties of native plants bred to be extra showy or disease resistant but lacking genetic diversity or value to animals. I, like other gardeners I know, planted them after mistaking them for their native cousins. They’re not doing harm, but neither are they doing anything to arrest the spiral toward mass extinction.

Reese: Please know that the most influential native plant botanical garden in the country (Mt. Cuba Center) has trialed the cultivars of native plants for their ecological benefits and found as should be expected, that each cultivar must be judged on its own merits. Some are better than the straight native as in the coneflowers where ‘Fragrant Angel’ scored tops for pollinators and many others were very close to being as good as straight species. These cultivars were even better than the other species of Echinacea tested. BTW, I grow E. purpurea, pallida, paradoxa, tennesseensis and laevigata as well as many cultivars. Remember that cultivars should also be judged on not just nutritional value, but other factors that increase benefits, such as length of bloom period, numbers of blooms, drought resistance, heat tolerance, hardiness, ease of production (cost) and durability. Please ask to speak to Sam Hoadley there as he leads the research on beneficial cultivars and has completed and undertaken several studies of different native species. Great guy and great speaker.

Please be aware that many cultivars originated as naturally occurring deviations in seedling populations, and as we know this actually diversifies the genetic pool, allowing Mother Nature to select the better form. We sometimes agree with her, and other times we may move along that diversifying form by crossing it with others that are demonstrating genetic variance. Logically, this actually furthers the cause of a broader genetic pool that can help in today’s crisis in showing which can cope and flourish.

Milbank: To get a sense of my missteps, I asked Matt Bright, who runs the nonprofit Earth Sangha, a native-plant nursery in Fairfax County (and a lecturer on botany for my nature boot camp) to walk through my yard with me.

He took aim at my day lilies: “I would remove them all. Those have also become badly invasive.”

He spied my creeping jenny on a slope: “Another nasty invasive.”

He condemned to death my rose of Sharon shrubs (natural areas “have really been torn up by these guys”) and my innocuously named summer snowflake viburnum.

Worst was my row of nandinas — “heavenly bamboo” — along the foundation. “You definitely want to remove it,” he advised. Its cyanide-laced berries poison birds.

Condon: This tactic is typical of the followers of Tallamy who want folks to perceive supposedly invasive plants as “bad” even though no evidence exists to support their accusations, especially in this instance. Mr. Milbank and Mr. Bright, who obviously supplied this information, have misspoken here. A study out of the University of North Carolina, Chapel Hill, published in 2022, explains that Cedar Waxwings are the only birds that might be poisoned, and that’s only going to happen if someone grows so many nandinas that these birds consume large numbers of fruits in a single feeding bout. If you grow just one or even a few plants, you are not going to poison waxwings.

Conservation Sense and Nonsense: Here in California, most berry-producing, non-native plants are considered “invasive” based on the assumption that birds eat the berries and spread the plants. Nandina was briefly on the list of invasive plants in California until knowledgeable people informed the California Invasive Plant Council that birds don’t eat the toxic berries. Nandina was removed from the invasive plant inventory long ago.

Bumblebee on Cotoneaster, Albany, CA. Cotoneaster is one of many berry-producing non-native plants on the list of invasive plants in California. Himalayan blackberries are another target for eradication in California. They are frequently sprayed with herbicide in public parks where children and other park visitors eat the blackberries.

I also have personal experience with nandina and cedar waxwings. Flocks of waxwings visited my holly trees in San Francisco every year. They did not touch my three nandina plants.

California buckeye (Aesculus californica) is an example of a native tree that is toxic. Its flowers are toxic to honeybees and its big brown seeds for which it is named were used by Indigenous people to stun fish to make them easier to catch. The bark, leaves, and fruits contain neurotoxic glycoside aesculin. Every negative characteristic attributed to some non-native plant species is equally true of some native plant species. No one mentions buckeye’s toxic characteristics because it’s a beautiful native tree. Photo Sacramento Tree Foundation

Condon: I’ve had a Rose of Sharon (Hibiscus syriacus) growing in my yard since I moved to my home in Virginia almost 40 years ago. In all this time, only one seedling from the plant I brought here has ever “volunteered” to become a second yard denizen. During the past 37 years, pollinators have fed at the original plant and then also at its offspring. What I’ve found by experience in my yard is that few plants can successfully move into a space that’s already filled with other plants. (Proving what physics tells us–that no two physical objects can occupy the same space). I’ve brought home numerous so-called invasive plants, only to have them disappear or simply stay put where I planted them. That’s because hundreds, if not thousands, of plants fill my yard.

Conservation Sense and Nonsense: Virginia is one of only four states in which rose of Sharon is considered invasive. Condon’s experience with rose of Sharon in Virginia suggests that lists of “invasive plants” are either inaccurate or are serving another purpose (perhaps both). The longer the list of “invasive plants” the more work is created for the “restoration” (AKA eradication) industry.

Rose of Sharon is not considered invasive in California. This is a reminder that the behavior of plants varies because of the wide range of climate and environmental conditions. Nearly one third of the plants on California’s list of invasive plants are not considered invasive in California. They are on the list because they are considered invasive in Hawaii, a state with a warmer, wetter climate than California. In naming rose of Sharon as a dangerous invasive, a media resource with a national readership has made a generalization that red-lines more plants than necessary. They become targets for eradication with herbicide and they deprive us of the biodiversity that is particularly important in a changing climate in which biodiversity ensures resiliency.

Milbank: Bright did praise two “good” species I have that contribute to biodiversity: a sycamore and a catalpa as well as a “great” American elm and a “phenomenal” dogwood. (I couldn’t take much pride in them, though, because all four were here long before I arrived.) And Bright assured me I wasn’t a particularly egregious offender; my one-sixth acre lot in town is typical of the urban/suburban landscape.

● ● ●

Lawns, and those useless, ubiquitous cultivars of trees, shrubs and perennials sold by the major garden centers, are squelching the genetic variety nature needs to adapt to climate change.

Reese: It’s actually the opposite. We need more plants in the mix. We need “the tumult of nature” to decide. We aren’t the jury, and we continue to interfere with our well-intended assumptions that we know best.

Lawns are full of wildlife when management is minimal. Mow. That’s all. Mow judiciously when “lawn weeds” are blooming. Watch birds feed on the many insects in the lawn including lepidopteran larvae. Realize that many moths pupate underground. Think of your lawn as haven for them and for the grubs birds relish as millions of acres across our country are being tilled for factory farms. Remember that the best habitat is mixed. Open areas bordered by wooded areas and most species love the borders. Our suburban landscapes are ideal if we just stop killing things.

This is a lawn that serves pollinators. Homestead Stencil Company

Milbank: The resulting loss of native plants in our fragmented urban and suburban landscapes deprives both plants and wildlife of the contiguous habitats they need to breed and, over time, to migrate in response to climate change.

The deck is stacked against nature in this fight.

● ● ●

If possible, you should remove the nastiest of the invasive plants if you have them: burning bush, Japanese barberry, Asian bush honeysuckle, English ivy, callery (Bradford) pear and a few others.

But leave the rest of your plants alone, for now. Tallamy ultimately wants to cut lawn acreage in half, but “there is room for compromise,” he said. Think of your noninvasive plants and cultivars as “decorations.”

Janet Davis, who runs Hill House Farm & Nursery in Castleton, Va., has a similar message for the purists who make you feel bad about your blue hydrangea. “Don’t give me crap about something that’s not native but not invasive,” she said. “I’m never going to tell you you can’t have your grandmother’s peony.”

Thus absolved, I shed my guilt about my yard full of ecological empty calories. I kept my hydrangeas, azaleas and roses but pulled out the truly bad stuff. I dug up the nandinas and replaced them with native winterberry holly, red chokeberry and maple-leaf viburnum. I removed the rose of Sharon and substituted American hazelnut and witch hazel. I uprooted the invasive viburnum and planted a native arrowwood viburnum in its place.

I also took a small step in the painful task of killing my beloved lawn. I used landscape fabric to smother about 400 square feet of turf. In its place, I planted a smattering of canopy trees (two white and two northern red oaks), understory trees (ironwood, eastern redbud), shrubs (wild hydrangea, black haw viburnum) and various perennials and grasses (Virginia wild rye, blue-stemmed goldenrod, American alumroot, woodrush, spreading sedge).

My 38 plants cost $439 at Earth Sangha. But these natives, adapted to our soil and conditions, don’t require fertilizer, soil amendments or, eventually, much watering. Over time, I’ll save money on mulch and mowing.

Reese: This one is so oft repeated and so very wrong. It depends on the plant, and it depends on the site. Plants in the wild require no input to succeed whether native or not because we have not messed up the soil and we have let the natural cycles of plant debris/decay improve the soil as it was meant to, creating a live, moist, interaction of microorganisms that work symbiotically to support the plant, which, btw has also been selected by nature for that site. It has absolutely nothing to do with origins. In fact, why would nonnative plants become “invasive” if they did not adapt as well or better than the native plants? I want to snort with laughter!

Milbank: Right now, my seedlings look pretty sad. Where once there were healthy lawn and vibrant shrubs, there is now mud and scrawny sprigs poking from the ground every few feet. I put up chicken wire to keep the kids (and me) from trampling them. The carcasses of my invasive plants lie in a heap on the gravel.

Condon: This statement supports my contention that ridding your yard (and, in the case of government, natural areas and parks) of “invasive” plants destroys habitat, leaving our wildlife high and dry. Follow the advice of Doug Tallamy, via Dana Milbank (and many others) and you make the environment far less hospitable to our wildlife by removing plants that supplied habitat NOW when our critters need it to survive.

Conservation Sense and Nonsense: This description of Milbank’s ravaged garden is consistent with my 25 years of observing native plant “restorations” on public land. They all begin with destruction, usually accomplished with herbicides. The first stage of these projects is often described as “scorched earth.” Years later, there is rarely habitat comparable to what was destroyed. Colored flags usually outnumber plants.

This is what a native plant garden on Sunset Blvd in San Francisco looked like after two years of effort: more colored flags than plants. The sign claims it is “pollinator habitat.” Since when do pollinators eat flags?

Milbank: But in a couple of seasons, if all goes well, my yard will be full of pollinators, birds and other visitors in need of an urban oasis. Years from now, those tender oak seedlings, now 6-inch twigs, will stretch as high as 100 feet, feeding and sheltering generations of wild animals struggling to survive climate change and habitat loss.

Conservation Sense and Nonsense: Destroying harmless vegetation contributes to climate change by releasing carbon stored in the living vegetation and reducing the capacity to sequester more carbon. Above-ground carbon storage is proportional to the biomass of the living vegetation. Destroying large, mature plants and trees releases more greenhouse gases in the atmosphere than the young plants and trees can sequester. Meanwhile, the climate continues to change and the native plants that Milbank prefers are less and less likely to be adapted to conditions. Native plant ideology is a form of climate-change denial.

A small forest of non-native trees was destroyed in a San Francisco park to create a native plant garden. Nine months later, this is what the project looked like: a tree graveyard.

Milbank: I won’t be alive to see it. Yet even now, my infant oaks give me something the most stunning cherry blossom never could: a sense of hope.

Conservation Sense and Nonsense: I feel bad for Dana Milbank. He has been successfully guilt-tripped into believing he has damaged the environment. He hasn’t, but destroying his harmless garden WILL damage the environment.

We hope he will find his way back to a less gloomy outlook on nature, which will outlast us all in the end. Altered perhaps, but always knowing best what it takes to survive. The way back from the cliff he is standing on is through a study of evolutionary change through deep time to appreciate the dynamic resilience of nature, which may or may not include humans in the distant future. Our message is “Embrace the change because change will enable survival.”

Suggested reading for those standing on the steep cliff created by nativism in the natural world:

California’s “Sustainable Pest Management Roadmap” is a 25-year poisonous pathway

California’s Department of Pesticide Regulation (DPR) has published a draft of a policy that would replace its Integrated Pest Management policy with a Sustainable Pest Management (SPM) policy that is different in name only. SPM makes a commitment to continue using pesticides in California until 2050, and by implication, beyond. It makes NO commitment to reduce pesticide use or reconsider the current targets of pesticide applications. It claims that the health hazards and damage to the environment will be reduced by identifying “Priority Pesticides” for possible substitution or “eventual elimination.” It doesn’t commit to identifying any specific number of dangerous pesticides nor does it provide specific criteria for selecting these dangerous products. It claims that increased testing and development of new products will result in safer products and puts these judgments into the hands of “stakeholders” with “experiential and observational knowledge” rather than scientists with expertise in soil science, endocrinology, toxicology, epidemiology, biology, botany, horticulture, etc. The “stakeholder” committee that wrote the SPM proposal for urban areas included the manufacturer of pesticides and other users and promoters of pesticides.

That’s not an exhaustive list of the many faults of SPM and the dangers that lurk in it. I hope you will read it yourself and consider writing your own public comment by the deadline on Monday, March 13, 2023, at 5 pm. The document is available HERE. It’s less than 100 pages long and it is a quick read because it is basically a collection of bullet-points.

This is how to comment: “DPR is accepting public comments to inform the prioritization and implementation of the Roadmap’s recommendations through March 13, 2023 at 5 p.m. Comments can be shared in writing to alternatives@cdpr.ca.gov or by mail to the department at 1001 I Street, P.O. Box 4015, Sacramento, CA 95812-4015.” Please note that Department of Pesticide Regulations is not offering revisions, only “prioritization and implementation.”

My public comment on California’s “Sustainable Pest Management Roadmap”

A summary of my public comment is below. A link to the entire comment is provided at the end of the summary:

Public Comment on
“Sustainable Pest Management Roadmap”
(AKA “Pathway to poisoning the environment for another 25 years”)

My public comment is focused on pesticide use in urban areas because of my personal experience and knowledge of pesticide use where I live. These are the broad topics I will cover in detail with specific examples later in my comment:

Since glyphosate was classified as a probable carcinogen by the World Health Organization in 2015 and the manufacturer of glyphosate settled 100,000 product liability lawsuits by awarding $11 billion to those who were harmed by glyphosate, public land managers have been engaged in the process of substituting other, usually equally or more dangerous herbicides for glyphosate to deflect the public’s concerns. The Sustainable Pest Management Roadmap (SPM) formalizes this process of substitution without addressing the fundamental problems caused by pesticides.
SPM endorses the status quo that exists now. Affixing the word “Accelerating” to SPM is an extreme case of double-speak that deliberately obscures, disguises, distorts, or reverses the meaning of words. SPM ensures that toxic pesticides will be used in California for more than 25 years, to 2050, and likely beyond. SPM therefore accelerates the damage to the environment that is occurring now. Given that climate change will enable the movement of more pests into areas where they are now suppressed by weather, greater use of pesticides should be anticipated so long as the underlying issue is not addressed.
The underlying issue is that pests have been identified for eradication that in some cases cannot be eradicated and in other cases should not have been identified as pests either because they are innocuous or because of the valuable ecological functions they perform. The key question that SPM does not address is whether pesticide use is truly necessary in the first place. Unless we focus on whether a pesticide is actually necessary, all other issues are merely window dressing for perpetual pesticide use.
SPM proposes to identify “Priority Pesticides” for possible substitution without any clear definition of “Priority Pesticides,” a process that is ripe for manipulation. Given the substitutions that are occurring now, we cannot assume that further substitutions would be less toxic. SPM puts the classification of “Priority Pesticides” into the hands of “stakeholders” without clearly identifying who stakeholders are. SPM says “stakeholders” were involved in the development of the proposed policy. Those stakeholders included only users and promoters of pesticide use. There was no representation on the Urban Sub-Group of organizations such as Californians for Pesticide Reform, California Environmental Health Initiative, Beyond Pesticides, Center for Environmental Health, Environmental Working Group, etc. Nor was there any visible expertise in the fields of science that are capable of analyzing and evaluating the impact of pesticides, such as soil science, endocrinology, toxicology, entomology, botany, biology, or horticulture. SPM ensures that this exclusion will continue during the implementation phase by suggesting that “experiential and observational” knowledge should be represented on an equal footing with undefined “science.” The word “science” is being used and abused by advocates for pesticide use who dangle it as a magic talisman, conferring fraudulent credibility.

My entire public comment is available here:

spm-public-comment-1 Download

The Oxalis Obsession

As a long-time reader of Jake Sigg’s Nature News, I am very familiar with his passionate crusade against Oxalis pes-caprae. When oxalis appears in the landscape in January, Jake gears up his campaign again. This year the Westside Observer published an article by Jake about oxalis that reaches a new level of urgency and asks land managers to increase their use of herbicides to kill the plant.

In the past, Jake has advised careful and relentless hand-pulling of oxalis with its bulb intact. Now he acknowledges that hand-pulling is useless to eradicate oxalis. Although herbicides have been used on oxalis in San Francisco’s parks for 25 years, Jake now wants MORE herbicides to be used. 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.

Spraying Garlon on Twin Peaks in San Francisco, February 2011

From January to March, virtually all the herbicides sprayed by NRD in the so-called “natural areas” were sprayed on oxalis. If it were possible to eradicate oxalis with herbicide, why is there more oxalis now than there was 25 years ago, when NRD (then known as the Natural Areas Program) started spraying herbicides in the “natural areas?” A lot of herbicide has flowed under the bridge in the past 25 years, but oxalis thrives. What is the point of pouring more herbicide under the bridge of sighs? We’re pouring more fuel on the fire with nothing to show for it.

One of many pesticide application notices on oxalis in Glen Canyon Park in February 2023.

The University of California Integrated Pest Management Program explains why it’s not possible to eradicate Oxalis pes-caprae with herbicides: “Several postemergent herbicides including triclopyr and fluroxypyr (selective for broadleaf plants) and glyphosate and glufosinate (nonselective) effectively kill the top growth of this weed but are harmful to most ornamentals, so be careful these herbicides don’t drift onto desirable plants. These herbicides don’t kill the bulbs, and regrowth from bulbs should be expected.” In other words, you can kill the above-ground top growth and other non-target plants in the vicinity, but you won’t kill the oxalis.

Chemical Warfare?

On one hand, Jake urges public land managers to escalate chemical warfare against oxalis. On the other hand, he accuses oxalis of “chemical warfare” (AKA allelopathy), secreting chemicals that kill other plants. This accusation is pure speculation on Jake’s part. He offers as “evidence” of his speculation that after oxalis dies back in April “we’re left with bare ground for the rest of summer and autumn.” He ignores the obvious fact that annual spraying of gallons of herbicide on oxalis in the “natural areas” could be causing the bare ground. It has apparently not occurred to him that many herbicides are non-selective, killing everything they touch, not just targeted plants. And those herbicides that claim to be selective are very mobile in the soil, capable of killing adjacent plants through their roots. If you don’t want to see bare ground, don’t spray herbicides!

Jake asks for more research on how oxalis interacts with other plants in his article published by Westside Observer. He is apparently unaware of the research that has been done by scientists at University of Montana to address the question of how competitive oxalis is in plant communities that include native plants: “Oxalis is a poor competitor. This is consistent with the preferential distribution of Oxalis in disturbed areas such as ruderal habitats, and might explain its low influence on the cover of native species in invaded sites.”

The study explains why oxalis does not suppress the growth of other plants, including natives. Oxalis makes more phosphorous available in the soil, which essentially acts as a fertilizer for other plants: “These results are consistent with our field data and suggest that Oxalis may improve P availability in the field.”

This study was published in 2007. It found that Oxalis pes-caprae does not suppress the growth of other plants and, in fact, increases nutrients in the soil. Jake apparently doesn’t know about this study and related studies that found that pollinators are as interested in O. pes-caprae as they are in native plants.

Jake’s accusation that oxalis is waging “chemical warfare” against native plants does not come out of nowhere. The same accusation was used against eucalyptus trees for decades until a definitive empirical study proved that eucalyptus is not allelopathic. The California Invasive Plant Council removed that accusation from its evaluation of Blue Gum eucalyptus in 2015 (along with the accusation that eucalyptus kills birds). As the readers of Jake’s Nature News know, his hatred of eucalyptus is second only to his hatred of oxalis. There was never evidence that eucalyptus is allelopathic and there is no evidence that oxalis is allelopathic.

Does biodiversity justify poisoning nature?

Jake justifies his crusade against oxalis based on his belief that its existence threatens biodiversity. Since there is no evidence that oxalis kills other plants, there is no reason to believe its existence threatens biodiversity.

Jake also asks us to include only native plants in the measure of biodiversity, but he is alone in that belief. Scientific measurements of biodiversity include all species of plants and animals, whether considered native or non-native. The Recreation and Open Space Element of San Francisco’s General Plan explicitly acknowledges that both native and non-native plants contribute to biodiversity: “Parks and open spaces in San Francisco include both native and non-native species, both of which can contribute to local biodiversity.” (Policy 4.1, Recreation and Open Space of San Francisco General Plan)

Jake ups the ante against oxalis by claiming that wildlife requires solely native plants, a fundamental tenet in native plant ideology. Again, this claim is unsupported by evidence. As Professor Art Shapiro (UC Davis) says in his Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions, “Most California natives in cultivation are of no more butterfly interest than nonnatives, and most of the best butterfly flowers in our area are exotic.”

coyote hunting in oxalis field. Copyright Janet Kessler

On one hand, Jake claims that oxalis deprives birds and other foragers of food. On the other hand, Jake acknowledges that oxalis is foraged by gophers and scrub jays (based on one observation). Jake wants it both ways because that serves his purpose.

If native plants were any benefit to wildlife, that benefit is quashed by the widespread use of herbicides being used in the “natural areas.” For example, Himalayan blackberries are an important source of food for birds and other wildlife in San Francisco’s parks and are also eaten by children visiting the parks. The blackberries are routinely sprayed with herbicides in the so-called “natural areas.” Wildlife is exposed to the herbicides and they are also deprived of important sources of food.

A recent survey of 24,000 gardens in the UK found that pesticide use had a significant effect on bird life. The study found that gardens that used pesticides had fewer species of birds than similar gardens that did not use pesticides:

“Pesticide spraying impacted the positive effect [surrounding habitat quality] had on bird richness. Specifically, ‘species richness [number of species] increases with the surrounding quality, both for gardens that do not use pesticides and for gardens that applied pesticides, but this effect is significantly less strong when pesticides are applied’ the study indicates. Scientists zeroed in on three active ingredients: the weed killer glyphosate, the neonicotinoid insecticide acetamiprid, and the synthetic pyrethroid deltamethrin as resulting in the most damaging pesticide impacts to bird species’ richness.” Note that the study’s definition of “surrounding habitat quality” made no distinction between native and non-native plants. The British are not strong supporters of native plant ideology.

Nativists keep using huge quantities of herbicide to kill vegetation they don’t like, while also claiming that their eradication projects benefit birds. This is a fundamental contradiction. Their eradication projects are harmful to birds and other creatures that live in our parks and open spaces.

Jake’s Lament

In his article, Jake laments that people are accepting changes in the landscape because they don’t remember what the landscape looked like 100 years ago. His “baseline view” of what landscapes should look like is much further in the past than most people’s memories of the landscape.

The climate has changed significantly in the past 100 years. When the climate changes vegetation changes. We should welcome the changes because they are required for the survival of any landscape. When the climate changes, plants and animals must move, adapt, or die. The changing landscape is an indication that plants are adapting to changing conditions.

We cannot stop evolution, nor should we try. Herbicides are a futile attempt to stop evolution. Herbicides cannot stop evolution, because plants evolve a resistance to them. After 25 years of constant herbicide use in San Francisco’s parks and open spaces, we should assume that they are less effective every year.

While San Francisco’s Recreation and Park Department has significantly reduced its use of herbicides since 2010, the Natural Resources Division that is responsible for the “natural areas” has not. Natural Resources Division is now using more herbicides than the rest of the parks. Source: San Francisco IPM Program, Department of Environment

Wild by Design: A history of ecological restoration in the U.S.

“This is a superb book. Laura Martin’s research takes us where no restoration literature has gone before, asking, ‘Who gets to decide where and how wildlife management occurs?’ Martin tackles this question with unmatched clarity and insight, illuminating the crucial discussions we must have to secure a future with thriving natural species and spaces.”—Peter Kareiva, President and CEO, Aquarium of the Pacific

The author of Wild by Design, Laura J. Martin, is a professor of environmental history at Williams College.(1) She has written a comprehensive history of ecological restoration in the US that is consistent with my own observations of the restoration industry in the past 25 years. It’s a story of the gradual transition from a conservation ethic to a preservation ethic and finally to the restoration ethic that we see today. The story is punctuated by milestone federal laws and actions that facilitated the transition. Environmental non-profits and academic ecologists used those laws to professionalize and monetize the restoration industry that exists today.

By the end of the 19^th Century, the public began to react to the environmental degradation caused by unregulated resource extraction. In 1902, a survey of naturalists around the country determined there were 1,143 bison left in the country; virtually all were in captivity. The American Bison Society was founded in 1905 in reaction to the disappearance of bison in America. Their activism led to the creation of federal game reserves on former Indian reservations where captive bison were introduced. The game reserves were the model for the National Wildlife Refuge system that was greatly expanded by President Teddy Roosevelt.

A photograph from 1892 of a pile of American bison skulls in Detroit, Michigan waiting to be ground for fertilizer or charcoal. (Photo Wikimedia Commons)

The creation of the Wild Flower Preservation Society (WFPS) in 1901 was modeled on the successful campaign of the Audubon Society to save birds killed to serve as ornaments on fancy hats. It was as much a campaign to shame women into abandoning the fashion fad as it was an effort to legally ban the practice. Likewise, the Wildflower Preservation Society applied social pressure. They were critical of organized excursions to visit wildflowers because they picked and trampled the wildflowers. WFPS said that “Weddings are a new menace to our native plants” because of their use of wild flowers. Their criticism was initially aimed at their own community, but “it moved toward policing the behavior of so-called new immigrants to the United States—especially children.” The moralistic scolding by these early native plant advocates was a preview of the finger-wagging now aimed at those who choose to plant a diverse garden.

These advocacy organizations are precursors to the many environmental non-governmental organizations that are influential in pressuring government to invest in ecological restorations today.

Conservation and Preservation

The goals of conservation and preservation are similar, but some differences were observable in the past 200 years. Both ethics are committed to protecting the environment, but conservation allows the sustainable use of natural resources while preservation protects nature from use. The presidencies of both Teddy and Franklin Roosevelt were committed to conservation.

Teddy Roosevelt created the US Forest Service based on the premise that government can and should regulate public lands to manage natural resources. Franklin Roosevelt’s conservation programs were based on the same principle, but were motivated by the economic emergency of the depression as well as the environmental disaster of the Dust Bowl in the Midwest. The Civilian Conservation Corp (CCC) was created to provide jobs as well as to plant a “shelter belt” of trees across the Midwest of the country as a windbreak to stop dust storms (and many other projects). Ecologists were critical of CCC projects because they expanded recreational opportunities and put “a stamp of man’s interference on every natural area they invade.” They preferred to exclude humans and their activities from nature. This is another early indicator of the conflicts between preservation and conservation that persist to the present day.

Sharp Park, Pacifica, CA. Photo by Erica Reder, SF Public Press

Government investment in ecological research

Ecological research in the United States was fundamentally altered after World War II, which ended with the beginning of the atomic era. Atomic bombs were dropped on Japan to end the war without much thought given to the consequences. After WWII, the federal government made big investments in science, creating the Atomic Energy Commission and the National Science Foundation, which funded ecological research to study the impact of radiation on the environment and those who live in it. Conservation Sense and Nonsense published an article about those studies and the impact they had on ecological research.

These studies legitimatized destruction of ecosystems to study effects of the destruction and the concept was expanded from radiation to pesticides in the 1960s. They also provided funding to the academic profession of ecology that was small and is now enormous. The dependence of ecological studies on government funding remains to this day and government funding of ecological projects has created the restoration industry that now extends far beyond academia. Destruction of existing habitat is still considered the prerequisite to restoring a historical landscape. Often, destruction is the first and only stage of the project because of the persistent fantasy that the native landscape will regenerate without further help.

In the late 1960s Daniel Simberloff tented and fumigated 6 mangrove islands off the eastern short of Florida with methyl bromide to kill all life on the islands. The objective of the project was to study how long it would take to repopulate the islands with insects.

From Conservation to Restoration

The post-war economic boom of the 50s and 60s greatly increased the impact of human activities on the environment. The federal government built a vast highway system that fragmented and disrupted ecosystems. We built huge dams, and channeled riparian ecosystems. Open space was rapidly covered by housing and industrial development. Wetlands were drained and filled with rubble to create more land.

People who cared about the environment began to react to the loss of nature and wildlife that lives in nature. Although Aldo Leopold is idolized by the native plant movement, his concern about the degradation of nature was primarily for wildlife. His interest in vegetation was as habitat for wildlife. He was opposed to government programs devoted to killing animals perceived as predators of game animals because he believed that wildlife is best served by expanding their habitat. In fact, he was opposed to the expansion of government’s role in conservation because “he believed restoration would be most efficient and effective if pursued by private citizens.” He did not prefer native plants because “Farmers had the opportunity to conserve plants such as ragweed and foxtail (an introduced grass), ones ‘on which game, fur, and feather depend for food.’” In other words, in the 1940s one of the icons of the native plant movement knew that wildlife is not dependent upon native plants for food. One wonders if native plant advocates have actually read Leopold’s treatise, A Sand County Almanac.

Aldo Leopold’s son, Starker Leopold, had as much impact on conservation in the United States as his father. In 1963, he published the Leopold Report that changed the direction of conservation in the National Park Service. The Leopold Report recommended a goal for national parks of maintaining historical conditions as closely as possible to those of “primitive America.” When the Leopold Report was adopted as official policy by the National Park Service in 1967, it committed NPS to restoring park lands to pre-settlement conditions. NPS officially changed this policy in 2021, but we don’t see any change locally in their projects because NPS is decentralized and local parks are autonomous.

Restoration Goals

Professor Martin says that “historical fidelity did not become a widespread restoration goal among ecologists and environmental organizations until the 1980s.” The arrival of Columbus in the new World in 1492 was arbitrarily selected as the date after which all new plant species were “deemed nonnative, unwanted reminders of human (colonist) presence and activity.” On the West Coast, 1769 is the equally arbitrary date to confer non-native status because it is the date of the first Spanish expedition to California.

Many now question the goal of replicating historical landscapes. After 40 years of effort, there is a growing recognition that it is not a realistic goal, especially in a rapidly changing climate. The Society for Ecological Restoration has changed its definition of ecological restoration from “the goal of intentionally altering a site to establish a defined, indigenous, historic ecosystem” in 1990 to “the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed” in 2002. Try telling that to the restorationists on the ground who are still trying to eradicate naturalized non-native plants that have been here for nearly 200 years. Non-native annual grassland in California is a case in point. It has been repeatedly burned, mowed, plowed, and poisoned for 25 years without any visible progress toward native perennial grassland.

Blaming non-native species

Around the same time that historical fidelity was identified as the goal of “restorations,” land managers and ecologists decided that the existence of non-native species is the main threat to native species. I suppose the “logic” was that the main difference between historical landscapes and present landscapes is the existence of non-native species. Concern about non-native species spread among federal agencies such as the National Park Service and The Nature Conservancy (TNC) began aggressive campaigns to kill non-natives, “which were newly framed as the main threat to wild species…nativity would become a precondition to wildness—of plants and animals both.” TNC’s methods have become increasingly deadly and destructive: using fire and herbicides to kill plants, poisoning honeybees, aerial hunting of sheep, pigs, and goats. As a former donor to TNC, their methods finally became intolerable to me.

Professor Martin believes that the identification of non-native species as the scapegoat was not based on experimental evidence, but merely a description of the strategies used by public land managers, as well as The Nature Conservancy. Non-native species were a convenient scapegoat because they were easily identified and were an easy substitute for identifying and remediating the underlying conditions causing so-called “invasions.” “Although the role of invasive species in native species extinction has since been challenged by some ecologists, the influence of this fear on species management has been enormous…The US federal budget for invasive species management increased by $400 million between 2002 and 2005, for example.”

Endangered Species Act

The Endangered Species Act (ESA) was passed in 1973, along with companion laws such as the National Environmental Protection Act and others. These federal laws created more funding opportunities for ecological projects as well as the legal justification for ecological restoration projects.

Federal laws permit the reintroduction of legally protected plant and animal species to places where they no longer exist. The ESA confers the same protections for reintroduced species as it does for naturally occurring species. Such reintroductions have become a tool for the restoration industry. I have seen that strategy used in the San Francisco Bay Area. If we had not been successful in preventing the reintroduction of a legally protected turtle, it would have justified the destruction of the non-native forest in my neighborhood park because the turtle requires unshaded nesting habitat within 500 feet of the water source in the park. The park remains largely forested because that is one of the few battles we have won in 25 years. Reintroduced, legally protected species are the Trojan horses of ecological restorations.

Compensatory mitigation is an equally powerful tool for the restoration industry. Federal law requires an Environmental Impact Statement (EIS) for projects that will have a significant impact on the environment, such as big developments like building Disney World in Florida. Disney World was built on an enormous wetland that was lost by the development of the park. The EIS for the project agreed that the impact would be great, but it “mitigated” the impact by requiring Disney to fund the creation of a new wetland in a distant location.

The funding generated to create fake wetlands built a new industry of commercial companies to design and build them. Academic restoration ecologists questioned the functional equivalency between created and natural wetlands: “’however accurate [the Comprehensive Everglades Restoration Plan] is the restored community can never be authentic.’” The tension between commercial and academic restorationists continues today.

The Society for Ecological Restoration published findings that mitigation wetlands were not functionally equivalent to the wetlands they were meant to replace. In Florida only half of the promised mitigation projects were actually built. Those that were built were colonized by “undesirable plant species” such as cattail and melaleuca in 32 of 40 projects.

Projects that earn carbon credits are creating the same opportunities to generate funding for restoration projects in distant locations. The Nature Conservancy was successful in defining carbon offsets as an international market when the Kyoto Protocols were signed in 1997. They understood that a reforestation project would be cheaper in Costa Rica (for example) than a comparable energy efficiency project in the US. Such distant projects don’t benefit those in the US who now have a power plant in their backyard that is being offset by a forest in Costa Rica.

It’s a game for those who know how to play. I have witnessed local examples in the Bay Area. An oil spill in the bay generated millions of dollars of compensatory damages to fund unrelated “restoration” projects. How does planting eel grass compensate for hundreds of birds killed by the oil spill? When the San Francisco airport expanded runways, the airport had to pay compensatory mitigation that funded the restoration of native plants at India Basin in San Francisco that hardly compensates for the increased air traffic enabled by the new runway.

Conclusion

Professor Martin is surprisingly frank about the future of ecological restoration in America:

“Whatever paths restorationists choose, restorations must happen in tandem with other changes in human behavior. If we don’t reduce the ongoing harms of racism, fossil fuel burning, overconsumption by the wealthy, and toxic industrial chemicals, restoration will offer no more than a temporary repair, a way to move a problem to some other place or time.”

I would go one step further in my assessment of the restoration industry. I would say that the methods used by restorationists are directly contributing to environmental degradation.

Professor Martin asks the right questions in her concluding chapter: “Who benefits from restoration? Who is harmed?” Those who earn their living in the restoration industry are the primary beneficiaries. According to a 2015 study entitled “Estimating the Size and Impact of the Ecological Restoration Economy,” environmental regulation has created a $25 billion-per-year restoration industry that directly employs more people than coal mining, logging or steel production. Given recent investments in restoration projects of billions of dollars by California and federal infrastructure funding, this figure is undoubtedly an underestimate.

Who is harmed? Wildlife and humans are harmed by the destruction of useful habitat with herbicides. Harmless animals and plants are killed because they have been arbitrarily classified as “invasive.” And all Americans are harmed by the waste of public funds that could be used to benefit society and/or the environment.

(1) Laura J. Martin, Wild by Design: The rise of ecological restoration, Harvard University Press, 2022. All quotes are from this book.

Part III: Appealing to the City of Albany to save its eucalyptus forest

I am publishing my letter to the Albany City Council about the City’s plans to destroy most of the eucalyptus forest on Albany Hill. I am publishing it in three segments because it is long. The first segment explained why it is not necessary to destroy the forest. The second segment explained the consequences of destroying the forest. The third and final segment explains why it is unlikely that the forest can be replaced by native trees.

Now you have my version of the full story. If this is a place or an issue you care about, please consider writing a letter of your own to the City Council of the City of Albany.

Conservation Sense and Nonsense

Albany Hill. Source: Google Earth

December 5, 2022

Albany City Council
1000 San Pablo Ave.
Albany, CA 94706

Dear Albany City Council:

SEE Part I and Part II of Appealing to the City of Albany to save its eucalyptus forest. Part III is the concluding segment:

The uncertain fate of monarchs on Albany Hill is a suitable introduction to my final issue. The proposed plans for Albany Hill claim the destroyed eucalyptus forest will be replaced by new trees. I will explain why it is unlikely that the eucalyptus forest can be replaced by another forest. Plans for a newly planted forest are described in various ways, some of which seem contradictory:

“[Margot] Cunningham’s [Albany’s Natural Areas Coordinator] team is pursuing grants to cut down most of the blue gums and plant the city’s side of the hill with a mix of native species and more drought tolerant trees for monarchs to roost.” (1)
“WHEREAS, the City is investigating consultants to design a plan to remove eucalyptus in a way that retains and restores more fire-resilient native plant communities and minimizes soil disturbance and soil erosion.” (2)
“More droughty Eucalyptus species can be planted to preserve the butterfly habitat.” (3)
“This plan will include but is not limited to: plantings of other tall trees in areas of the hill where monarchs have traditionally clustered; survey of the existing native understory which will be allowed to grow after eucalyptus removal; and analysis and design of additional plants of Albany Hill-sourced native plants.” (4)

Somehow, this diverse, drought-tolerant, fire-resilient, tall, native (with droughty eucalyptus species?) forest is expected to survive without irrigation: “If drought-tolerant tree species are planted as seedlings, in the fall with sufficient planting site preparation and adequate rain fall, minimal if any irrigation will be required.” (5) When predicting the fate of the existing eucalyptus forest, the plans assume that the drought will continue. When predicting the fate of a replacement forest, the plans assume that the drought will end.

Most public land managers irrigate newly planted trees (whether native or non-native) for at least 3 years. Established trees rarely require irrigation to survive because they have extensive root systems that have better access to moisture in the soil than newly planted trees without extensive root systems. Tree species that are drought-tolerant when mature trees, require irrigation as they grow their root systems. Replacing healthy trees that don’t require irrigation with new trees that require irrigation seems an unwise choice in the middle of an extreme drought.

The City of Albany should have learned that lesson when they built Peggy Thomsen Pierce Street Park at the western foot of Albany Hill. Only native trees were planted in that park. They weren’t irrigated. Five years after the park opened in 2017, most of the trees are dead (see below):

Peggy Thomsen Pierce Street Park, November 2022. Conservation Sense and Nonsense

The City of Albany’s list of approved street trees is a valuable source of information about what tree species are capable of growing in Albany. A tree species that cannot survive conditions for street trees is also unlikely to survive on the ridgeline of Albany Hill, where wind conditions are extreme and there is little moisture. There are about 65 tree species approved for planting as street trees in Albany. Five are native to California, but only three are native to the Bay Area. Native big leaf maples are said to be “in decline.” Buckeyes aren’t suitable street trees, but may be suitable for open space. None of the listed native trees are suitable monarch habitat for a variety of reasons: canopy too dense to provide sufficient sunshine; deciduous therefore bare in winter; short stature, etc.

Historically, areas on Albany Hill that are now forested with eucalyptus were treeless because native trees are not adapted to the challenging climate conditions. If the eucalyptus forest on Albany Hill is destroyed, Albany Hill is likely to be treeless again. That is the horticultural reality of Albany Hill.

In conclusion:

It is not necessary to destroy the eucalyptus forest on Albany Hill because it is not dead.
Destroying the eucalyptus forest on Albany Hill will increase fire hazards and safety hazards.
Destroying the eucalyptus forest will destroy habitat of monarch butterflies.
Plans to replace the eucalyptus forest with native trees are unrealistic.

Please consider reinstating the 2012 Albany Hill Creekside Master Plan. It is still a good plan that will not do unnecessary damage to Albany Hill and its human and animal visitors.

cc: Albany Fire Chief
Albany Natural Areas Coordinator
Albany Urban Forester
Creekside Science

Update: Shortly after I sent my letter to officials of the City of Albany about their plans to destroy most eucalyptus on Albany Hill, they revised their plans because of two updated reports that were done in November and December 2022. Basically, they no longer plan to destroy most eucalyptus on Albany Hill for two main reasons:

Eucalyptus trees are the overwintering habitat of monarch butterflies. They cannot be replaced by native trees of short stature without the open canopy that filters sunlight but also provides a windbreak the monarchs need.
Epicormic sprouts on the eucalyptus trees indicate they are recovering from drought and are expected to survive and eventually replace their canopies.

These are the sources of information that corroborate my brief summary of the main reasons Albany is no longer planning to destroy most eucalyptus trees on Albany Hill:

Presentation to Albany City Council about Albany Hill by Margot Cunningham on December 8, 2022: https://www.youtube.com/watch?v=DkVPkBX6vcA
Update on Monarch survey of Albany Hill by Stuart Weiss: https://www.albanyca.org/home/showpublisheddocument/53671/638179437113270000
Updated fuels management survey by Carol Rice: https://www.albanyca.org/home/showpublisheddocument/53673/638179439800970000

They still intend to remove dead trees to reduce fuel loads, to which I have no objection. Some dead eucalyptus may be replaced with more drought tolerant species of eucalyptus from Western Australia.

To be clear, I don’t think my letter about their original plans for Albany Hill were influential in their revising their plans. My letter is consistent with the advice they received from an ecologist with expertise in monarch butterflies and a consultant in fuels management. Credit belongs to the preference of monarchs for eucalyptus and to eucalyptus for being indestructible.

April 2023

Bay Nature: https://baynature.org/2022/10/20/the-nearly-unkillable-eucalyptus-meets-its-match/
Resolution No. 2021-105. A resolution of the Albany City Council, authorizing the appropriation of funds to the Albany Hill Eucalyptus Project in the amount of $100,000
https://www.albanyca.org/home/showpublisheddocument/52453/638028259461770000
Staff Report to City Council regarding Albany Hill Eucalyptus Project, May 2, 2022
https://www.albanyca.org/home/showpublisheddocument/52453/638028259461770000