Daniel Simberloff gave the keynote address to the symposium of the California Invasive Plant Council (Cal-IPC), entitled “Invasive Species Denialism and the Future of Invasion Management.” Simberloff is the most vocal academic defender of invasion biology. His presentation to Cal-IPC contains interesting clues about more effective strategies for the critics of invasion biology, of which I am one. In a nutshell, Simberloff dismisses critics easily with a few waves of his hand, but he stumbles when faced with the economic and ecological costs of the methods used to eradicate so-called “invasive species.” He can defend the theoretical hypotheses of invasion biology, but he finds it difficult to defend the “restoration” industry that invasion biology spawned, specifically the use of pesticides.
Simberloff opened his presentation with this rogue’s gallery of the critics of invasion biology. Some readers will recognize some of these “deniers.” If not, you might recognize some of the many books the “deniers” have published.
Simberloff categorized the criticisms of invasion biology then flipped them off, one by one. Keep in mind as you read Simberloff’s summary that it does not do justice to the actual criticisms of invasion biology.
- Critics say that most non-native species aren’t harmful.
- Simberloff says we don’t know how harmful non-native species are because few are studied, their impacts are often subtle, and there is often a time lag before they become harmful. He believes that all non-native plants are potentially harmful to ecosystems.
- Critics say that some non-native species are beneficial.
- Simberloff says that critics only report the benefits, while ignoring the negative impacts of non-native species. (Actually, most critics are proposing a cost/benefit analysis that acknowledges both positive and negative impacts.)
- Critics say that invasion biology is xenophobic.
- Simberloff says that if you’re looking for xenophobia, you often see it. He calls this the “law of instrument” or if your instrument is a hammer, everything looks like a nail. (Frankly, I didn’t understand the point he was trying to make, but I have tried to describe it accurately based on what he said.)
- Critics say that trying to eradicate non-native species is futile.
- Simberloff says this argument ignores the progress that has been made in the technology of eradication methods. He used the “early detection and rapid response” strategy as an example of progress in eradicating non-native plants. That strategy focuses on small populations of non-native plants, basically acknowledging the futility of trying to eradicate large areas of well-established non-native plants.
- Much of Simberloff’s presentation was devoted to describing many developments in genetic engineering, such as CRISPR to drive species to extinction and gene silencing. All of the examples of such developments were aimed at killing insects (such as mosquitoes) and animals (such as rats and mice), with one exception. He was particularly enthusiastic about island eradications of which there are hundreds, and hundreds more on the drawing boards. Only one gene-editing project on plants is trying to develop a genetic method to eradicate phragmites.
Things finally became interesting, when Simberloff took questions: “Dan, you mention the “futility” argument, but what about the notion that the cost in environmental damage (e.g, pesticide use and nontarget impacts) is too high for some well-established invaders?” Simberloff’s answer to this question was surprising and encouraging to critics of pesticide use to kill non-native species:
“Absolutely, it’s a huge problem, not only on non-target species, but also the fact that evolution of resistance leads to greater use of pesticides before they are useful and leads to greater impact on non-target species. I didn’t talk about this, but yes, of course the cost both economically and ecologically might be too great even if management eradication is feasible. But that’s not what denialism is about. Denialism willfully denies that there are impacts or they confound arguments about values as if it is an argument about science.”
The Executive Director of Cal-IPC recognized the dangers of Simberloff’s answer because pesticides are the primary tool used by the “restoration” industry and much of the conference was devoted to telling over 650 employees of the “restoration” industry about new developments in pesticide use. Those new developments are not good news to those who are concerned about the dangers of pesticides. For example, a new “drizzle” technique increases the concentration of the active ingredient and lowers the volume of the application, increasing toxicity of the application. Another alarming presentation described the use of drones to spray herbicides on hundreds of acres of phragmites in the Suisun Marsh.
The absence of good alternatives to pesticide use in eradication projects is another source of pressure on the “restoration” industry and therefore on Cal-IPC:
- Jon Keeley’s presentation about the interaction of fire, fire prevention, and plant invasions included the observation that using prescribed burns to eradicate non-native plants results in more non-native plants, not more native plants.
- A land manager in Southern California acknowledged that pressures to reduce pesticide use threaten the future of his project: “Natural herbicides result in more time intensive and costly weed control, with less confidence of success. Where herbicide application is completely restricted, other weed control methods like hand weeding or mowing can be implemented successfully, but they often fall short of herbicide in effectiveness. This resulting reduction in effective weed control must be taken into account in future plans for habitat restoration and management, and our existing programs will have to reevaluate the proposed efforts, cost of those efforts, and expectations for success, both short and long term.” (Scott McMillan, abstract)
- Finally, with the exception of a few timid questions from participants, no mention was made about the threat of climate change on the future of native ecosystems. Simberloff likened critics of invasion biology to “climate change deniers.” In fact, it’s fair to say that those who demand that we replicate native ranges existing 250-500 years ago are more accurately called climate change deniers.
The Executive Director of Cal-IPC tried to save the day by portraying those who oppose pesticides as extremists, based on what he considers “unscientific” studies. But Simberloff wouldn’t take the bait. He wasn’t willing to dismiss the concerns about pesticides. Instead, Simberloff passed the buck:
“I’ll beg off on answering that question on grounds that I’m not a social scientist or psychologist. This is not my area of expertise. There is some reason for the extremists because Monsanto has sometimes lied to us and there have been problems associated with pesticides. I leave this question to policy scientists.”
Simberloff reveals the flaw in the “restoration” industry
As a critic of invasion biology and the use of pesticides, I have always been frustrated that critics of invasion biology do not use the damage done by eradications as a reason for their criticism. With the exception of Tao Orion’s Beyond the War on Invasive Species, none of the books written by critics have used this argument. It is a missed opportunity and Simberloff’s presentation to Cal-IPC is an indication that it is the strongest argument against eradication projects that are inspired by invasion biology.
Invasion biology is a theoretical construct. It does no harm to ecosystems until it justifies the use of harmful methods to eradicate non-native species. I humbly ask that critics of invasion biology wake up to this opportunity. Pesticides are a winning argument against “restoration” projects that eradicate non-native plants. Any cost/benefit analysis of new eradication projects should include the ecological and economic costs of pesticides in the equation.
Beyond Pesticides points the way forward
I try not to leave the field without offering a compromise because opposition without solutions is not constructive. I offer this sage advice from Beyond Pesticides about case-by-case evaluations of weed invasions that will reduce damage to ecosystems. Beyond Pesticides responded to this question: “I’m working on a pesticide policy in my community and am interested in how you might suggest we deal with “invasive” species. Can you point us in the right direction? Martin, Boston, MA.” This is BP’s thoughtful answer:
“It’s Beyond Pesticides position that invasives, or opportunistic species, should be dealt with on a case-by-case basis, with established priorities and a plan. With any unwanted species, there needs to be an understanding of the ecological context. We need to be asking the right questions: What role is the plant currently playing in a landscape—what niche is it currently filling? If we remove this plant, what will fill that niche? Will we be replanting the right native species to fill that niche? What are the detrimental impacts of letting it spread? Is there a way we can isolate it to stop its spread? Can we ever remove this plant altogether, or will we be working at control indefinitely? These are important questions that we need to be asking before we even consider management methods. Regarding policy, requiring an individualized invasive species management plan seems to be the right answer, though unfortunately many pesticide reform policies sidestep the issue and simply exempt invasives to avoid opposition. Just like all organic approaches, we’ll want to place a focus on prevention and working with ecological systems, rather than against them, making even least-toxic pesticide use a last resort. There is a strong potential to undermine the stability of an ecosystem if we simply go in and immediately break out the strongest tools in the toolbox without a plant replacement strategy. On a turf system with common weeds a simple answer is grass plants. But, in forested areas already subject to intrusion (from construction/logging, etc.), rights-of-way, and urban areas, the focus is on alternative vegetation or ground cover. Sometimes, little should be done except simple mechanical cutting to keep these species in balance. This is an interesting and, at times, contentious issue that environmentalists grapple with, so there is certainly room for fresh ideas on how to approach opportunistic species without the use of toxic pesticides. For more information, we encourage you to watch the talk given at Beyond Pesticides 37th National Pesticide Forum in New York City by Peter Del Tredici, PhD, senior research scientist at Harvard’s Arnold Arboretum (www.bp-dc.org/ invasives).”
6 thoughts on “Invasion Biology vs. The “Restoration” Industry”
There is so much low hanging fruit in this post it is hard to begin. With the exception of Michael Poulin few of these authors are not well known or actively engaged on a day to day basis to discredit invasion biology. The fact they spent time on it at all makes me think they are worried to some extent. It is funny to me how someone can call science writers and researchers anti-science because it doesn’t match up with their subjective views. If you arevgoing to stop or slow the invasion management system, you have to stop feeding it with money. That would be the weak spot.
Please explain your comment. I don’t assume it is a hostile comment, I just don’t understand it. What do you mean by “low hanging fruit”? Are you questioning Simberloff’s presentation or this article? Michael Pollan (not Poulin) is well known, but all the others are known to me and the invasion biologists who work in the field and that’s the audience for this post. (I have read all their books except for Tassin–whose book is in French–and Guiasu.)
I agree that the only way to slow the “restoration” industry to is stop “feeding it with money.” The question is how to convince the government agencies that are funding it to stop funding it. Convincing government that the projects are poisoning the environment and not achieving anything seems like a good way to do it. Do you have better suggestions?
There is so much wrong with his arguments, it is hard to know where to start. That is what I meant by low hanging fruit. It almost to easy to see the errors in his arguments. He outlined the ultimate belief system. There is nothing scientific from his mouth. I don’t think people who work in the conservation industry really know any of the books mentioned. If they did they would see them like ‘fleas on a big dog’. It causes some discomfort but the dog goes on. I talked to a DNR official about a large phragmites removal project in Lake Huron. I sent in some studies on the removal of phragmites, herbicide effects on amphibians, and if the removal takes place biodiversity decreases. The response was very odd. She told me I was the only person to complain. The herbicide wasn’t going to be used in wetlands and then a weird apology because they were going ahead with it anyway. None of it was true. I think it is going to take a complete revision of what is called conservation. It will have to start with education. I am not sure when it will end though. This whole thing is just so damaging to people as well as the environment.
Thanks for explaining. Yes, it’s frustrating to try to engage people who really don’t seem to know what they are doing, but let’s not give up on trying because–as you say–they are doing a lot of unnecessary damage.
I plan to teach this new conservation ethic to students next year at my farm which I consider a working laboratory of ideas. I am retiring from my nursery business and will likely publish a book too. David Theodoropolous is an inspiration to me. Rich now the invasion scientists are combining plant disease organisms, plant pests, possible public nuisance species (murder hornets) as a single category to get funding. If you say you are against invasion science, then invasion scientists will ask why are you against the end of a disease or the prevention of an outbreak of an insect pest. Recently at a farm show I told a group of people, I love invasive species. You could clearly see their faces drop. What I meant was, I love the beneficial effects of multi-flora rose, phragmites and autumn olive bush and then present them with images of those animals that use those wonderful beneficial plants and the other native plants that grow within them and the animals that use them. Yes. Plants are not a disease I could say. Yes. Nature did not make a mistake and herbicides will not solve your problems. It will only damage the environment and those poor souls who are applying them. It is one large uphill battle is some ways to tell someone we are not anti-science.
I agree that the attempt to conflate plant “invasions” with pathogens and insects is confusing the public. They are very different issues. It is unnecessary and harmful to treat plant invasions like pathogen and insect invasions.
I’m glad to hear that you are preparing a course about these issues. I agree that Theodoropoulos was the pioneer on this issue and I am grateful to him as well.
I suggest you take a look at this presentation by a horticultural professional for ideas about your course: https://www.youtube.com/watch?v=lTYEC-LBTxs&feature=youtu.be
Carol Reese is an Extension Horticulture Specialist at University of Tennessee. She is a nationally-known speaker, blending equal parts gardening knowledge, natural lore, and quirky humor. Carol is the gardening and nature columnist for several newspapers, as well as a contributor to several gardening magazines. She was the Q&A columnist for Horticulture Magazine for several years. Her B.S. and M.S. in Horticulture are from Mississippi State University.
Carol made a presentation to the Charlotte Garden Club recently that you can see at the link provided above. Carol describes her presentation: “Facts and Fallacies about Native Plants has its humorous moments, but it is mostly to combat the idea that a garden must be native or you are irresponsibly failing the wildlife. Using a mixture of science and personal experience, I refute much of Doug Tallamy’s tenets in his book Bringing Nature Home. I expose the ridiculous idea that we can somehow stop the globe from evolving and adapting, and that in fact, we should consider the benefits of change when we examine the big picture factoring Father Time into the equation. I leave people comforted on many levels that they are not sinners when they plant gardenias.”
Thank you for your work on this issue. Thank you for your readership.