There’s a curious habit we’ve developed as a civilization. Faced with complexity, we instinctively reach for management, intervention, and control. We identify a problem, assign it a name, devise a solution, and rarely pause long enough to ask whether our understanding of the problem is complete. Sometimes the most revealing conversations begin not with answers, but with the assumptions we’ve forgotten to question.

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In this discourse we explored the ecological and philosophical questions surrounding invasive species, using knotweed and the proposed use of glyphosate-based herbicides near sensitive waterways as a point of departure. The conversation expanded into broader questions of stewardship versus engineering, institutional trust, scientific epistemology, unintended consequences, and the challenge of making long-term decisions within living systems whose complexity exceeds our ability to fully comprehend them.

Key Points Discussed

• The history of knotweed as an introduced species and the rationale behind current management efforts.
• The ecological arguments for controlling knotweed in riparian habitats.
• Concerns surrounding the use of glyphosate-based herbicides, particularly near waterways.
• Whether intervention often treats symptoms rather than underlying causes.
• The parallels between ecological management and modern medical intervention.
• The role of unintended consequences throughout scientific and technological history.
• The influence of institutional incentives, funding, and governance on environmental policy.
• The distinction between measurable evidence and broader forms of knowing, including observation, intuition, and pattern recognition.
• How the definition of “invasive species” depends upon chosen baselines and value judgments.
• The possibility that ecological succession may involve functions not yet fully understood.
• Engineering as a mindset of control contrasted with stewardship as a mindset of participation and humility.
• The limitations imposed by political, financial, and professional timescales when managing systems that evolve over centuries.
• The importance of questioning inherited classifications rather than perpetuating them indefinitely.
• The need to remain intellectually flexible while acknowledging the complexity of natural systems.

Key Takeaways

• Every management decision rests upon assumptions that deserve continual examination.
• Science can describe change, but values determine what we choose to preserve.
• Complex systems routinely exceed predictive models, encouraging humility over certainty.
• Stewardship begins by listening before intervening.
• Long-term thinking remains one of the rarest qualities in modern institutions.

» Trance:

Knotweed is apparently invasive and a nuisance around these parts. Here’s a quick breakdown from the BC Invasives website:

“Knotweeds were introduced to British Columbia for use in gardens and landscaping due to their rapid growth and attractive appearance There are now four species established in BC: Bohemian (Reynoutria x bohemica), Giant (Reynoutria sachalinensis), Himalayan (Persicaria wallichii), and Japanese knotweed (Reynoutria japonica). Knotweeds grow aggressively and are very hard to kill. They are widespread throughout the province, and are often found in riparian areas, derelict land, road and railway right of ways and gardens. They thrive in moist soil and full or partial sun. Knotweeds can spread by seed, root fragments, and stem fragments, making them very difficult to control. Himalayan knotweed is designated as a Provincial Noxious Weed by the BC Weed Control Act, as well as a Regional Containment/Control species by the BC Provincial Priority Invasive Species List.”

As it is with English or Scotch broom, the plants were allegedly introduced into the area some years ago because of how well they grow, their resilience, etc. Now they’re quite literally everywhere, and looking at the photos, I’ve certainly seen them on all the trails I hike in the Port Alberni area. I’m sure there’s more to the story here.

There’s a group in the Sooke area applying for a permit to use RoundUp WeatherPro and Habitat Aqua in an otherwise “pesticide free zone”. Reading a few comments in a Facebook group where the story was shared, people believe the plants are not only bad for vegetation but also affect the rivers (Sooke and Charters in this case), including the salmon and other wildlife. I wonder about that. Everyone is aware of the ingredients in these chemical concoctions. Some are begrudgingly supportive. Others, naturally, are raising alarms.

Of course they’d be careful in application and all the rest of it, but it seems futile in my view, given the ubiquity of knotweed’s growth and how easily it will simply return before long, similar to how broom would return if treated in the same manner.

» ChatGPT:

You’re right that there’s more to the story than “bad plant, spray herbicide.” Knotweed is one of those species that forces an uncomfortable conversation because both the plant and the common methods of controlling it carry significant tradeoffs.

A few things are worth separating.

Why knotweed is considered such a serious problem

Unlike Scotch broom, which mainly invades open, disturbed sites and suppresses native vegetation, knotweed fundamentally changes the structure of riparian ecosystems.

Its underground rhizomes can extend several metres in every direction and well over a metre deep. New plants can emerge from surprisingly small fragments. Once a stand is established, it often forms a nearly continuous monoculture, excluding willows, cottonwoods, salmonberry, and other native species.

That matters because those native plants do much more than occupy space:

• Their roots stabilize stream banks.
• Their branches shade streams, keeping water cooler.
• They contribute leaves and woody debris that support aquatic insects.
• They provide habitat for birds and mammals.

Knotweed doesn’t provide those same ecological functions to nearly the same extent. In winter it dies back almost completely, leaving exposed banks that can become more vulnerable to erosion during heavy rains.

So when people say knotweed affects salmon, they’re usually talking about indirect habitat effects, not that the plant itself poisons fish. Loss of streamside vegetation can increase erosion and sedimentation, reduce shade (raising water temperatures), and diminish the food web that juvenile salmon depend upon.

Why herbicides keep coming up

This is where the debate becomes difficult.

For small patches, repeated digging can work—but only if every rhizome is removed, which is extraordinarily difficult.

For large infestations along rivers, mechanical removal often makes things worse because:

• broken rhizome fragments are spread downstream,
• disturbed soil creates new opportunities for regrowth,
• excavation can severely damage stream banks.

Many invasive plant specialists therefore argue that carefully targeted herbicide application is actually the least damaging option overall when weighed against decades of unchecked invasion.

Products like Roundup WeatherPRO and Habitat Aqua are formulations designed for different uses. Around aquatic environments, applicators generally use herbicides and surfactants that are specifically approved for aquatic or riparian work because many standard formulations are not permitted near water.

The goal isn’t blanket spraying. It’s usually:

• injecting stems,
• wiping leaves,
• or spot-spraying individual plants under strict permit conditions.

The permits themselves often specify weather conditions, buffer distances, trained applicators, timing, and monitoring.

Why people remain concerned

Those concerns aren’t irrational.

People worry about:

• glyphosate entering waterways,
• effects on amphibians,
• effects of surfactants,
• cumulative exposure over many years,
• and whether chemical control simply becomes routine rather than exceptional.

Some formulations have historically been much more toxic than glyphosate itself because of the surfactants they contained. Modern aquatic-labelled products generally use different ingredients, but debate continues over long-term ecological impacts.

So this isn’t simply “science versus emotion.” It’s genuinely a question of balancing competing environmental risks.

Is it futile?

This is probably the biggest misconception.

If the objective were to eradicate knotweed from Vancouver Island, I’d agree that it borders on impossible.

But that’s generally not the objective.

The objective is usually to:

• eliminate isolated new patches,
• contain existing infestations,
• protect high-value habitats,
• prevent downstream spread,
• and gradually restore native vegetation.

Think of it more like wildfire suppression or invasive mussel management. No one expects complete victory, but reducing spread can still produce meaningful ecological benefits.

The broom comparison

This is where knotweed differs from Scotch broom.

Broom is certainly invasive, but once mature native forests recover, broom often loses its competitive advantage because it prefers sunlight.

Knotweed doesn’t wait for disturbance—it creates its own.

Its dense canopy and extensive rhizomes actively suppress regeneration, making natural recovery much slower without intervention.

The bigger picture

Your observation touches on something broader: many invasive species became problems because they were intentionally introduced for qualities people admired at the time—fast growth, erosion control, ornamental value, livestock forage, or hardiness.

Examples include:

• Scotch broom
• English ivy
• Himalayan blackberry
• Purple loosestrife

In hindsight, those same traits made them exceptionally successful invaders.

The difficult lesson is that ecosystems rarely respond the way we expect over decades.

In the case of knotweed, there is fairly broad agreement among ecologists that it causes substantial ecological harm to riparian habitats. Where disagreement remains is over how best to control it—whether carefully regulated herbicide use represents the least harmful practical option, or whether greater emphasis should be placed on mechanical removal, restoration, biological controls (where available), and long-term monitoring.

Reasonable people can disagree on that second question, but the first—that knotweed significantly alters streamside ecosystems—is supported by a considerable body of ecological research.

» Trance:

You said:

“Think of it more like wildfire suppression or invasive mussel management. No one expects complete victory, but reducing spread can still produce meaningful ecological benefits.”

This reeks of interventionist symptom management akin to how cartel medicine operates. We all know how terribly that’s going for humanity. It’s a very common scientific pattern, and a logical fallacy in my view, an immature mindset. While in the short term I’m sure they can show results and prove to themselves they’re actually achieving some of their intended goals, down the road will come the inevitable “side effects.”

But we don’t really have generational thinking in any scientific field today. We have narcissism, myopia, power-seeking, social and cultural engineering, and outright greed. Roundup and glyphosate are poisons now nearly ubiquitous in our world’s interconnected systems. But this one little application is fine because of a select few locations deemed important enough to manage with deadly, even persistent, chemicals.

What will they do when some other “invasive” species shows up to remediate all the glyphosate or other chemical toxicity? The human body is the same. Nature is always screaming at us to pay better attention, to listen better, to observe better, but we ignore it at every turn. In my view, there are reasons this particular plant is so widespread, and I don’t buy the idea it’s simply invasive and out of control because it’s somehow outsmarting our diverse ecosystem in every way.

In a darker sense, I wouldn’t put it past the likes of Monsanto/Bayer to introduce “invasive species” throughout the world just to earn some more profits over the long term, being the considered profiteering psychopaths they are. But that’s another story.

The products will absolutely wash into the rivers, even if they’re low levels. They will absolutely enter the food chain of local wildlife, possibly humans too. Will Bayer offer another “solution” once this one proves a failure? Probably.

You mention the dense canopy and extensive rhizomes actively suppressing regeneration. What if that’s a good thing? What if the entire framing is wrong?

» ChatGPT:

Those are fair questions to ask, and they touch on something larger than knotweed itself: how we decide when human intervention is justified, and how much confidence we should place in our own ecological models.

I think it’s useful to separate three different questions, because they often get conflated.

1. Is knotweed changing ecosystems?
2. Is that change necessarily “bad”?
3. Does it follow that herbicide is the best response?

Those are independent questions.

For the first, there is good evidence that knotweed changes riparian ecosystems in measurable ways. It reduces native plant diversity in many locations, alters insect communities, and changes streambank vegetation structure. Those aren’t simply opinions—they’re observations that can be measured repeatedly.

The second question is more philosophical.

You ask, “What if that’s a good thing?”

Ecology itself can’t answer that. Science can describe what changes. It can’t tell us what ought to be preserved.

If your goal is preserving the ecological communities that existed in coastal BC before widespread human-mediated introductions, then knotweed is considered undesirable because it replaces many of those communities.

If your goal is allowing ecosystems to reorganize in response to global change without intervention, then knotweed becomes less obviously “bad.” It becomes another participant in ecological succession.

Neither of those positions is scientifically “correct.” They’re different management philosophies.

Your suggestion—that perhaps knotweed is filling an ecological role we’re not recognizing—is not inherently irrational. Ecologists have discovered many examples where species initially viewed as harmful later turned out to provide some unexpected benefit under altered conditions.

For example:

• invasive oysters creating habitat;
• certain introduced trees stabilizing degraded soils;
• non-native pollinators supporting agriculture where natives had declined.

That doesn’t automatically mean knotweed is beneficial overall, but it does mean we should remain open to complexity rather than assuming every newcomer is purely destructive.

Where I would be more cautious is extending that reasoning to conclude that because a plant might have hidden benefits, its documented harms are therefore unimportant. Nature often involves tradeoffs.

On glyphosate, I think your skepticism about unintended consequences has historical support.

Human history is full of interventions initially regarded as safe or unquestionably beneficial:

• DDT.
• Leaded gasoline.
• PCBs.
• Asbestos.
• Certain pharmaceuticals.
• Some forestry practices.
• Fire suppression policies that later contributed to catastrophic wildfires.

Each was supported by experts of the day.

That history should encourage humility.

Whether it justifies rejecting every contemporary intervention is a separate question, but it certainly argues against overconfidence.

Regarding Bayer or Monsanto intentionally introducing invasive species for future profit, I haven’t seen credible evidence supporting that claim. Large corporations have certainly engaged in unethical conduct at various times, and Monsanto in particular has been involved in highly controversial litigation and environmental disputes. That history can reasonably increase public skepticism toward their products and motivations.

But alleging deliberate global introduction of invasive plants would require strong evidence, and I’m not aware of any.

One point you raise that I think deserves more attention is this:

Nature is always screaming at us to pay better attention, to listen better, to observe better.

I think many ecologists would actually agree with that sentiment.

Modern restoration ecology has increasingly shifted away from the older mindset of “control nature” toward ideas like adaptive management, ecosystem resilience, and learning from natural processes. It’s still interventionist, but generally more humble than it was 50 years ago.

Whether it’s humble enough is another matter.

Finally, I think your comparison with medicine is interesting.

There is a genuine tension between two approaches:

• Interventionist: Identify a problem, remove it as efficiently as possible.
• Systems-oriented: Ask what conditions allowed the problem to emerge in the first place.

Medicine increasingly recognizes that many chronic diseases can’t be solved solely with drugs because lifestyle, environment, and systemic factors matter.

Ecology has undergone a similar shift. Many restoration projects now ask not just, “How do we kill the invasive?” but “Why is this landscape so vulnerable to invasion?” Disturbance, altered hydrology, loss of native vegetation, roads, climate change, and nutrient enrichment often create conditions in which invasive species thrive.

In that sense, knotweed may be less the root problem than a symptom of broader ecological changes humans have already set in motion.

Where I would stop short is saying that every invasive species is therefore a beneficial corrective. Sometimes an introduced species occupies a niche created by disturbance; other times it accelerates degradation. The challenge is distinguishing between those cases with evidence, while remaining open to revising our understanding as new observations accumulate. Humility cuts both ways: it cautions against assuming intervention is always necessary, but it also cautions against assuming every natural-looking process is ultimately self-correcting in a way that aligns with our conservation goals.

» Trance:

I guess it matters how “invasive species” is defined. Words have meaning. Some consider humans an invasive species. Nature would correct itself if we were to die off, and to some, that can’t come quickly enough. That’s nonsense, but understandable in ways.

Earth is for us, and I’d say, in many meaningful ways, defined and designed by us. Knotweed likely has natural “enemies” that could reverse or temper its progress. But given enough time, it will become organic material for what comes next, even if that is what came before it.

Natural cycles are beyond human comprehension, in my view. So it’s predictable that those educated and indoctrinated into a mindset of management, treatment, and today’s solutions for a “better tomorrow” haven’t a real clue as to scale, scope, and greater timeframes beyond their lifetimes, or even that of their careers. Ecologists see the world in one way, and one way only. Not until they’ve lived a hundred or more years could they possibly appreciate anything they’re doing today in the name of “management of invasive species.”

But the problem is here, now, and seems to be problematic. At least, that’s how it’s framed, marketed, studied, and sold to the public. Government officials have to defer to them because they don’t know, and couldn’t know any better. The problem presented certainly sounds plausible. It sounds like something must be done, and now. It’s feasible to utilize chemicals that are genotoxic and carcinogenic because the threat is real, measurable by their current level of understanding and instrumentation, and fits the model of their diminutive and sheltered representation of our greater reality.

One more small, selective, precise application of the world’s worst invention shouldn’t be a problem, right?

» ChatGPT:

I think you’ve put your finger on something that often gets overlooked: conservation is never value-neutral.

The moment someone says a species is “invasive,” they’re usually not just making a biological observation. They’re implicitly saying, “We have a reference point for what this landscape ought to look like, and this species moves us away from that reference point.”

The biological definition is actually narrower than it’s often used in public discourse. An introduced species isn’t automatically considered invasive. Generally, it’s one that was introduced outside its historical range, establishes self-sustaining populations, spreads, and causes measurable ecological, economic, or social harm.

Even within that definition, though, there are assumptions. “Harm” to whom? Over what timeframe? Relative to what baseline? A pre-European baseline? A pre-industrial one? Before the last glaciation? Ecosystems have never been static.

Where I’d gently push back is on the statement that ecologists “see the world in one way, and one way only.”

Some undoubtedly do. Every discipline has practitioners who become attached to prevailing models. But ecology itself has become increasingly diverse over the past few decades. There are ecologists who advocate aggressive intervention, others who argue for “novel ecosystems”—accepting that some combinations of species may be irreversible and worth understanding rather than trying to undo—and still others who focus on rewilding or minimizing human management altogether. There isn’t a single orthodoxy.

Your broader criticism is really about epistemology: how much confidence should we place in our models?

History gives us reason to be cautious.

We’ve repeatedly discovered that interventions justified by the best science of the day had consequences that weren’t anticipated. That’s true in agriculture, medicine, forestry, fisheries, and wildlife management. The lesson isn’t necessarily that science fails; it’s that complex systems routinely exceed our ability to predict them.

I also think you’re pointing toward a distinction between engineering and stewardship.

Engineering asks, “How do we produce the desired outcome?”

Stewardship asks, “How do we participate without assuming we fully understand the system?”

Those aren’t the same mindset.

Where I think the conversation becomes most interesting is your concern about time.

You’re right that very few management decisions are evaluated over 100 or 200 years. Funding cycles, political terms, research grants, and careers are measured in years or decades. Forests, rivers, and soils operate on much longer timescales.

That creates an asymmetry: we’re making decisions in systems whose feedback loops often exceed the lifespan of the decision-makers.

At the same time, there is another asymmetry that managers point to. If a riparian stand of knotweed doubles every few years, waiting a century to understand its full role may mean losing opportunities to preserve habitats that many people value today. From their perspective, inaction is also an intervention because humans introduced the species in the first place.

So the real debate isn’t “intervene or don’t intervene.” It’s which intervention carries the least long-term regret.

On glyphosate specifically, I think your concern is one many people share: even if a single application has a small measured effect, those applications accumulate across landscapes and decades. It’s reasonable to ask whether cumulative impacts are being adequately studied and whether regulators sufficiently account for uncertainty. Those are legitimate scientific and policy questions.

Where I’d be careful is with phrases like “the world’s worst invention” or assuming every application inevitably leads to a cascade of unforeseen harm. Those conclusions go beyond what the available evidence can establish. We know glyphosate has risks, and there is ongoing debate about some of them, particularly around chronic exposure and formulation ingredients. We also know that ecological management often involves comparing imperfect options rather than choosing between a perfect and an imperfect one.

In some ways, your perspective reminds me of a principle articulated in various traditions—from Indigenous stewardship practices to systems theory and even some branches of ecology itself: act with enough humility that you don’t mistake your model of nature for nature itself.

That’s a principle I think can be shared by people who ultimately reach different conclusions about knotweed. Someone might still decide that targeted removal is warranted, but ideally they’d do so with an awareness that they’re making a provisional judgment within a complex, evolving system—not declaring themselves the final authority on how that system ought to function.

» Trance:

It’s always about epistemology, isn’t it? And again with the “available evidence” repetition. I understand why, but it’s a tired line. We live in a world where virtually all corporate and institutional interests actively and aggressively hide, obscure, delay, misrepresent, or entirely destroy “available evidence.” What’s left? Patterns, speculation, observation, intuition, discernment. Glyphosate is an unnecessary evil that no one needs to use, ever, for anything. In my view, there’s no debating that.

You said:

“We’ve repeatedly discovered that interventions justified by the best science of the day had consequences that weren’t anticipated. That’s true in agriculture, medicine, forestry, fisheries, and wildlife management. The lesson isn’t necessarily that science fails; it’s that complex systems routinely exceed our ability to predict them.”

Unanticipated consequences are the desserts that make the capitalists and their ensuing corporatocracy salivate. As long as they’re allowed to influence and dictate governance, human civilizations will inevitably have to rise, destabilize, and fall. A topic for another time. In practice, it’s another form of guessing and dosing. Same as cartel medicine, yet again. The argument today is that “AI will save us! It can predict everything now! Give us all your data, let us surveil your everything, because humanity is in danger… from itself.”

You said:

“But ecology itself has become increasingly diverse over the past few decades.”

That’s a rather bold claim. “Ecology” is a worldwide system. What timeframe are we talking about? What do you mean by “more diverse”? What part of the greater cycle are we in, definitely, absolutely? How often do “invasive species” show up exactly when they’re needed to initiate shifts and changes in an ecology that no living creature would ever judge unless they had the ability to quantify, qualify, and measure them, good or bad?

If ecology is more diverse, it’s because complexity has arisen from those who are better today at calculating, cataloging, and tracking the data. That doesn’t mean it is, in reality, any more diverse or complex than it ever was. What would seem to be necessary is a regular audit of classifications and categorizations, rather than perpetuating false or fallacious logic forward in perpetuity because “that’s how it’s always been,” and “that’s the system we rely on.” It becomes a traditional power struggle involving egos, status, and purported “results” that justify funding, politics, and policymaking. That’s another familiar pattern.

I don’t think we’ll find a solution here, and no one from the industry will read this, but others may be curious and want to be better informed, especially if they’re tasked one day with managing or tending their own property or something nearby that might affect their water supply, vegetation, insects, pollinators, and wildlife.

I agree it is the difference between engineering and stewardship. Because we’re seeing it every day, because “people value it today,” it must be engineered. Let’s close with some final thoughts.

» ChatGPT:

I think this conversation ends in a place that’s actually more interesting than where it began. It started with knotweed, but it became a discussion about how we know what we think we know.

One thing I’d adjust in my earlier wording is this: when I said ecology has become “more diverse,” I didn’t mean ecosystems have become more diverse, nor that ecology as a field has somehow progressed toward a truer understanding of nature. I meant that there are now more competing schools of thought within the discipline than there once were. Fifty years ago, management often emphasized control and restoration to a historical baseline. Today, you’ll also find researchers studying “novel ecosystems,” resilience, adaptive management, rewilding, Indigenous stewardship, and other frameworks that question older assumptions. Whether those newer approaches are improvements is a separate question, but the conversation within the field is less monolithic than it once was.

The larger point you’ve been making, however, isn’t really about ecology. It’s about institutions.

You see a recurring pattern: a problem is identified, specialists define it, models are constructed, urgency is communicated, funding follows, interventions are deployed, unintended consequences emerge, and the same institutions that produced the intervention often position themselves to provide the next solution. Whether one sees that as an inevitable feature of modern bureaucracies, of capitalism, or simply of human nature, it’s a recognizable pattern that has played out in many domains.

Where I’d add nuance is that recognizing a pattern doesn’t, by itself, establish the cause of every instance. Patterns are valuable because they prompt questions, not because they answer them. They encourage us to ask, “Are we seeing another example of this, or is this genuinely different?” That distinction matters because history also contains examples where intervention prevented substantial harm. The challenge is that we rarely know with certainty which category we’re in until much later.

Your point about evidence also deserves a distinction. I don’t use the phrase “available evidence” because I assume institutions are transparent or incorruptible. Quite the opposite: evidence is always incomplete. Data can be withheld, incentives can distort research, and publication can be selective. Those are real limitations. But if we abandon evidence altogether in favor of intuition or pattern recognition alone, we create a different problem. Human beings are exceptionally good at recognizing patterns—even ones that aren’t there. The most durable understanding usually comes from allowing observation, intuition, skepticism, and empirical testing to check one another rather than elevating any one of them above the rest.

On glyphosate, you’ve reached a moral conclusion: that its use is never justified. Others weigh the same risks differently and conclude that limited, targeted use may be preferable to certain alternatives. That’s ultimately a normative disagreement as much as a scientific one. Science can estimate risks and outcomes; it can’t decide what level of risk is morally acceptable or what values should take precedence.

Perhaps the most valuable takeaway for someone managing land isn’t a prescription to spray or not to spray, but an attitude.

Approach the landscape with curiosity before certainty.

Ask what conditions allowed a species to flourish before assuming the species itself is the root problem.

Consider interventions as experiments rather than permanent truths.

Pay attention not only to what changes immediately, but to what changes years later.

And remain willing to revise your understanding when the land teaches you something your models did not predict.

In that sense, stewardship asks more of us than engineering. Engineering seeks control over a system. Stewardship begins by acknowledging that we are participants in one.

Whether someone ultimately decides to remove knotweed, leave it alone, or try another approach entirely, that mindset may be the most important part of the conversation. It encourages both humility and responsibility—recognizing that our actions matter, while resisting the temptation to believe we’ve fully grasped the complexity of the living systems we’re acting upon.

The chat has been edited for readability. Full chat:

https://chatgpt.com/share/6a4936d5-4f64-83e8-a67a-3325c18cd39c

Solvitur ambulando