The tail of application wagging the dog of knowledge: is ecological science fit for policy?

This is a guest post by Carsten Dormann. It is his invited keynote lecture at the 2021 Annual Meeting of the Gesellschaft für Ökologie in Braunschweig (specifically on 1 Sept 2021 at 8:15). The topic of the conference was “From Science to Policy”, and he deemed it necessary to question whether thus step is not a bit early.

Dear fellow ecologists, dear ladies and gentlemen,

it’s an honour to be given the opportunity to talk to you about something I deeply care about. As you will see, it is not a scientific talk, but rather reflections on the current state of ecology as a science, and more specifically, a science to be taken seriously by policy. As the title of the talk suggests, my impression is that “applied ecology” is a much larger body of ecological research than “academic ecology” or “fundamental ecology”. And this “applied ecology”, in my view, does not build on ecological knowledge, but only pretends to do so. It is thus a case of the tail wagging the dog.

Let me start with two anecdotes, one COVID-related, one about oil. At the rise of the B.117 variant of COVID (now called “alpha”), early indications were that it would transmit 70% better, but not increase mortality. BBC’s “More or less” presenter Tim Harfort put the following statement to his interviewee: “Thank god it is only 70% more transmissible, not 70% more deadly!” She put him right: “Actually, 70% more transmissible will lead to far more deaths than 70% more deadly, as the disease will infect much more people; and a higher exponential increase in infections multiplied with a constant proportion of deaths is worse than a lower exponential increase multiplied by a higher proportion of deaths.” “Mortality” sounds worse than “transmission”, but it is the effects that count, not the word.

The point of this anecdote: our intuition may easily fool us; we have to do the maths.

The second anecdote is about “peak oil”. Back in 1956, when a geologist called M. King Hubbert coined the term “peak oil”, this was about the rate of oil production in an oil-dependent world, not about greenhouse gas emissions. Having analysed oil production data, he predicted its peak for the 1970s. The fundamental flaw of his concept became apparent in the following years: oil production and even oil exploration was heavily demand-driven; oil field exploration was simply too expensive at the low oil prices of the 1950s, but picked up dramatically during the oil crisis of the 1970s. The higher oil price made new extraction technology affordable, such as deep-sea drilling or oil sands. The moral: it was an economic pattern that Hubbert wrongly attributed to geology.

The motivation for these anecdotes will hopefully become clear in due course.

The leading question behind this talk is “Is Ecological Science fit for policy?” One difficulty in answering this seemingly simple question lies in the huge variability of what we refer to as “Ecology”. As insiders of this discipline, we, all of us, are likely to be aware of which sub-fields that are more developed and which lack scientific rigour; which are very close to application, even to engineering; which aloof and theoretical; which that are mainstream in our teaching, and which are considered orchidean, even esoteric.

Looking from the outside, be it as an environmental manager in a big company or a governmental body tasked with countering the loss of biodiversity, such internal rifts and nuances are much less apparent. Ecology, as a science, benefits in the perception of the outside world from those scientific disciplines already part of policy since many decades: law, economics, medicine, engineering, history. Outsider as I am to all of these, I still suspect they harbour a similar diversity of schools, thoughts, ideas and approaches, and dare I say it, competences, as our own field of Ecology. However, the pressure of demand from policy has forged a subliminal understanding, within each of these fields, that in order to retain influence over political and societal decisions, critical and dissenting voiced must be channelled to and reflected within disciplinary conferences and workshops; they must not be allowed to taint the glossy image that each of these disciplines presents of itself to the world beyond.

I am no historian, no economist and also no sociologist. So these thought are largely speculative, although formed by discussions with colleagues from exactly these “established” policy-forming fields of science. I was amazed, when a relative of mine, who studied Mechanical Engineering, literally bit his tongue when I criticised an engineering blunder made by one of his colleagues. He agreed, heavyhearted and only after several glasses of wine, but his upbringing in his profession triggered immediate defence mechanisms against any such accusation. My criticism, which only repeated points made in a newspaper article I had read, touched his feeling of belonging to the accused profession. He identifies very strongly with Mechanical Engineering and hence any critique of his profession, justified or not, is a criticism of himself.

Again, I cannot speak for you, dear audience, but I personally hardly feel any defence reflex when I hear a colleague being taken to task by the media. More often than not, I am actually rather pleased when another overblown statement by a fellow ecologist is shredded by skeptical journalists and meticulous investigation by a layperson. It may be part of my misanthropic character, but I rather suspect that scientists by and large are individualistic and quirky and hence do not easily feel a strong sense of companionship with somebody, just because that somebody happens to have studied the same subject. So what I guess I am saying is: ecologists don’t make for a tight-knit bunch such as legal scholar, engineers or medical doctors.

Does that matter? To see that it does, imagine you were asked to review a report submitted to a federal legislative body on, say, the effect of insect decline on agriculture, forestry and natural ecosystems in your country. This topic is so broad, that many of us would feel qualified to comment at least on parts of such a report. Now imagine further, the report suggests that a future with an 80% loss of insect biomass would actually be beneficial to agriculture, leave forestry largely unaffected, but would be catastrophic for natural ecosystems. What would your comment be, and why?

I suggest that your comments would hugely depend on your own background in ecology and whether you know the background of the scientists who wrote the report. Your background is important because it will show whether you look at insect decline as a loss of pollinators, or as a loss of crop pests. And their background is important, as it allows you to better agree or disagree with their way of thinking: “Ah well, Christian Ammer always looked at it this way.” If my surmise is correct, we base our acceptance of a scientific report not on its content, but on how well it chimes with our view of the world. And since every ecologist has a different outlook, one cannot expect them to agree.

Scientific consistency is important at the science-policy interface, because it represents a check against advocacy bias. Why would any scientist agree to write a policy report? Seems an obvious waste of time! There is a very good reason why ecologist would in fact be willing to provide an answer to such vaguely scoped question: the lure of influence! The chance to change the dismal state our natural world to the better! The opportunity to bring to the forefront of legislation a topic so important to the biological world as climate change or loss of biodiversity or eco-farming or groundwater pollution or … you name it.

Advocacy is common to all walks of science. It becomes problematic in a judicial sense when the expert witness, and this is what such a report stands for, is not reporting impartially. In court, any witness with a clear grudge against the accused would clearly be incredible. Similarly, advocate ecologists become incredible as scientific witness. Well, I am not suggesting that we should not have an opinion, but we should have a system in place that provides checks and balances for whatever opinion we may have when making scientific statements. And that is what legal scholars, engineers and even economists have: a way to make a statement credible to their community. I imply, and state explicitly, that we ecologists do not have such a system. My statement will rub you up the wrong way, and I would not defend your statement to my grandmother! And rightly so, I guess.

The above-mentioned tightly-knit disciplines sing from the same hymn sheet. They may disagree on many aspects, but they have a canonical training so that every scholar knows the way the others in the field think, which arguments have weight, which methods are reliable. Legal scholars may disagree, but they are convinced that their profession is sound: why? Because they know how each other lawyer thinks. Their mindset is similar, their philosophy and logic is trained and tested during their education to follow the same lines and standards!

Returning to the insect decline-report, I would not trust any of my colleague’s statements unless I know how they think and work. In Ecology, some such statements are “expert guesses”, others are based on lengthy meta-analyses. Some consider “unnatural”, genetic-engineering alternatives, others mix in their love of six-legged creatures. Some will regard the problem abstractly, theoretically, mathematically, others will rely on experimentation. But across this diversity of justifiable approaches, which are sound enough to make a sweeping statement? Does a genetically-minded entomologist accept the approach of a theoretician? The experimentalist that of a conservation biologist? I suggest they would not. I believe we have quite a bit of faith in our approach, but less in theirs. We do not understand their approach enough, and we weren’t forced in our training to actually understand it. I claim that we do not know which approach to take for a given problem, which approach is the most likely to yield the correct answer. We weren’t taught the tools of our own trade! And if we were, we still would not employ them, but hope that our approach would be qualitatively good enough.

When we face global problems, who knows what will be the best approach? There are issues of scaling-up local processes, which we can only tackle theoretically. But there are deficits in our process understanding which we can resolve only through experimentation. It is no fluke of human behaviour that we have sub-disciplines in virtually every field of science: it is a necessity.

At the same time, any scientific field, including Ecology, must have coherence. If it has not, it remains a loose assortment of ideas and methods, like medieval medicine: stubbornly sticking to traditional practice such as blood-letting despite ample evidence of its harmfulness and in the face of substantial progress in physiological understanding. Such science not only performs worse than it could, it also absolves malpractice.

In medicine and physics, coherence came with undeniable evidence of superiority of correct science. Pasteur’s sterilisation “simply worked” for preventing wine from turning sour, irrespective of whether winemakers shuddered at the idea of cooking their product. When you lose 30% of your business to germs, you happily embrace some short heating under pressure, and hide this practice under the term “pasteurising”.

My view on Ecology is that of an incoherent discipline. While we have ecology textbooks, particularly Begon/Harper/Townsend, Krebs, Wittig/Streit and Nentwig/Bacher/Brandl, I dare to claim that few in this room were actually forced to understand them in each detail. Ecological teaching is still heavily driven by anecdote and personal experience. In particular theoretical ecology and ecosystem ecology are given short shrift in most universities, because they don’t seem to contribute to progressing Ecology. In historic analogy, the Maxwell equations of electromagnetism were ignored by experimental physicists, because they were difficult. Only because they worked magnificently, they managed to become staple food for any modern physicist. Being right is a powerful argument.

My dire reading of the state of Ecology is that we work in a specific way, and not in another, because that’s what we were trained in. Epistemologically, that’s a disaster! If we want to solve a problem, we should use the best possible method, not the most convenient. That, in turn, requires that Ecology students must be taught the full breath of topics, approaches, ecosystems and organisms. Handling mice in the field, identifying spiders, simulating partial differential equations and measuring marine carbon fluxes. This is not the place, and I am not the right person, to develop the elements of such an Ecology curriculum. But I strongly believe that we need a dramatic overhaul, a canonical curriculum of Ecology, based on concepts, skills and techniques that generalise, not on the individual competences of the lecturer.

I think that such a canonical curriculum is needed because of a side-effect, which motivated this talk today. We would start to understand each other! If we all knew how to carry out behavioural experiments with hoverflies, we would be able to evaluate the importance, or lack thereof, of this approach. If we had all learned how to take field measurements of decomposition rates, we would be better positioned to assess models of ecosystem carbon balance. We might not like doing it, but in the interest of a comprehensive understanding of natural processes we ought to do what is best for science. How shall we ever make progress if we turn around at every wall that comes in our path? Think of the bias we produce by accepting coarse approximations because we can’t be bothered to do it right? The catch-phrase here is “Better some poor estimate than none at all.” If this statement were correct, and I doubt it, it is only correct transiently; it implies that we have to strive for better estimates, not give up and run with poor estimates.

I hear your objecting. But your arguments are advocative, not epistemological. That is, you argue for Ecology to have an impact, not for Ecology to know more.

So, that was my analysis. What’s for therapy?

To proceed with making ecology an applicable science, four elements are required:

(Initiative 1. Define a set of principles, laws, theories, fundamentals.)

(Initiative 2. Define a set of procedures, models, rules to apply these principles to specific situations)

(Initiative 3. Evaluate the track record)

(Initiative 4. Identify the limit of competence and possible system understanding)

Element 1: Define a set of principles, laws, theories, fundamentals.

Ecological systems differ hugely. Arthropod abundance in tropical forests are very different from particle absorption in urban parks, yet both must be investigated from the same scientific stance. What are the “fundamentals” that allow ecologists to make educated guesses about either? How can a Singapore-trained ecologist formulate expectations about how the marine ecosystem of the Baltic functions? While arguably Ecology has no “law”, we are not theoretically ignorant either. Ecological systems, with very few exceptions, build on energy captured by plants, consumed by herbivores (if we allow fungi to be included in this category as well), which in turn are consumed by higher-order consumers. More energy input can only be translated into more biomass in all these trophic levels, if plants are not limited by nutrients. And such constraints exist at each level, and they are heavily physiological, and not species-specific. Now, I cannot claim to have developed such a set of principles, but others have contributed substantially to it, and whether you pick up the book by Mark Vellend or Michel Loreau, the key is here to see the fundamental ingredients of ecological theory, and not be sidelined by the many cases where we find these principles do not yield the full picture. My point is that we need to know what our building blocks are, before we build an expectation. Of course, these fundamentals are also fundamental to teaching Ecology.

So, first element: theoretical principles. But what do we do with them? The second element is thus a “identify a set of rules, procedures, a workflow of how to approach an ecological problem by applying the building blocks”. An engineer, building a bridge, is fully aware of a long checklist of engineering rules: statics, material engineering, computing resonance frequencies, calculate torsion, wear and tear, maintenance intervals, and, of course, legal requirements. What is on the checklist of ecology?

Any approach to a problem in ecology, fundamental or applied, can be expected to start with a few reasonable basics: what are the main compartments of the system?; what are the main fluxes of energy, water, carbon?; what are the main constraints for plant and animal population growth; what the limiting resources for the subsystem of interest? In our human-dominated world, I deem it reasonable to ask which of these pools and fluxes is most strongly affected by human activity, how our input and harvesting scales relative to natural processes. Probably we may want to elucidate whether individual species have disproportionate abundance, and whether there is communality in traits within each relevant community. The spatial boundary of the system of interest should be delimited, and the temporal scale of dominant fluxes must be discovered. All that is probably what many ecologists do anyway, without giving it much thought. Doing it a bit more formally we may avoid barking up the wrong tree, such as identifying hundreds of tree species in a tropical forest when the leading process of change is fire.

So, theoretical principles, and rules for addressing ecological problems. But will this lead to better application? The third element is thus indeed to evaluate our recommendations, to build a track record.

The technical term here is “to build an evidence base”. Whatever our ecological fore-bearers and ourselves have suggested in ecological applications needs to be evaluated. Did it work out? Were suggestions revised, adapted, withdrawn? Did the system respond in roughly the way we anticipated, or did some element of surprise render all our suggestions void?

Building such an evidence base has substantial scientific value, as it allows us to compare our guesses (call it “predictive hypotheses”, if you prefer) with reality. When did we get it right? Which element was missing on our step-2-checklist? Were first-step fundamental violated? So we can learn from our guesses, particularly those that went wrong.

And we can also show off those that went right! We can be the bridge architect, who can point to reference works across rivers and canyons. “Nothing is as sexy as success.” as the saying goes, and sure we all want Ecology to be sexy!

Really, evaluating evidence is a no-brainer, an obvious win for ecological science and its application.

But we must also know when to stop! Having identified a set of principles, defined a checklist of rule, and evaluated their usefulness, we must also learn when to shut up. Our knowledge, our system understanding can only take us so far, given the enormous complexity of virtually any ecological system. It would be unreasonable to expect detailed quantitative long-term predictions for specific species, for example. When multiple drivers vie for influence over a specific system, how can we possibly predict which way evolution and randomness will move it? Delimiting the domain of our knowledge, in time, in space, in detail, is crucial for credible applications. If we pretended to know what the central European landscape will look like in 2100, as the scientific literature sometimes seems to suggest, we should consider ourselves clairvoyant, not scientists. No economist is expected to know what the market will be like in 20 years, so why should we strive for the impossible? It is not a sign of weakness to admit unpredictability, or ignorance, but an act of credibility.

So, there you have it: I believe that ecology is not ripe yet for policy advise on a big scale:

1. We have no common ground to keep in check the advocative bias of scientific statements at the policy interface. At present, we cannot reliably tell between an advocate and an impartial witness, and the same person cannot be both.

2. We have no track record of Ecology-led advise to be superior to “common sense”. I believe it is, but we need the facts to show off with.

3. Our discipline, Ecology, lacks coherence due to a lack of a canonical academic curriculum.

Beyond provocation, I hope this talk has hinted at some possibly ways forward. I firmly believe that we need to provide the next generation of ecologists with a much more comprehensive education, one that teaches fundamental principles, application rules, evidence-assessment and domain limitations. A curriculum that allows ecologists to talk a common language irrespective of whether they studied in Kiel or Konstanz, in Kiew or Kyoto, and whether their main interest lies in carbon sequestration or carabids.

I hoped during this talk I managed to step on some toes; my aim was to challenge the current (applied and fundamental) ecological modus operandi. Thank you very much for enduring my opinionated statements, particularly in this very uncommon and hopefully never-to-be-repeated online experience!

Featured image by Hebrew Matio, CC BY-SA 4.0 via Wikimedia Commons


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