What Values Inform Our Ecological Debates?

In the not so distant past, before there was a “collective fixation on global warming as the mother of all environmental problems,” as Jon Foley lamented in 2009, biodiversity was the poster child for environmental crises. It was an issue that captivated journalists, scientists and greens alike–much as climate change does today. Indeed, concern over  the loss of biodiversity and how that impacted the overall health of the planet was once a frequent topic of discussion in leading scientific journals. For example, here is the summary overview of a review article for Nature in 2000 by a group of biologists:

Human alteration of the global environment has triggered the sixth major extinction event in the history of life and caused widespread changes in the global distribution of organisms. These changes in biodiversity alter ecosystem processes and change the resilience of ecosystems to environmental change. This has profound consequences for services that humans derive from ecosystems. The large ecological and societal consequences of changing biodiversity should be minimized to preserve options for future solutions to global environmental problems.

At this time, there was a lively debate within the field of ecology as to what extent species richness (i.e., diversity) contributed to productive (and resilient) ecosystem function. (This debate pivoted off a 1972 paper by Robert May, published in Nature, that suggested ecosystems with higher diversity actually tended to be less stable; the mathematical formula that May used–which upended a long-held assumption in ecology– was revisited last year.)  In 2010, Michel Loreau published an excellent essay on the state of this debate, tracing its history, underlying tensions, and connection to global environmental policy. He noted:

The relationship between biodiversity and ecosystem functioning has emerged as a central issue in ecological and environmental sciences during the past 15 years. The idea that greater plant diversity allows greater plant biomass production dates back to Darwin (McNaughton 1993Hector & Hooper 2002), but it was only in the 1990s that the interest in the effects of biodiversity on ecosystem functioning penetrated experimental and theoretical ecology. This interest spread very rapidly, leading to an entire new research field at the interface between community ecology and ecosystem ecology (Schulze & Mooney 1993Tilman 1999Chapin et al. 2000Loreau 2000Kinzig et al. 2001Loreau et al. 2001Loreau et al. 2002bHooper et al. 2005Balvaneraet al. 2006Cardinale et al. 2006Cardinale et al. 2007).

Loreau goes on to discuss the experimental field and laboratory research that “has now clearly established that biodiversity does indeed affect ecosystem processes.” But the final verdict was not exactly ironclad, as he sort of admits here:

Although rigorous empirical support for the new diversity”“stability theory is scantier than for the effects of diversity on biomass and production, a few experiments that have manipulated species diversity have provided clear evidence for its stabilizing effect on ecosystem properties in both plant communities (Tilman et al. 2006) and aquatic food webs (Steiner et al. 2005).

In any case, the biodiversity = robust ecosystems train had already left the station, as Loreau explains:

Because its initial impetus was provided by the societal relevance of the issues it was addressing, biodiversity and ecosystem functioning research also impacted on social sciences and environmental management. The results of this research supported the work of the Millennium Ecosystem Assessment (2005) on the links between biodiversity, ecosystem services and sustainable development. The value of biodiversity as insurance against the uncertain provision of ecosystem services is being incorporated formally in ecological economics (Armsworth & Roughgarden 2003Baumgärtner 2007).

Meanwhile, in a 2009 historical overview of ecological paradigms, Matt Chew observed that “different concepts of stability, diversity, and complexity” have, over time, shaped the studies that have sought to identify the most essential properties of ecosystem function.

Regardless, a new review paper just published in Nature coronates biodiversity as the winner of this long-simmering debate. Among the paper’s key findings:

There is mounting evidence that biodiversity increases the stability of ecosystem functions through time.

Diverse communities are more productive because they contain key species that have a large influence on productivity, and differences in functional traits among organisms increase total resource capture.

Coincidentally, and just before I saw the latest Nature paper, I had inquired on twitter about the status of the biodiversity/ecosystem function debate. “Which side came out on top,” I asked?  One scientist responded, “Neither.. it was a theoretical vs. non-theoretical ecologists debate.” Another said, “It’s a subjective question, b/c it asks what we value about ecosystems.”

Precisely. The debates we’re now having over planetary boundaries and tradeoffs between development and conservation are based, in large part, on subjective notions, so asking what we value (and why) seems like something that should be a big part of the discussion.

25 Responses to “What Values Inform Our Ecological Debates?”

  1. Tom Fuller says:

    I guess the first question really is, ‘have ecosystems been more stable in the past?’ Before we start talking about changes we’re causing, don’t we need an understanding of changes we’re not causing?My limited understanding is that we are discovering that a Platonic ideal of nature undisturbed is a myth, that ecosystems are by nature unstable and even ephemeral, and restoring an ecosystem involves very subjective judgement calls that tell us far more about ourselves than about nature.

  2. Eli Rabett says:

    The ecologists are not calling current times the sixth major extinction for nothing.  OTOH, Keith is pulling we can’t chew gum and walk, one track look over there business he is so famous for.  Newspapers have more than a single column Keith.Yes Virginia, we can have two huge problems and it does not help that one of them (climate change) makes the other (ecocide) worse.  That doesn’t necessarily make it more important but it does mean that both have to be kept in mind.

  3. BillC says:

    What Rabbett says is beside the point of this article. We need to be a little bit clearer about why we value what we value and in some cases, understand that we are not going to get our way if what we few “elite” value for occasional aesthetic pleasure is the same as what many value for sustenance.

  4. BillC says:

    #1 Tom Fuller – I think the issue of whether undisturbed nature is a myth or not is less important than understanding that it’s been on its way out, for a long time now.

  5. Tom Fuller says:

    I agree, BillC, but my real point is that we have to have measurements or we end up with silly comments like Rabett’s. Fact-free pronouncements of ecocide interfere with real analysis. Sixth Extinction has about as much connection to reality as the Fifth Element, and where’s Milla Jovovich when we need her?

    Humans are dramatically altering the environment. We are threatening the long-term existence of countless species. We are terraforming this planet without a plan. But a plan starts with measurements. Not nightmarish fantasies.

  6. Dean says:

    No measurements? Fact-free? I understand that estimates of the current extinction event vary, and many are considered debatable in various degrees. But measurements are being taken and whatever the level of debate, the phrase “fact-free” does not seem to apply. I also don’t think that most scientists involved hold to the old myth that pre-modern societies had no impact on the environment. They had many impacts, but for the most part, causing an extinction event was not one of them. However, some scientists studying the issue think that the suggested connection between human migration to the western hemisphere and extinctions that occurred then could be considered the start of the current extinction event. Another controversial idea, but one that also shows that the said myth is not strong within the scientific community.

  7. MarkB says:

    Talk of ‘ecocide’ begins with panglossian thinking. We are in the best of all possible worlds, and any change is necessarily bad, in both proximate and ultimate senses. An ‘ecosystem’ is an accident of history. The Gods of Nature did not chose species to coexist with one another. An ecosystem is the accident of what happened to be available at a particular time, plus, given time, evolution. The place I’m sitting right now was covered with a mile of ice 20,000 years ago. The ecosystem that had preceded that ice sheet was utterly destroyed. When the ice sheet retreated, it left a dry, windswept tundra like nothing on the planet today. Gradually, a new ecosystem replaced the old, and a new one after that. And so it goes. No particular combination of species has an ‘ecosystem’ right to exist. And any combination of species will eventually reach a balance that ecologists label a system. The concept of good and bad ecosystems is nutty in the extreme.

  8. Dean says:

    @7 – So does the fact that a large landslide could wipe out a village and kill hundreds of people mean that it is not a problem if we drop a bomb on them and kill them? The concept that an extinction event is a bad thing is at some level dependent on our values, whether or not the stability-diversity argument holds up. If we are not going to apply our values to our impacts on nature, why should we apply them to our impacts on each other? Natural events kill people all the time, but murder is bad. Natural events can cause extinction events, but that doesn’t mean it is okay for us to. Nature may not care, but who is asking nature? The vast majority of us humans care. Whether they care _enough_ to stop it is another issue.

  9. huxley says:

    The view from 40,000 feet is that environmentalists have spent the last fifty years searching for a Holy Grail, an environmental crisis so potent that it would stop humans from changing the planet any more.

    We have seen so many of these threats du jour: insecticides, pollution, overpopulation, global cooling, ozone depletion, global warming, crop monoculture, the sixth extinction, biodiversity, the coming plague, climate change, and, now — hot off the Nature press — planetary boundaries and tipping points.

    Environmentalism seems to be a computer program that can only turn out one kind of answer. “Any color [you] want, so long as it is black,” as Henry Ford said.

    I too worry about the environment and the grand terraforming experiment we humans have undertaken. I don’t question that we need scientists studying the earth and looking ahead for planetary boundaries.

    But I spent most of my adulthood living in fear that civilization was about to collapse because of some tipping point. I did not expect to live into the 21st Century. Yet I have and I look out the window and see a mostly flourishing world, more crowded, but otherwise not that different from the one I remember as a child.

    Of course, that’s the way it is with tipping points. Things are stable and good until they aren’t.

    I don’t have an answer to this. However, I would like environmentalists to reflect on their habitual warnings of doom.

  10. Tom Scharf says:

    Mastery over the environment is a good thing.  Period.  

    Certainly we must be careful of unintended side effects, but we need not be fearful of them.   Progress has a price, and there is a valid question on what that price should be.  

    Trying to progress as a species while never making a mistake only works to severely inhibit progress, and guess what?  You make mistakes anyway.

    History is littered with misguided feel good conservative policies. Stop forest fires has now “progressed” into intentionally setting scheduled forest fires before too much ground build up occurs.  I predict scientists will soon discover that the randomness of old fashioned forest fires also plays an important role in the eco-system. 

    Nervous Nannies such as Eli are counter productive to even their own causes.  

  11. Jeffn says:

    ” Natural events can cause extinction events, but that doesn’t mean it is okay for us to.”

    That’s an interesting point. I don’t necessarily disagree with the thrust of it, but leaves me cold too. Are humans not “natural” parts of the ecosystem? An extinction event caused by a parasite hitching a ride on a bird is “natural” as long as the bird never rests on a boat?
    One other thought to toss out there- human attempts to “manage” and “preserve” ecosystems have been quite damaging as well. Yellowstone is a good example.

  12. BBD says:


    Following on from Dean at # 7…

    I could easily beat Mrs BBD to a pulp. That doesn’t mean it’s okay that I do.

    Does that clarify a little? Or are you still ‘left cold’?

    We have a responsibility because we know what we are doing.

    Although we can avoid that responsibility by retreating into glibness and denial.

  13. Jeffn says:

    True, you do tend to drift to glibness and denial, but it’s not as simple as you’re strange example. A den of foxes will eat every chicken in town. So will a den of BBDs. Is the latter “unnatural” chicken extinction?
    An effort to restore the chicken population would devastate the native worm population- a natural or man-mad and therefore unnatural outcome?
    It is, in fact, impossible to name an animal that has no affect on its environment so at what precise point does human impact transition fron natural to unnatural?

  14. Nullius in Verba says:

    Would it be good, then, for genetic engineers to go out and create more species diversity? And release it all into the wild?

    Diversity = Good, right?

  15. Eli Rabett says:

    Cassandra was always right.  Bear that in mind

  16. Eli Rabett says:

    Eli has a somewhat longer view than most here, probably because the bunny is somewhat older, and also because his parents were born at the turn of the 20th century and lived a right long time, let alone their parents.Nature was pretty much undisturbed 200 years ago.  Population density was much lower, technology much cruder and less intrusive.  No contrails until about 50 years ago.So yes, compared to today, nature was little disturbed 200 years ago, which is not so long ago.

  17. Anteros says:


    Cassandra was always right.

    Ehrlich was always wrong.

    Is it a gender thing?

  18. kdk33 says:

    Actually, from a rabbit’s point of view people are perfectly natural, it is the rabbits who are a scourge.  A wise rabbit would lobby for rabbit condoms so people whould have an unmarred landscape in which to thrive.

  19. huxley says:

    Cassandra was always right.

    But the modern environmental Cassandras have a very checkered record when it comes to prophecy.

    All their Seventies claims of imminent global starvation and death of the oceans were wrong. It is arguable that environmentalists have the blood of millions on their hands on account of their opposition to DDT.

    Some of my skepticism about climate change stems directly from all those earlier scientific claims and computer models that were wrong.

  20. BBD says:

    Is it a gender thing?


  21. Eli Rabett says:

    Troy did not fall in a day

  22. Biodiversity? How about deadzones off the coasts of most every populated area in North America and  Europe with rapid increases in Asia? How much biodiversity do they have now? Not much, just a homogeneity of algae and jellyfish. Is that bad? For all the organisms except jelly fish and a species of two dinoflagellates, of course it is. Whats going to happen when they merge?Deforestation and its loss of biodiversity? Is that good? What benefits might we expect?Perhaps a deeper understanding for why we value biodiversity can be understood when one puts down the axe from the grindstone against conservation. (which is common, most commenters here forget that conservation is ignored and marginalized most everywhere and for all the chatter about WWF or NRDC bear in mind, on balance, the revenues from Exxon Mobil are greater than Saudi Arabi’s GDP). @Huxley: Bloodied hands from DDT? You should check to see how fast Mosquitoes acquire resistance to DDT– its quite fast. In any public health decision there are negatives, how many cases of cancer, birth defects, failed crops were averted, for instance. DDT for all would have “bloodied” a great many hands, would it not? Such a conjeture absent the counter balance of the broad and deep knowledge base underpinning DDT bans is of little use. 

  23. Dave H says:

    Diversity provides buffers and redundancy that protect ecosystems as a whole from the stresses experienced by individual species. For example, the less diversity, the greater the ease with which disease can gain traction in a population and spread uncontrollably – at the extreme end, monocultures are inherently fragile and susceptible to total collapse. Preserving biodiversity boils down to a value judgement only in the same way that self-preservation does.

  24. Tom Fuller says:

    Nobody is arguing against biodiversity. Nobody is campaigning on the platform ‘kill, kill, kill.’ 

    I don’t think many, if any at all, argue that man has not had a significant and negative impact on many species. I must say I’ve never hear or read that.

    And I don’t think I’ve ever had someone say they are happy to live with mass extinctions if that is the price we must pay for development.

    But despite what Dave H says, preserving biodiversity is not at all about value judgments. It is about numbers. 

    There is an order of magnitude difference in scientific, academic peer reviewed estimates of the number of extant species. There is an order of magnitude difference in scientific, academic peer reviewed estimates of the number and rate of extinctions.

    There is a monumental difference in the geographic range estimated to be necessary to support vertebrate species and the actual range that is currently supporting them.

    Past efforts in support of biodiversity have actually helped. Why are we not referring to them and learning from them?

    This could so easily become a mirror of the climate debate–will we learn nothing from all this?

    1. Get some real numbers. Have them checked by professional statisticians.

    2. Those who are trying to advance economic development are not automatically in favor of contributing to a mass extinction. Tattoo that sentence backwards on your foreheads and look in the mirror. Frequently.

    3. Instead of trying to block development, establish best practices and push for them to become part of the process. Support those who try to adhere to them, instead of criticizing minor lapses. The world is messy.

    4. Recognize that biodiversity has its own rhythm and pace. Do not try and freeze life snapshot-style.

    5. Every now and then, re-read Stephen Jay Gould’s book, Wonderful Life. Just so you won’t walk around all discouraged.

  25. Doug Allen says:

    My values are reason, science, humanism, and compassion, not necessarily in that order.  From Erasmus and the  humanists up to the present, I’ve learned to be skeptical of truth claims that can’t be tested; therefore science and scientific method are my touchstones for truth.  From Jesus and Buddha I’ve learned to be compassionate and try to minimize suffering in the world.  Like everyone else, I poorly measure up to my ideals, but I keep on trying.  With training in biology and teaching of same, I value biodiversity and love to see my students awed by the incredible richness of the flora and fauna;  I hope they will want to preserve as much of it as possible even without proof that it’s good for humans to do so. Biology is a science of observation, and Darwin was a genius in seeing patterns in nature that had escaped so many before him.  As for the contentious and politicized topic of global warming/climate change, I was aware of warming where I lived (New York and Colorado) the past few decades, more so than most because I coached cross country skiing! So I guess you could say I was in the AGW camp from the beginning.  When I first saw Mann’s hockey stick, I began a thorough study, reading the IPCC assessments and eventually almost everything else. Since age 11- really!- I had been fascinated by weather and climate, and the Hockey Stick contradicted what I had learned in textbooks all those years- look Ma, no medieval warming period and no Little Ice Age!  My study has taken me from a strong AGW’er to a lukewarm one. I’m more impressed by observations of the empirical data and the climate record than by models that necessarily simplify this incredibly complex science and who’s projections can only be tested over a period of decades.  With over 14 years of flat-lining temperatures and no acceleration in either temperature or sea level rise as the models project, despite accerating CO2 levels, call me very skeptical of the CAGW alarmism that seems to have become part of the liberal and green political narratives.  I think science, liberal politics, and conservation are all hurt by the unreasonable and unscientific devotion to CAGW climate models which year after year find less and less support in the empirical data. 

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