Here, belatedly, is my promised follow up to the preceding Rambunctious Garden post. I’ve been travelling recently, and found myself sharing an old-style train compartment with a curious fellow who introduced himself as ‘Nick’. With the faint goaty aroma that enveloped him, his suspiciously round shoes and the bumps on his head poorly concealed with a demotic flat cap, it didn’t take me long to figure out who he really was. I like to think I managed to hold my own with him, but here at any rate is the transcript of my conversation with the old devil.
Nick: So, Chris, what are you reading there?
Chris: It’s a couple of blog posts by an agronomist called Andy McGuire.
Nick: Cool. What does he say?
Chris: Well, Nick, essentially he argues that
the view that agriculture should mimic nature is based on the mistaken notion that there is a ‘balance’ in nature
‘balance of nature’ ideas assume that ecosystems are in equilibrium, that they operate in accordance with meta-local rules and display emergent properties. None of this is true.
these ideas also mistakenly impute complexity and optimisation (or ‘nature’s wisdom’) to ecosystems, including the idea that pests are best controlled by retaining a complex agro-ecosystem
thus, finally, (and quoting Andy directly) “If what we see in natural ecosystems is not optimized, but random…we should be able to do just as well or better. We can, with ingenuity, wisdom, and a good dose of humility, purposefully assemble systems that outperform natural ecosystems in providing both products and ecosystem services.” The lesson, in short, is the one that gives Andy’s post its title – ‘Don’t mimic nature on the farm – improve it’.
Nick: I’m not your student, you know – you can spare me the bullet points.
Chris: Sorry.
Nick: But I like the cut of his jib. So nature’s not in balance, eh? It’s all randomness, disorder and chaos. I like that. I like that a lot.
Chris: Yes, I suppose you would. But that’s the first of my problems with his arguments. Manichaeism is all very well in religion – you know, heaven and hell, God and the Devil…
Nick: (splutters) Look, I was just a plain member and citizen of the celestial community, OK? The fact that certain fragile-egoed upstarts don’t like hearing truth spoken to power is not my fault.
Chris: Yeah, Nick, whatever. But leaving that aside, in the natural world there’s surely scope for some shades of grey. I mean, Andy seems to take the view that ecosystems must be either wholly optimised and in balance, or else wholly random. This neglects the surely more plausible possibility that they might be partially optimised and in balance, but also subject to random occurrences. His analysis draws heavily on Ford Denison’s work1, which makes the important point that organisms are more optimised than ecosystems because natural selection operates on the former and not the latter. That makes sense, but the fact that there’s a powerful optimisation mechanism acting on organisms doesn’t mean that they’re wholly optimised or in balance. By reverse logic, the fact that the optimising forces acting on ecosystems are weaker doesn’t mean that there is no optimisation.
Nick: Well, maybe. But then you’d have to specify what those external optimising forces at work in the ecosystem actually are.
Chris: Not necessarily. It’s possible for there to be emergent forces resulting from the interactions between the elements of the ecosystem which have that effect, without invoking some additional agency. I mean, for goodness sake, just take the evolved morphology or behaviour of predator and prey species, like wolves and bison. You can’t understand it as a sui generis form at the level of the species – it only makes sense as an emergent interaction between the species. And that’s just a simple dyadic relationship – there are so many additional complexities, some of which we probably don’t even know about, whereas others such as the ecology of keystone species or disturbance/stability dynamics we do. And yet McGuire argues, with little substantiation, that there are no emergent effects in ecosystems. You don’t need to hold to some strong Clementsian superorganism type view of ecosystems to argue to the contrary – I think those examples I’ve just given suffice, or Grime and Pierce’s arguments about the evolutionary strategies that shape ecosystems2. And I do wonder why people get so het up trying to disprove emergence in ecosystems. In economics, a discipline far more wedded to methodological individualism than is possible in biology, nobody seems to quibble about the notion of the ‘invisible hand of the market’ as an emergent property despite its quasi-mystical overtones.
Nick: The invisible hand of the market?
Chris: Yes, Adam Smith’s doctrine that people pursuing their own narrow self-interest in the market unwittingly produce socially beneficial aggregate outcomes.
Nick: People acting just for themselves produce social good? That’s the most depressing thing I’ve heard in ages!
Chris: Don’t worry, Nick – there are plenty of critics who argue that the invisible hand is more like an invisible foot, in which the mere pursuit of self-interest produces more collective misery than deliberate attempts to cause social harm3.
Nick: Now you’re talking!
Chris: Anyway, my point is that McGuire’s creating a straw man. If you look at the way people have articulated the ‘balance of nature’ concept, it’s much more sophisticated than some mystical notion of a steady equilibrium state. Look at people like Aldo Leopold or John Vandermeer or J. Baird Callicott – they don’t construe ‘balance’ at all in the way McGuire charges. I don’t necessarily agree with everything Callicott says, but he makes a lot of interesting points about emergence and balance in his essay on the topic4 – including that “stability is a notoriously ambiguous concept in ecology, and has more recently been parsed into several more specific concepts – persistence, resistance and resilience” (p.124).
Nick: Not human traits I have much admiration for…
Chris: Well, that’s as maybe, but a couple more points about this. First, while writers like Emma Marris and Andy McGuire are keen to distance themselves from Clements and pin their colours to Gleason’s standard, some of the people they cite in their favour like Stephen Jackson are much more ambivalent: Jackson says that while he considers ecosystems to be fluid and contingent, he also considers them to be entities with particular attributes and processes that are repeatable in space and time – and that Gleason and Clements aren’t quite the polar opposites that are often supposed5. By the way, he also reckons that ecosystem assemblages usually hang together only for about 12,000 years or so, which might be encouraging news for malcontents of civilisation and its unholy alliance of Homo sapiens with cereal crops.
Nick: Well, I like unholy alliances…but, oh, the fun I could have if that happened. (Collecting himself) Anyway, your second point?
Chris: my second point is that it might be better if we stuck with the quantifiable ecological science of concepts like resilience or resistance. Otherwise we just start yelling our preferred metaphors at each other. ‘Nature’s in balance!’ ‘Oh no it’s not, it’s in flux!’. Balance, schmalance, flux, schmux. This isn’t science, it’s just mythologisation.
Nick: Well, people need their mythologies…
Chris: You would say that, wouldn’t you, otherwise you’d be out of a job.
Nick: I’ll ignore that remark.
Chris: Yes, people need their myths and their shorthands. But as I suggested on Andy’s blog, the ‘balance of nature’ myth, though problematic in some respects – including real world cases such as the removal of indigenous peoples from nature reserves – is less problematic than the ‘flux of nature’ myth, which has been used through the ages to justify might is right, and the defeat of countless relatively sustainable agricultural systems and peoples in favour of destructively productivist ones. It’s not just me that thinks this either – various ecologists have pointed to the dangers of the ‘flux of nature’ metaphor along the lines of the ‘anything goes’ problem I identified in my previous post6. That’s why I think Andy’s post, despite I’m sure his noble intentions to articulate a scientific truth as he sees it, strikes me as ideologically loaded. It buttresses humanity’s already well developed tendencies towards hubris in supposing that it’s a simple thing to design human-improved ecosystems.
Nick: Yes, well if it weren’t for human hubris, my job would be a darned sight harder. But since you mention ‘human-improved ecosystems’ let’s talk about agriculture, which you haven’t really mentioned yet. Andy’s main point surely is that you can’t rely on the ‘balance of nature’ myth to design good agricultural systems. I mean, ever since I got humans kicked out of Eden (heh, heh), they’ve had to get by through agricultural systems that rely on humanity’s infernal ingenuity to improve on what the natural world can offer, and not through ‘mimicking nature’. Ford Denison is surely right that it’s misguided to mimic nature – things like perennial grain crops just ain’t gonna work.
Chris: Let’s try to unpick this carefully. So first, yes of course any type of agriculture is an ‘improvement’ on nature from a human point of view (or at least from the point of view of those humans practising it), though I don’t see how it can be described as an ‘improvement’ in any other transcendent sense. Nothing new there. I think what Andy’s really gunning at is the notion that we can best improve on our agro-ecosystems by better mimicking nature. In some situations, I’m sure he’s right. In others, I suspect he isn’t. I don’t think there are any cast iron laws of agro-ecosystem assembly that rule nature mimicry in or out. At one level, all agro-ecosystems involve nature mimicry: we’re a long way from creating purely synthetic food, much as the prospect appeals to some. At another level, I think Andy is using Denison’s ‘misguided mimicry of nature’ point misguidedly. Take perennial grain crops. If Denison is proved right that the perennial grain breeders will be unsuccessful – and I suspect he will be – the reason won’t be because the breeders erred in trying to mimic nature. It’ll be because they erred in not mimicking nature enough. To put it crudely, in nature we find short-lived, prolifically reproducing species and long-lived, cautiously reproducing species – not long-lived, prolifically reproducing species. Farmers have made use of this by, for example, rotating between annual cereal crops and grazed perennial grass leys – that’s a great example of good nature mimicry in an agro-ecosystem. But trying to keep your perennial grains and eat them? I’m not so sure. There are loads of other examples of good nature mimicry in agro-ecosystems, like mob-stocking to mimic the grass-ruminant-predator relationship I mentioned previously, or the research on the relationships between ants, scale insects, parasitic flies, ladybird beetles and parasitic wasps in traditional coffee production systems which suggests counterintuitively the need to retain ants in those systems7. Andy may not consider these things ‘complex’. Well, they’re complex enough for me, but what really matters is that there’s enormous scope for improving agriculture by mimicking nature. Denison’s point, surely, is not that it’s necessarily misguided to mimic nature, but that it’s easy to mimic nature misguidedly.
Nick: OK, OK – so there’s a role for nature mimicry after all. Are we done yet?
Chris: Nearly, Nick, nearly. One last point. A nice thing about Denison’s approach is that he’s very attuned to tradeoffs in a way that I think Andy’s posts miss. We may be able to ‘improve on nature’ in agriculture, but what are the costs? If I were trying to develop a new pumpkin variety, I’d probably want to improve on nature by hand pollinating my plants. If I had some kind of high value crop in a polytunnel, maybe I’d improve on nature by deliberately importing some pollinating insects. If I had a five acre field of these plants, I’d hope nature would just do the job for me. Maybe we’ll get into a situation where we’ve messed with nature so much that it’ll stop doing some of these jobs for us – in fact we’re probably already there in some cases. I think it’ll be hard for us to assume responsibility for many of these ‘ecosystem services’ at as low a cost to us as nature has provided, but as a thought experiment suppose we had to choose between a mini-drone we’d devised that could pollinate all our crops better than insects at virtually no cost, or the insects themselves…which choice, and why? Is the human ‘improvement’ of nature the obvious way to go here? Not to me. There’s also another tradeoff I’d highlight that I think Denison misses in a comment picked up by Andy when he says “Local sourcing of nutrients in natural ecosystems…is a constraint imposed by the lack of external inputs, not an example of ‘nature’s wisdom’” (Denison, p.106). Maybe that’s so in the sense that there’s no wise superorganism type ecosystem in a strong Clementsian sense, but I think Denison misses the opportunity here to apply his tradeoff approach, understood as “having more of one good thing usually means having less of another” (Denison, p.44). In human agroecosystems it’s easy to import extra inputs, but this usually imposes costs of various kinds elsewhere in the total system. Are tradeoff free improvements achievable through increasing the flow of exotic inputs, or, to put it another way, is there an ‘invisible hand’ in the exotic input market? Maybe, but how often? The tradeoff if we let exotic inputs get out of hand is the speed, scale and uncertainty of anthropogenic change, not to mention its social costs, which Denison in fact alludes to and so do most of the other ecological writers I’ve already mentioned. That’s where the ideological character of the ‘flux of nature’ myth becomes troubling, because it intersects so readily with the hubristic myth of human overcoming.
Nick: Yeah, well there’s a lot of those folks living down my way. What was it God said to me just before he banished me – “By the abundance of your trading you became filled with violence within”8. Wish I could have quoted Adam Smith to him back in the day. But anyway, if you’re so down on the flux of nature metaphor, what alternatives do you propose?
Chris: I think we just need to be careful about any metaphors for nature that we use, because they never capture the entire reality that we have to deal with. I agree of course that we need agriculture, and that the ‘balance of nature’ myth isn’t always our best guide, but sometimes it is, and the ‘flux of nature’ myth can also be seriously misleading. We just have to tread a very narrow path in designing agroecosystems, and always keep in mind social goals (what kind of society is this agriculture ultimately for?) as well as just productivity goals. But sometimes I think any kind of human living involves a Faustian pact of one sort or another – we’re damned if we do, and damned if we don’t.
Nick: Well, that’s really made my day. Thanks, Chris – it’s been great talking to you.
References
1. Denison, F. (2012) Darwinian Agriculture, Princeton.
2. Grime, P. & Pierce, S. (2012) The Evolutionary Strategies That Shape Ecosystems, Oxford.
3. Hunt, E. (2002) History of Economic Thought, Armonk.
4. Callicott, J.B. (1999) ‘Do deconstructive ecology and sociobiology undermine the Leopold land ethic?’ in Callicott, J.B. Beyond The Land Ethic, Albany.
5. Jackson, S. (2006) ‘Vegetation, environment, and time: the origination and termination of ecosystems’ Journal of Vegetation Science 17: 549-55.
6. Eg. Pickett, S. and Ostfeld (1995) ‘The shifting paradigm in ecology’ in Kinght, R. and Bates, S. (eds) A New Century For Natural Resource Management, Washington DC; Perfecto, I. et al (2010) Nature’s Matrix, London.
7. Perfecto et al, op cit.
8. Ezekiel, 28: 16.