New conservation, old conservation

In 1999, at the inaugural Student Conference on Conservation Science in Cambridge, I was feeling pretty pleased with myself. I’d just given my first conference talk - something to do with extinction risk and phylogeny in birds - and it seemed to have gone OK. I was meeting lots of interesting people, sharing the cosy impression that our research was on track to make some real difference to conservation efforts. Then Stuart Pimm stood up to give the plenary.

He showed a map of the world’s biodiversity in which Europe was essentially blank; pointing this out he called on us to focus all our efforts on those parts of the world where there actually was some diversity to conserve, and to stop fiddling around with inconsequential bits of so-called ‘conservation biology’ while biodiversity hotspots burned.

This was a bit of a shock, and something to which I have repeatedly returned over the years in an attempt to articulate why it angered me. Of course this demonstrates the success of Stuart’s approach - it has led me to question constantly my motivation for doing the research I enjoy, and not to kid myself that it matters more than it really does. To his credit, too, he has put his money where his mouth is in the form of savingspecies.org, an organisation specifically aimed at preventing extinctions using the most practical means available.

But the total dismissal of Europe as a place worthy of conservation attention still irks me, because it is in this continent that all of my formative experiences of the natural world occurred. I never left Britain until my teens, Europe until my twenties (not until five years after Pimm’s speech, in fact), and yet already by that time I’d developed a keen appreciation of the value of nature even in the impoverished, human-dominated countryside of my native land.

I was reminded of this old grievence recently on reading Michael Soulé’s Conservation Biology editorial, The “New Conservation” (available at michaelsoule.com), which I highly recommend. In this impassioned essay, Soulé lands some hefty blows on the so-called ‘New Conservation’ which, in his definition, “promotes economic development, poverty alleviation, and corporate partnerships as surrogates or substitutes for endangered species listings, protected areas, and other mainstream conservation tools,” its mission “primarily humanitarian, not nature (or biological diversity) protection”. He qestions whether it deserves to be called either new or conservation, and concludes that “conservationists and citizens alike ought to be alarmed by a scheme that replaces wild places and national parks with domesticated landscapes containing only nonthreatening, convenient plants and animals”.

I have a great deal of sympathy with these arguments, and firmly believe that our remaining wildernesses are a priceless universal heritage that must be cherished. And yet a couple of phrases took me back to Pimm’s talk, and to my uneasiness with a total focus on wilderness-based conservation. Soulé asks, “Is it ethical to convert the shrinking remnants of wild nature into farms and gardens beautified with non-native species, following the prescription of writer [Emma] Marris [in her book Rambunctious Garden]? … I doubt that children growing up in such a garden world will be attuned to nature…”

Well, I did grow up in such a world, and as a matter of fact I am pretty attuned to nature.

It’s a cultural thing. Unlike in the vast expanses of the New World, on this crowded island we have become accustomed to coexistence with nature (accepting we have not looked after it as well as we should have, as articulated by Tim Birkhead in another passionate piece you should read). Not only do many of our most valued landscapes, from hay meadows to heather moorland, depend on human intervention - leading us to question the idea of what 'natural' means, or when our baseline should be drawn - but we also know well that nature cares not for prettiness or authenticity. The National Park on my doorstep is beautiful, a source of inspiration to many but a long, long way from uninhabited wilderness, with its agriculture and settlements, abandoned mines and active quarries. The kingfishers I see on the canalised River Don, in the middle of Sheffield remain special despite emerging from banks of Himalayan balsam and Japanese knotweed.

Of course this is not an argument for neglecting wilderness where it does still occur. But rather to acknowledge that people can be profoundly inspired by the semi-natural, the domesticated, the biologically impoverished. Millions of us have been, including many who are now striving to reconcile the wellbeing of people with the continuing prosperity of the natural world, treading the path between old and new conservation that will enable happy and healthy future generations to enjoy and be inspired by nature too.

An Appreciation of John Steele

When I received the sad news, yesterday, that John Steele had died of the cancer that had afflicted him this last year, my instinct was to share the passing of a scientific hero as widely as possible. I duly tweeted, but given the general lack of response I wondered if perhaps his legacy is not as widely appreciated as I believe it should be. Hence this personal appreciation. I never met John, although I had been corresponding with him over the last couple of months, and was due to speak to him the morning after he was hospitalised for what turned out to be the final time. As an aside - the fact that I was approached, in such a generous manner (His first email to me ended: “This email is a rather long-winded way of saying - welcome; and I look forward to useful and illuminating discussions”) to collaborate with someone whose work, as you’ll see, has been an inspiration to me, is one of those great egalitarian things that happens from time to time in science, and I was thrilled to have this opportunity. But, as a result of this limited personal interaction - just a handful of emails - my appreciation is limited to John’s work, both his publications and this new, unpublished material to which I was contributing, which was buzzing with intriguing and innovative ideas.

Actually, I can’t hope to do justice to John’s wider scholarship here, and cover only really that small part of his work which addressed the issue of differences in temporal and spatial dynamics between marine and terrestrial ecosystems, an issue that has been central to my own research. As I set out in an earlier post, my own journey to the position now where I (reasonably confidently) call myself a marine ecologist has been rambling and convoluted. Along the way, certain of John’s papers stood out like beacons, reassuring me that there was indeed a path to follow, no matter how overgrown.

Mainly, these beacons consisted of a clutch of papers published in the early 1990s, in particular a 1991 paper in the Journal of Theoretical Biology (Can ecological theory cross the land-sea boundary?) and a 1994 Phil Trans paper with Eric Henderson on Coupling between phyiscial and biological scales). Similar ideas were further developed in papers in Ecological Research (Marine Ecosystem Dynamics: Comparison of Scales) and Bioscience (Marine Functional Diversity). All of these, in turn, were building on John’s 1985 review in Nature, A comparison of terrestrial and marine ecological systems.

Key to all of these papers is the idea of scale, both spatial and temporal, and especially how the scale of variability is different in marine than in terrestrial systems. Because the seas act as an enormous thermal buffer, variability is fundamentally different there than on land. I’ve been playing with some data to try to show this (see below), but the concept is simple: if you stand in one place for 24 hours on land, depending where on Earth you are, you might easily experience a temperature range of 20˚C or more. In most places, the temperature of the sea - even at its surface - won’t vary nearly this much in a year. Spatial variation is similar - you will typically find much more variability (along all kinds of axes, not just temperature) in a square kilometer of terrestrial habitat than in a square kilometre of sea. This clearly has impacts on the organisms living there: if you’re a lizard and you’re too hot, you can maybe move a metre or two from full sun into the shade. A marine fish might have to move hundreds of kilometres (or tens of metres deeper) to achieve a similar drop in temperature. So these patterns of environmental variation are clearly important in order to understand species’ responses to climate change, and can explain some of the subtle differences already seen between marine and terrestrial species (see for example recent papers by Sunday et al., Burrows et al.).

One of John’s major insights was that physical and biological processes were typically more closely coupled in space and time in marine than in terrestrial systems. This stemmed from his strong background in physical oceanography. Indeed, in our recent correspondence he confessed “I have no systematic training in biology”; rather he epitomised the interdisciplinary nature of fisheries science, in which connections between the physical environment and biological resources have always been recognised in a way that terrestrial ecologists have only relatively recently accepted. Despite this lack of formal training, his ecological insight was astute, as apparent throughout his 1974 book The Structure of Marine Ecosystems, from which, incidentally, I took the opening quote for the Royal Society Research Fellowship application which currently supports me: “The first impression one forms of any community is usually of the diversity of species present, and of the differences in numbers, with some species abundant and others scarce”. That book has some interesting parallels with Alec MacCall’s later Dynamic Geography of Marine Fish Populations, in that it’s ecological content (MacCall’s book is, in my view, an excellent primer on macroecology, though the word is not used) was destined to be overlooked by most ecologists because the word ‘marine’ appears in the title.

This has inevitably only scratched the surface of John’s work. What drove him, I think, to return time and again to the marine-terrestrial comparative idea is summed up best in the abstract of the Journal of Theoretical Biology piece: “It is proposed that theories developed in one sector can be tested most critically in the other, with potential for greater generality.” This idea has guided my own research, and was constantly in mind while writing several papers, for example this one which begins with a Steele quote (“I argue that we should attempt to address the question of [ecological] generalizations capable of crossing the land-to-sea boundary”) and, in particular, this opinion piece I published last year. A piece which, I was delighted to discover, John had seen: “I had read your recent TREE paper with interest, and of course, appreciated your references to my cry in the wilderness two decades ago.” I hope that in continuing this search for generality, and performing critical tests of theory, I might send up one or two small flares of my own which - even if they don’t light the path all that brightly - might at least lead others to John’s more illuminating beacons.

Natural history and desk-based ecology

The recent Intecol meeting in London, celebrating the British Ecological Society’s centenary, was perhaps the most Twitter-active (Twinteractive?) conference I’ve been to, with Twitter-only questions at plenaries and plenty of discussion across multiple parallel sessions. One such discussion I dipped into (#ecologyNH) concerned the extent to which a 21^st Century ecologist needs to know natural history, a question I’ve been pondering for a while, and one which surfaced again only yesterday in an exchange triggered by Matt Hill (@InsectEcology) and also drawing in Mark Bertness (@mbertness), Ethan White (@ethanwhite) and others. Now the answer to this of course depends on your particular specialism. If you’re a field ecologist then reliably being able to identify your (perhaps many) study species is clearly critical, and many ecological careers outside of academia require very good identification skills in order to assess habitats, prioritise conservation areas, and so on. But ecology’s a broad field, too broad for any one of us to master all of its subdisciplines, and there are skills other than natural history that are equally useful. In particular, an increasing number of us do a kind of ecology which involves sitting in front of a computer screen and playing with other people’s data. In my case, this is macroecology, trying to understand what determines the distribution and abundance of large groups of species over regional to global scales. Is it really necessary for me to be able to put a face to every species name in my dataset in order to extract the kind of general patterns that interest me?

My view is that the answer to this depends on how we define ‘natural history’. As I’ve posted before, I don’t consider myself much of a natural historian, under the rather narrow definition of being able to key out a large number of species; and I don’t believe this holds me back as an ecologist. But on the other hand, I do think that a ‘feel’ for natural history is important. By this, I mean that understanding in general terms the kinds of organisms you work on, and the sorts of ways in which they interact with each other and with their environment, is likely to enhance your understanding of any dataset, and thus will point you in the direction of interesting questions (and away from silly ones). In the same way, I don’t see why a fisheries minister, for example, should be expected to be able to identify every fish on a fishmonger’s slab in order to make sensible policy decisions; but having some general understanding of fish and fisheries above and beyond numbers on a balance sheet seems important to me.

That’s my general thesis, but if you want some specifics, I believe there are some real practical advantages to be gained from a macroecologist taking the time to learn a bit about the natural history of their system, too. First, we all know how easy it is to introduce errors into a large dataset; being able to relate a species name to a mental image of the kind of organism it represents provides an efficient way to spot obvious errors. This is really just an extension of basic quality control of your data - simple plots to identify outliers and so on. But errors need not be outliers - for instance, if you’re looking at the distribution of body size across a very wide range of species, an obvious mistake, like a 50g cetacean or a 50kg sprat, may not be immediately apparent. One such error was only picked up at the proof stage in this paper, when my coauthor Simon Jennings noticed that one of the figures labelled a 440mm scaldfish which he told me was ‘unrealistically big’, in fact over twice the likely maximum length. He was quite right, as a better knowledge of Irish Sea fish would have told me at the outset; fortunately this time we caught the error on time, and it didn’t affect our conclusions at all.we corrected the figure and did the quick check on all the other species that we should have done at the outset.

Of course, there are more formal ways to check data against known limits, but the point is that a bit of expert knowledge - a basic understanding the range of feasible values for a feature of interest - goes a long way. Having worked on many different taxa, not all of which I have personal experience of, my approach to this is to work with some kind of (preferably colourful) field guide near at hand that I can dip in to to remind myself that points of a graph = organisms in an environment.

Some outliers, of course, remain stubbornly resistant to quality control, and you eventually have to accept that they are real. Here again, a bit of natural history can help you to interpret them and to suggest additional factors that may be important. For instance, I have worked quite a bit on the relationship between the local abundance and regional distribution of species. Such  ‘abundance-occupancy’ relationships (AORs) are typically positive, such that locally common species are also regionally widespread. I put it like this: if you drove through Britain, you’d tend to see the same common birds everywhere on your journey, but the rare ones would vary much more from place to place. However, although AORs are well-established as a macroecological generality, there are often outlying species, for instance species with very high local densities but small distributions. Identifying such points (‘Oh, they’re gannets’) and knowing something about them (‘of course, they nest colonially’) can help to explain these anomalies.

Such simple observations - ‘gannets don’t fit the general AOR’ - can then lead to more general predictions - ‘AORs will be different in species that breed colonially’ - that can influence future research directions. In my experience, observations of natural history will frequently suggest new explanations for known patterns, or will lead you to seek out study systems meeting particular criteria in order to test a hunch. A fascination with natural history may lead you to learn about a new ecosystem -  deep sea hydrothermal vents, say - which you then start to think may be perfect for testing theories of island biogeography or latitudinal diversity gradients.

You might also start to question models that gloss over natural historical details. On a winter walk in the Peak District I made the very obvious observation that the north-facing side of the steep valley was deeply frosted while the other, only a hundred metres or so distant but south-facing, was really quite pleasantly warm. This got me thinking about how the availability of such microclimates would not be captured in most of the (kilometre scale) GIS climate layers people use in species distribution modelling, yet could be crucial in determining where a species occurs. This is unlikely to have been an original thought, and is not one I’ve followed up, but it emphasises how real world observation can colour your interpretation of computational results.

More generally, real world observation - ‘going one-on-one with a limpet’, as Bob Paine puts it in a nice interview on BioDiverse Perspectives - gives you a sense of the set of plausible explanations for the phenomena that emerge from datasets at scales too large for one person to experience. This in turn leads to a healthy scepticism of hypotheses that fall outside that set. To paraphrase an earlier post of mine, simply plucking patterns from data with no feel for context and contingency is unlikely to lead to the understanding that we crave.

That said, however, there are benefits to be had from putting aside one’s personal experience and being guided, from time to time, by the data. I guess I’m influenced here by working on marine systems, where the human perspective is not a good guide to how organisms perceive their environment. We simply can’t sense the fine structure of many marine habitats, or how dispersal can be limited in what looks like a barrier-less environment. Bob Paine admits as much: directly after the limpet quote, he says “How do you do that with a great white shark or blue whale? There’s this barrier to what I would call natural history.” He goes on to talk about the problems with relying on personal experience when working on systems such as terrestrial forests with very slow dynamics. These long-term, large-scale, hard-to-access systems are, I would argue, exactly where the methods of macroecology and other computational branches of our science come to the fore. It is also, dare I say it, where coordinated observational programmes like NEON can make a real contribution.

But let me finish with perhaps the most important justification for spicing up computer-based ecology with a bit of natural history. We’re supposed to be enjoying ourselves, and for most ecologists surely that means getting out into the field, in whatever capacity - for work or for fun - and wherever it may be, from our back gardens to the back of beyond. My personal view is that doing this whenever you can will make you a better ecologist. But even if I’m wrong, it ought to make you a happier ecologist, and that’s important too.