I attended the BES Macroecology meeting in Oxford last Thursday and Friday. It was a great meeting. Check out a storify of the conference tweets for details. I suppose it says something about me, but everytime I get >24 hours of all macroecology, I get reflective on trends I see. As I noted last year, macroecology is in a self-aware and self-reflective adolesence. And this was evident again this year. A great deal of the conversation was on topics like “what is macroecology?”, “is macroecology working?”, “should we move past pattern to to process?”. and “how does macroecology relate to conservation and the public/policy dialogue?”. For those of you who hang around macroecology, these seem like perennial conversations. There was a great conversation with many enlightening thoughts shared on all of these topics.What follows are my own thoughts on the state of macroecology (as observed in the non-self-reflective science talks in the conference and building on the self-reflective thoughts others shared).
The first thought has been sneaking up on me for a while but really came home to me this conference: macroecology is going through serious mission creep. Maybe you have to have called yourself a macroecologist circa 1995-2000 to see this. Brown & Maurer’s seminal 1989 paper that was one of the launching points for macroecology set the agenda as “Our goal is to understand the assembly of continental biotas in terms of how the physical space and nutritional resources of large areas are divided among diverse species.” Brown’s 1995 book on macroecology pretty clearly identifies species abundance, body size, and range size, the distributions of those three variables across species, and the relationship between those three variables as macroecology. Rosenzweig’s 1995 book “Species Diversity across Space and Time” pretty clearly adds species richness including the species area relationship and the latitudinal diversity gradient (sorry Rob W. – you’re right but I am lazy*). Gaston & Blackburn’s 2001 book on macroecology keeps exactly the combined scope of Brown & Rosenzweig. Note that there is nothing really that is spatially explicit and aside from some of Rosenzweig’s book and the LDG in Gaston & Blackburn there is very little incorporation of the environment. I think you could count on the fingers of one hand the number of maps across all three books. But at this macroecology conference, I saw gobs of macroevolution, conservation-inspired analyses, climate change, thermal tolerance, and more generally species-environmental fit analyses, and more. It was great. I applaud all of it. we should and need to go to all these places. And I saw a lot of highly spatially explicit drawings (aka cool maps!). But we most definitely are in the midst of mission creep on macroecology. This is all a good thing. But its not surprising we’re a little confused what exactly is macroecology right now .Macroecology is not our advisers’ version anymore.
My second thought is everybody is making the connection between macroecology and conservation. Unlike the last thought which snuck up on me, it has seemed glaringly obvious that macroecology is a (the?) pivotal science for conservation efforts. It seems like a lot of other people are thinking the same thing. In my randomly assigned discussion group 2 of the 8 or so people self identified as conservation biologists who just came to a macroecology conference. The rest of us (including macroevolutionists and others) all are thinking about conservation biology. This is a very good thing.
The last thing I want to touch on is the relationship of macroecology to process. This has long been a sore point for macroecologists as we repeatedly apologetically acknowledge that we are better at patterns than process and publish calls to move on to process about once a year. I was pleased to see this embarrassment diminishing and several people made a robust defense of the importance of patterns even without process (a role as the lone looney I’ve been asked to fill out on speakers panels more than once in the past, so I was glad to see others jumping in). It seems we’re finally getting over this hang up. Ironically, one reason we may be getting over this hangup is I think we’re actually starting to get a serious handle on processes in macroecology. They’re not necessarily what we all were trained to think of as processes (e.g. equilibrium focused differential equations of population processes). Mark Vellend has upset the apple cart in community ecology with his 2010 paper and book forthcoming this month by pointing out that community ecology really only has four processes: drfit, selection, dispersal and speciation (which closely parallel the big 4 of evolution). It is at this level, that I think macroecology has really found its legs with identifying a core set of processes, not surprisingly overlapping with those of community eology.
To wit, I would suggest that the following list of processes is comprehensive for macroecology:
- Dispersal (colonization and spatial spread)
- Trait evolution (possibly on a phylogeny)
- Environmental fit of a species/traits (this is sometimes phenomenological and sometimes goes down to detailed physiology)
- Speciation (modelled mostly as a rate – not at a detailed level of speciation processes)
- Stochasticity (amenable to sampling and central-limit type analyses)
- Local & global extinction
Energy capture and allocation might go in there somewhere as well. Some (actually all) of these processes could be unpacked into the core processes of evolution or population or community ecology, but that would be an unfortunate mistake (just as Mark didn’t unpack speciation into its evolution level processes like reproductive isolation and sexual selection). These processes are right-sized for the macro scale and are the level at which macroecologists think about things. This is why we are finally getting traction on processes – we’re picking our own. I heard references to these proceses over and over during the 1.5 days of science talks at BES Macroecology. And I saw many instances of people pulling several of these processes into simulation models and showing how they explain and fit empirical data. Processes have arrived to macroecology!
Although I followed the twitter feed on the conference, I am curious what others who are attended are thinking after a few days of distance and reflection. What are your big picture thoughts that don’t fit in 140 characters? Do you feel the same way about processes that I do?
*Rob Whittaker made an elegant rant about how we’ll never make progress on the global variation of richness if we continue ot insist on only looking at it as a pattern vs. latitude.