In a paper published in Ecology Letters in 2004, Mathew Leibold, Marcel Holyoak, Nicolas Mouquet, Priyanga Amarasekare, Jonathan Chase, Martha Hoopes, Robert Holt, Jonathan Shurin, Richard Law, Dave Tilman, Michel Loreau and Andrew Gonzalez reviewed the metacommunity concept in ecology and the four paradigms or approaches that have guided theoretical and empirical work on metacommunities till that point. Twelve years after the paper was published, I spoke to Mathew Leibold about his motivation to work on this topic, the making of this paper and the impact of the ideas in this paper on metacommunity research.
Citation: Leibold, M. A., Holyoak, M., Mouquet, N., Amarasekare, P., Chase, J. M., Hoopes, M. F., … & Loreau, M. (2004). The metacommunity concept: a framework for multi‐scale community ecology. Ecology letters, 7(7), 601-613.
Date of interview: 2nd November 2016 (via Skype)
Hari Sridhar: I wanted to start by asking you a little bit about the motivation for this paper. I realize that this came out of an NCEAS working group. How was this group formed?
Mathew Leibold: Sure, sounds good. It was a great thing, actually. The way this happened is that I started using the word metacommunity in some of my talks. And whenever I’d use it, people would say, well, that’s not what I mean by a metacommunity. And so I’d say, well, what do you mean? And they’d say, well, you know, lots of patches connected by dispersal, by species that interact, and I’d say, well, that’s what I mean as well. So it was kind of interesting. And I realized that what people objected to was the way I was thinking about the processes. And so, I was talking to Bob Holt, and he said, well, this sounds like a perfect thing for an NCEAS Working Group. You should put one together. And so I did; we did. And that’s how it came to be. It was kind of interesting because I thought, when I wrote the proposal for the NCEAS, I thought there would be two different ideas. But in our first meeting, in the first morning, we realized there were four ideas, and so our job doubled.
HS: Tell us a little more about what the confusion was. You said they weren’t okay with the way you were using the term?
ML: Sure. So when I was using it, in the paper, I was arguing for the perspective that’s called species sorting, And my perspective was that if species were going to be doing things like that then species needed to be present in the region in order to be able to colonize patches that were good for them. That’s not a very fancy idea or anything. But other people had thought about metacommunities as being more related to metapopulations; metapopulation theory like Hanski and stuff like that. And then, when we met, we suddenly realized that Hubbell had been talking about neutral theory, and that some of the models were actually different from the metapopulation models.
HS: On the website, I see that the NCEAS working group had 15 people. Tell us a little bit about how you decided who to invite to the group?
ML: Yeah. So we invited people who had been thinking about these things, mostly based on the papers they had published. And then the other thing was to try to get some younger scientists who, maybe, we didn’t know exactly what they thought, but that would also be in the group. What I’ve learned is that when you have a working group, it’s the younger scientists that end up doing all the work, and the older scientists just, you know, show up. I probably shouldn’t say that!
HS: Stepping back a bit, could you also tell us a little bit about when you started thinking in terms of metacommunities, I realized that you did a PhD on plankton communities. Was this idea there right from the beginning?
ML: Well, I wouldn’t say that. You know, I was interested in food webs and kind of combining competition and predation theory together. But when I was studying ponds, I realized that they were very dynamic and that things would change through time quite a bit. You know, species would show up one year and be absent the next year and things like that. And so that’s when I started saying, well, you know, if they’re going to go extinct in a patch and then the patch comes back to being suitable for them, they have to come from somewhere. And so I started thinking about that and using theory to look at that. That’s when I sort of started thinking about metacommunities.
HS: I want to ask you about two key sources that you cite: One is by Gilpin and Hanski about metapopulations, and then there’s David Sloan Wilson’s paper on metacommunities. Tell us a little bit about what influence these papers had on your thinking.Was the paper by Wilson where the word metacommunity was used first?
ML: Well, after writing the paper, I realized that the word had been used before by Hanski, I think in 1991, in a book. We quoted the Wilson paper as the first time the word had been used,but since then we found that somebody else had used it before. The Gilpin and Hanski paper was one of the important papers that kind of extended metapopulations to metacommunities. And then the Wilson paper… David Sloan Wilson was on the faculty where I did my PhD. And he presented that paper early on to us, you know, in a lab lunch kind of presentation. And it’s a very different way of looking at metacommunities. It’s a quite complicated model of self organization of species and interactions. And so it doesn’t really fit in to the framework that we have in the 2004 paper. It’s kind of quirky and stuff.
HS: Did you consider using a different term for what you were describing?
ML: No, I didn’t, I thought it was a pretty good word. It kind of caught the spirit of it.
HS: Can you tell me a little more about how the working group worked? How often did you meet? Did you all get together in one place, or was lot of the discussions over email? I see that there’s a whole series of papers and book chapters that came out of this group.
ML: Most of the important, intellectual stuff was done at NCEAS. It’s a group that had money to bring people together. So they would bring the group together in Santa Barbara for five days at a time. I think we had three meetings. And yeah, so it was just, you know, we got together, we usually broke up into subgroups, you know, like, three or four people on each subgroup, and worked on different aspects of the problem. And eventually, when the writing part came, well, that we did through email and stuff like that.
HS: Were all the people in the working group authors on this paper?
HS: Did you do most of the writing for the paper?Do you remember how long it took you to write the first draft?
ML: I’d say I did a good chunk of the writing. I don’t remember exactly how much. I don’t remember how much time… I think took us about a year to put the paper together after we finished.
HS: Did you do the writing when you were back in your university?
HS: I wanted to ask you a little bit about Figure 1 in the paper. I mean, I can imagine something like this being drawn on the board in NCEAS. Tell us how this figure came about and how long it took you toput this together?
ML: Yeah, I don’t like that figure. This is what happens when you work with other authors. It’s, you know, some of the authors said we have to have a figure, okay. I don’t like it and I, to be honest, I don’t understand it. But yeah, it took a long time.
HS: In the Acknowledgments you thank a couple of people – S. Hall and P. Geddes.Who were these people?
Did this paper have a relatively smooth ride through peer review?Was Ecology Letters the first place you submitted this to?
ML: Yeah, it was. And I think we it was a pretty smooth ride. I don’t remember.You know, none of my papers have ever been accepted the first time around. I’m not a very good writer. So, I know it went through some revisions, but no, it seemed like, as I rememberit, it was, you know, reasonably straightforward.
HS: When the paper came out, did it attract a lot of attention?Was it discussed a lot?
ML: Yeah, I mean, it’s the most successful paper I’ve been involved with. And since then, metacommunity ecology has taken a life of its own. With my previous student, Jon Chase, I just finished writing a book for Princeton Monographs on metacommunity ecology, and it’s just amazing to see what people have done.
HS: At the time when you were writing this paper, did you anticipate at all that it would attract so much attention? It’s been cited over 2000 times. Do you have a sense of what it gets cited for?
ML: Yeah, I think it gets cited for being sort of, you know, the catalyst paper for metacommunity thinking or thinking about ways in which there’s feedback between the regional community and the local communities. And yeah, so I think people have been very creative. You know, right now I’m working on a project where we’re trying to get rid of the four paradigms. I think they were really useful for a while. But now they are kind of getting in the way because they are highly idealized and not really likely to actually apply to more realistic situations.
HS: This is something I wanted to ask you about. You say “It is clear from the review that any synthesis that links these four approaches to each other would greatly facilitate empirical work, and would provide a much more realistic framework for understanding ecology at these larger scales. Has that happened or is it happening?
ML: Well, it’s happening.You know, what I think has happened is that in various pairs, you know, two at a time,there are very good models that look at the four approaches. But I think it’s only very recently that people have started trying to do all four at once. For example, Ovaskainen et al. (2019) and Thompson et al. (2020), both use simulations to examine a wide range of possible scenarios, but still don’t really address the full scale of phenomena in a more analytical way. And I have a post-doc, Bertrand Fournier, who finished recently, and through his work we have a paper that kind of does it. And then this project that I’m working with now is trying to do that even more so.
HS: This paper came at a time when you were already well-established but do you think it had any kind of direct impact on your career? That’s the first part of my question. And the second is, how did it influence the future course of your research?
ML: So let me ask answer the second one first, which is that, since then, that’s what I’ve been working on. It’s metacommunity ecology in various forms. And so, in fact, on my career, well, I mean, I think when people think about my name, they associate it with metacommunity ecology, and I think, to a degree, the reverse is also true – when they think about metacommunity ecology, I’m one of the people that they think of.
HS: It’s now 12 years since this paper was published.How has your thinking about these ideas changed since then?
ML: Well, one way to think about it, I guess, is that the ideas in that paper kind of work when you think of species pairs. If you think of two species they are likely to fit one or the other of these things. But when you have hundreds of species, all sorts of combinations are going on. And I think that’s what we don’t have the tools to think about yet.
HS: You say “We suspect that numerous other ecological phenomena will either be discovered or will be reinterpreted in the context of metacommunities and view this as an extremely exciting area for future work”. To what extent has that happened in the 20 years since this paper was published?
ML: I think it’s happened quite a bit. One of the places, one of the areas, that I thought would be the most exciting was to combine it with evolutionary ecology. So, you know, instead of just assuming that all species stays the same, they can adapt to local conditions. And there’s quite a bit of stuff on that. I had another working group that looked at that, and we ended up with a paper in TREE; I can’t remember the year, I’m gonna say 2008. It’s by Urban et al. Mark Urban is the lead author. So that was really exciting. And then another area that kind of took off a little bit is the idea of metaecosystems, and so there are some papers on that.
HS: You talk about one specific case – the idea of community-wide character displacement – and say that interpretations related to community-wide character displacement have not focused on metacommunity kind of interpretations. Now, do you see more metacommunity thinking in that area of research?
ML: I’d like to say yes, but maybe not. There is a little bit of that. There’s a big literature on coexistence through stabilizing niche differences versus fitness equalizing things.
HS: Chesson’s work
ML: Yeah, although those papers don’t necessarily use the meta-community approach.
HS: In the 12 years since this paper was published, have you ever read it again?
ML: Yeah, I’ve read it a couple of times. I haven’t read it very recently.
HS: In what context have you read it?
ML: I think mostly just to see what the paper actually said. I mean, when I cited it for stuff, sometimes I’ve had to check to make sure that, in fact, my memory was correct.
HS: You mentioned a book that you’re just bringing out on metacommunities. Wasn’t there another book as well, soon after this paper was published?
HS: Was that the proceedings from the working group, i.e. a collection of chapters written by people from the working group?
ML: It was a combination. I think, about half of the chapters were, you know, aspects of the work we did in the working group. For example, we had one group of people looking at predation and one group of people looking at competition. I did a little bit of work with Richard Law on assembly cycles. And then we also invited people who had not been in the working group to contribute chapters, mostly on the empirical side. One thing we tried to do, for example, was to have one empirical study that illustrated each of the four paradigms. And so, those chapters came from outside. And then we also had a couple of other chapters,by people that we knew had interesting ideas that we hadn’t considered.
HS: This working group and this paper brought together many people for the first time. Since the paper, have you continued to work with these people, i.e. was this like a catalyst to start new collaborations?
ML: Yeah. I guess,yes. That would be the answer in general. Not all of the things that I’ve done with people have resulted in publications, but a lot of the people in there are people that I continue to interact with and work with.
HS: Would you count this as one of your favorites among all the papers you published?
ML: Yes. I mean, I think it’s tremendously exciting when you write a paper and it gets such a response and leads to new ideas by other people, and you know, kind of stimulates and catalyzes things. So, you know, I’ve learned a lot from the work that people have done related to this paper.
HS: What would you say to a student who is about to read this paper written 12 years ago? Would you point them to other papers they should read in relation to this?If you had to add a disclaimer on the paper what would it be?
ML: I think the biggest disclaimer is not to take the paradigms too seriously and to think about other ways of thinking about the processes involved rather than the cartoons that are in that paper.