Species interactions matter: reflections on the International Biogeography Society meeting in Tucson

In research, proper choice of a field site is key to the success of a project – and so too for conferences. The International Biogeography Society hosted its annual meeting in Tucson, Arizona this January. The weather was sunny and warm, and the desert was an ecologically fascinating place to bring a few hundred ecologists for a week. I imagine many of the European attendees got more sun at the conference (even with most of the sessions being indoors!) than they had gotten, or would get, in several months back at home. Watching a desert sunset, drink in hand, wearing only a t-shirt – all in the dead of winter – these things go a long way in facilitating conversations and friendly collaborations.

I like small meetings like this one because it is possible to talk to most of the other attendees, and get a sense of what nearly everyone is working on. It helps with horizon-scanning – identifying the ideas whose time has come and gone, the key problems yet to be solved, and the people who are pushing these boundaries.

At this meeting the key concept that stood out to me was species interactions. Classic macroecology and species distribution modeling takes a coarse-grained look at nature and assumes that these interactions are unimportant or lead only to noise at large spatial and temporal scales, with other processes like climate being more important. This is probably a fiction, but it is a convenient one. This meeting highlighted a number of ways people are moving past this story towards a more nuanced and useful view of species interactions. A number of scientists showed data from the paleoecological record and the contemporary world that argued strongly for species interactions playing a major role in biogeography and macroecology. I want to highlight a few presentations that have changed my own thinking.

There was a big push to better understand the role of fungi and herbivores. Vojtech Novotny showed some impressively challenging field experiments with insect and fungus removal or transplants in tropical forests – his argument was that these interactions, especially the fungal ones, are critical for understanding density dependence and diversity levels. Similarly Andreas Menzel and Jason Pither both showed compelling data for the role of mycorrhizal fungi in mediating successful plant invasions and colonizations of new environments. My takeaway is that to understand plant diversity we need to do a much better job of understanding fungal diversity and its interaction with plants – at both small and large scales.

There was also a big push to better address the roles of mammals with natural environments. Humans, of course, count as mammals! Jack Williams showed some incredible data reconstructed from witness tree records showing how human-caused land use modification may have a complementary and potentially larger role than climate in eastern North American plant distributions. Jessica Blois also made a strong argument for better integrating species interactions into our understandings of paleoecological change, and Sarah Supp showed how removals of different types of granivore mammals (at the Portal experiment) have no influence on some macroecological patterns (abundance curves) but strong ones on others (abundance of individual species). My takeaway is that we need to better think through the effect of humans on biogeography, and also need to think about what metrics and statistics we have on hand that will be sensitive to these effects.

The meeting was a wonderful opportunity to turn over some of these ideas in my mind, and think about how to take them into research in the coming months and years. I hope to be shifting my own work more towards incorporating interactions into models of community dynamics, and towards incorporating human disturbance into models of regional diversity. It will be harder, but it will be worthwhile.

While these ideas were shared on slides in darkened rooms, the real conversations and contemplation happened out in the sunlight, with the magical light of the Sonoran desert as backdrop. Location matters, especially to biogeographers!

One Comment Add yours

  1. haiyang says:

    Hi Ben,
    FYI, please also check this one here.

    So there should be a chance to incorporate plant-microbe interactions into models of community assembly, right?

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