ESA 2012 preview: talks to see on Thursday


8:00: Christopher Clements on using microcosms to test Optimal Linear Estimation as an extinction predictor. Who says microcosms aren’t relevant to nature? Here’s a clever use of them: as a testbed for a proposed method of using species sighting records to predict when species will go extinct. You can’t test the OLE method in the field because in the field you don’t know and can’t manipulate true extinction rates. But you can know and manipulate extinction rates in the lab. Turns out that the various sources of error in the OLE approach scale highly nonlinearly with key variables, which seems like something that’s really useful to know if you want to use the OLE approach in nature.

9:50: Gian Palamara on predation effects on time to extinction under demographic stochasticity

10:30: Spencer Hall on host resource use and disease risk. Like everyone else, Spencer probably rues his luck when he’s scheduled to talk late in the meeting. But I love it when Spencer’s scheduled to talk late in the meeting, because by Thursday I’m getting tired, and Spencer gives such an energetic talk that just watching him is like a massive caffeine hit. 😉

11:10: Chi Yuan on variation in species’ sensitivities to environmental fluctuations and their role in coexistence. In the abstract, Chi notes something I’ve also noted: the more species you have, the narrower the mathematical limits on how negatively correlated their responses to environmental fluctuations can be. This indicates a limit to how many species can coexist via mechanisms that depend on each species responding very differently to environmental fluctuations than all the others (e.g., one plants likes it wet while another likes it dry). It also illustrates that such mathematical limits are not just “artifacts”, but actually have real-world consequences. Anyway, Chi’s talk is mostly about how a different aspect of species’ responses to the environment–their sensitivities to environmental fluctuations–can allow stable coexistence of many species. Even if species all respond in a positively correlated fashion to environmental fluctuations–e.g., drought is bad for all plants–they all can coexist if they differ in their sensitivity to those fluctuations (e.g., some plants suffer less under drought conditions than others).

1:30: Lina Li on temporal environmental variation and species coexistence in resource competition models. Remember how Chris Klausmeier and I were discussing a competition model of his which, at first glance, appeared to vindicate a zombie idea of Hutchinson’s about how environmental fluctuations can produce stable coexistence? And how we eventually figured out what the coexistence mechanism in that model was, but didn’t reveal it because we thought we might write a paper on it? Well, Lina Li is going to reveal it in this talk–the coexistence mechanism is a storage effect (just to be clear, she’s been working independently of Chris and I, and has also explored the idea more thoroughly). I think it will be great for Lina to get this idea out there. It’s an idea that has kind of bubbled under the surface for many years in ecology (Peter Abrams obtained some results very closely related to Lina’s in a 1984 paper), but has never hit the mainstream the way it should have. Which has led to unfortunate and widespread misunderstandings. In particular, a lot of people have this image of the storage effect as something that only happens if species have certain rather special life histories–seed banks or resting eggs or really, really long-lived adults or something. Which is wrong–the storage effect actually can arise in all sorts of ways having nothing to do with special life histories. For instance, Lina will show how it arises in the context of standard MacArthur-type models of resource competition. Indeed, Chris and I concluded that it’s kind of hard not to get a storage effect!

1:50: Shripad Tuljapurkar on phenotypic variation, stochasticity, and the evolution of senescence

1:50: Galen Holt on how dendritic stream networks, and the constraints they place on where species can disperse to, affect coexistence

2:10: Angela Brandt on soil heterogeneity, plant-soil feedbacks, and species coexistence

2:10: Yue Li on quantifying spatial coexistence mechanisms in desert annuals

2:10: Benjamin Baiser on predicting food web structure of phytotelmata communities with metacommunity models
2:50: John DeLong on exploitative and interference competition in a protist predator-prey system

3:20: Yours truly on demographic stochasticity, invasion rates, and higher order interactions. Just to let you know, this talk will be about work in progress; I haven’t completed all the really cool, sophisticated state space model fitting I said I was going to do in the abstract. So if you come, you’re not going to see a complete story, but you’ll see what I think are some interesting and somewhat surprising results. And as always, there’s free beer at my talks. 😉

3:40: Matthew Hammond on spatial variation, synchrony, and stability in rockpool communities

3:40: Regis Ferriere on coevolution of diversity and invasibility along temperature gradients due to body size evolution. I have to admit, whenever I hear about body size allometry-based modeling work like this, I always wonder how much “work” is being done by the allometry, and how much is being done by auxiliary assumptions (here, assumptions about how competition works, the genotype-phenotype map, and lots of other things). In other words, if you assumed something very different about allometry, but kept all your other assumptions the same, which if any of your results would change? Body size allometries tend to get taken for granted because they’re features of real data–but if they’re features of real data that actually don’t much affect model behavior, are they really that important? Indeed, in the only paper I can think of off the top of my head that looked at this (in the context of a different question), the answer was that the body size allometry wasn’t important at all. So Regis, if you’re reading, consider this your first question! 😉

3:40: Jose Capitan on the competitive exclusion principle in stochastic competition models

4:00: Stephen Hausch on intraspecific diversity and species coexistence. Stephen is my student, but I’d attend this even if he weren’t.

4:20: Tad Fukami on plant-soil feedback, community assembly, transient dynamics, and coexistence

4:20: Rachel Penczykowski on nutrient enrichment, lake stratification, and disease in zooplankton

4:40: Lei Dai on critical slowing down as a warning signal of population collapse

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