I interviewed awesome ecologists at the 2011 Ecological Society of America meeting in exchange for reader donations, which paid for my conference attendance. This is one in a series of posts about those interviews.

I almost missed my first interview at ESA.

After 14 hours door-to-door to get to my hotel in Austin with no chance for sleep in almost 48 hours, I was more than a little out of it. I have absolutely no memory of arriving at my hotel or crawling into bed. While I was clearly alert enough to tweet coherently, I forgot to change the time zone before setting my alarm. And so I was woken up by a lucky phone call just minutes before I was to meet Aaron Berdanier.

After a frantic battle with some epic bedhead, I made it to our rendezvous point, and off we went to Mekong River to discuss ecology over delicious noodle bowls.

Aaron is currently a Research Associate in the Natural Ecology Resource Laboratory at Colorado State University, but he’s leaving soon to start his PhD with one of the coolest ecologists on the planet, Jim Clark. With Jim Clark, Aaron hopes to explore limits to species distributions. This is part of a really fundamental question in ecology: Why are species where they are? It’s a deceptively simple question with a whole lot of unknowns.

Understanding what controls where a species lives means considering the species niche, which Aaron recently summarized nicely. Here’s a snippet that explains the basics of a niche and the difference between the fundamental and realized niche:

G. Evelyn Hutchinson […] envisioned the niche as a “multidimensional hypervolume” where many variables restrict the persistence of a species (Hutchinson 1957). Hutchinson’s niche is defined as the conditions that enable a population to have births greater than deaths. With this definition, Hutchinson removed the niche from the place and pulled the focus to the species. Thus there are no “empty niches” that could be filled; the niche is an attribute of the species (fitting with the individualistic view of the community that was defended the year before by Robert Whittaker). “Species, not environments, have niches” (Pulliam 2000).

Hutchinson went on to address the issue of requirements versus impacts with the fundamental and realized niches. Each species has some set of habitat conditions that allow it to exist…, which are the fundamental requirements for that species. But, when other species are present, they can affect the species directly (through prediation or parasitism) or indirectly (by consuming limiting resources), thereby reducing the portion of the niche that is realized. Even though Grinnell’s Thrashers [a type of bird] can theoretically persist in chaparral environments, they may not exist there in reality if, as suggested by Elton, there are predators that consume their eggs (Fig. 2).

I do recommend reading the entire post to get a more nuanced understanding of niches, but, basically, everything from climate to other species to chance is responsible for why species are where they are. Figuring out the particulars is tricky, but necessary, if we want to make useful predictions (and we do!).

Aaron wants to work on species distributions because environmental change is something that all species have to deal with – all species are always moving (or not!) in response to change. Plus, the speed of climate change makes this a really important problem right now: it’s a perfect example of a case where understanding how nature works will help people live better. We need to understand what will happen to species distributions to understand what’s going to happen to ecosystem services, disease carrying mosquitoes, forest fires, and more.

But species distributions aren’t all Aaron thinks about! In the last few years, he’s worked on biogeochemistry and primary production (how much of the sun’s energy plants can convert to physical stuff). Lately he’s been trying to pin down exactly how much nitrous oxide (N₂O) is ending up in the atmosphere. I went to a very good talk he gave on this topic (see here for the abstract). Like carbon dioxide, N₂O is a greenhouse gas, but N₂O is 310 times better than CO2 at trapping heat. That’s no laughing matter.  A good chunk of N₂O emissions is from agricultural fertilizer use, but figuring out exactly how much fertilizer is being used and how much emissions that causes is hard to estimate. The current methods result in a great deal of uncertainty – so uncertain as to make the N₂O estimates almost useless! But Aaron has figured out a way to combine places we have good estimates with places we don’t in a model that gives us much, much more certain estimates of N₂O. Wow, right?

When he’s not doing math to save the planet, you might find Aaron blogging. I was curious about why he blogged; since scientists are busy, there’s got to be a payoff! He started blogging as a way to think through ideas since learning (through teaching) that the best way to understand an idea is to explain it. Blogging is also a way to come up with and record ideas that might otherwise be lost to the margins of papers. In a way, it’s a ‘lab idea notebook’ on the internet! He reviews articles, making them more accessible by giving them additional context and using more natural language, in a way you can’t necessarily do in a journal article. Sometimes his posts have a bit of analysis, like this one on ESA presentations. Ultimately he likes to do a little bit of science in each post. You could say that’s the whole goal of the blog.

I also wanted to know about the kind of feedback he gets from blogging. I know I’m thrilled whenever you all comment here, but his posts don’t provoke many responses. Even though I’ve been reading (and loving) his blog for months, I don’t think I’ve ever commented. But despite the lack of comments on his blog, he’s reaching a much larger audience than he ever expected. Aaron really loves teaching and plans to make it a big part of his career, but as a teacher, you’re limited to the students in your classes. So he was excited that the potential (and actual) audience for his blog is just so much larger.

Aaron does have a fair amount of experience teaching undergraduate students and hopes to one day teach and mentor at a small liberal arts college. I was amazed that he’s already thinking of how to translate his research interests into tractable projects for undergraduate students! He’s very interested in getting students into a graphical, quantitative mindset. I was happy to hear that he recognized that learning to interpret complex graphs – something scientists do without pause every day – isn’t easy and needs to be taught.

Now Aaron is doing important ecological work using very sophisticated modeling techniques, but he didn’t start college hoping to become an math-y ecologist. He was definitely still passionate about the environment back then, and he thought that environmental studies was the way to go. But his professors really emphasized scientific thinking and quantitative skills, and he came to really enjoy that way of approaching and interpreting the world. He wants to give his students that same vehicle of science for exploring the world someday.