EEB graduate student Susanna Campbell (left) explores the poster session.

“I'm very pleased to report that our 15th annual Early Career Scientists Symposium - Stable Isotopes in Ecology, Evolution and Conservation was a big success, featuring a great panel of inspiring speakers, an excellent poster session and 120 registrants from 10 universities,” said EEB Professor and Chair Diarmaid Ó Foighil.

The symposium was held Saturday, March 16, 2019 in the Biological Sciences Building on the University of Michigan’s campus in Ann Arbor.

Stable isotopes of common and trace elements have a wide range of applications in modern and ancient ecosystems. They offer important tools for investigating plant and animal physiology, dietary ecology, life history, food-web analysis, nutrient cycling, migration and paleoecology, with new isotope systems, new approaches and new kinds of questions emerging in every decade. 2019 symposium speakers were experts in terrestrial and marine systems, modern and ancient ecosystems, animals, plants and microbes. The symposium featured topics for a broad range of interests in ecology, evolution, earth history and conservation.

The 2019 Early Career Scientists Symposium was held in the Biological Sciences Building for the first time.

Keynote speakers were James Ehleringer, Distinguished Professor of Biology, University of Utah, and Tamsin O’Connell, a reader in Isotopic Ecology, Department of Archaeology, Cambridge University, UK. The early career speakers (and their titles at the time of the event) were: Sean Brennan, postdoctoral research associate, University of Washington; Pete Homyak, assistant professor of ecosystem and soil microbial processes, University of California, Riverside; Allison Karp, Ph.D. candidate, The Pennsylvania State University; Fiona Soper, postdoctoral research associate, Cornell University; Julia V. Tejada-Lara, Ph.D. candidate, Columbia University and American Museum of Natural History, New York; and Erik van Bergen, postdoctoral research fellow, University of Helsinki. Read more about the speakers and their presentations on the ECSS 2019 website. Graduate and undergraduate students and postdocs from all universities and disciplines were invited to present their work during a poster session.

“I was blown away by how professional and well organized the symposium was, and the level of engagement and attendance,” said Soper. “I can't think of anywhere else that hosts an analogous event, and it's a great idea. It's rare to see a symposium organized around a diverse tool or theme, rather than a more focused topic, but the result was that I learned far more, and it was very engaging to switch gears with every talk.”

Dan Fisher and Jim Ehleringer discuss research questions.

Common themes

“Two themes impressed me,” noted EEB Professor Catherine Badgley, who was the ECSS committee chair. “One was the ability of different stable-isotope systems to record individual variation in physiology and ecology; the individual variation is the basis for environmental sorting of individuals and populations under changing environmental conditions at seasonal and annual scales and sorting by natural selection over multiple generations. The second theme was the ability of practitioners to investigate research topics at different spatial and temporal scales – from the individual study plot year by year to landscapes over geologic time.”

Along the same line, Brennan said, “Isotopes can provide unique insights into a diverse array of difficult questions spanning a broad range of spatial and temporal scales (days to millions of years; micrometers to continents). In general, the questions addressed centered around understanding what gives rise to the underlying ecological and evolutionary patterns we observe in nature in terms of biogeochemical cycles, landscape/ecosystem change, and biological production from heterogeneous systems. There was also a tangential theme related to how such an understanding informs effective conservation.”

“There were many examples of using isotopes to cast a totally new light on what had in some cases been very intractable problems for a long time,” noted Soper. “I can't think of any other methodological tool that has such incredibly diverse applications (from sloth diet to paleoclimate to plant competition and beyond!)”

Homyak noted the “use of isotopes to answer field-specific questions not answered by other approaches.” Bian Wang, a graduate student in the Department of Earth and Environmental Sciences, who was on the organizing committee, noted the following common theme, “Realizing the complexities of isotope systems and how they could confound our interpretation of (paleo)ecology and (paleo)ecosystems.”

There was a nice turnout for the poster session in the west atrium of the Biological Sciences Building.

Interesting research

Brennan said he found all of the presentations compelling. “The presentation about how body size of herbivores has a strong influence on the degree to which the carbon isotope ratio of an animal's diet is recorded in their teeth was very fascinating. It has important implications for how this isotopic tracer is used to unravel ecological processes today and in the past.

“The presentation about how hydrological connectivity influences the production of nitric oxide (NO) was also fascinating and illustrates how powerful a synthesis approach to ecology and isotope biogeochemistry can be to gain a better understanding how landscapes respond to environmental change.

“The presentation of integrating isotope data with phylogenetics was an outstanding example of how powerful the integration of multiple interdisciplinary tools can be used to gain insights into very difficult questions and phenomena that play out across ecological and evolutionary timescales,” said Brennan.

“One of my favorite takeaways was from the poster session, actually,” said Soper. “A student was interested in the drivers of mammoth extinction, and thought that knowing the age at which baby mammoths were weaned might help discriminate between competing hypotheses. To establish whether there might be isotopic patterns that indicated weaning time, he sampled a mother and baby elephant at the local zoo (where he took his children) over several years. The isotopic patterns he found in the elephants could also be identified in mammoth tusks, and he could use that to infer weaning age in long-dead mammoths and find support for some extinction hypotheses. Fascinating!”

Homyak was impressed with the research “using isotopes to understand which ecosystems should be preserved for salmon populations” and “using isotopes to unravel mechanisms controlling ecosystem processes.”

The speakers answer audience questions as a panel. Left to right: Tamsin O’Connell, Erik Van Bergen, Sean Brennan, Fiona Soper, Julia Tejada-Lara, Pete Homyak, Allison Karp, James Ehleringer.

Where research is heading

“Research on stable isotopes is heading in many different directions, from investigation of individual life histories to cycling of nutrients in soils to movement of populations over large landscapes,” said Badgley. “The amount of data has expanded vastly over the years, enabling isotope researchers to investigate changes in population and ecosystem ecology over short and long time scales.”

“I think one powerful direction will be to integrate our understanding of isotopic variation across earth's systems with the age of big data, advances in computational modeling, complementary tools such as genetics and genomics, remote sensing, and more traditional long-term ecological monitoring,” said Brennan. “I think isotope biogeochemistry provides a unique window into processes that are otherwise invisible. But, it is a tool among many other complementary analytical and computational tools.”

“There has been a real explosion of people working with isotope data, which has allowed a critical mass of baseline data, new instrumentation improvements and methods to coalesce,” added Soper. “Because of this, we have the context to interpret data in a way that wasn't possible even a few years ago, and there is real feedback/snowball effect that leads to more hypotheses, more data, etc.”

Homyak believes the research is headed “towards unraveling mechanisms not answered using traditional techniques.” Wang believes this area of research is headed toward “combining various sources to answer big-data questions.”

Advantages of holding an early career scientistists symposium

“The opportunity to hear from seasoned practitioners as well as early-career scientists is a good way to experience both breadth and depth of the subject matter,” noted Badgley. “The senior scientists were highly appreciative of the research that the early-career scientists are pursuing.”

“I think the early career aspect makes for a unique research approach that generates a high volume of very new ideas – people at our career stage aren't approaching questions with an entrained sense of what works and what doesn't (intellectual baggage, if you will) and so we are more apt to try risky projects or new methodological approaches,” said Soper. “When this pays off, it really pushes the field forwards! There is a level of energy and excitement about the topics that really shines through for many of us who have not yet presented similar work over and over.”

“I think the big advantage is that it provides a unique forum where young scientists that have just spent 5-10 years as students/postdocs interrogating the current state of their respective fields can give a fresh perspective on old and emerging practices, hypotheses and future directions,” said Brennan. “I would say this is quite unique about the symposium.”

Homyak saw the symposium as an “opportunity for young researchers to expand collaborations, network, and feel appreciated by the scientific community.”

“This was a great opportunity to bring scientists at all career stages (and particularly early career) together, establish networks and promote collaboration,” said Wang.

Deborah Goldberg asks a question of a speaker.

The poster session

“The poster session was one of my favorite parts,” said Soper. “Again, it's rare to see students from such different fields come together because of a common tool and it allows for an unusual level of cross-pollination of ideas.”

“It was useful to have a long poster session as part of the program so that all of the poster presenters can get the full attention of the audience,” said Badgley. “This poster session was lively and well attended the whole time.”

”The posters I saw were excellent,” reported Brennan. “The research questions were interesting and important and the analytical approaches and resulting interpretations of findings were stimulating and well presented.” 

“This year we made a special effort to highlight stable isotope research done at U-M,” noted Wang. “It was a successful poster session and our strength in this field was impressive.”

Homyak believes the poster session is a keeper. “It is a great opportunity for young scientists to present their work.”

Summing it up

“My experience at the symposium was fantastic,” said Brennan. “It was very stimulating, including the presentation portion, the poster session, and all of the surrounding conversations throughout the weekend.”

“I am not exaggerating when I say that that was the most new science I think I have ever learned in the space of one day!” exclaimed Soper. “I've been sharing what I learned about butterfly evolution and mammoths excitedly with friends in my own field and they're just as fascinated as I was.”

Homyak called the symposium an “amazing opportunity. I feel lucky to have had the chance to visit U-M and talk about my work.” When asked if he wanted to add anything, else, he said, “just a big thanks.”

Congratulations and appreciation to the hard-working logistics team* and the multi-unit (EEB/Department of Earth and Environmental Sciences/U-M Museum of Paleontology) 2019 ECSS committee**

*Molly Hunter, Kati Ellis, Gail Kuhnlein, John Megahan, Dale Austin and Fiona Story.

**Jake Allgeier, Giorgia Auteri, Catherine Badgley (Committee Chair), Dan Fisher, Katie Loughney, Knute Nadelhoffer, Ben Passey & Bian Wang.

Most of the presentations are on the ECSS playlist of EEB’s YouTube channel.

The ECSS 2019 speakers, front left to right: Tamsin O’Connell, Sean Brennan, Allison Karp, Erik Van Bergen, Fiona Soper, Julia Tejada-Lara, Pete Homyak, Jim Ehleringer. ECSS planning committee, back left to right: Ben Passey, Katie Loughney, Giorgia Auteri, Catherine Badgley, Bian Wang, Dan Fisher, Jake Allgeier, Knute Nadelhoffer.