Prestigious Journal Science Publishes Colgate Professor’s Study

Will Cushman

How do you get an article you co-authored published in one of the top science journals in the world while at the same time inspiring students to care about ecology and the environment? Well, you could climb some trees for starters.

Last month, at the beginning of her first semester at Colgate as Assistant Professor of Biology, Catherine Cardelús became the first Colgate faculty member ever to be published in the prestigious international science journal Science.

Appearing in the journal’s October 10 issue, the article, titled “Global Warming, Elevational Range Shifts, and Lowland Biotic Attrition in the Wet Tropics,” is the result of truly groundbreaking research performed by Cardelús and several of her colleagues in the tropical rainforests of Costa Rica.

While doing post-doctoral research at the University of Florida, Cardelús studied the relationship between global warming and its effect on tropical plant species. More specifically, she and her colleagues studied the effects of global warming on the upslope migration of species and its resulting implications.

While her own data were collected and published during her dissertation work at the University of Connecticut, Cardelús began collaborating with colleagues who had also worked on elevational gradients. By combining their datasets, they were able to study the relationship between global warming and its effect on tropical species, particularly the upslope migration of species and its resulting implications, during her postdoctoral work at the University of Florida and over the summer at Colgate.

“It was grueling, but a lot of fun,” Cardelús said. The study involved hiking eight hours into a remote, isolated rainforest. A rainforest that makes up the last remaining “continuous elevational gradient” in Central America – it runs unbroken from sea level to an elevation of 3000 meters. This unique tract of land was important for Cardelús’ research as it provided the only site in which she could study global warming’s effects on species’ ranges on a continuous slope.

This was followed by hours upon hours of collecting and identifying over seven thousand plant specimens.

“It took a lot of time and intense work to collect the data,” Cardelús said. “We needed very broad, large data sets in order to look at broad patterns of species richness.”

The fun part? Cardelús’ field laboratory, where she collected the specimens, was literally in the canopy of the rainforest, some 30 meters above the forest floor, and involved climbing enormous trees with the help of ropes, ascenders and crossbows. Such a unique research setting meant that the majority of the data Cardelús and her colleagues collected was also unique. In fact, the research was so one-of-a-kind that the conclusions the team came to were altogether groundbreaking, so groundbreaking that it led to its publication in Science. After the paper was written, the original AP media press release was picked up by some 225,000 media outlets.

As a result of their research, Cardelús and her colleagues came to the conclusion that global warming could adversely affect the species richness of tropical lowlands. Cardelús explained that when the warming causes temperatures to rise above what a species has adapted to live in — its “thermal optimum” — it will migrate upslope, to cooler elevations. In their article, Cardelús and her colleagues asked what will happen at the lowest elevations, where there won’t be species adapted to warmer temperatures to replace those that have migrated upslope.

“Surprisingly,” the article states, “this question has scarcely been considered in a broad biogeographical framework.” It was exactly for that reason that the team’s study received such attention.

Today Cardelús plans to continue the research she started for the article here at Colgate with students in the lab. She said that it was during her own undergraduate studies at Barnard College that a professor first got her really interested in the field.

“I knew I wanted to do tropical biology despite never having been to the tropics,” she said. “I was just inspired by plants.”

Recognizing her passion, Cardelús’ parents funded her first trip to Costa Rica to work at a field station for two months after her graduation from college. On her third day down there, she was invited to go tree climbing in the forest.

“When I climbed [the tree], I saw how much was in the canopy. … Thirty percent of species live in the canopy,” she said. “Seeing that got me completely hooked.”

Cardelús hopes to in turn inspire her own students, both in the lab on campus as well as through real field experience in Costa Rica. Currently, Cardelús is proposing a tropical ecology course about ecological diversity, complete with an extended study component to the same Costa Rican rainforests she first studied as an undergraduate.