When Gary Grossman arrived at the Warnell School of Forest Resources in 1981, he realized there was a jigsaw puzzle that needed to be solved. With research interests focused on population dynamics and community ecology, Grossman was interested in what we now call biodiversity—but at the time, it was a novel idea still being explored. As a fisheries ecologist—a burgeoning field but one with few faculty positions across the country—he was interested in pushing boundaries. “The paradigm of the past is nature was this jigsaw puzzle, with species A eating something over here and species B eating something over there, and the world was this giant equilibrium system,” says Grossman, who retires Sept. 1 after teaching and conducting research at Warnell for 41 years. His experience with fish told him there were different forces at play, though, and the line of research he chose became one of his career achievements. What made that original concept a paradigm were the mathematical theories supporting it. Today’s computing power to determine complex algorithms didn’t exist at the time, and as a result, everything worked out if all the elements remained at an equilibrium. “In the fish world, it has long been known that environmental unpredictability had a large influence on fish populations—and this was counter to the paradigm,” he added. So, in 1982, he published two papers that showed that ecological systems could be arrayed on a continuum, and that species abundance could be determined by a combination of floods, droughts or major storms that happened the previous year. “So, biodiversity isn’t necessarily determined by each species specializing on a different habitat or on different foods, but also by the interaction of environmental unpredictability with the innate characteristics of the species involved. For example, different stream fishes have different reproductive times and biodiversity in the next year may be determined by who happened to be reproducing when a flood or drought occurred. So, their young might be wiped out that year and the population could decline catastrophically.” Grossman’s work on environmental unpredictability became foundational research; to date one paper has been cited more than 500 times and another more than 270 times. Through his lab, Grossman also took on research that was experimental in nature, identifying and investigating mechanisms in ecology. Using the southern Appalachian’s diverse stream ecosystems as his canvas, Grossman built models to better understand the relationship between stream velocity and drift feeding fishes such as trout and minnows. By examining habitat choice as a cost/benefit relationship, Grossman and his students were able to predict optimal habitat for species in Georgia and Alaska. This type of information is vital to biologists and fisheries managers. “I believe we have an obligation to provide information that can help us preserve, conserve and manage natural resources,” adds Grossman. But while Grossman enjoys his work—and takes to North Georgia trout streams on the weekends whenever he can—it’s only one aspect of his identity. Grossman’s activities outside of the lab push him creatively, and he’s found his own equilibrium through poetry, music and art. These creative pursuits inspire new questions in research, and vice-versa. In more recent years, this creativity has also influenced his teaching. He’s found ways to work music and video into classes on natural resources, winning several awards along the way. In one class, for example, Grossman challenges students to write songs and create music videos about Georgia’s flora and fauna. As he enters retirement, Grossman plans more time for exploring cold-water streams, poetry, perhaps even some drawing. His mother told him he could do anything—and also never told him he excelled at any of it. But, says Grossman, most accomplishments come from hard work and a lot of effort—so why not try? “The similarity between science and art is seeing something you see every day, but seeing it from a new vantage point,” he says. “I think I’ve been fortunate in finding alternative ways of looking at the world that have turned out to add to our knowledge base.”
