Research dedicated to finding ‘grounds for hope’ honored with academy membership
Decades before embarking on a career that continues to take him to some of the most biodiverse places in the world, Karl Zimmerer first encountered global food geographies in his grandparents’ backyard in Elizabeth, New Jersey. There, his grandparents, from the hill country of the Ukraine-Poland border who fled persecution, grew and ate the fruits of the diverse cherry trees, cabbages, wheat varieties, sunflowers, and herbs that they brought from the old country.
“I grew up in a pretty diverse setting and had immigrant grandparents with food traditions outside the mainstream conventional ones in the United States,” said Zimmerer, professor of geography and member of the ecology and rural sociology programs at Penn State. “I also had a parent with Type 2 diabetes, so we were careful about food choices and quality. It made me aware of food connections not just to geography but to health and well-being.”
The American Academy of Arts and Sciences honored Zimmerer, who has dedicated four decades and made numerous contributions to environment-society geography, biodiversity, land use, and food security—including seven books and more than 100 articles in journals like Nature and the Proceedings of the National Academy of Sciences—by electing him to the 2024 member cohort.
The honor lauds an ongoing career committed to finding what Zimmerer calls “grounds for hope” in the food systems and land use of places and societies undergoing major changes.
Real places, real people, real food
Zimmerer took the lessons from his family to Antioch College, Ohio, where he studied biology and physics. Undergraduate work-study internships across the country in places such as Kansas, Montana, and Tennessee started Zimmerer’s focus on environment-society interactions. He then went to graduate school at the University of California, Berkeley. He joined geographers working with environmental scientists and food specialists on global problems in the nascent field of food geographies. Graduate study and field experiences further honed his interest in how the interactions of human impacts and the capacities of nature are central to the past, present, and future of food biodiversity and sustainability.
“I had a lot of experiences working in real places with real people, real food, real landscapes, and really dynamic changes,” said Zimmerer. “I thought, ‘Wow, environment-society research is such a rich and important area to work in.’”
While Zimmerer’s research on food geographies has taken him to Vietnam, Nepal, India, China, Rwanda, and Mediterranean countries, he has spent much of his career in the Peruvian and Bolivian Andes, returning to Peru three times in 2023 alone.
Located in the tropics but having several climates due to its geography, Peru is a biodiversity hotspot, boasting more than 4,000 kinds of potatoes and similarly extraordinary diversity in other food plants. Home gardens and small fields in the Peruvian Andes—measuring less than a quarter-acre—contain, on average, 146 different crop species, such as maize, beans, squash, chiles, cereals such as quinoa, root vegetables, and herbs, according to research conducted by Zimmerer and colleagues in 2022.
The area also sits at the forefront of a rapidly changing climate, which will impact those crops and the people who depend on them. Zimmerer said his work suggests there are grounds for hope—for biodiversity and for communities—even in the face of complex, rapid changes.
“My research is about understanding this dynamic current situation and seeing how it came out of the changes of the historical past,” Zimmerer said. “How does history help us to understand the current day? And then we project into the future to understand what the findings mean for these environments and communities five, ten, fifteen, twenty, fifty years down the road.”
He first visited the Peruvian Andes in the 1980s while researching his master’s thesis on a legume known as the popping bean. Unlike other beans that people usually boil, the popping bean is toasted or popped like popcorn, Zimmerer explained. He focused on how small-scale farmers and the Indigenous Quechua people produced, used, and consumed it, and how the bean contributed to sustainability.
“We quickly realized that these were probably some of the oldest lineages of beans in the world, because they were what people would have cooked before they had ceramics and pots to boil water,” he said, explaining that bean domestication started at least 3,000 years before ceramics were invented. “So, for a few thousand years, how are people cooking this stuff? They likely heated stone and had popping beans cooking on them. This is how the early ancestors of the Inca, one of the world’s great civilizations, would have survived.”
When the U.S. National Academy of Sciences ran a conference on “The Lost Crops of the Inca” a few years later, Zimmerer led the popping bean chapter. Credited with “discovering” the bean, though he disputes that description, Zimmerer said his first experience in the Andes—working with several highly knowledgeable communities and well-informed local scientists—showed him the importance of understanding the popping bean and, later, other foods as currently and historically crucial to people, landscapes, and knowledge systems surviving times of intense change.
Versatility as grounds for hope
The Shining Path insurgency broke out in Peru, where Zimmerer was living and working, in the 1980s and spread to much of the countryside. At the time, people in the countryside grew 80% to 90% of the food they ate, said Zimmerer. How did they manage that during war?
“When I started my work, the scientific understanding was that food biodiversity existed in micro-niches,” Zimmerer said, explaining that a single crop in a highly specific environment was thought of as limited to that area.
Zimmerer found that much food biodiversity existed not in stable, specialized micro-niches but in their versatile adaptive capacities to “non-equilibrium systems.” For instance, during the war, people took the crops they liked and valued and grew them closer to home, which he terms close-to-home cultivation, instead of farther away in the fields, where they risked getting caught in the fighting.
“I found that many human-plant interaction systems have a lot of versatility associated with them,” he said. “Even before the war, there were other kinds of intense changes, such as historic climate changes, and versatility gave these systems the capacity to adapt to intense change.” This versatility was and is currently reinforced by the seed systems of small-scale land users and Indigenous people, which Zimmerer has studied extensively, since they occasionally rely on seeds from different micro-environments. Culture is a further source of specific positive links to this versatility, a research insight that Zimmerer has developed in scientific journals as well as ones as wide-ranging as the Proceedings of the Modern Language Association and Allpanchis (“Our Earth”), an Andes-based journal.
The Green Revolution in the 1990s and early 2000s provided another opportunity for Zimmerer to carefully investigate the precepts of conventional wisdom of the field. At the time, he explained, introducing irrigation projects in developing nations was predicted to homogenize crop production and “wipe out” biodiversity. Zimmerer’s research, published in Nature, found that an extensive irrigation system had existed in the Andes as early as 3,500 years ago.
“As irrigation influenced these food systems, people were changing what they grew, but it was often changes with adaptation in the community-based irrigation that was becoming more common,” he said. “Community irrigation projects shifted crop types but didn’t decrease diversity. It’s a very important outcome because it suggests that irrigation for climate change adaptation, if done the right way at the right scale, doesn’t necessarily destroy food biodiversity.”
Addressing global change
The honor from the American Academy of Arts and Sciences is the latest that Zimmerer has earned over his career. Others include two Fulbright fellowships, a John Simon Guggenheim Fellowship, and fellow status for the American Association for the Advancement of Science. And he’s not done.
Zimmerer is currently working on several interdisciplinary research projects with collaborators at Penn State and in communities, universities, and civil-society groups around the world. One project assesses how people in Colombia and Peru used biodiversity to navigate the COVID-19 pandemic. Another project with Ramzi Tubbeh, who earned his doctorate under Zimmerer’s mentorship, examines 600 years of people sharing resources in ways impacting food biodiversity in Andean communities from Inca times to the present. A third project analyzes 10,000 recipes to see how people adapt their cooking to climate change impacts.
“As an environment-society researcher, I’m really obsessed with how to address the biodiversity and sustainability of food systems amid the global change drivers of climate change and urbanization and associated effects such as migration,” he said. “My family influences also intersect with framing these food and biodiversity issues in the large-scale dynamics of global change. We’re talking about the most important challenges facing sustainability and society. They are right in front of us.”