Meet Tom Fleischner — The Naturalist Who Named and Protects the Mogollon Highlands

Tom Fleischner champions biodiversity in the Mogollon Highlands

This story is part of a monthly series highlighting Arizonans working on climate and answering readers' questions. It seeks to connect and inspire people who care about protecting a livable climate by showing quieter, science-driven leadership.

Not all climate leadership happens at rallies or in policy debates. Some leaders build the scientific foundations that make resilience possible by cataloging life and bringing overlooked landscapes into view. Tom Fleischner, a naturalist based in Prescott, is one of those people.

Discovering a biodiverse crossroads

After moving to Prescott 37 years ago — following childhood in Ohio and research on marine mammals and seabirds in western Washington — Fleischner set out to learn the region he was teaching. He found a striking band of habitats running along the Mogollon Rim, stretching from southwest New Mexico through central Arizona. The area harbors range-edge populations and a rare mix of genetic stocks from across North America and Mesoamerica, concentrated by strong elevational variety.

“It’s right where the Sierra Madre feeds in all this incredible biodiversity. You have genetic stocks from plants all over North America and Mesoamerica meeting here,” Fleischner said.

Naming the Mogollon Highlands and building evidence

Fleischner felt that the region’s informal label — the Arizona Central Highlands — failed to capture its defining geologic feature or its identity. He proposed the name Mogollon Highlands to highlight the Mogollon Rim and to help attract scientific attention. In 2017 he and colleagues published the first paper using the name, documenting that snakes, conifers and birds are more abundant or distinct in this band than in adjacent, more homogenous landscapes. Fleischner continues to present research and push for broader study and funding across the geologic corridor.

The Natural History Institute: art, science and public engagement

What began as a Prescott College program evolved into the nonprofit Natural History Institute, which Fleischner launched in 2012 to integrate art, science and the humanities. Today the institute operates from a historic stone building near downtown Prescott, hosting public talks, exhibits and hands-on displays designed to reconnect people with the natural world.

Visitors find crafted natural objects — a braided “manzanita ball,” maps in accordion books, and other artworks — alongside scientific displays. Fleischner’s wife, Edie Dillon, is an artist in the community, and the institute intentionally blends creative practice with rigorous natural-history work.

Collections, digitization and a growing crisis

The institute curates roughly 12,000 biological specimens, mostly plants but also reptiles, taxidermied birds and trays of pinned insects. Many specimens form time-series — for example, samples collected before and after wildfires — and some date back to the work of 19th-century botanical explorers like Cyrus Pringle. Student interns have digitized the collection so data are preserved online, an essential safeguard in Arizona’s variable climate.

National natural-history collections have declined in recent decades as funding priorities shifted and genetic research expanded. Scientists warn that losing physical specimens undermines the ability to compare past and present communities and to detect ecological responses to climate change.

Why this matters for climate resilience

Range-edge populations and ecotones like the Mogollon Highlands are valuable natural laboratories for understanding species’ responses to warming, drought and fire. Fleischner argues that maintaining and expanding collections and on-the-ground study is a modest investment compared with the rising economic costs of climate-amplified disasters — costs that have increased substantially in recent decades.

“I think there’s a natural human inclination to be fascinated by biodiversity,” Fleischner said. “And I think it’s really easy to recharge that in people. That’s kind of what the institute and my life’s work is all about.”

More about the author

Joan Meiners is a climate reporter at The Arizona Republic and azcentral.com. Her work has appeared in Discover Magazine, National Geographic, ProPublica and The Washington Post Magazine. She holds a doctorate in ecology focused on native bees. Follow her on Twitter @beecycles and Bluesky @joanmeiners.bsky.social, or email joan.meiners@arizonarepublic.com.