The Power of Place: Why Tennessee’s Biodiversity Matters to the World

A Long, Living Landscape

Tennessee stretches nearly 450 miles from east to west, an eight-hour drive that carries you from the bottomlands of the Mississippi River to the ridges of the Appalachian Mountains. That span covers an astonishing diversity of landscapes—rolling pasture, karst caves, floodplain forests, mountain streams—and supports a richness of life unlike anywhere else in the country.

Tennessee is, in fact, the most biologically diverse inland state in the United States. From salamanders and mussels to migratory birds and black bears, it holds some of the most ecologically important—and climate-resilient—habitats on Earth.

As someone who has spent a lifetime in medicine and public service—and who now helps lead The Nature Conservancy’s (TNC) global efforts to protect nature—I believe this biodiversity is not just beautiful. It is essential. It supports our health, economy, culture, and future.

And it’s all connected. In Tennessee, our story begins with rivers.

Mississippi River Floodplain © Rory Doyle

The Duck River: A Global Treasure in Our Backyard

I first visited the Duck River, a couple of hours southwest of Nashville, many years ago as a boy. Back then, I didn’t think much about its global significance. I only knew it as a quiet, clear stream, winding through the countryside, alive with fish and shaded by sycamore. I’ve returned many times since—and what I’ve come to understand is that this river is not just special to us. It’s special to the world.

The Duck is the most biodiverse freshwater river in North America. It supports 151 species of fish, 60 species of mussels, and 22 aquatic snails—many found nowhere else on Earth. It also provides drinking water for nearly 250,000 Tennesseans and supports farms, families, and businesses along its 284-mile course.

Much of the Duck flows over karst terrain—a landscape of limestone, caves, and underground streams. This geology helps explain its unique biodiversity. Karst systems are rich in calcium carbonate, the mineral mussels use to build their shells. These creatures—quietly filtering water and supporting aquatic life—are a cornerstone of freshwater health.

For over two decades, The Nature Conservancy has worked to protect and restore the Duck River. We’ve established conservation easements, improved streamside vegetation, and collaborated with farmers and utilities to safeguard both water quality and ecological integrity.

But the Duck is under threat. Rapid development and degraded water quality recently earned it a place on American Rivers’ list of America’s Most Endangered Rivers. And that is a warning we cannot ignore. The health of this river is directly tied to the well-being of the people and wildlife who depend on it.

Last fall, Governor Bill Lee issued an Executive Order aimed at protecting watersheds across the state—momentum that began with the Duck River and has now expanded statewide. It’s a powerful example of how science, policy, and community can come together for lasting impact.

Bookended by Greatness: From River Bottoms to Mountain Peaks

Tennessee’s biodiversity is a gift of geology and geography. We sit at the intersection of two of the most iconic and globally significant natural systems in North America:

To the west, the Mississippi River Basin, encompassing 31 states and over 1.2 million square miles.

To the east, the Appalachian Mountains, a global focal area for biodiversity and climate resilience, stretching across 13 states.

Together, these two systems frame Tennessee—bookending our state with powerful forces of nature and explaining much of the state's rich biodiversity. And our role in protecting them is pivotal.

Tennessee Smoky Mountains © Byron Jorjorian

West Tennessee: Healing the Mississippi River Basin

In West Tennessee, the land flattens, the skies open, and the river becomes king. The mighty Mississippi River, and its tributaries, once flowed through vast bottomland forests and wetlands, teeming with wildlife and natural floodplains.

But much of that land was drained and cleared for agriculture over the last century, producing food and jobs, yes, but also leading to increased flooding, water pollution, and habitat loss.

That’s why TNC is working to restore wetlands and reconnect floodplains—not to roll back history or slow economic progress, but to make the landscape more sustainable for the future. These powerful nature-based solutions help:

· Filter water before it reaches rivers

· Store carbon in soils and vegetation

· Reduce downstream flooding

· Create habitat for waterfowl, fish, and amphibians

Collectively this work supports local farming, improves ecological health, and reduces nutrient runoff that affects the entire Mississippi River Basin, all the way to the Gulf of Mexico. In this way, West Tennessee becomes part of a 31-state collaboration—a continent-wide strategy to restore one of the largest freshwater systems on Earth.

This map shows the migratory pathways where mammals, birds and amphibians are moving. Circled in red is the Appalachians landscape, which species are increasingly relying on with shifting weather patterns. © Dan Majka/The Nature Conservancy

East Tennessee: A Global Focal Area in the Appalachians

Drive east along I-40 and you begin climbing into the Cumberland Plateau (where as a child we took our annual, one-week summer vacation at Cumberland Mountain State Park), then the Ridge and Valley, and finally the Southern Appalachians—a place of old-growth forests, clear streams, and deep cultural roots.

The Appalachian Mountains are one of the most ecologically important and climate-resilient regions in the world. They are a TNC Global Focal Area—one of just a few such designations worldwide.

This region supports:

· Thousands of plant and animal species, many endemic

· More species of salamanders than anywhere else on Earth

· Vital climate corridors that allow species to migrate in response to warming (see dynamic map)

· Old forests that store carbon and help stabilize the climate

Here in Tennessee, TNC’s Appalachian work focuses on three sectors:

· Freshwater Conservation – protecting karst systems and underground aquifers,

· Land Protection – securing at-risk tracts of ecologically valuable land, and

· Forest Management – restoring fire-adapted ecosystems and increasing biodiversity

Rumbling Falls Tennessee © Stephen Alvarez

In places like the Cumberland Plateau, we’re protecting a maze of caves and underground rivers—part of the largest concentration of karst topography in the United States, with over 11,000 documented caves (more than any other state). These systems provide clean drinking water, habitat for rare cave-dwelling species, and resilience in the face of climate extremes.

Old Town and the Harpeth: Where People and Nature Meet

And now, let me bring this story back home—to Old Town, the farm where Tracy and I live in Franklin, Tennessee, and to the Harpeth River, which winds gently through our land.

The Harpeth, like the Duck, is rich in freshwater life and ecological history. For Tracy and me, the Harpeth River is a classic story of opportunity and challenge.

It’s a thriving ecosystem, home to dozens of fish and mussel species, running through diverse habitats. But it’s under extreme pressure—from nutrient pollution and wastewater impacts from nearby Franklin. Yet it’s regenerating—through strong community and agency partnerships led by the Harpeth Conservancy, backed by science and legal frameworks.

We see hope—and momentum—in the Harpeth. It takes action. With continued support, monitoring, and stewardship, it can become both a triumph of local conservation and a vital case study in balancing people and nature.

Running through our front yard, the river reflects the connection between people and place, between memory of a thousand-year-old ancient civilization and stewardship of an historic home and surrounding lands. This place we call home has seen Indigenous temple mounds rise, families settle, and nature reclaim its rhythms.

At Old Town, Tracy and I have also worked to restore native grasslands, protect riparian buffers, and steward the health of the soil and water. We eat from Tracy’s garden and rotate our livestock pastures. We’ve nurtured more than 85 native tree species as a state-certified arboretum, preserved federally protected wetlands, and regularly welcomed community partners—from students to preservationists (Tracy is on the board of the National Trust for Historic Preservation) to conservationists—to walk and learn alongside us.

And that, to me, is what The Nature Conservancy is all about. Our mission is simple but powerful: to protect the lands and waters on which all life depends. Not just for the sake of nature, but for people—for health, for security, for beauty, for legacy.

Tracy on horseback accompanied by me and Olaf the pony. Surveying the pastures of Old Town.

Why We Do This Work

Tennessee’s biodiversity is more than a scientific fact. It is a living, breathing inheritance. And what we do with it—how we protect it, share it, and sustain it—matters not just to us, but to the world.

When we restore floodplains in the west, we protect people from floods in downstream cities. When we preserve forest corridors in the east, we help species adapt to climate change. When we save a river in the middle of the state, we save ourselves.

So Tracy and I share stories. And when we tell these stories, stories deeply rooted in place, shaped by science, and animated by people, we inspire action.

This is the power of Tennessee. This is the power of story. And this is why we do what we do: so people and nature thrive—together. For generations to come.