Researchers learn more about the extraordinary biodiversity of the Clemson Experimental Forest

The Clemson University Board of Trustees designated 3,265 acres of the 18,000-acre Clemson Experimental Forest as an “ecologically sensitive zone” during its fall quarterly meeting. The decision follows nearly a century of systematic exploration and documentation of its biodiversity.

A checklist of the flora of the Clemson Forest assembled using plant specimens collected over six decades shows the forest is home to approximately 1,200 species of vascular plants, including 44 rare species tracked by the South Carolina Department of Natural Resources and 17 species recommended for tracking.

Lorena Endara, curator of the Clemson University Herbarium, an institution that preserves botanical plant specimens from the forest and the region collected since the early 1900s, echoes the voice of many botanist who recognize that the Forest’s plant diversity is remarkable due to its unique location and history.

“There are very few places in the Southeast with this biodiversity,” Endara said. “It’s in a privileged place, because we’re so close to the mountains. The flora of many different regions converges here, which is one of the reasons why it’s so rich.”

The primary reason for this is the diversity of habitats in the foothills of the Blue Ridge Mountains compared to the Smokies. While the Smokies have a 4,000-foot elevation gradient and varied soils, the foothills’ biogeographic history connects them with both the maritime provinces and the Blue Ridge through the Savannah River corridor.

Additionally, human activity has influenced plant distributions in the Clemson Experimental Forest through planned or unplanned reintroductions and habitat destruction.

“The Clemson Experimental Forest has a mixture of plants native to South Carolina. Some may have been part of an experiment or introduced for horticulture and then escaped, while others remain from when people lived in the area,” Endara said. “It’s a combination of factors, but that’s what makes it incredible.”

In 2024, researchers identified three newly verified rare species in the forest, as determined by the South Carolina Department of Natural Resources: Polygala senega, Triosteum perfoliatum and Eupatorium altissimum.

The Forest’s Role in Clemson’s Land-Grant Mission

Clemson College began supervising the land in 1939 under an agreement with the federal government. Over nearly 100 years, careful management has transformed the land from depleted row crop farmland to a resource for teaching, research and outreach, as well as a valued community asset.

While scientists continue to learn more about the diversity of plant and animal life in the Forest, it also plays a key role in the University’s land-grant mission of teaching, research and outreach, fulfilling founder Thomas Green Clemson’s vision of a “high seminary of learning” that would benefit the citizens of South Carolina.

A recent survey of Clemson University faculty showed that 18 percent currently use the Forest in their teaching, and 64 percent across all colleges are willing to use it.

Thirty-seven classes in forestry, wildlife, ecology, biology and botany currently use the Forest to provide students with experiential learning opportunities and bring abstract concepts to life.

Endara, who is also a lecturer in biological sciences, incorporates the Forest into her plant taxonomy lab, where students learn how to identify plants.

“I bring plants from the field into the lab and use them to show students key identification features,” Endara said. “These skills will be valuable for their future careers in plant sciences, and they also increase their appreciation for plants.”

Forestry research and instruction have taken place in the Forest for generations and continue today.

Clemson University Provost Bob Jones, a two-time Clemson graduate, earned a Bachelor of Science in forest management in 1979 and a Master of Science in forestry in 1981.

“I found that exploring that forest was part of my well-being,” Jones said. “I’ve hiked virtually every single mile of every trail in the Forest, and I did that as a student. I remember so much from my experiences learning in the field that when I came back as provost many years later, I revisited those trails, and deep memories came flooding in.”

As in previous generations, today’s Clemson faculty use the Forest to teach students forest management protocols and research new techniques that could benefit the South Carolina forestry industry and the state’s environment.

“Research in the Clemson Experimental Forest really spans many different disciplines,” said Rob Baldwin, professor and executive director of the Clemson Experimental Forest. “We have soils research going on in the Forest. We have wildlife research going on in the Forest. So, there are many, many questions that focus on the Clemson Experimental Forest that Clemson faculty have been engaged with that are important both to people here and to global challenges such as climate change.”

Don Hagan, associate professor of forest ecology, studies the effects of fire and plant invasions on population, community and ecosystem-level processes in forest ecosystems. He also teaches forestry classes and serves as faculty advisor for the Student Association of Fire Ecology.

“I use the Forest for research and Creative Inquiry classes,” Hagan said. “For example, I’ll take small groups of undergraduates there to conduct small-scale studies. Its proximity makes it convenient. We also use it for larger, long-term grant-funded studies. We currently have a study in the South Experimental Forest examining the effects of fire on soil and water quality, funded by the Department of Energy with collaborators from around the world.”

Associate professor of forest operations Patrick Hiesl researches forest operations and engineering, focusing on the cost and productivity of harvesting operations on both small and large forest areas. His work also explores the use of modern technology in forest management.

“We study the effects of harvesting equipment on erosion, sedimentation in streams and other impacts,” Hiesl said. “The biggest benefit of using the Clemson Experimental Forest is knowing the ownership isn’t going to change anytime soon. We have control over what happens and can experiment in ways that wouldn’t be possible on commercial forest land. We don’t have to manage a particular stand for maximum profit, so we can ask different questions, implement new practices and push science forward.”

Balancing Uses

The Clemson Experimental Forest contains more than 100 miles of trails used for hiking, trail running, mountain biking and horseback riding. With more than 100 miles of shoreline on Hartwell Lake, Issaqueena Lake, Twelve Mile Creek and other water bodies, the public also uses the Forest for outdoor activities such as fishing and hunting.

So, while the Forest serves as a hub for teaching and research and contains some of the area’s most diverse and rare plant life, it also provides space for refuge, reflection and outdoor recreation.

The U.S. Census Bureau’s 2023 population growth data showed that most of South Carolina’s 46 counties gained population, with Spartanburg and Greenville among the fastest-growing counties. While not in the top 10, Pickens and Anderson counties grew by a combined 3.15 percent.

This population growth means the forest is under more pressure than ever before to accommodate the recreational needs of the surrounding community.

“The folks that use the Forest really do value it, and they’re passionate about what the Forest means to them,” Baldwin said. “The unique thing about it is that each user group — whether horseback riders, mountain bikers, hikers or others — deeply cares about protecting and taking care of this resource. When we have places like this close to where we live, even in high-density areas, it’s very important to have spaces where we can retreat and reconnect with nature.”

While the Forest is essential to the University’s teaching and research efforts, its role in recreation and the well-being of the community means Clemson will take steps to improve infrastructure and increase safety for all users.

“Clemson is in the forever business, and we want the Forest to forever provide these resources to the people of the surrounding communities,” Baldwin said. “No other important public space I can think of is left for various user groups to self-manage. What we want to do is make the forest a safer place and a more sustainable environment for recreation well into the future.”