If you live in Columbia County, there is a chance you have passed through an ancient forest without knowing it.
Unlike most forests in the county, which have regrown on former farmland over the past 80 to 120 years, ancient forests are patches of woodland believed never to have been tilled. In Gallatin, such forests cover about 20% of the town, or more than 5,000 acres, according to ecologists with the Hawthorne Valley Farmscape Ecology Program in Ghent. Across Columbia County, the program identified about 700 ancient forest patches spanning more than 45,000 acres, or 11% of the county.
“These areas are very special because these ancient forest remnants harbor forest organisms, plants, and critters that were lost after agricultural conversion, so these areas are acting as refugia,” said Eli Arnow, chair of Gallatin’s Conservation Advisory Council.
On Sunday morning, July 26, Arnow led 13 people through an ancient forest on land owned by his family. He organized the walk to help residents recognize such areas and understand what it takes to protect them.
Before entering the woods, Arnow asked participants to clean their shoes on a boot scrubber he had brought, reducing the chance that they would carry seeds, soil, earthworms, or insects into the relatively undisturbed area.
He then held open a section of a 7 1/2-foot-tall fence as the group walked single file into a 13-acre deer exclosure he built about five years ago.
Inside, the forest understory was dense with shrubs, saplings, and wildflowers. Outside the fence, deer had browsed much of the same vegetation nearly bare.
“All of this unbrowsed mapleleaf viburnum,” Arnow said. “There’s a little bit outside but it’s absolutely hammered and will never flower.”
Arnow described deer browsing as the most significant threat to the forest. The deer population has increased, he said, while the number of registered hunters has declined.
“We have to teach people that [ancient forests] are valuable because most people have no idea,” Arnow said. “There’s so much potential for beauty.”
The history of a forest can sometimes be read in the ground beneath it. One way to identify an ancient forest, Arnow explained, is to look for humps and hollows in the soil.
The Hawthorne Valley program used lidar, short for light detection and ranging, to map the landscape. The technology can reveal decades-old plow lines left where farming flattened the ground, as well as the pits and mounds created when trees uproot and fall.
Gallatin’s hilly uplands were poorly suited to farming and show relatively little evidence of plowing. They contain abundant fallen wood, however, which Arnow said is critical to a healthy forest floor.
Post-agricultural forests often have sparse understories, he said, while ancient forest remnants support richer and more varied layers of shrubs, saplings, and wildflowers. The distinction was especially visible inside the enclosure, where plants had been able to grow without persistent deer browsing.
Arnow said about 14 wildflower species, including trilliums and false Solomon’s seal, survive almost exclusively in ancient forests. Among his favorites are the early azaleas inside the enclosure, which have grown to about 3 1/2 feet and produce hot pink flowers in the spring.
“Last year, they bloomed for the first time in who knows how many decades,” he said. “It was spectacularly beautiful.”
Without conservation efforts, Arnow said, the ecological character of these areas could disappear.
Many of Gallatin’s ancient forest remnants are found on steep, difficult-to-reach uplands, where property is often less expensive. Building on such land, however, typically requires long driveways and septic systems that disturb the soil and understory.
As part of Gallatin’s continuing discussion over updates to its zoning regulations, the town is considering limiting driveway lengths on properties containing ancient forest to 500 feet.
Gallatin Town Supervisor Tara Silberberg attended the walk. She said the town is working on making information on ancient forests accessible to educate residents on the topic.
“That’s government and conservation together,” Silberberg said. “Instead of saying, ‘You can’t do this,’ say, ‘Oh, my God, look at this amazing thing you have, you should really worry about it and think about ways to protect it.’”
Arnow said protecting the remnants of ancient forests across the region does not necessarily mean leaving them entirely untouched. Instead, he argued, landowners who disturb them should take steps to repair or offset the damage.
“I think the balance is active stewardship,” Arnow said. “If you’re going to be creating disturbances, you’ve got to step up a little bit and build a deer exclosure and help offset some of that or do active restoration or do an invasive plant management.”