Nature

Some mountain conifers make the Piedmont their home

Eastern hemlock needles and cones in Charlotte, NC

In December, the familiar Fraser fir population reaches its fleeting peak in the Piedmont as Christmas trees are harvested from farms in the North Carolina mountains and brought to market. 

But two other species of conifers largely restricted to the mountains have found surprising refuge in our region — at least for the time being.

Nearly 20 years ago, I was assessing a large tract of land along the Uwharrie River that would eventually become the Three Rivers Landtrust’s Low Water Bridge Preserve. As I stood with a group of fellow conservationists on a knoll and gazed across a recent clearcut, I raised my binoculars and scanned the distant, forested hills. On a steep slope, among the bare hardwoods, stood tall pines with a pointed shape and shaggy texture, very different from the tight, flattened crown of a mature shortleaf, longleaf or loblolly. 

Cones at the base of a white pine in the Uwharries. Photo: Crystal Cockman

“Y’all, I think those are white pines,” I said — a bold claim for a lay naturalist among experienced foresters and botanists. 

White pines (Pinus strobus) were probably once common across the Piedmont. But as the climate warmed, their range contracted. Natural stands of white pine have been documented at only a few locations across our region, the most notable being a protected site in Chatham County.

This isolated stand in the Uwharries wasn’t on anyone’s radar. (Inexplicably, it still doesn’t show up on the USDA PLANTS database.)  After years of prodding, botanists assessed the site and determined it was indeed a naturally-occurring population, as opposed to trees that had naturalized from a long-forgotten planting.

They have likely survived thanks to the cooler, moister microclimate created by the north-facing bluff at the juncture of an unnamed creek and the Uwharrie River. Botanists also wonder if there are subtle genetic differences that make them more heat-tolerant, but those studies have yet to be conducted.

In 2012, the site was included in a massive controlled burn on almost half the property. Jay Bolin, assistant professor of biology at Catawba College, visited with his students five years later. He reported that a few trees died, but new seedlings were popping up on the exposed mineral soil. So the stand seems to be regenerating rather than stagnating or declining, for now.

Unfortunately, that’s not the case for Eastern hemlocks (Tsuga canadensis) in the Southern Appalachians. They’re being decimated by a non-native pest, the hemlock wooly adelgid. Their gray skeletons loom over many sections of the Blue Ridge Parkway. That makes the stand in Charlotte’s Latta Park even more remarkable. 

More than three dozen trees are scattered throughout the forested area covering roughly half of the park’s 32 acres. The laid-back elegance of their delicate needles and droopy limbs seems in keeping with the Craftsman bungalows nearby. Mature oaks and hickories dominate the canopy, providing a shady oasis for the hemlocks, which are prone to sun scorch. They prefer well-drained soil, but they can’t withstand drought.

The park’s steep clay slopes – bisected by a perennial stream – seem to meet those tricky requirements. Several appear to be well over 40 feet tall, with diameters of more than 20 inches.

Hemlocks flank a footbridge over the perennial stream in Latta Park. Photo: Ruth Ann Grissom

A few are much smaller, which I find intriguing. The county doesn’t have historic planting records, but their thoughtful placement suggests they were installed at the same time. If so, the size variation might simply be due to cultural differences in soil and moisture.

But I have another pet theory – a few have actually seeded in. This isn’t so far-fetched when you consider the errant specimen growing at the base of a large oak. I imagine a cone washing downhill and lodging against the trunk, or a squirrel dropping a seed from a perch.

Given the possible extirpation in their prime habitat, it’s poignant to see them doing so well in a region where they don’t naturally occur. How have these outliers managed to survive the wooly adelgid?  Lenny Lampel, natural resources coordinator with Mecklenburg Park and Recreation, believes they’re far enough from the mountains that the destructive insects simply haven’t found them. 

Yet. 

Climate change or an invasive species could claim these sites at any time. Their vulnerability only heightens my appreciation. Their very presence in these unlikely locations is transporting — grounding us in one place while hinting at another, offering the expansive possibility of hope.