Spruce-Fir Forest

What it is

Above about 5,500 feet, by the North Carolina wildlife plan’s figure, the hardwoods give way to conifers. On the highest peaks Fraser fir is the only tree that survives in numbers. On slightly kinder sites red spruce and yellow birch grow with it, and the state’s classification, as the plan summarises it, divides them into Fraser Fir Forest, with herb and rhododendron subtypes, and Red Spruce–Fraser Fir Forest. The plan likens the climate to Canada’s boreal forest for cold and describes it as wetter, with rain and fog gathered on the peaks. The national vegetation classification gives one of these forests, red spruce and fir over rhododendron, a global rank of G1 and finds it best developed between about 5,100 and 6,000 feet, on foggy, saturated ground and acid soils.

Where it is

The wildlife plan lists six areas in North Carolina: Grandfather, the Roan, the Black and Craggy mountains, the Great Balsams, the Plott Balsams and the Smokies. Totals depend on who measured and how, from more than 66,000 acres across the southern Blue Ridge in one estimate to more than 75,000 in North Carolina and Tennessee in another. The Smokies hold most of the red spruce. An Oak Ridge review put the species above roughly 1,200 metres at about 30,500 hectares, more than three-quarters of it inside the park. Georgia has none at all.

What it has come through

Much of what is known about the damage comes from Mount Mitchell. By 1966 the balsam woolly adelgid had killed between 82 and 98 percent of the larger fir in the stands measured there. In the summer of 1986 researchers on the summit measured cloud water as acid as pH 2.2, and another study found the lowest ratios of calcium to aluminium in red spruce needles yet reported from eastern spruce-fir. In the Smokies the Park Service records cloud water down to pH 2.0. The vegetation classification notes that some stands opened by the adelgid have stayed without forest for sixty years or more. On the Roan, Hurricane Helene took an estimated ten to twenty percent of the red spruce canopy in September 2024, by the Forest Service’s first assessment, and replanting has begun.