Many of the southern Appalachians’ signature tree species have undergone challenges ranging all the way to near extinction. As leaf season arrives, we check in on progress toward survival and reinvigoration among seven species.
As autumn approaches, great brush strokes and fine details of crimson, gold and orange appear across the mountains and hollows, valleys and creek sides. The maple, oak, sweet gum, hickory, sourwood, beech, cherry and walnut trees welcome the season in resplendent colors.
Living amongst this canvas are several tree species with a difficult past, struggling present and unknown future. To understand this set of native species, we have gathered facts into a report card of sorts on the state of some of the mountains’ great trees. As a former teacher, this writer’s view is that report cards contain a celebration of successes and a recognition of opportunities for improvement. So, let’s see how seven of our native tree species are doing.
American Chestnut
This giant of the forest once numbered in the billions across the eastern United States. Soaring to heights of over 100 feet with trunks exceeding 10 feet in diameter, these fast-growing mighty hardwoods were a staple in colonial American life. The timber was used for home building, railroad ties, furniture, posts and poles, fences and even caskets. The fruit, a favorite of wildlife, was also a cash crop in the mountains. Farmers fattened their cattle and hogs in the groves and the bark and wood were used to tan leather.
Today, mature American chestnut trees are almost nonexistent. The first blow came in the early 1800s with a condition called “ink disease” followed by a fungus called “chestnut blight” that decimated the remaining trees. They are, however, not extinct. While ultimately succumbing to disease, the roots of lost trees continue to sprout new growth. And, genetic-level science along with the discovery of a nonvirulent strain of the blight offer hope for the return of this queen of the forest.
Fraser Fir
The aromatic quality, up-turned branches and soft needles of this native species make it a favorite choice for a Christmas tree. While thriving on farms for this purpose, it is endangered in its natural high-altitude ranges. The cause: the balsam woolly adelgid—an invasive insect that was inadvertently introduced around 1900 and detected in the 1950s. By the 1980s, it had decimated the population.
The good news is that this tree, native only to the southern Appalachian Mountains, appears to be making a comeback. Living above 5,000 feet, this remnant of the last Ice Age can still be seen in the mountains of North Carolina, Tennessee and Virginia dotted by the standing skeletons of those that did not survive yet still contribute to the life cycle of the forest. Scientists have discovered that these stands of young trees are more resistant to the deadly insect than their older counterparts.
Eastern Hemlock
Often referred to as the “redwood of the east,” these giants can grow taller than 170 feet and live for more than 800 years. Their dense foliage begins at the forest floor and reaches to the canopy, creating a unique ecosystem utilized by over 120 species of vertebrates. Typically standing beside creeks and streams, this species prevents erosion, regulates water temperatures and increases oxygen levels—all necessary for aquatic species health.
Enter another tiny aphid-like insect, the hemlock woolly adelgid. Likely introduced in the early 20th century and identified in the 1950s, this invasive pest has reportedly infested over half the population of eastern hemlocks. The problems are also exacerbated by warmer winters allowing more of the insects to survive. Recent research shows that certain conditions, like increased sunlight, help the trees survive. Combined with a suite of careful forest management strategies, prognosis for the protection of this keystone tree species is hopeful.
American Elm
Think back to childhood days when, crayon in hand, we drew a tree. Unbeknownst to us, we were sketching an elm! The quintessential shape of a sturdy trunk with a canopy spread of four to five times in diameter is a picture of this classic tree. Once a popular choice for lining streets, the elm provides shade, conserves energy, intercepts storm water and sequesters large amounts of CO2 (keeps greenhouse gases out of the atmosphere) in urban environments. Historically, this species has been used for making furniture, agricultural implements, baskets, finish millwork and boats.
While once covering vast areas from the east to the middle of the continent, a shipment of logs in the 1930s infected with Dutch elm disease devastated this tree’s population. The fungus is carried from tree to tree by beetles; and, while younger trees continue to regenerate the forests, older trees succumb to the disease. The most common attempts to protect and heal this tree species are through regular inspection, proper pruning, injections of fungicide in the trunk and decades-long propagation of resistant varieties.
Red Spruce
Thriving in the cooler temperatures, moist environments and drier air of mountain tops, these trees are known for the color, straight grains and resilience of their wood. Prized for its tonewood properties, the spruce is used to make woodwind and acoustic string instruments as well as sash frames, paper pulp and boxes. Living up to 350 years, this tree has been used for poultices and medicinal teas by humans and as a varied food source and shelter for wildlife.
Voracious logging (and the resulting flash fires) pushed the Southern Appalachian stands of this tree to the steepest and/or economically unfeasible highest elevations. It is estimated that only 10% of the old growth spruce remained near the mountain peaks by the 1930s. However, many of these locations became protected park lands. And, restoration efforts continue with plantings of genetically diverse seedlings in favorable habitats.
Butternut
This tree species of exceptional wood and sweet, oily nuts is a cherished member of our forest communities. It is a native hardwood also commonly known as a “white walnut.” Musical instruments, boats and fine furniture are some of the items created from the wood. And, consuming and storing the nuts are practices shared by humans and wildlife alike. While it has a large range and is one of the most winter-hardy nut species (hickory, pecan, walnut), the number of individual trees in any given forest is naturally small.
The first report of diseased and dying butternuts was in 1967. The trees were infected with a non-native fungal pathogen that has since killed an estimated 77% of the butternut trees in Virginia and North Carolina. This tree appears to fare better in certain locations and has a diversity of genetic structures that might aid in the propagation and restoration of the species.
Ash
Perhaps the most well-known human uses for ash wood are in the making of tool handles and baseball bats. For First Nation cultures, it was (and is) an important source of material for basketmaking. It is also a popular choice for furniture, flooring and cabinets as well as a replacement for the loss of elm trees along city streets. In nature, its cavities are used for nests; it provides shelter; and, offers high-quality food for mammals, amphibians and birds.
Recent studies in the Blue Ridge Mountains of Virginia attribute “25% of tree deaths to non-native insects and pathogens.” The ash is among the 22 species affected. The cause in this case: a non-native insect called the emerald ash borer. First detected 20 years ago and thought to have arrived via wooden shipping crates from overseas, this bug has caused a sharp decline in tree density over the past 10 years alone. Amidst this dramatic mortality, scientists have discovered genetic variations in some trees that make them resistant to the threat.
Old school report cards of the paper variety had a comment section at the bottom for teachers to write a note—an observation or a point of encouragement for the student. Our note for the state of the mountains’ great trees begins with my father, an accomplished Master Gardener.
Two years ago, he reached into the refrigerator and handed us a repurposed plastic container filled with moist soil. Peeping up from inside were 13 tiny shoots of green—the inauspicious beginnings of American chestnut trees.
Being a person of a certain age, I asked if I was too old to be planting and caring for trees. His note from teacher to student was this: “It’s never too late to plant a native tree.”
Follow up: After losing one (delicious) sprouting chestnut to a hungry squirrel, a large seedling box and then individual baskets were constructed of chicken wire to protect the rest. Now, 12 healthy little trees, which we have named the Chestnut Grove, are standing against the odds. While their future may be uncertain, today’s report card would say they are thriving.
Did You Know?
In addition to producing oxygen, removing pollution and providing raw materials, medicine, wildlife shelter, windbreaks and flood control, consider these fun facts about trees:
- Planting one single native tree in an open field can increase bird species from near zero up to 80.
- Trees communicate with each other via “wireless” and an underground “Internet” by warning nearby trees of insect infestation via airborne chemical signals and sharing nutrients and information with each other using symbiotic relationships with fungi in the soil.
- Some tree roots are only 18 inches in depth but can grow hundreds of miles laterally (oak) while others can reach depths of 20 feet or more (walnut, pine and hickory).
- Scientific data finds that looking at and being amongst trees can measurably improve health.
- Trees keep records of climate and environmental changes through history in their rings.
- “Knock on wood” is a sentiment based on many folklore tenets that kindly spirits live in trees and can be awakened for protection.
- The colors of fall are in the leaves throughout spring and summer (even though we cannot see them), and make their debut when the amount of sunlight decreases in autumn.
The story above first appeared in our September / October 2023 issue.
