Take a nature walk anywhere in the Tennessee Valley and one of the first things you’ll notice is the vast array of wildlife.
Take a nature walk anywhere in the Tennessee Valley and one of the first things you’ll notice is the vast array of wildlife. Different birds sing, various trees grow and numerous fish swim in the streams and rivers. The biodiversity is beautiful; it’s what makes the Valley such a coveted place to visit, live and take in the sights. Some of the species living in our public lands and river systems occur nowhere else in the world.
At the same time, there are also many non-native and invasive species of plants and animals that have entered the southern U.S. forestlands. Non-native species are found in areas where they do not occur naturally but rather were introduced deliberately or accidentally by human activities. If they cause harm to their non-native areas—or to native species—they are considered invasive species.
A variety of dangerous insects, plants and other organisms have been introduced into the Valley, each making its mark on the ecosystem. Here are just a few you may encounter.
Introduced to America in 1966, the Asian Long-horned Beetle quickly spread from Brooklyn, New York throughout the eastern United States. The beetle attacks species of hardwood trees, such as elm, ash and maple, and the larvae feed on the vascular tissue underneath the bark. Within nine years of infestation, the hardwood trees die due to limited flow of water and nutrients.
This species presents a large threat to the Valley; it spreads quickly and can take out millions of acres of treasured hardwood trees. It threatens forests and recreation resources valued at billions of dollars.
The Asian Long-horned Beetle is black with irregular white spots, measuring at 1.5 inches long. If spotted, an infestation is most likely near. Unfortunately, at that point, not much can be done.
“Aside from not moving firewood, you can’t do a lot to protect your trees. However, if your tree does become infested, you must remove it. The beetles weaken the wood and make trees dangerous,” says , TVA Senior Land Condition Specialist Jack Muncy..
The Emerald Ash Borer, native to Asia, was discovered in Knox County, Tennessee in 2010. It has since spread to 65 Tennessee counties on the east half of the state. This non-native species can also be found in Georgia, North Carolina, Kentucky and Virginia.
The Emerald Ash Borer poses a threat to ash trees in the Tennessee Valley. Once infested, an ash tree dies due to lack of water and nutrients as the Emerald Ash Borer tunnels under the bark and feeds on the transportation tissue.
“The Emerald Ash Borer is transported mainly by humans through infected nursery stock, firewood, unprocessed logs and other ash products,” Muncy says.
Unfortunately, the best way to prevent an Emerald Ash Borer infestation is to destroy any surrounding infested ash trees or products.
The Asian native Hemlock Woolly Adelgid was introduced to the eastern United States nearly 60 years ago. This insect is causing harm and death to many hemlock trees in the region.
Although it takes a while to happen, Woolly Adelgids kill these large trees by penetrating plant tissue and disrupting the flow of water and nutrients throughout the tree.
“It is ironic that these massive trees could be laid down by something so small. The woolly adelgid measures just three millimeters long,” Muncy says.
There are several pesticides that can control the Hemlock Woolly Adelgids. Another option is to drench trees with insecticidal soap or horticultural oil. Although this must be done thoroughly and multiple times a year, it controls the Hemlock Woolly Adelgid without posing too much harm to other beneficial insects.
The Japanese Honeysuckle was first introduced to the United States in the early 1800s, but it has since spread quickly throughout the country, causing harm to native wildlife. “Early on, these invasive plants were used in residential ornamental landscaping to provide soil erosion control or to offer agronomic benefits. But they’ve now escaped into forestlands,” Muncy explains.
The Japanese Honeysuckle is fast growing, allowing it to spread to surrounding areas quickly. It tends to grow around stems of shrubs and other vertical supports. With lots of sun, the Japanese Honeysuckle forms tangles that smother other vegetation in the area, leading to the death of native plant species.
Luckily, controlling the Japanese Honeysuckle is easier than many other invasive species in the Tennessee Valley. For smaller infestations, a simple hand removal of the vines will do the trick. For larger infestations, it is best to mow the area at least twice a year or treat the infested area with herbicides.
For simple steps you can take to prevent invasive species in your community, read this information from The Nature Conservancy. Many cities in the Valley also have a full-time forester or arborist who will come to your property to check on the health of your trees, or you can search for a commercial arborist.
Managing public lands and the Tennessee River system, while also reducing the impacts of our operations on the region’s plant and animal species, along with their critical habitat, have been a part of TVA’s mission for decades (browse through our Sustainability Report and Natural Resources Plan). TVA understands how integral biodiversity is to the Valley’s eco-system and is dedicated to finding and developing new ways for protecting it throughout our operating footprint.