US 441 washed out by intense winter rainfall, January 2013
NPS Photo
Melting glaciers? No.
Stranded polar bears? Nope.
Sea level rise? Not in the Smokies.
Climate change impacts in the Smokies are more subtle than in many other parks. Many of our impacts are related to water. Water found in cloud cover, flash flooding in storms, and its lack during droughts. A big concern is whether or not our iconic high elevation Spruce-Fir Forest, already an island in the southeastern United States, will continue to flourish. If this forest continues to stay foggy and under cloud cover, there is great hope that it will survive. If conditions turn drier and warmer with little fog or cloud cover, its fate is uncertain.
Increased heat in the air and waters around the southeastern U.S. puts more water into the atmosphere, often leading to stronger storms and more rain. In the past 10 years, most of the park roads have experienced severe flooding or landslides, causing closures for extended periods of time. Increased rain may also come irregularly, with periods of intense wetness mixed in with periods of intense drought. This can lead to fewer young, drought-stressed trees and can increase the risk of unusual fire behavior.
The timing of seasonal changes in the park is also of concern. Overall, the park is not showing significant annual warming. However, this is not the case when comparing each month to itself from records going back to 1976. The spring months show the most variability and warming. Warm March weather can cause trees and wildflowers to put out leaves, but cold snaps with frost can occur in April and May, killing off the new leaves and forcing plants to use up energy reserves to create replacement leaves. Such patterns can lead to crop failure in apple orchards in surrounding counties, but it is unclear what the long-term impact will be on park’s forests. Perhaps these stressed trees will be more susceptible to forest pests and competing invasive species. Time will tell.
Invasive species from warmer or drying climates are also an issue in the Smokies. As the park's climate changes, species that could never have survived here in the 1950s are starting to settle in. The Green Treefrog and the Nine-banded Armadillo may have hitched rides to the park on vehicles or equipment, but they are now settling in and making themselves at home. Park managers need to decide whether to intervene or allow these species to find their place in the park. Will the genetics of the newly arrived Green Treefrog overtake that of the native Cope's Gray Treefrog through hybridization? Will Armadillos eat salamanders at a rate that is unsustainable to salamander populations?
Syracuse graduate student, Jordan Stark, deploys sensors to study climate in park forests.
NPS Photo
Seeing and Protecting the Future with Research
Thanks to its proximity to so many premier research institutions, the Smokies have been studied more and longer than most other parts of North America. Researchers have been repeating work conducted in the 1930s and 40s to look for changes in distribution, numbers, and sizes of the plants, insects, birds, salamanders, and mammals of these mountains. Such work can help us learn how plants and animals are responding to changes and identify refugia where changes are not happening so fast.
Weather in the mountains is complex and hard to predict; so is climate. More sensitive and fine-scale models can help park managers predict changes and respond by installing larger culverts under roads or by reducing woody fuel in drought-susceptible forests close to homes outside the park.
Visitors and Neighbors Helping the Park
Community scientists—volunteers without specific science backgrounds—are helping us keep track of the animal and plant changes in response to a changing climate. Teams of volunteers take notes on when leaves break from buds in the spring and when fall colors start—phenology—using the National Phenology Network’s Nature’s Notebook program. The casual visitor can take and upload a picture from a photo post along US 441 to help document the seasonal changes in the vista. Students from local middle schools have been monitoring salamander populations in areas expected to experience the fastest changes in climate.
Visitors can also help by keeping fuel efficiency and energy star ratings in mind when selecting new cars and appliances. You can also collect data on phenology in your own backyard using Nature’s Notebook.
