With an eerie name and ominous presence, ghost forests can be unmistakable signs of a rapidly shifting climate. However, researchers are pointing to another cause for their formation in North Carolina.

What’s happening?

As reported by Coastal Review, a team of researchers took a closer look at the forested freshwater wetlands along the Cape Fear River to find out. Like most forested freshwater wetlands in the southeastern United States, the Cape Fear wetlands are primarily composed of bald cypress trees, which are adapted to tolerate low levels of salinity. However, many ghost forests of bald cypress have formed around Smith Creek, a tributary of the Cape Fear River that has seen dredging activities since the late 1800s.

“What killed all the trees?” asked the publication. When combined with sea-level rise, increased dredging has caused saltwater intrusion, which has likely stressed and killed countless bald cypress trees, resulting in widespread ghost forests in the region.

To study how salt affects bald cypress and better understand how ghost forests form, researchers from the University of North Carolina Wilmington collected tree and sediment samples in areas with different salinity levels in Smith Creek. They built tree-ring chronologies for two sites. One with higher salinity, between 8 and 12 parts per thousand, and one with lower salinity, under five parts per thousand.

Why is the study of ghost forests important?

The sediment analysis revealed that a freshwater environment shifted to a saline one around the time of major dredging projects in the creek. At the same time, tree rings indicated suppressed growth in trees located at higher-salinity sites, especially after the major dredging events.

“Saltwater intrusion into forested freshwater tidal wetlands induces stress in bald cypress, facilitating ghost forest formation and the loss of important ecosystem services,” the study reads.

The continued decline of bald cypress trees can potentially hinder a wetland’s ability to control floods, especially when hurricanes track along the coastline. Ghost forests can also further decrease water filtration, impacting water quality in the region.

Fewer bald cypress trees can also contribute to habitat loss for various species. As a whole, these losses can lead to increased flooding and erosion and harm to the surrounding communities and economies that depend on these crucial wetlands.

What’s being done about the formation of ghost forests?

While speaking to the Bay Journal, U.S. Geological Survey wetland ecologist Greg Noe noted the significance of studying ghost forests. “Some of the changes are really dramatic,” Noe said. “Ghost forests are enigmatic. They’re big changes. They’re an effective canary in the coal mine for demonstrating sea-level rise on the landscape.”

The steady increase in global temperatures is directly linked to sea-level rise. The melting of glaciers and ice sheets in the Arctic, combined with the thermal expansion of water, has increased the volume of the oceans. Besides increasing the threat of saltwater intrusion, rising temperatures have also played a major role in causing a spike in extreme weather events.

As we gain a better understanding of the impacts of human activities on rising global temperatures, more initiatives are being implemented worldwide to reduce our reliance on planet-heating fossil fuels. This has been paired with the promotion of renewable energy resources such as wind and solar energy.

Join our free newsletter for good news and useful tips, and don’t miss this cool list of easy ways to help yourself while helping the planet.