Ghost Forests Spread Along US Coasts as Rising Seas Kill Coastal Trees — "We're About 50 Years Behind"

Coastal woodlands turning into 'ghost forests'

The Chesapeake Bay and other coastal regions are showing an increasingly haunting landscape as saltwater pushes inland, killing cedar, pine and many hardwood species. Scientists say rising global temperatures are driving sea-level rise and allowing saltwater to intrude into freshwater-dependent forests and estuaries, a process called salinization.

How saltwater kills forests

Saltwater intrusion replaces or contaminates the freshwater that trees need to survive. Tree mortality often occurs slowly over years or decades, so visible die-offs today can reflect environmental changes that began decades earlier. As forest ecologist Stephanie Stotts of the University of Maryland Eastern Shore — a coauthor of a recent Annual Review of Marine Science article — told Knowable Magazine, "We're about 50 years behind," meaning the current effects reflect past saltwater exposure.

What replaces the trees?

Instead of reverting to native salt marsh, many dying coastal forests are being colonized by invasive reed grasses such as phragmites (common reed). The Minnesota Aquatic Invasive Species Research Center describes phragmites as "a tall, densely growing perennial grass that can take over large areas, displacing native vegetation and reducing habitat quality for fish and wildlife." The result is a very different ecosystem with altered habitat value and function.

Why this matters

These so-called "ghost forests" have several ecological and societal consequences:

• Carbon balance: Living forests store large amounts of carbon. When trees die and decay, stored carbon can be released back to the atmosphere, reducing the landscape's role as a carbon sink.
• Coastal protection: Standing forests help dissipate wave energy and reduce storm surge. Dead stands and invasive reed marshes offer less protection, increasing erosion and vulnerability to storms.
• Biodiversity: Native marshes support oysters, clams, shrimp and many bird species. Invasive-dominated stands often provide lower-quality habitat.

What scientists recommend

Researchers link accelerating saltwater intrusion to human-caused warming and sea-level rise. Mitigation and adaptation strategies include rapid cuts to greenhouse gas emissions, transitioning from fossil fuels to renewable energy, and local actions such as restoring native marshes, managing invasive species like phragmites, and using living shorelines or other nature-based defenses to protect coastal ecosystems and communities.

"Saltwater intrusion is not simply flooding of a static landscape — it involves hydrologic, geomorphic, biotic and human-driven processes that together reshape coastlines," the review authors write.

Understanding and responding to ghost forests requires both global climate action and local conservation and restoration efforts to preserve coastal ecosystem services, protect biodiversity, and reduce risks to human communities.