On the Texas coast, tropical black mangrove trees are on the move.

Winter freezes have typically killed off these salt-tolerant trees. But as the climate warms, they’re surviving further north and replacing salt marsh grasses and shrubbery.

Mangrove tree

Schalles: “As they continue to establish and grow, they grow to a much higher, taller canopy height. They have woody structure rather than softer herbaceous structure. So the fundamental habitat is changing.”

That’s biologist John Schalles of Creighton University. He’s using satellite and airborne imagery to map coastal habitats – and the changes he’s documenting are a concern for tourism, fisheries, and wildlife.

Endangered whooping cranes, which over-winter on the Texas coast, are especially vulnerable.

Schalles: “They don’t like habitat where there’s woody growth blocking their line of sight. So this potentially threatens their use of critical habitat.”

Schalles says even modest projections of global warming indicate that by the end of the century, mangroves will invade and begin replacing salt marsh vegetation – not only along much of the northern Gulf coast but also up the east coast of Florida into Georgia and the Carolinas.

Reporting credit: ChavoBart Digital Media.
Photo: Mangrove tree. Copyright protected.

More Resources
John Schalles publications and presentations
Texas Mangrove Research Symposium 2013 (starts on p. 27)
Black mangrove on the move on the Gulf coast of Texas
Black mangroves on the march?

Erika Street Hopman is co-founder of ChavoBart Digital Media, an audio and video production firm with a focus on scientific and environmental media. ChavoBart Digital Media contributes original reporting,...