Inside the Tulane Greenhouse, an ‘Experimental Playground’ for Environmental Research

About a mile from Tulane University’s uptown campus, a greenhouse sits tucked away near the Mississippi River levee. Inside, buckets of sand created from recycled glass sit alongside trays of various marsh grasses and young cypress trees small enough to fit in your palm.

This greenhouse is where researchers from the Tulane Department of Ecology and Evolutionary Biology in the School of Science and Engineering use carefully controlled conditions to test new ideas. What makes certain cypress trees more tolerant of saltwater than others? Can plants grow in sand made from recycled glass bottles?  The greenhouse is where answers to these questions are put to the test before new innovations are introduced in the marshes, forests and restoration sites across south Louisiana and the Gulf Coast.

The 1,500-square-foot greenhouse is equipped with an adaptive system that lets researchers control temperature, light and other conditions. This allows faculty, staff and students to grow Gulf Coast plants under conditions that more closely resemble the natural environment — or help cool plants off during sweltering summers.

“Most research is conducted on local plant species from the marshes, bayous and beaches of the Gulf Coast that thrive in our local environment,” said Keith Clay, professor emeritus of ecology and evolutionary biology at Tulane. “The greenhouse is a key resource for education and research.”

The goal is to translate those discoveries into new ways to restore Louisiana’s disappearing coastline.

That mission is personal for Bek Markel, a Tulane research technician and alum who oversees the facility and much of the day-to-day operations.

Markel (SSE ’19, SSE ’20) grew up in south Louisiana. And from their time as a student to their current role, they’ve dedicated themselves to researching the “hidden networks” of microorganisms holding together the ecosystems they grew up exploring.

One of the biggest concerns for south Louisiana is the loss of marshland, which can increase saltwater intrusion, kill vegetation and accelerate erosion. Markel is researching how bacteria and fungi may help some cypress trees survive in areas where salinity levels would otherwise be lethal.

“We salt stress the trees, identify which ones are doing well and then see if we can identify microbes that may be helping them survive,” Markel said. “We’re losing the trees that can lessen the wind effect of a storm surge. So how can we retain these storm protectors? Can adding certain bacteria to trees help them survive?

“This building is kind of an experimental playground. If you have an idea, this is where you test it.”

Markel knows the greenhouse so well they could probably give a tour blindfolded: Here, beach grasses and morning glories are used to study how native plants can stabilize sand dunes. Elsewhere, plants are being grown to support butterfly research.

Another of the greenhouse’s most promising projects is its work with Glass Half Full, a New Orleans-based recycling company founded in 2020 by two Tulane graduates. The company has diverted millions of pounds of glass away from landfills by turning it into sand that can be used to address coastal erosion.

Tulane researchers found that both dune and wetland plants grew as well in recycled glass sand as they did in natural beach and river sand, offering a possible alternative to natural sand dredged from offshore environments, a process that is costly and can damage marine ecosystems.

Following the greenhouse studies, an experimental island incorporating recycled glass sand was built in nearby Bayou Bienvenue, ready to support new plant growth.

“Plants are the main thing holding together our land,” Markel said. “There’s something special about studying what makes your home feel like home and working to preserve it for later generations.”