As more salt water washes into their habitats, plants either adapt or get squeezed out by the competition. If species seem fated to get squeezed out, humans can intervene by moving the plants further inland, away from the rising tides that threaten their productivity. To investigate which might need rescuing, Bonto traveled to where the marshes of Mississippi meet the Gulf Coast, a hotbed of coastal plants that provide homes to wildlife and protect people from flooding and erosion.
“I thought it would be a good idea to focus on this area of wetlands, which people don’t normally pay attention to because they’re seen as swamps,” Bonto said. But people should: “They’re essentially the barrier that protects us from the impact of sea level rise.”
Bonto focused on four islands within the Grand Bay National Estuarine Research Reserve, chosen for their differing salinity levels, treatments (two islands had been burned), and plant species, including juncus roemerianus (a.k.a. black rush), a flowering plant dominant in the brackish waters; spartina alterniflora (smooth cordgrass), dominant in the salt marshes; and spartina patens (salt hay grass), an important food source for birds. The plants were transplanted around the reserve in order to study how they respond to different conditions.
For three days last October, Bonto hopped aboard a boat and skimmed the calm marsh waters to collect data from the islands. The lush pockets of green, soaking in the Southern waters and brimming with wildlife, were a world away from the cities that Bonto’s called home.
“It was kind of like a getaway from what I’m typically used to seeing,” Bonto said. “It was a really nice change.”
Before dawn, then again at midday, she ventured out to measure the water potentials of each plant. The first measurement would show her the plants’ overall water availability, while the second shows how much stress the plants are under. Water potential is one of many factors used to determine the health of a plant and its ability to thrive.
Bonto brought her data back to Whittier College for analysis, with guidance from Professor of Biology Cheryl Swift, who has been her mentor since she was a first-year student. It was Swift, in fact, who led her to Mississippi, as the professor had connections to other researchers in the area.
Speaking this past spring at Whittier’s annual undergraduate conference, Bonto spelled out how the math was not in the spartina species’ favor. While juncus roemerianus could adapt, the other two might need help migrating to areas that put less strain on them. Spartina alterniflora, in particular, could not establish itself beyond the brackish marsh.
“What this in turn means is that frequent monitoring of wetlands may be needed,” Bonto said.
The work isn’t done. This summer, she plans to conduct similar research on trees in coastal Louisiana, near New Orleans. Since the area is only about a two-hour drive from the Grand Bay reserve, she also plans to return to Mississippi to conduct further research.
Beyond Whittier, Bonto plans to eventually earn a Ph.D. and become an environmental sciences research professor like her mentor, Swift. “I love working with her,” Bonto said. “She’s a great professor and very passionate.”
