One tree at a time, volunteers and activists grow a new forest of Louisiana cypress trees
Young trees may already provide a degree of hurricane protection
NEW ORLEANS (WVUE) - Near the St. Bernard-Plaquemines Parish line, not far from the Mississippi River, 20-25 foot tall cypress trees appear as though they have been there for decades.
In fact, most of them are less than a decade old.
“This tree is flushing out with the spring and, for all intents and purposes, it looks really, really happy,” said Eva Hillmann, Ph.D., a coastal scientist with the Pontchartrain Conservancy.
Over the last ten years, volunteers and environmental groups have planted 40,000 bald cypresses in the Big Mar area.
Hillman said the trees were mostly one-year-old and about three feet high at the time of the plantings.
With a success rate of 70% here, the plantings have produced an almost “instant forest.”
Hillmann credits the explosive growth in Big Mar to the nearby Caernarvon Fresh Water Diversion, which feeds the tree’s nutrients.
The state’s plans to divert Mississippi River water into Barataria Bay and Breton Sound have drawn pushback from members of the seafood industry, who fear fresh water and fertilizer runoff will damage fisheries.
Hillmann believes the trees, and willow trees that grew naturally in the diversion area, already provide a degree of hurricane protection.
“If that storm surge hits a wall of trees this size, that’ll knock down that storm surge some.”
Some of the young trees already have produced cypress knees, while others bust out of the plastic protectors wrapped around them at the time of the planting to prevent nutria from devouring the trees.
The earliest plantings failed almost entirely because of nutria.
Across South Louisiana, cypress trees once blanketed the landscape.
In some places, trees were spared the logger’s ax only to be finished off by saltwater.
The state of Louisiana is spending billions of dollars piecing back together parts of its rapidly disappearing coast, pumping sediment from dredging projects to create islands, ridges, and marsh.
Reconstructing a forest entails a labor of love, one tree at a time, grown off-site in the first year or so.
“I know that we want to create thousands of acres of land overnight, but you do have to take a bit of a long view,” Hillmann said.
They have planted another 40,000 trees in the Manchac land bridge area along I-55, where Hillmann said the success rate is 83 percent.
Recently, the Pontchartrain Conservancy conducted its first planting, of 2,500 trees, in the Madisonville area with the hope of restoring a cypress forest wiped out by saltwater decades ago.
“It’s just really rewarding,” said Cameron Field as he checked recently on the newly-planted cypress. “We’re making a difference and you can actually see it.”
Scientists say the culprit in the demise of the forests along the north shore of Lake Pontchartrain was the Mississippi River Gulf Outlet, cut through the marsh in St. Bernard Parish.
Designed as a shortcut to the Gulf of Mexico from the Port of New Orleans in the 1950s, the MRGO drew in saltwater that killed 27,000 acres of marsh, including a large cypress stand in St. Bernard Parish.
Later, it funneled storm surge from Hurricane Katrina into St. Bernard and eastern New Orleans.
Congress ordered the channel closed in the aftermath of the 2005 hurricane season, first with a rock dam across the MRGO.
Scientists say the closure immediately lowered saltwater levels far up in the basin and gave young trees in places such as Manchac a fighting shot at survival.
However, St. Bernard Parish blamed the dam for repeatedly worsening flooding in fishing communities during the 2020 hurricane season.
“The elected officials and the citizens of St. Bernard parish were against the opening of the MRGO back in the 1950s and no one listened to us,” said Parish President Guy McInnis.
The parish argues the surge rolled right over the structure, but the wall prevented the water from receding.
“We need to think about people and their lives and their industry,” McInnis said, arguing that much of the channel has already silted in over the last 15 years.
The new two-mile-long storm surge barrier along the St. Bernard-Orleans Parish line now provides surge protection, said McInnis, who is pushing the state and the U.S. Army Corps of Engineers to partially open the rock dam.
“Just put a 56-foot gap here, and remember, this is 35 feet deep here,” McInnis said, standing at a photo of the rock dam in the parish TV studio. “We’re going to go down about 10 feet and leave a 25-foot wall under the water to stop the salinity.”
The issue is a non-starter for many state officials and scientists.
“I would expect soil salinity to start increasing up in the basin,” McInnis said.
The new forests face longer-term challenges, including rising seas, which threaten to inundate the forests with saltwater.
Three years ago, scientists tried plantings on a more industrial scale through aerial seedings of forests.
The project mostly failed, Hillmann said, because young cypress requires periods of low water for seeds to germinate.
“You need a time frame between three weeks to three months and we just don’t have many periods of low water for that period in this area,” she says.
Even today, Louisiana’s old-growth trees are the largest living things in the United States east of the Sierra Nevada Mountains.
While the challenges are many, Hillmann is optimistic about the prognosis for the new forest in Big Mar.
“This land area is growing, the willow forest tells me this land is stabilizing, the trees we planted are surviving,” she says.
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