- An estimated 74 percent of bottomland forest in the Tensas River Basin has been converted to agriculture.
- Though much of the forest has been cleared, the Tensas River Basin contains some of the largest remaining blocks of bottomland hardwood forests in the United States.
- Conservancy staff monitors carbon accumulation by checking the height and diameter of trees and then converts that into the mass of carbon. Once planted, monitoring occurs at years three, five and 10 and then every five years after that.
By Tom Eisenhart
Driving east on Route 4 toward Louisiana's Tensas (pronounced 'Tensaw') River Basin, the view to either side is one of endless acres of cotton and soybeans. I'm riding with Ronnie Ulmer, a program manager for The Nature Conservancy in Louisiana, who remembers a very different landscape.
Born and raised in this part of northeast Louisiana, Ronnie recalls that, as a child, this road was surrounded by bottomland forest, with trees arching cathedral-like high above the pavement. Over time, he sadly watched the forest cleared for agriculture.
"I saw huge machines fell and roll the trees into rows," Ronnie says. "They didn't even take the timber; just set fire to them and let it burn."
Having seen land converted to agriculture that in many places was unproductive for crops, Ronnie is now part of an effort to restore forests to benefit wildlife and the people in his community. Yet the benefits of a 500-plus-acre forest restoration project Ronnie manages extend much further. Called the Stevens Northwest Airlines Carbon Sequestration Habitat Restoration Project, it is one of the first projects in the Conservancy's voluntary carbon offset program and where we are visiting today.
Room for Bears and Birds
The project is part of the Conservancy's Tensas River Basin Project, an effort to restore large, contiguous blocks of bottomland forest habitat. Doing this provides more room for the state and federally threatened Louisiana black bear to roam and places for migratory birds to rest and breed.
The forested lands on the perimeter of where we stand are in various states of maturity. They represent lands that are part of a U.S. National Wildlife Refuge and acreage enrolled in the USDA's Wetlands Reserve Program (WRP) and Conservation Reserve Program (CRP). Ronnie explains that this project offered an opportunity to "fill a hole," linking the other nearby forested lands.
At the same time, the former soybean fields also provided an opportunity to design the project with carbon sequestration in mind.
Two years ago, the Conservancy planted more than 175,000 trees on 410 acres of the project. It's a mix of 15 species, including oaks, sweet gums and persimmons. The project's remaining 124 acres is composed of fire breaks and fence rows.
Benefits Accrued Over Time
At this point, the trees aren't much to look at; in fact, we looked hard to see the stems of the knee-high saplings in the thick surrounding grasses and brush. But in two years, the trees will be waist-high; in another five, as tall as an adult. The trees will continue to grow and expand at that rate until they reach 70 years, when their growth slows considerably.
Over the life of the project, Conservancy scientists estimate that it will sequester about 156 metric tons of carbon per acre. That's a conservative estimate, according to Ronnie. "We've discounted the amount of carbon we expect to accrue by about 40 percent to reach a level where we feel comfortable with our estimates," he explains.
Once the project completes its 70-year life, the mature stand of bottomland forest that will tower over where we stand will continue to provide important benefits.
Ronnie grins when he tells me that trees, like people, start slowing down and taking it easy once they reach 70. "At that point, they won't be sequestering as much carbon any more, but they will be providing homes for interior-nesting songbirds, providing protection from severe winds and cooling areas underneath them."
That thought fills Ronnie with the satisfaction of knowing that one day a child like he once was will have the forests to explore and enjoy.