The Magnificent Mangrove

Leveraging Blue Carbon and Natural Systems to Remove Carbon Dioxide From the Atmosphere and Help Clean the Air

For several decades, scientists at LSU have studied mangroves, a coastal super-tree that thrives in saltwater and deltaic areas around the globe, such as in the Louisiana Mississippi River Delta. What makes it “super” is its ability to grab carbon dioxide from the air and store the carbon in its leaves, wood, roots, and—importantly—soil. In deltaic areas where sediment is brought by rivers to the sea, new layers of soil and mud can accumulate quickly, burying more carbon.

Although coastal habitats cover only 2% of the total ocean area, they stockpile about 50% of the carbon in ocean sediments. Mangroves are the masters, as they can capture and store two-to-ten times more carbon than other trees. This is because they live in water (thus the term “blue carbon”) where dead plants and trees take a long time to decompose—effectively trapping the carbon instead of releasing it back into the ever-churning carbon cycle where eating, burning, and otherwise consuming organic matter (by humans, animals, bugs, or bacteria) lets carbon dioxide back into the atmosphere.

“You have to look at the net,” said Robert Twilley, professor in the LSU College of the Coast & Environment. “You have the carbon sequestration rate, and then you have the storage. It’s like a savings account. Maybe you have a lot of money in your account, but if you don’t add or spend, the economy doesn’t care. Maybe you’re depositing a lot but spending at the same rate—then it’s just a big flux number. If you want to build wealth, it matters a great deal how much you put into your account on a regular basis—while saving. Mangroves are excellent at this.”

LSU has been collaborating with state government and industry—including oil and gas companies—to find ways to protect, restore, and expand mangrove habitats in Louisiana and use natural ecosystems to help fight climate change, with the added benefit of also protecting local communities and industry against storm surge and supporting key fisheries.