Every so often we hear about a new so-called superfood—something so unbelievably ideal that it checks all the nutritional boxes and, in theory, protects us from a host of problems. Kale. Açai berries. Seaweed.
There’s an environmental equivalent, a plant that does for its ecosystem what kale does for us. It prevents shoreline erosion and goes one step better, actually accumulating soil in its root system and building up new ground. It thrives in brackish or even saline water that would kill most other plants. It creates a buffer zone and slows saltwater intrusion. It sequesters carbon at an impressive rate. It provides habitat for fish and terrestrial animals. And we’re killing it off.Are you subscribed to Erosion Control magazine? Click here for a free subscription!
The plant is the mangrove tree. Dense forests of them were once found throughout the tropics. “Dense” is the operative word here; mangroves have a tangle of exposed roots, very difficult for humans to navigate, and if you’re developing a coastal area for tourism, your instinct is probably to cut them down to create a stretch of recreational beachfront. Once you do, though, you might find that beach rapidly disappearing without the protection those roots provide.
A recent study shows that losing large areas of mangrove forest has another consequence. Worldwide, mangroves store more than 4 billion metric tons of carbon, equivalent to the annual emissions from 67.5 million cars, or more than a year’s worth of carbon emissions from all sources from the entire country of Poland. The carbon is sequestered not only in the trees but also in the soil beneath them.
For various reasons, though, we’ve cut down 30 to 50% of the mangroves in the world in the last 50 years. Only part of the loss is due to tourism; often the mangrove forests are cleared to grow rice or palm oil, or to farm shrimp. If we’d stopped cutting the trees down even as late as 2000, researchers say, the surviving forests would have sequestered roughly 4 million more metric tons of carbon from the atmosphere.
Researchers are now focusing on Indonesia, which has the most mangrove forests—about 30% of the world’s total—and also the highest rate of loss.