NASA uses its satellites to study mangroves because of the trees’ ability to capture carbon dioxide from the air. CO2 is a greenhouse gas that absorbs heat in Earth’s atmosphere, warming the planet. “Mangroves store a lot of carbon in the trees and in the soil underneath their roots—two to three times more per acre than other ecosystems,” says Fatoyinbo.
But these ecosystems do more than help remove CO2 from the air. Many species thrive in and around mangrove forests. Their root systems protect fish laying their eggs and raising their young. The branches shelter many bird species. And all sorts of creatures—from insects to tigers—spawn, nest, find shelter, or hunt around mangroves. Together, these animals create a vast and intricate food web—an interconnected system where organisms eat other organisms to obtain energy (see Mangrove Food Web).
People also need mangroves. Large mangrove forests collect sediment, like sand and silt, which builds up shorelines. That helps prevent coastal erosion—the wearing away of coastlines by flooding and waves. In addition, deep-rooted mangroves serve as a buffer against big storms and enormous waves called tsunamis, protecting coastal communities further inland.