And while the trees may not stand quite as tall, they are quite abundant in Indonesia. Nearly a quarter of the carbon stored globally in mangroves can be found in Indonesia.
They also found that these productive forests—located in the some of the world’s wettest, cloudiest, and most remote regions—are significantly taller than previously reported. Equatorial West Africa and South America are hot spots for giant mangroves, with forests that match the height of tropical rainforests.
Simard and colleagues also charted the relationship of tree height to rainfall, temperature, and the frequency of cyclones in each forested area. Globally, these three factors explain 74 percent of the differences in mangrove height.
The other quarter depends on local factors, mostly the availability of nutrients and how salty the local swamp is. “The trees can cope with salt water, but they don't necessarily like it,” said Simard, who has done fieldwork in mangrove forests in Gabon. “The less saline it is, the less stressful it is for their productivity.”
The researchers used global digital elevation maps from NASA’s Shuttle Radar Topography Mission and lidar altimetry measurements from NASA’s IceSat satellite to produce the new maps. They are a snapshot view, covering only a single year, but can serve as a baseline for nations or international organizations trying to monitor how climate is affecting these valuable ecosystems.
NASA Earth Observatory images by Joshua Stevens, using data courtesy of Simard et al. (2019). Story by Carol Rasmussen, NASA Earth Science News Team, with Mike Carlowicz, NASA Earth Observatory.
This story was originally published on February 27, 2019 by NASA