When invasive species enter the picture, things are rarely black and white. A new paper has revealed that some plant invaders could help fight climate change by making it easier for ecosystems to store “blue carbon” — the carbon stored in coastal environments like salt marshes, mangroves and seagrasses. But other invaders, most notably animals, can do the exact opposite.
“We were aware of the effects of invasions on other facets of these habitats, but this was the first time we really delved into blue carbon storage,” said Ian Davidson, a marine invasions biologist at the Smithsonian Environmental Research Center (SERC) and lead author of the new study. While blue carbon has become a buzz word in climate change circles, it has not appeared in many conversations about invasive species, especially in the marine realm.
The paper, published Monday, Oct. 1, in Global Change Biology, is the first meta-analysis to look exclusively at marine habitats when tackling the issue of invasions and carbon storage. Previous carbon storage research has focused largely on terrestrial environments like forests. But marshes and mangroves can store carbon an estimated 40 times faster than forests. And over the past century, biologists estimate the world has lost 25 to 50 percent of its blue carbon habitats, with an additional 8,000 square kilometers disappearing every year. Understanding these ecosystems is critical as policymakers work to mitigate both climate change and the impacts of invasive species.