Invasive plants may boost blue carbon storage

Washington: 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.

Lead author Ian Davidson said, “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.”
While blue carbon has become a buzzword in climate change circles, it has not appeared in many conversations about invasive species, especially in the marine realm.

The paper 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.

“It’s now part of global climate change solutions to get carbon credits in forests. But for blue-carbon habitats, the marine version, that has been slower to materialize,” said co-author Christina Simkanin.

The scientists used the data to calculate how much plant-based biomass or soil carbon changed in each place in the presence of an invader. Over time, plant-based pools of biomass can be converted into valuable blue-carbon storage “sinks” that are locked in the soils beneath these habitats.

The authors also cautioned against viewing invasive species as unlikely heroes. Carbon storage is one metric that some invaders could enhance, but managers still need to consider the other impacts invaders can have, such as biodiversity loss or habitat shrinking.

The real question, the authors said, is how to manage environments where an invasive species has already taken hold and evaluate the true costs and benefits of eradication.

“Ecosystem managers will be faced with a decision to eradicate or control invasive species,” said Cott. “The information contained in this study can help managers make decisions if carbon storage is a function they want to enhance.”
The study appeared in the Journal `Global Change Biology`.