How ecosystems can keep pace with rising sea level

Mangrove expansion and climatic warming could facilitate ecosystems to keep pace with rising sea level, according to a landmark study.

In the research, the team of Villanova University biologists have documented that coastal wetlands in the southeastern United States are responding positively to rising temperatures both in their growth and in their ability to build soil to keep pace with sea level rise.

The Villanova researchers found that experimental warming both doubled plant height and accelerated the transition from marsh to mangrove. Mangroves are woody trees with more complex roots than their grassy marsh plant counterparts. When subjected to temperatures similar to those that will occur in a warmer future, mangrove plots showed increased surface elevation which is a measure of the wetland's ability to build soil and keep pace with sea level rise.

"Our study provides some evidence that the ongoing reshuffling of species on earth's surface could allow for some adaptation to the same global changes that are causing them," said Chapman. "Conserving and restoring our coastal wetlands can help humans adapt to climate change."

With their unique structure and migration to higher latitudes caused by climate change, mangroves may help coasts keep pace with sea level rise and combat severe weather events like hurricanes.

"The study links the growth of individual plants, and particularly their roots, to the survival of an entire ecosystem. The long-term strength of the mangrove effects we identified may determine what the maps of our southeastern coastlines look like in the future," said Langley. "This mangrove effect could benefit coastal wetlands around the world."

"Our experiment highlights the impact multiple interacting aspects of climate change, such as warming and sea level rise, can have on the outcome of species invasions resulting from climate change -- and on the capacity of those communities to protect shorelines," concluded Coldren.

The study has been published in the Journal of Ecology.