Marshes may be more resilient to climate change and associated rises in sea level than previously thought, according to recent research
published in the Proceedings of the National Academy of Sciences. The study shows that as levels of atmospheric carbon dioxide increase, more CO2 gets taken in by marsh plants. This spurs higher rates of photosynthesis and plant growth, causing marsh plants to trap more sediment above ground and generate more organic soil below ground, the researchers explain. The process can increase the rate of soil accretion nearly enough to allow marshes to keep up with rising sea levels. In fact, the researchers say, it may increase a marsh’s threshold for water inundation by up to 60 percent. “Essentially, we found it’s a self-rising mechanism marshes use to build themselves up,” said Marco Marani, a researcher at Duke University who helped conduct the study.