Damaged Wetlands Are Less-Effective Carbon Sinks
Changing a wetland also leads to smaller, much less noticeable changes in the way that ecosystem functions. Wetlands are powerful carbon sinks, and destroying a wetland moves the carbon from wetland soil out into the atmosphere. But what if people damage a wetland and then let it bounce back? It appears to come back in full flourish, but unfortunately, the wetland’s soil tells a different story. Moreno-Mateos discovered that even after 50 to 100 years of recovery, wetlands that were recovering from damage contained about 23 percent less carbon than unaffected wetlands.
Wetlands Need Water Flow
Why is this the case? Well, for one, wetlands like company. Specifically, they like the company of water. When development occurs around a wetland, people may preserve the land but cut off its water flow. With good oxygen flow, the microbes that live in wetland soil are happy. Oxygen helps respiration, and this makes for good carbon cycling. Without good water flow, the decomposition and soil-building cycle in the wetland turns into a scene from a boggy compost heap. Water-logged and oxygen-poor, the decomposition process turns into fermentation, and carbon accumulation slows right down.
More Understanding Is Required to Inform Wetland Restoration
What story does this tell to those who decide to pave over a wetland, but create other habitat in its place? The story is one that challenges our current ideas about wetland management. A wetland that’s been hurt will need a lot of time to heal – likely more than 100 years. Even a wetland that’s been recovering for 100 years may not have all of the functioning of a wetland that was never damaged, even if the place looks diverse and abundant.
The story these wetlands tell is one that says that we need to work harder to protect the wetlands we have. We also need to work harder to understand the ecological dynamics of the tiny organisms that live in wetland soil, so that we can help damaged wetlands heal. If people could intervene in the process and help reactivate the carbon cycle in a restored wetland, what would that look like? What would people need to do to create better carbon sinks from damaged wetlands? This tale is yet to be told, but Moreno-Mateos hopes that the answer might be in the microbes, tiny organisms that work in soil, turning vegetation into stored carbon. Perhaps they might be able to give us clues as to how to speed a wetland’s carbon processes along, turning the appearance of restoration into a functional reality.
Moreno-Mateos, D., Power, M.E., Comín, F.A., Yockteng, R. Structural and Functional Loss in Restored Wetland Ecosystems. (2012). PLoS Biol 10(1): e1001247. doi:10.1371/journal.pbio.1001247. Accessed January 30, 2012.
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