Flooding significantly impacts the carbon cycle, primarily by altering carbon storage and exchange rates between the soil, atmosphere, and aquatic environments.
Impact of Flooding on the Carbon Cycle
Here’s a breakdown of how flooding affects the carbon cycle:
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Changes in Carbon Storage: Flooding can influence the amount of carbon stored in different ecosystems.
- Salt Marshes: Deeper flooding, often associated with sea level rise, can decrease the amount of carbon stored in the soil of salt marshes. According to research, this can "decrease long-term soil C pools," reducing the capacity of these habitats to act as carbon sinks.
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Altered Carbon Exchange Rates: Flooding affects the rate at which carbon is exchanged between the soil, atmosphere, and water bodies.
- Increased Carbon Release: Flooding can "quicken C exchange between soil and atmosphere," meaning that more carbon is released from the soil into the atmosphere as carbon dioxide or methane (both greenhouse gasses). This diminishes the overall carbon storage potential of the flooded area.
Specific Effects in Salt Marshes
Salt marshes are particularly vulnerable to the effects of flooding on the carbon cycle:
- Net Carbon Storage Threat: The combined effect of decreased carbon storage and increased carbon release threatens the ability of salt marshes to act as net carbon sinks.
- Biogeochemical Cycling Changes: Understanding the complex biogeochemical cycling under future flooding conditions requires "manipulative studies." These studies are essential to predict and manage the impact of flooding on these vital ecosystems.
| Effect of Flooding | Impact on Carbon Cycle |
|---|---|
| Deeper Flooding | Decreases long-term soil carbon pools, quickens carbon exchange with the atmosphere. |
Conclusion
In summary, flooding, especially deeper flooding associated with sea level rise, can disrupt the carbon cycle by decreasing long-term carbon storage in soils (like those in salt marshes) and by accelerating the exchange of carbon between the soil and the atmosphere. These changes can reduce the effectiveness of ecosystems in sequestering carbon and may contribute to climate change.
