What is a key function of wetlands in an ecosystem?

Wetlands are crucial components of ecosystems due to their ability to act as natural buffers against storms and floods. This function is primarily due to their unique characteristics, such as saturated soil and vegetation that can absorb excess water. When heavy rains or storms occur, wetlands can help mitigate flooding by capturing and holding rainwater, slowly releasing it over time. This capacity not only reduces the immediate impacts of severe weather events on nearby communities and landscapes but also protects water quality by filtering pollutants and sediments from runoff. Additionally, the vegetation in wetlands can dissipate wave energy, further contributing to flood protection.

The other options do not accurately reflect the primary ecological functions of wetlands: facilitating marine shipping routes is unrelated to wetland ecology, while creating barriers to invasive species and supporting high-density urban development are not functions typically associated with the nature of wetlands. Wetlands are more about conserving biodiversity and natural management of water resources than supporting urbanization or preventing invasives.