What type of wetland is characterized by being dominated by grass?

The correct answer is characterized by wetlands that are predominantly dominated by grasses and other herbaceous plants rather than woody vegetation. Marshes are typically found in areas that are intermittently or permanently inundated with water, allowing them to support a diverse range of plant species, particularly those that thrive in saturated soil conditions. The presence of grasses in marshes plays a crucial ecological role, providing habitat for various wildlife, stabilizing soil, and filtering pollutants from water.

In contrast, swamps are wetlands that usually contain a significant amount of tree and shrub vegetation, making them distinct from marshes. Estuaries serve as transitional zones where freshwater from rivers meets and mixes with saltwater from the ocean, and they can have a variety of vegetation types but are not specifically dominated by grasses. Hydric soils refer to soils that are saturated with water for a part of the year, which are a characteristic of wetlands but not a type of wetland itself. Thus, the defining feature of a marsh as being grass-dominated sets it apart from the other options.