The plant species in the marsh and wet meadow are adapted to grow in wet soils, which are saturated throughout the growing season. The soils contain very little oxygen and appear gray in color. Cattails and sedges are called obligate wetland species because they can only grow in this environment. Other species, like Blue Vervain, can survive here but also grow in drier conditions such as on the meadow slope. Wetlands play a crucial role in the landscape by reducing storm water surge, limiting flooding, improving the quality of water entering streams and rivers and recharging groundwater. Wetlands also provide habitat for an abundance of plant and animal species and are the most diverse ecosystems in this region.