Wetlands are special habitats that form in areas where the soil is saturated for portions or all of the year. These conditions support an array of plants not found in the adjacent uplands. Marshes, bogs, and meadows are wetland habitats with nearly year round saturation. In California, many wetlands are seasonally wet; that is, they are saturated for only part of the year, usually the winter and early spring. Although some wetlands can be wooded, most California wetlands are dominated by annual and perennial herbaceous plants, including cattails, tules, rushes, and sedges. Wetlands provide important functions by reducing the impact of floodwaters, removing pollution, and providing food and shelter fro wildlife.