Managing Wetlands for Wildlife
Wetlands across the US provide habitat for thousands of wildlife species. Wetland preservation and management is important for wildlife management throughout the US. Almost 35 percent of our rare wildlife species are located in wetlands or at least are dependent on them. Waterfowl such as ducks and geese love wetlands, but many species of wildlife use wetlands along with other habitats. Wetland plants are important as they stabilize soils and reduce erosion. Wetlands act as huge sponges to store water, which helps to reduce flood damage. The water then percolates back into the earth where it helps to recharge the ground water supply and/or maintain water levels in streams and rivers. A one-acre wetland holding water to a depth of one foot, will store 330,000 gallons of water!
Wetlands essentially function as the land’s kidneys to filter pollutants and sediments from surface water. Freshwater capture and slow runoff water using both emergent and submergent plants. When water is slowed, pollutants and sediments drop out of the water. Wetland organisms intercept nutrients and pollutants, trapping them in wetland plants or substrates. Although too many pollutants can damage them, wetland plants also help to circulate and reuse nitrogen, phosphorus, and other essential nutrients. Many local governments have used this phenomenon to their advantage, constructing wetlands to filter treated wastewater and reducing the overall cost of treatment operations.
Types of Wetlands
Wetlands can vary greatly depending on how much water is present, how long water is present, how the water got there, the type of soil, and the kinds of vegetation present. All wetlands, regardless of size and water depth, provide important wildlife habitat although management practices may differ between them. Additional chapters in this section explain the types of wetlands in more detail and provide suggestions for protecting and managing them.
Swamps have saturated soils, may have standing water during part of the year, and are dominated by water-tolerant trees. Types of swamps include bottomland forests on floodplains, conifer swamps, and dense shrub swamps. Marshes are another type of wetland covered periodically by standing or slow-moving water. Soft-stemmed plants such as cattails, sedges, and rushes dominate a marsh’s nutrient-rich soils.
Wet meadows, sedge meadows, and wet prairies are similar to marshes in that they also contain grasslike vegetation. However, these wetlands typically have only seasonally saturated soils and little or no standing water. Seasonal wetlands are shallow, temporary wetlands that can have standing water from late winter through early spring. Examples are seeps, which usually provide a year-round source of water, and vernal pools, which vary in size from a few square feet to over an acre. These wetlands can be important for breeding and migrant waterfowl, amphibians, and other wildlife.
Bogs and fens are wetlands with a thick accumulation of organic matter called peat. The acidic water of a bog is nutrient-poor because the bog is fed by rain water. Acid-loving plants are found in them. Fens are relatively rare in many places. Unlike bogs, they are fed by groundwater that has passed through calcium and manganese rich mineral soils. Fens are typically more nutrient-rich than bogs, they support sedges, rushes, and some shrubs.
Wetland Management and Enhancement
Wetlands should be preserved whenever possible, but recognize that wetlands are a dynamic system that will change with time. Those wetlands that have been dredged, drained, filled, or otherwise altered offer an opportunity for restoration. Keep in mind that a restored wetland need not hold water all year long, because many do not. Temporary wetlands are usually less than two feet deep and often retain water during the fall, winter or spring.
Wetland management and enhancement can be performed to improve wetland functions. However, this can be difficult, and improving surrounding uplands may be more effective. Enhancement efforts may include manipulating water depths; mowing, burning, or planting; removing nuisance plants; adding nest structures and other habitat and wildlife management improvements. Remember that wetlands can influence, and are influenced by, what goes on around them. Having clear goals along with a site-specific plan are the keys to successful habitat management.