Habitat Management

A healthy marsh is one rich in plant and animal diversity. To accomplish this, refuge staff use a variety of tools to mimic the dynamic processes that, until recently, naturally occurred for thousands of years. Prescribed burns, grazing, managing water levels and controlling exotic plants are just a few of the tools that the refuge staff use to manage a healthy, productive and diverse marsh ecosystem.

Key food for wildlife includes the leafy portion of plants, flowers, seeds and the underground rhizomes and tubers. If wildfires are suppressed, years of dense vegetation will shade the soil surface, preventing seeds of other plants from germinating or surviving. Burning removes a lot of the dead plant matter and allows other species of plants to grow.

A productive burn removes vegetation that is just above ground. It is usually conducted while there is still some water on the surface. The water prevents the soil from overheating and helps protect plants' root systems. After a fire, most vegetation will sprout from the roots and the marsh is quickly covered with new growth. In addition, as the sunlight warms the soil, many other plants will sprout from seed.

Grazing is used to increase the value of marsh and wet prairies for wintering waterfowl, nesting mottled ducks and many other wildlife species. The combination of prescribed fire and grazing sets back plant succession and produces a marsh with higher plant diversity. The higher diversity of plants means more food for a wider variety of wildlife species.

Another key food item for wildlife includes insects because of their high protein content. Insects are an important part of the diet of young birds in order for them to grow and develop properly. It is also important for adult birds so they can breed successfully. Standing water in grazed areas will warm more quickly than in areas with heavy growth. Warmer water increases production and growth of invertebrates, including insects.

Water is managed on the refuge with water control structures, levees and weirs. These structures are also used to prevent saltwater from intruding into the freshwater wetlands. It is the combination of grazing, prescribed burning and the management of water and salinity levels that provide the best conditions for producing native food for wildlife.

Another management tool used on the refuge is the control of exotic plants. These plants are often fast growing and highly invasive and outcompete native plant species. Because of this, exotic plants can quickly reduce the diversity and value of habitat, ultimately affecting wildlife. Water hyacinth, Chinese tallow, and giant Salvinia are a few of the exotic plant species that are controlled on the refuge.