Image Details

Neal Smith National Wildlife Refuge in Iowa is the site of a large-scale tallgrass prairie and oak savanna restoration effort by the U. S. Fish and Wildlife Service. The Service has been returning former cropland to native prairie here since 1992. Refuge staff manage about 5,600 acres of restored tallgrass prairie and oak savanna.  

Prairie restoration conserves wildlife habitat and fosters carbon storage, and is considered a nature-based solution.  Nature-based solutions are sustainable practices that use environmentally friendly features or processes to make landscapes more resilient.   

For thousands of years, tallgrass prairie covered the Midwest. Then European settlers plowed grasslands and drained wetlands for farming, imperiling the prairie ecosystem. 

As the Service has restored large tracts of tallgrass prairie here, the refuge has seen an increase in breeding pairs of numerous grassland birds, including Henslow's sparrows, Grasshopper sparrows, and Bobolinks.

Prairie plants enrich the soil and recharge groundwater, while providing important habitat for grassland birds, pollinators and other wildlife. 

Prairie-restoration methods used include: 

• harvesting and planting native prairie seeds 
• mowing to inhibit invasive species invasive species
  An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.
  
  Learn more about invasive species
• removing trees and non-native invasive plants 
• applying prescribed fire 
• monitoring plants and wildlife
• reintroducing bison and elk. 

Image Details

Planting Native Plants

The reconstruction or rebuilding of prairie begins with seeds. The refuge only uses local ecotype seed − seed taken from plants within the 38 surrounding counties. Staff and volunteers collect seeds from dozens of plant species in summer and fall. Some seeds are purchased from prairie nurseries; others are harvested on the refuge by machine or by hand.

During the winter, volunteers and staff remove stems, leaves and debris from the hand-collected seed. Most of the cleaned seeds are added to a seed mix and spread onto prepared soil. The seed mix is also added to previously planted prairie to increase native plant diversity. More than 200 species of prairie plants have been sown on former farm fields.

Some rarer or fussier prairie plants are grown in late winter in the refuge greenhouse, where they can grow without competition from other plants. Seedlings are transplanted into larger containers so they can develop strong root systems. 

Prescribed Fire

Periodic fire stimulates the growth of prairie plants by removing last year’s dead plant material, allowing sunlight to reach new shoots emerging from the ground. Fire also promotes the sprouting of many prairie plant seeds by removing the outer seed coat. Frequent fires prevent trees from becoming established since they are not adapted to fire like prairie plants. 

Before the arrival of European settlers in the Midwest, Native Americans intentionally set fires in late summer and fall to create quality habitat for animals such as bison, elk and deer. The practice also reduced the risk of wildfire. Refuge staff primarily apply prescribed fire in the late fall and early spring when conditions are best for burning. Sections of the refuge are burned, in rotation, every one to three years.

Invasive Species Management

Non-native plants or animals are ones that have been introduced since European settlement. Invasive plants are non-natives that cause environmental harm, often because they have no natural enemies here. 

Unless they are managed, invasive plants may out-compete native prairie and savanna plants. This can also harm wild animals that need the native prairie and savanna for food and shelter. Refuge staff use a range of methods to manage invasive plants, depending on the species. Fire and grazing are commonly used tools. Mowing invasive plants before they go to seed is also important for many species. Other plants must be removed by pruning or sawing, then treated with herbicides.  Herbicides are used when no other method of control will work.

Image Details

Grazing

Grazing animals, such as bison and elk, are nature’s mowers. Grazing increases the amount of sunlight and water that can reach the ground, stimulating plant growth. Bison prefer to eat grasses, which allows wildflowers to spread and increase their diversity. At certain times of year, elk prefer to browse on trees and shrubs, which helps prevent the prairies and savannas from changing to forests. 

Grazing animals also spread native plant seeds to new areas both through their digestive systems and by collecting and shedding seeds in their fur. Bison create bare areas on the prairie by rubbing and wallowing, building habitat for certain types of plants and animals. Many other animals, from white-tailed deer to mice and grasshoppers, also graze on prairie plants.