Sunday, July 10, 2016

Igniting diversity in prairies

Much of the remaining prairie in the Midwest Region is fragmented and surrounded by agriculture or threatened by urban sprawl. Along with our counterparts with state agencies, we have been working to replace or restore our prairies for several decades.
Unfortunately, tall warm-season grasses are often dominated when trying to emulate a native prairie restoration. Early prairie seed mix contained more grasses like Indian grass, big bluestem and switchgrass than forbs like blazing star, aromatic aster and beardstongue. This is one reason why prairie restorations often result in nothing more than tall grass monocultures.
We recently have moved away from seeding that results in monolithic stands of grass to providing an increase of diversity in prairie seed mixes. We currently plant seed mixes with less than five pounds per acre of grass seed and as many forbs as we can afford for that project. However, these plantings, many of which were not supposed to contain any tall grasses, can still end up being tall grass monocultures.
Growing-season or summer prescribed burns are encroaching the Midwest Region to remove the monoculture. Also called lightning season burns, the Georgia State Chapter of the National Wild Turkey Federation is where it sparked. After several years of studying the effects on upland game bird management, this wildlife management tool started spreading to Oklahoma, Kentucky, and Tennessee. With more growing-season burn successes, it is advancing north and several national wildlife refuges and state fish and wildlife agencies are igniting across the Midwest.
Through our Wildlife Restoration Program, we partner with states to acquire and manage natural areas. The program provides funding for the selection, restoration and improvement of wildlife habitat and for wildlife management research. Funds for these conservation activities come from federal excise tax on sporting arms, handguns, ammunition and archery equipment. These funds are collected from manufactures and we distribute them each year to state and territorial wildlife agencies to get real work like this done on the ground.
Conservation of natural areas typically contain some of the last remaining intact, high-quality wildlife habitat, including grasslands. We are changing our burn plans to use fire during the growing season as a more effective wildlife management tool to diversify the sea of grass.
“All of these types of burns have resulted in less dense grass populations and an increase in forb abundance and diversity,” said Bryan Eubanks, wildlife biologist for the Illinois Department of Natural Resources.
“Not only do growing-season burns improve the species composition of prairie plantings, but they also greatly improve the structure of these plantings by killing clumps of warm-season grasses and removing exotic shrubs,” continues Eubanks.
Growing-season burns look different than a spring or fall season burn when completed. It’s primary fuel source is the dead plant layer from last years growth, called duff or thatch. Burning duff leaves a mosaic pattern of vegetation. This is created by the fire slowing creeping underneath actively growing plants, leaving them standing upright. Thus, natural areas that undergo burns still provide valuable cover for insects, herps, birds and small mammals.
By conducting summer prescribed burns, birds are able to produce a successful hatch and wildlife are able to seek refuge during active fire. Removing the thatch, increasing sunlight to the ground and stimulating new plant growth high in quality is very palatable for wildlife.
“We are amazed at how well they [growing-season burns] have done,” said Brad Feaster, public lands supervisor for the Indiana Department of Natural Resources.
“I like to see that mosaic pattern after a burn, leaving areas of cover for wildlife,” continued Feaster.
Seth Grimm, fire management officer for Detroit Lakes Wetland Management District explained that most national wildlife refuges in Minnesota conduct summer prescribed burns. “It’s a completely different beast, producing immediate beneficial results for plants and wildlife.”
From the experiences of Eubanks, Feaster and Grimm, low relative humidity and wind to carry the fire are essential factors for a successful growing-season burn. Fuel load is also important, so these burns are typically not conducted consecutively on the same site.
“These burns accomplish grant project objectives, like providing breeding habitat for grassland birds,” explains Kyle Daly, wildlife biologist for the Midwest Region Wildlife and Sport Fish Restoration Program.
“Without varying burn timing, biologists typically end up with low diversity, grass dominated plantings that is not good habitat for these species,” continued Daly.
When conducting prescribed burns, managers are restricted to certain weather conditions, smoke management and labor requirements. Adding several more months to burn allows greater flexibility.
We can do more for wildlife by using these summer prescribed burns. Prescribed fire’s ability to quickly turnover nutrients may lead to increased food supply, offer open areas to easily move around and forage as well as favored habitat for nest sites.
In the glowing light of a hundred tiny flames, blooming like wildflowers, our biologists and fire management officers are learning how to spread the flame during the growing season in a way that is safe for people, wildlife and the wider habitats that we all call home. These burns provide a diverse plant community, benefiting the wildlife that depend on it.
Learn more about our wildland fire program: