A Great Day for Spring Walk
You wake to clears skies, bright sunlight, light but steady wind and no bad weather in the forecast. It is a great spring day!  You have been waiting for a day like this all winter.  It is a good day to make an excuse not to go to work.  So, you decide to head to your favorite wildlife management area to enjoy the sights and sounds of nature that have energized humans for generations.

As you guide your vehicle across the countyside, you see it.  There, on the horizon, a small wisp of smoke or is it a cloud.  No, it is not a cloud.  As you close the distance, the wisp transforms into a grayish-black towering plume of smoke with flames leaping wildly at its base.  Suddenly you realize this is the wildlife area, one of your favorite places and it is awash with flames, devouring the grasslands ahead of it.  You ask yourself, "what arsonist released this monster?"

Then suddenly, as you approach closer, people appear out of the smoke.  There, along the perimeter of the fire, moving along methodically.  One person has a drip torch in hand.  Igniting a short stretch.  Then a couple more, one driving a truck with water tank and pump and the other dragging a hose extinguishing the back flame of the fire line laid by the torch person.  Then you realize.  No.  This is not arson.  This is a prescribed burn being conducted by the local wildlife unit crew.

Iowa’s landscape was once dominated by tall grass prairie.  Historically, fire was an integral component of the prairie ecosystem and held invading forests at bay.  The fires were naturally occurring as well as intentionally started by Native Americans.  Though Iowa’s grasslands are no longer the dominant ecosystem on the landscape, maintaining these isolated grasslands still requires mimicing historic natural processes through management.   The probability of naturally occurring fire holding back forest succession on these grasslands is very limited, as a result of the small size and fragmented distribution of grasslands across the Iowa landscape.  Therefore the hand of managers is needed to produce regular intervals of fire and to prevent the succession that would reduce the number and diversity of the birds, mammals, reptiles and amphibians that thrive in Iowa's grassland environment.

In Iowa, fire is primarily used in grassland management; however, it may also be used for managing savannahs and woodlands.  Recent media attention has focused on prescribed burns that have gotten out of control and has questionned whether these intentionally set fires are necessary.  For the resource manager, a prescribed burn is a critical tool that is not used indiscriminately.  When fire is chosen as a management tool, it is used with specific goals in mind.    The appropriate use of fire may accomplish any of the following:  it may reduce weed competition in a new prairie planting, set back woody succession, shift plant composition from introduced cool season species to native species, reduce residual plant litter, release nutrients tied up in the residual plant litter, shift the plant composition to native forbs or native grass species. In grassland management, one or more objectives may be desirable.

There are a number of aspects that affect the outcome of a burn.  One aspect is the timing of the burn within the annual growing cycle.  Burns may take place during the spring, summer, fall or winter.  The timing of a burn is important to obtain the desired results as the timing of the burn generally influences species composition.  Some considerations are:  Do we want to inhibit introduced cool season grasses?  Do we want to inhibit woody plants?  Do we want to promote forbs or a specific group of forbs?  Do we want to promote native grasses or a specific grass species?

Yet another consideration is the frequency of burns.  Do we burn every year, every other year or at a longer interval of 3-7 years?  When we are working with new prairie reconstructions or degraded remnant prairies the frequency may be fairly often, at least until the stand is dominated by the desired species.  In older well-established stands, the frequency is generally less often.

Yet another important aspect of burning is the amount of the site to be burned.  Do we burn the whole site or a portion of the site?  During the native grassland establishment phase, with a limited number of grass species, the whole site may be burned.  In native prairie remnants and prairie reconstructions with numerous grass and forb species, generally only a portion is burned in order to protect possible critical insect populations.

As humans we tend focus our attention to immediate individual things (i.e. a burn, a tree or a bird) that we can see and not on populations and longer term more cryptic changes to ecosystems.  As such when we observe or arrive at an area that has just been burned we tend to think of how a prairie or wildlife species has been destroyed by fire and not as to how this burn contributes to a healthy ecosystem and vigorous wildlife populations.  The later is the central mission of the Wildlife Bureau and is the reason for the calculated management decision to use fire as a tool to disrupt your spring day.

So, the next time you observe a prescribed burn being conducted, don't get steamed because your spring day wasn't what you thought it was going to be, rather with your new knowledge consider the process that is taking place and what the management objective might be for the site.  Think about it in terms of the plant community and the animal community.  What will those communities be without a burn?  What will they be with a burn?  For the resource manager, a prescribed burn is the tool of choice used to maintain the grassland system with its associated plant and animal species.  Those plants and animals will lose without its use. 

For additional information regarding the Wildlife Bureau's prescribed burning activities and how fire improves habitat for wildlife contact your local wildlife management biologist or Ron Munkel at (641) 332-2019.

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