Scott Rall: Big fires are a big deal for wildlife
My love/hate affair with trees is in full bloom again this spring. Spring is burning time and the list of habitat burns on my list is pretty daunting. Grassland burns in the spring can be seen all over the county and this entire area of the state, for that matter. The primary reason to burn grasslands and native prairies in the spring is to reinvigorate the native grasses and hurt the non-native cool season grasses.
The prairies that the buffalo roamed on in North America are gone forever and that is from many causes. First and foremost is that they have been plowed up and no longer exist. Native prairie is the most endangered habitat type on the continent today. Less than 3 percent of the native prairie that existed in Minnesota survives yet today.
The second reason that the remaining prairies are forever changed is the same reason we have invasive fish and plants everywhere we do not want them. There is a grass called smooth brome that was never here when the buffalo roamed. It is a cool season grass and like many of its related cousins it did not exist on the prairies of yesteryear. It was brought here from England and has been death spiral for native prairies.
Native prairie grasses need fire. Fire eliminates the dead accumulated understory and the black ground warms up faster. This gives a longer growing season to these desirable warm season grasses.
Smooth brome is a cool season grass and greens up in early spring, and because of the competition it creates for sunlight and moisture it gets a jump-start on the other more desirable grass species. You can plant and nurture a stand of native grass to its full potential in about four years. If this native grass stand is not burned or otherwise manipulated for the benefit of warm season native species they will almost completely disappear from sight in 5-10 years.
They still exist in the soil but in an almost dormant state. Fire in the spring will injure the smooth brome that is up and growing and this injury knocks it back, allowing desirable grasses a head start in the growing season.
Native grass that can easily grow to a height of 6-8 feet will be overcome by non-native cool season brome and in a very short time (as little as 5-8 years) the stand will be thin, stagnant and only about 12 inches high. Native grasses stand little chance against their non-native competition. This is why native grasses need a fire at least once every five years. Quality grassland need management and those that don’t get it will go downhill fast.
Fire does one other very important thing. It kills trees, or it will if you’re lucky. I read that the only place in the Midwest that had any sort of trees when the settlers came were on the south facing hillsides. This was because the frequent uncontrolled fires started in the prairies by lightning, pushed by the predominant northwest winds we have in the spring, always burned them up. Uncontrolled fires in today’s word do not exist so tree control in grassland prairies is only done by habitat managers who do controlled burns.
Controlled burns can properly manage unwanted volunteer trees if they are done properly and at the right times. Fire can kill small trees with trunks about the size of a broom handle or smaller. Once a tree gets bigger than that, fire is far less effective.
Little trees are easier to deal with. When they are left unattended for too long they turn into chainsaw material and the labor costs associated with their management will increase tenfold.
It is wise to deal with unwanted trees in prairies when they are fire manageable and not wait till the costs skyrocket. In my own experience fire management costs to control little trees and invigorate native grasses is about $30 per acre. On the other hand, if you have to call in a contractor with the big equipment to remove larger trees the cost can exceed $300 per acre. This is not $300 for each acre that has a tree but $300 per acre on the whole parcel. If trees are scattered over 80 acres this computes into $25,000.
These high costs after the trees have gotten out of hand is why so many grasslands are managed poorly. Staying on top of the problem every 3-5 years is the only answer. Once a burn is completed we monitor to see how many trees survived the fire, and in August we then go out and apply the proper chemical to kill the remainder. This, too, can be a multi-year process. Some of the trees injured but not killed by the fire might take more than one growing season to reach a height taller than the grasses that they inhabit in order for the manager to locate them.
Trees can be a great thing when they are the right species and are planted in the right spots. I love planting trees, and the local chapter of Pheasants Forever did what I think is the largest wildlife tree plant in the past 20 years about five years ago near Lake Bella on a wildlife management area. The planting cost about $8,000 and consists of many long rows of eastern red cedars surrounded by shrubs to keep the snow from filling them up. This planting provides cover for wildlife in the winter and is a cover type severely lacking in our area.
When you look over a grassland prairie you might not see a single tree. After a burn is completed that same spot might very well have 5,000 trees standing about two feet tall. Small trees are hard to see until a burn is completed. Many land owners do not even know they have a tree problem until a chainsaw is the only answer.
There are folks who think than any tree is a good tree. If these same folks would brush up on a little grassland ecology they would not have this mindset any more. Volunteer trees have a very detrimental impact on almost all grassland nesting species. This include ducks, pheasants, and many ground nesting song birds.
Trees shade out grasses that try to grow beneath them. They also allow avian predators a great perch with which to see, locate and kill nesting birds. Trees also supply mammalian predators the hollow cavities with which to raise their young. Raccoons, possums and skunks eat a lot of ground-nesting bird eggs and tree removal makes them live elsewhere, thus improving nesting success.
My side-by-side Polaris Ranger with a 60-gallon tank is a great fire rig. I added a retractable 50 hose on the spray wand to reach spots the rig cannot safely go. You really need to be careful on side hills and other steep areas. I add a commercial weed eater with a super sharp saw blade on the business end along with a small chain saw and I can get quite a bit of habitat management done in a day. I have never used all 60 gallons of water at any fire I have done and I hope I will never need to.
The old saying that “it is better to have and not need than to need and not have” is certainly my fire water motto.
When you manage prairies for the benefit of wildlife there is a certain amount of nest destruction that happens every year. This is the short-term pain that results in the long-term gain. The improved conditions of the grasslands and the removal of volunteer tress results in much better wildlife production in the future years. This increased production for the next 5-7 years far and away offsets the small short term losses of spring grassland fires.
Nesting bird themselves are not killed by the fire. They will move off before they are injured. These displaced birds will, in most cases, re-nest in an adjacent area. This is why you never burn the entire spot at one time. About 20 percent of the grass is burned each year and over the five-year period all the grass is maintained.
After a burn I did a few years back on my parents’ property the native big blue stem grass grew to over nine feet tall. I really did say nine feet tall. All of the people I showed it to had never seen anything like it.
Native grasses need fire and this is one of my very favorite habitat management activities I participate in every year. We have completed seven burns and have eight more to go before the deadline of May 15. The deadline is set so when nesting is in full swing the birds are not disturbed.
If you have never seen a grassland controlled burn, check out the next big plume of black smoke you see from a safe distance. As the grasses crackle loudly in the fire you should know the wildlife will be better off for it.