Prescribed Burn at Hagerman

By Helen Petre, with contribution from Kathy Whaley

In January, 2011, the topic for Second Saturday will be Controlled Burns, with speaker Richard Baker, Chief Firefighter for the Wichita Mountain Wildlife Refuge (shown in photo by Becky Goodman).

The last weekend of August, 2010, was a little smoky around the Meyers unit at Hagerman National Wildlife Refuge. Not to worry. This was just another routine prescribed burn. Burns are an integral part of maintaining the grasslands of Hagerman. Historically, approximately 3,750 acres of the 11,320 acres of Hagerman National Wildlife Refuge were grasslands. Fires were set either by lightning or intentionally by Native Americans.

Why burn:

Prescribed burns restore habitat in areas where agriculture has changed historic grasslands to different, less wildlife-friendly ecosystems. Common native grasses that grow in Grayson County include big bluestem (Andropogon gerardi), little bluestem (Schizachyrium scoparium), Indian grass (Sorghastrum nutans), switch grass (Panicum virgatum), side oats grama (Bouteloua curtipendula) and eastern mock grama grass (Tripsacum dactyloides). Grasslands also support wildflowers, including Maximilian sunflower, heath asters and milkweeds and also those little yellow Huisache daisies (Amblyolepsis steigera) that are everywhere at Hagerman in August.

What happened to these vast grasslands? When farmers settled and began plowing the land, large grazing animals including wapiti (Cervus elaphus) and bison (Bos bison) left the area, and the remaining plant community changed drastically. Farmers suppressed fire, even in areas where they did not plant, and honey locust (Gledistsia triacanthos), juniper (eastern red cedar, Juniperus virginiana), and other undesirable woody species invaded lands that were once vast prairies.

At Hagerman, winter wheat (Triticum aestivum) and other food plots are still planted for the migrating birds, but the Refuge is working towards restoring several upland areas to their historic vegetative cover - grasslands. Bobwhite (Colinus virginianus), dickcissel (Spiza americana), meadowlark (Sturnella magna), and other birds thrive and nest on grasslands, and burning and restoring grasslands should attract them to Hagerman.

Conducting the burn:

Weather is a key factor for prescribed burning and conditions are monitored hourly from the actual fireline. It is imperative to wait for the correct moisture and weather conditions for a prescribed burn, which is why the last weekend of August was just right this year. Relative humidity should be fairly low to allow for a good burn, but the vegetation cannot be too dry/too wet or the burn will not meet the objectives of safely removing unwanted trees, adding nutrients to the soil, and reducing the “fuel load” to lessen the risk of wildfires near homes. The air temperature should also be moderate, not too hot or too cold. Wind speed and direction are critical. The best winds for burning in this area are between 5 and 10 mph. If wind changes speed or direction during a fire, this could cause a dangerous situation.

For the recent burn at Hagerman, there were about 8 crew members working together to conduct the burn. Fire lines around the entire 800 acre Meyers Unit that was burned were mowed and a dirt line was put in the day before the burn to greatly decrease the chances of the fire escaping the designated burn area, or “spotting over”. Using a drip torch, the fire boss starts a test fire along a road or other fire break on the side of the field against the wind to ensure the fire will react as it is expected to. This is the backing fire. If conditions are as expected, the fire boss starts another parallel (flank) fire on the side with the wind while the initial fire burns, and this fire burns towards and joins the backing fire. It is important that firefighters on both the backing and flank fires keep in contact with radios or even cellular telephones.

The Fire Crew follow along the fire break with swatters (flappers), or poles with large, flat rubber pieces that are used to beat out any fire that moves the wrong way. Some firefighters also carry backpack sprayers with water and fire-retardant foam , and some even drive brush trucks (vehicles designed for wildland firefighting) or four-wheelers along the fire line to spray water on any grassy area that might carry fire and in case the wind changes. The fire is monitored for several hours after the burn to make sure there is no chance of fire moving outside of the burn unit. It is also checked for the next several days before it is considered a completed burn.

Bright green of sprouts of grasses and wildflowers are already appearing in the burned area!

For more information about Hagerman National Wildlife Refuge, the official website is http://www.fws.gov/southwest/refuges/texas/hagerman/index.html and for information on programs and activities at the Refuge, see http://www.friendsofhagerman.com.