Burn it down to build it up: Controlled burns at Trustom

USFW use drip torches to spread the fire in a controlled burn. (Ink drawing by Hugh Markey)

Trustom Pond has been scorched. The path that normally leads visitors to a lush meadow now leads them to a scar that blackens a third of the field. The smell of burnt grass and brush can be pungent, and the rectangle is almost offensive in contrast to the rest of the region. Yet the scar is not the result of vandals, nor even of a lightning strike. The burn at Trustom is part of US Fish and Wildlife’s (USFW’s) controlled burn program, designed to bring the meadows back healthier than ever.

“This is a process that’s been going on since the early ‘90’s,” says Nick Ernst, wildlife biologist with USFW. “We try to get to all the areas every few years.” The procedure involves dousing the fields with a mixture of diesel and gasoline and the result is a fire that burns at a high temperature and that dissipates quickly without burning too deeply.  By doing so, invasive grasses and shrubs are cleaned out, leaving room for more beneficial native plants. “Trustom was once an agricultural area, and had a lot of alfalfa growing in this field. It’s  very fertile, but that’s made it vulnerable to invasive species, like autumn olive and honeysuckle, as well as cool season grasses that tend to mat over in the winter. That means other plants have a tougher time germinating in the spring.”

Ernst says that burning is more effective than mowing because it eliminates leaf and grass litter. “Species like Savannah Sparrow and Bobolink, which nest on the ground, like moderate amounts of thatch, rather than the deep mats left by cool season grass. By doing this in the spring rather than the fall, we can do a better job of controlling the cool season vegetation, which also means greater benefit to the pollinators.” Roughly 1/3 – 2/3 of an area is burned at a time, and the rest is untouched. Even in the burnt areas, some shrubs survive. “Doing it this way creates a much more natural mosaic, rather than mowing the whole area down.” Plants like honeysuckle and autumn olive are already greening up, expending much of their energy in doing so. That makes burning more effective, since the plants will be less able to regenerate.

Extensive preparation goes into a burn, Ernst says. There is a burn boss, whose job is to assess things like wind direction and speed. The relative humidity should be neither too low nor too high. “They’re really conservative with their options,” which maximizes burn effectiveness, and is the reason none of the burns have gotten out of control. The crew of about a dozen wear fireproof pants, hard hats, and special boots. All have had training in firefighting, making them as adept at putting out fires as setting them. In fact, some of the crew will volunteer to fight wildfires in the West at other times of the year. Before the burn begins, two tankers of water roll in courtesy of DEM and the National Park Service. The process takes roughly eight hours.

A field closed to the public is another region that had been recently burned. Next to it, Ernst points to an area that is lush with new growth. “That section was done last year,” he says. Without his comment (and without botanical expertise), it would be impossible to distinguish it from an area that had been untouched. The blackness of the burned region is broken up here and there with whitish bones of deer and groundhog. The bones are from animals long deceased, now exposed to the daylight with the burning of the grass. Although the area is pockmarked with dens and tunnels from other rodents, Ernst says the slow progress of the burning, coupled with the fact that much of the habitat is left untouched, gives most of the wildlife plenty of time to either hunker down or get out of the way.

There is another section by the Red Maple path which had seen burning the year before. USFW has worked with Rhody Native, a local non-profit (“dedicated to preserving the biodiversity of Rhode Island’s native plant communities”, its website says) to acquire some 1500 native flowering plants that have been put in at Trustom, Ninigret, and Chaffee preserves, and some of the plants had been placed last fall in an effort to encourage more early-season blooms for pollinators like bees and butterflies. “Cold seeding of this area in the fall gives the plants a chance to build strength and achieve a higher rate of success,” Ernst says. “We won’t manage this area further for another two or three years, as the plants have a better chance to establish themselves.” Each of the next several years should yield increasing numbers of native plants in bloom.

While the initial impression may be shocking, the long term effect of controlled burns echo a process that has taken place for millennia. “A lot of these areas have burns as a natural part of their history. As nearby land becomes more densely populated, that element doesn’t exist. So it’s actually a good way to restore the balance. It’s really great to see things green up so lush. Any time we can mimic the natural process, I think it’s a good thing.”

2 Comments

  • Good story on burns. Burning is a natural part of nature. Many species are fire dependent, i.e. they require periodic fire. Small burns also preempt the big and disastrous ones.

    One thing, they do not douse the fields with gas and diesel. That is the mixture in the trip torches, but most of the field just burns on its own. We would never douse our fields with gas or diesel.

    We burn in Virginia for ecological and forestry reasons. Some background. http://johnsonmatel.com/blog1/2009/01/burning_questions.html

    • Hi John,

      Thanks for writing. The mention of dousing the fields was intended in a colloquial sense, rather than a literal one. I appreciate your sharp eye, and I enjoyed your article on the topic!

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