UF Research: Suburban Backyard Woods Benefit From Controlled Burns
GAINESVILLE, Fla. — Controlled burns intended to restore forest ecosystems that once depended on natural fires may be just as effective in suburban backyards as they are on large open tracts of land, according to a new University of Florida study.
The study determined burning tiny remnant tracts of longleaf pine forests between fairways on golf courses – territory known as “the rough” – both decreased invasive hardwood trees and increased the diversity of plants normally found in the Southeast’s native pine forests.
The findings hold one key to saving longleaf pines, which are fast declining, and the unique ecosystem that depends on them. What little of them remains often can be found only in small patches in urban or suburban areas because the pines typically grow in high, dry areas that are prime locations for golf courses, housing and other development.
“What this study shows is that you can do backyard burning and have beneficial environmental effects,” said Francis “Jack” Putz, a UF professor of botany and co-researcher on the study with Kimberly Heuberger, who graduated from UF recently with a master’s degree in botany. The findings were reported last month in an article in the journal Restoration Ecology.
Longleaf pine forest once covered at least 60 million acres in the Southeast. However, logging, development and other trends have reduced that to just 2.5 million acres, Putz says. The trees – and the ecosystem that accompanies them, which is rich in threatened or endangered native species such as the indigo snake and gopher tortoise – depend on periodic fires. While the flames do not harm longleaf pines – among the most fire-tolerant trees in the world – fire kills off young oaks and other hardwoods that otherwise would shade out the pines and the hundreds of plant species that flourish beneath the pines. Fire also adds nutrients to the soil, encouraging growth of the pines and native plants.
To ensure the health of the few remaining large tracts of longleaf pine ecosystem, park and wildlife managers routinely do controlled burns to mimic the effects of natural fire. But Putz said that practice ignores the large amount of longleaf pine forest fragments in suburban back yards, golf course roughs, undeveloped lots, and other areas around towns and cities. He and Heuberger decided to see if fires in these small suburban tracts could be used to produce similarly beneficial effects.
The researchers chose a 100-acre Gainesville-area golf and residential community for their experiment. They selected 20 patches of longleaf pines, all less than one acre in size. All the plots were located along the edges of fairways between the golf course and the houses, with some as close as 9 feet from the homes.
The researchers did controlled burns on 10 of the patches during the spring growing season, setting aside the other 10 as controls. Nine months later, they measured and compared the density of invading live oaks and other oak species. The result: There were significantly fewer oaks in the burned patches than in the unburned ones. Not only that, the diversity of plant species native to the longleaf pine ecosystem was considerably greater in the burned patches.
Additionally, Putz said, the diversity of native flowering plants increased in the burned patches – making the burning not only environmentally sound but also aesthetically pleasing.
Putz said the researchers notified homeowners before the burns, which were so small and of such low intensity that simply stepping on the flames would extinguish them. Most homeowners welcomed the process, which the golfers also appreciated because it made their golf balls easier to spot in the blackened, cleared underbrush.
“The burns turned out to be cost effective, not difficult to implement, successful in terms of controlling hardwoods and stimulating flowering, and accepted by the community,” he said, adding that all controlled burns – no matter how small – should be overseen and managed by fire officials.
Steve Pyne, a professor in the biology and society program at Arizona State University who specializes in environmental history and the history of fire, said the research demonstrates the importance of fire even where it is not traditionally expected or welcomed.
“Conservation biology has to deal with those places people live in as well as those they don’t,” he said. “Some of those sites demand fire. This paper shows, with a concrete example, why this matters and how it might be done.”
Putz said local governments should work toward connecting forested roughs and other remnant forests to create larger longleaf pine communities that could be managed periodically with controlled burns.
“This shows some of the benefits of restoration on a very small, neighborhood scale,” he said. “What we should develop is a network of these small areas that don’t require mowing or herbicides, but that could simply be managed by fire every two to three years.”