A Florida Island Battles Green Invaders

Sanibel Island declares war against nonnative plants

  • Mark Cheater
  • Apr 01, 2002
THE VAST FIELD is littered with splintered branches, crushed red berries and dead leaves, and tire tracks indent the mud where a thicket used to stand. Sawdust fills the warm, blue sky as a trailer-sized wood chipper noisily consumes a tree trunk. Rob Loflin surveys this war zone in southern Florida and smiles. "I'm the king of devastation," he jokes, standing next to the shattered red stump of a recently pulverized Australian pine.

Loflin is the director of natural resources for Sanibel Island, a city of about 6,000 residents just off the coast of Fort Myers, Florida. At his bidding, a crew of men and machines are sawing down and grinding up nearly every piece of vegetation on this 300-acre plot. Despite appearances, this is part of an ambitious and nearly unprecedented conservation program: an effort to rid an entire community of weedy nonnative plants by 2010.

Across the country, some foreign plants and animals--known as "exotics" or "aliens"--are causing ecological and economic head-aches. Whether introduced accidentally or intentionally, these species are crowding out or killing native flora, fauna and crops.

Exotics cost the nation an estimated $138 billion each year and pose the primary threat to 42 percent of America's imperiled species, according to scientists at Cornell University.

Florida is suffering more from this biological invasion than any other state on the continent. More than 900 exotic plant species--everything from the infamous kudzu to trees such as the Australian pine, melaleuca and Brazilian pepper--have moved in, finding the state's mild climate, absence of enemies and disturbed soils much to their liking.

Southern Florida, tropical and isolated, is most beleaguered, with nearly 18 percent of its natural areas dominated by foreign plants. The situation here has "reached crisis status," according to ecologist George W. Cox of San Diego State University.

Sanibel Island has responded to the crisis by declaring war on nonnative plants. Officials from the city, state and federal governments, along with the Sanibel-Captiva Conservation Foundation (SCCF), are working with residents to remove Brazilian pepper, Australian pine and other green invaders--even if it means, as on this property, razing almost every living thing in sight.

"It looks awful, like a development project," Loflin, a biologist, shouts over the grinding noise of the tree chipper. "But if you look closely, all the exotic vegetation is being removed and the native vegetation is being preserved." He points to a few native cabbage palm trees left standing in the otherwise denuded landscape.

To show why it's necessary to reduce the invaders to mulch, Loflin drives 50 yards down a dirt road and pulls off to the side. A few feet from the shoulder, a wall of green rises toward the sky. In the foreground are Brazilian peppers--10-foot-tall bushy trees with shiny leaves and clumps of bright red berries. Behind these are Australian pines--50-foot-tall evergreens with reddish trunks, dangling branches with needlelike leaves. "Here we have nothing but exotics," says Loflin. "You'd normally have 70 species of native plants here. But there's not a native in sight."

The pines were first planted by farmers eight decades ago as windbreaks, Loflin says. Brazilian pepper was introduced to Sanibel in the 1940s as an ornamental. Fast-growing, fecund and with few enemies in Florida, these and other foreign plants flourished. They eventually overran the island's wetlands and savannas--including those at the 6,300-acre J.N. "Ding" Darling National Wildlife Refuge on Sanibel--to the detriment of birds and other creatures for which the island is well-known.

"This area is particularly important during migration for wood warblers, tanagers, orioles and other songbirds," says Loflin. "But with all the exotics, they don't use it. They can't--because there are no insects and fruit, so there's no reward for them to forage here."

That is steadily changing, however. In the four years since Sanibelians launched their attack on exotic plants, they have managed to reclaim about 60 percent of their island--including most of the wildlife refuge. Native plants--cordgrass, buttonwood trees, cattails, sawgrass, leather ferns, cabbage palms and others--quickly move back in after the exotics are removed. "Restoration happens naturally after clearing," says Loflin. Referring to the property now being cleared, he adds, "Give it six months and a rainy season, and you'll have savanna habitat."

The major beneficiaries of the habitat restoration effort are birds--not only the tanagers, orioles and other migrants that pass through Sanibel, but egrets, ibises, wood storks, herons and other resident wading birds. Less high-profile species benefit, too: bobcats, marsh rabbits, raccoons, indigo snakes and gopher tortoises.

"It's almost instant gratification when you take the pepper out. The wading birds come in, the frogs start breeding," says Brad Smith, a biologist with SCCF. "The diversity comes back so quickly."

In addition to restoring most of the 1,200 acres of land it owns on the island, SCCF has also worked to educate islanders about the threat posed by exotics and the urgency of removing these plants. Public support is crucial to Sanibel's effort, Smith and Loflin say, because exotics don't respect property boundaries.

To get homeowners in on the effort voluntarily, city officials offer to reimburse 20 percent of their costs of removing exotics, and will haul away the guilty plants for free. If residents fail to accept these "carrots," then officials wield a stick: a mandate to comply, with fines for those who don't.

"To most people who come here from the north, this is a foreign idea. They think they can grow whatever they want," says Paul Duval, a retired dentist who, with his wife, Marilyn, moved to Sanibel five years ago from Massachusetts. "But once they become educated about the problem with exotic plants, they support the city's program."

The Duvals have become eager foot soldiers in Sanibel's war against exotics--pulling up pepper plants, attending seminars on native flora, serving on the city's native plant commission. And they are reaping the benefits. "Every day is a wildlife surprise around here," says Paul Duval, laughing and pointing to a gopher tortoise burrow scraped in the sand near his house. "That's the motivation for clearing the pepper."

With the help of residents like the Duvals, Loflin is confident of ridding the island of the worst exotics by 2010. Part of Sanibel's key to success, he says, is cooperation. But part of it is luck, he adds: "We're fortunate we're on an island that's 11 miles long, so we have a finite area we're dealing with."

Later, Loflin stands on a bridge over a pond at a state botanical area. The site was overrun by pepper a few years ago, but is now a mÄlange of cattails, cabbage palms, cordgrass and dozens of other plants. On the path leading up to the bridge is a small clump of feces with fur in it: bobcat scat. The biologist watches a gallinule wade in the plants on the edge of the pond, pecking at them with its red beak.

"Is this satisfying work? Absolutely," he says. "Working on a degraded ecosystem and then getting it restored and seeing wildlife utilize it--that's extremely rewarding."

Senior Editor Mark Cheater happily agreed to travel to Lee County, Florida, last winter to report this story.

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