By JEANNE MALMGREN

© St. Petersburg Times, published September 26, 1999

Project: Eradicate Old world climbing fern Jim Goodwin lets the swamp buggy roll to a stop on a steamy September morning and turns off the engine. He looks around at the tea-brown water beneath and the green walls rising on all sides. Project: Biocontrol research Gary Buckingham's job is to be careful. Project: Eradicate Burma reed Burma reed is "public enemy No. 1 in Miami-Dade County," says Roger Hammer, a botanist with Natural Areas Management, a division of the county's park and recreation department. Say goodbye to these 11 plants The Florida Nurserymen and Growers Association has asked nursery owners to stop selling these plant species.

In this war the enemy is silent, and wearing green.

Always on the move, it creeps across borders, looking for new territory to conquer.

The defenders of Florida shoulder their weapons -- machetes and backpack sprayers and deadly bugs -- and blast away at the invader. But it keeps coming, its appetite unappeased.

This army of green has been called "biological pollution" or "botanical invaders."

Or, more bluntly: "weeds from hell."

Basically, they are plants that don't belong here, species native to someplace else, usually a tropical climate. Some are brought here intentionally, as a source of cattle fodder, for example, or a pretty new landscape shrub or, as in one sensationally misguided plan, to dry up the Everglades.

Others are stowaways, accidentally shipped into Florida along with imported goods or in ballast water released by ships just arrived from exotic ports.

The trouble starts when the imports run amok here, without the insects and diseases that keep them in check in their own areas. They reproduce like crazy and gobble up habitat with the zeal of Attila the Hun.

See related story: In with grazing, out with baaaad plants To fight exotic weeds, Florida is deploying sheep. The problem in the first test? Gators.

That threatens Florida's unique biodiversity, says Daniel Austin, director of environmental sciences at Florida Atlantic University and one of the first people to sound the alarm about invasive exotics, in the 1970s.

"These non-native plants are changing the composition of our wild lands, to the point that food and available space is disappearing for our native plants and animals," Austin says. "They're altering the way the landscape is put together."

About one-third of all plant species growing here are what scientists call non-indigenous pest plants. That's more than any other state except Hawaii.

"This is Florida," says U.S. Rep. E. Clay Shaw, R-Fort Lauderdale. "There's no shortage of noxious weeds."

Shaw, a second-generation nursery owner, has been a vocal enemy of exotic pest plants for years. In 1992 he was instrumental in getting the pesky melaleuca tree added to the Federal Noxious Weed List.

Most of us, though, aren't scientists or politicians. We're blissfully unaware of the silent invasion going on around us.

We see a lush wall of green by the roadside and we don't realize it's Brazilian pepper, an aggressive shrub that has claimed hundreds of thousands of acres in Central and South Florida. We admire a graceful stand of Australian pines at the beach, not knowing they disrupt dune formation and crowd out valuable shoreline plants such as mangroves.

Invasive flora now populate an estimated 1.5-million acres in Florida, ranging from isolated single trees to nightmare infestations of several thousand plants per acre. Removing them is costly; this year the Legislature voted to double its spending on the problem, to $30-million. Counties, regional water management districts and private land managers spend millions more.

More than 400 people statewide work full time on the problem, including Don Schmitz, a biologist with the Bureau of Invasive Plant Management, a division of the Department of Environmental Protection.

"This is an ecological train wreck we're trying to prevent," says Schmitz.

In 1984 Florida became the first state to have its own Exotic Pest Plant Council, an interagency group that monitors botanical invasions. Every two years the council updates its list of the worst offenders, ranking them as to aggressiveness.

The list, which now has 125 species, carries no legal power over whether a plant can be bought or sold. Still, it's not popular among nursery owners, who fear that the pest plant council will "blacklist" a plant that's a popular seller.

Water hyacinth, a floating aquatic plant, is one of the list's "most wanted." It's also one of the state's success stories. A pest that clogged nearly all of Florida's rivers in the 1960s, it now has been reduced to tolerable levels. Melaleuca, the "punk" tree imported from Australia to help dry up South Florida swamplands and which at the peak of its infestation covered almost half a million acres, now is under control in much of the Everglades.

Even as land managers celebrate those victories, other threats loom.

"It's not just Brazilian pepper and melaleuca and Australian pines anymore," says George Gann, a Miami botanist who is surveying exotic plant species in 10 South Florida counties. "The ... number of exotics is increasing."

Eradicating pest plants on public lands is one thing; convincing private property owners to join the war is another.

Anyone who has ever paused to listen to wind whispering in the branches of an Australian pine knows the irony of invasive species: Many are quite beautiful. We hate to think of ripping them out of our yards, even if they are pests on public lands.

Sooner or later, though, some will become illegal.

Although many local jurisdictions in Florida, including Hillsborough and Pinellas counties, already outlaw planting of a few tree species, several cities and counties have gone even farther. In 1997 Miami-Dade County passed a first-of-its-kind landscape ordinance that strengthened a previous ordinance on pest plant species. Any time a piece of property is developed or a house is renovated, all exotics must be cleared from the tract. Several species are illegal to sell, propagate or transport; 32 others cannot be planted near natural areas.

Palm Beach County decided that all property owners must remove Old World climbing fern, another "most wanted," by 2006. The city of Sanibel strictly regulates eight pest species, including Brazilian pepper, air potato, earleaf acacia and melaleuca. In 1997 Gainesville started a program to eliminate the invasive Chinese tallow tree from the city.

Many plants on the Exotic Pest Plant Council's list are available to homeowners because they're still sold in retail nurseries. This spring a groundbreaking agreement was reached between the council and Florida Nurserymen and Growers Association. The two groups collaborated on a list of 11 invasive species not of great economic value to the nursery industry. Florida Nurserymen officials will ask their member nurseries not to sell those 11. Land managers hailed this as a promising first step in slowing the spread of invasives in and out of private yards.

Will we ever win this war?

Schmitz, the DEP biologist, says he doubts it. The very nature of nature ensures a continuing flow of pest plants into the state.

But we're doing better than we were a few years ago, Schmitz adds.

"I'm optimistic that within 10 years we'll be able to reclaim thousands and thousands of acres which would have been doomed."

So the fight against botanical blight rages on, all over Florida. It's dirty, sweaty work, about as glamorous as weeding your yard and much more daunting, usually carried on in remote areas, far from the public eye.

- More information on exotic pest plants, and the full list of invasive species, can be found on the Web site of the Florida Exotic Pest Plant Council, at http://www.fleppc.org/.

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