BOYNTON BEACH, Fla. (AP) — The slashing of a machete through underbrush — a distinct metallic ting as regular as a metronome — marked the battleground in South Florida’s fight against a tireless enemy whose only needs are sunshine and soil.
Deep in the last remaining intact portion of the northern Everglades workers hired under a new land management agreement hacked at an invasive fern that kills native swamp bay, wax myrtle and dahoon holly trees with a smothering blanket of lime green leaves.
“Welcome to the frontline,” said Rory Feeney, land resources bureau chief for the South Florida Water Management District during a tour of efforts to control invasive vegetation in the Arthur R. Marshall Loxahatchee National Wildlife Refuge.
The district has sole responsibility for exotic plant management in the 144,000-acre refuge west of Palm Beach County after it settled a dispute last year with the U.S. Fish and Wildlife Service. The two agencies were at odds over a 65-year relationship that required the federal government to control invasive species in Florida’s largest national wildlife refuge while leasing the land from the district.
A new 20-year lease puts the onus for invasive cleanup on the district, but the wildlife service agreed to pay at least $1.25 million annually to the district for the effort. If only $1.25 million is paid, the 20-year lease is reduced by one year. If $2 million or more is paid, the lease is increased by a year.
Feeney said the federal agency paid $2 million last year and dedicated another $2 million for the current budget year. The Florida Fish and Wildlife Conservation Commission chipped in $1 million, and the district has earmarked $2 million for lygodium removal.
The annual goal is $5 million per year for five years to beat down the refuge interloper.
“It was a matter of inconsistent funding for many years,” said Feeney, about how the lygodium got such a deep foothold in the refuge. “After five to six years it will be about maintenance.”
While lygodium collapses tree islands under its weighty canopy, the melaleuca kills the native flora that acts as the base for a food chain that supports dozens of threatened and endangered species including wood storks and snail kites. Graying tree trunks like whiskers on the mottled green and gold landscape mark areas where melaleuca treatment has been successful.
“It’s a bit cliché, but there really is only one Everglades. There is nothing else like it in the world,” said LeRoy Rodgers, the district’s lead invasive species biologist. “And what we are seeing with invasives is they don’t just replace a couple native species, they actually transform the ecosystem into something that is not the Everglades.”
Water managers estimate the refuge has experienced a 600 percent increase in lygodium in the past 20 years.
The flowerless fern was first detected in Martin County in 1965, going mostly unnoticed until something triggered a growth spurt in the 1990s. Once established, the native of Australia, Southeast Asia and Africa sends out underground shoots that can regrow an entire plant if not fully removed. It’s also a notorious breeder, unleashing spores into the air where they have spread the fern to Central Florida.
On Tuesday, more than 50 people in suspender-style waders and 20 pounds of herbicide in tanks on their backs crunched through toothy sawgrass and thorny greenbrier vines to chop with machetes at the lygodium. They are brought in by airboat, gliding over well-worn trails where churned-up sediment turns the water the color of Willy Wonka’s chocolate river. When water levels get to low for airboats in the northern part of the refuge, the operation makes a systematic march south.
But manpower isn’t the only tool the district is using to fight the fern.
About $750,000 was also approved this year to continue projects that raise colonies of insects to attack the fern, which is particularly dense in Everglades National Park, the refuge and the Kissimmee River region.
“This is the quintessential river of grass,” Rodgers said Tuesday, gesturing to yawning fields of wheat-colored sawgrass in the refuge. “If we just walked away, 75 percent of this would be melaleuca and Old World climbing fern.”
Information from: The Palm Beach (Fla.) Post, http://www.pbpost.com