Invasive, Hurricane Irma-damaged pines to be yanked on Sanibel Causeway island

G’day mate. And, good-bye.

A small stand of exotic and invasive Australian pines will be cut down this week on a causeway island park between the south Fort Myers mainland and Sanibel Island.

A contractor for Lee County Parks & Recreation is removing 11 trees on Causeway Island B. That's the island that has restrooms, drinking fountains and Gulf-side picnic tables.

Portions of this island will be closed during the work. Weather permitting, the tree removal will be completed by Friday, Dec. 22.

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No lane closures or other impact is anticipated for motorists crossing the causeway.

Causeway Island A and its trees will be unaffected.

The Australian pines on Causeway Island B are between 20 feet to 40 feet tall. Some of them have been there for 40 years or more.

Park leaders say they have to go because, following Hurricane Irma and other storms, soil erosion and exposed roots made them unstable.

Trees are deemed hazardous when 75 percent or more of their root systems are exposed, said Betsy Clayton, county spokeswoman.

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The trees will be replaced with native species as part of a Sanibel Causeway Shoreline Stabilization project. That's in the design phase, with tree and vegetation installation more than a year away.

To be sure, the trees' removal won't render the island barren. There are  plenty of palms and other vegetation.

However, the Australian pines dominate the island's Gulf side and have framed countless photos of island sunsets.

And, to many it feels rotten to have to take down trees in a hyper-sunny region where shade is a prized commodity.

But Australian pines have proven to be a bad fit for Florida, said Cathy Olson, ecologist and Lee County conservation lands manager.

Australian pines are natives of the South Pacific islands, Australia and Southeast Asia.

There were a smattering of them in Florida in the late 1800s, then “in the 1900s, they started taking off and running,” Olson said.

Well, not literally running, she amended.

Without the pests and predators of their native homelands, however, the Australian pines grew like crazy.

Australian pines now can be found throughout South and Central Florida, the West Indies, Mexico, and elsewhere in tropical regions outside its native range.

In Florida, measured growth rates have ranged from 3 feet to 5 feet a year under adverse conditions to 10 feet a year when the trees were cultivated and given TLC.

They sprout in clusters and tend to grow super-close together.

A single 4- or 5-year-old tree can produce thousands of seeds that are borne by the wind to new sites.

Their shallow roots make them vulnerable to erosion and to toppling in high winds.

Ecologists' biggest beef with Australian pines in Florida is that they create a monoculture.

“The needles fall and become a dense mat, where nothing else can grow,” Olson said. “It disrupts entire ecosystems.”

Southwest Floridians' relationship with Australian pines is complicated, however.

Periwinkle Way, an arterial road on Sanibel Island, was lined with towering Australian pines before Hurricane Charley swept through in August 2004.

Charley toppled scores of the pines, which in turn brought down miles of powerlines and did millions of dollars in damage to city and private property across the island.

After Charley the city of Sanibel and some citizen volunteers made a concerted effort to replace Australian pines on the island's public lands with native species.

Still, some residents said the trees were pretty and added to the island's ambience. And, if some fall down during a hurricane, so be it. Other trees also can be toppled.

That's why Sanibel City Council  more than 10 years ago adopted an ordinance that said existing pines on private property could be retained.

The ordinance also says:

•Australian pines can't be planted or sold on the island;

•The city can remove Australian pines that threaten public infrastructure – power lines, lift stations, roads – in the event of a hurricane or other high-wind storm; and

•The city can remove Australian pines from city property.

Dick Muench, retired operator of family-owned Periwinkle Park Campground on Sanibel, calls removing the roadside pines "the best thing the city manager did."

Muench likes the native trees that were replanted in their place, noting "they're starting to make the canopy come back again."

He's no hater of Australian pines: Muench just thinks the taller ones are too risky to keep around.

There are Australian pines at the campground, "but we keep them pruned down to 20 feet or less, and with no large limbs."

And, should a storm compromise one of them, Muench said, "we'll take it out."

Australian pine facts

• Scientific names: Casuarina cunninghamiana, C. glauca, C. equisetifolia

• Other common names: Ironwood, beefwood, she oak, horsetail tree

• Origin: Australia, South Pacific islands, Southeast Asia

• Introduction: Several Casuarina species were introduced to South Florida in the late 19th century as windbreaks and for shade and lumber.

• Habitat: Beaches, pinelands, hammock and tree island communities in the Everglades, disturbed areas such as filled wetlands, road shoulders, cleared land and vacant lots.

•Law: Possession of Australian pine with the intent to sell or plant is illegal in Florida without a special permit.