From climate change to polluted waters to pythons, there’s always something threatening the beauty and serenity of the Everglades ecosystem. The latest monster is a fungus, and it’s killing trees at a stunning pace.
“Laurel wilt is one of the most devastating tree diseases we’ve seen, it’s incredibly fast moving,” said Jason Smith, a University of Florida scientist who is studying the scourge. “It kills trees within a couple of weeks, and within three to four years, all the trees larger than three inches in diameter are dead in a forest."
NBC 6 went with Smith as he led a group of researchers from around the world on a field trip through the Big Cypress National Preserve. They went to see the impact of laurel wilt disease up close. It leaves its calling card everywhere: dead, brown, swamp bay trees.
“They’re a critical component of the ecosystem so their loss is significant,” says Smith, explaining that swamp bay trees are a crucial part of Everglades tree islands, which are vital habitats for deer, bobcats, and other animals.
A tiny, invasive bug from Asia, the ambrosia beetle, spreads the fungus that causes the sickness. One of the scientists peeled back bark from an infected tree and showed the other researchers the visual evidence of disease.
"The distortion here, the funny color, is from the fungus, that’s associated with these beetles, and that’s the fungus that kills the trees, that’s the fungus that doesn’t belong to this ecosystem, the trees don’t know what to do about it, they freak out, get this allergic reaction, and die,” said Jiri Hulcr, a University of Florida forest entomologist.
Laurel wilt is also affecting South Florida’s avocado industry. It has already killed 8,500 trees. That’s a $3.4 million impact. However, farmers can spray pesticides to control it. That can’t be done in wild areas.
“There’s so many trees that have been killed, the estimates are that throughout the southeast U.S. more than half a billion trees have been killed by this disease since 2002,” Smith said.
Laurel wilt showed up in the Everglades in 2011. Forest managers are trying to stop it, with controlled burns and bio controls to kill the beetles.
“But in reality it only really takes one beetle to kill the tree,” Smith explained, so curing the sickness by eliminating all the bugs is a tall order.
Scientists are studying the few trees that seem to survive the infestation, hoping they can find genetic resistance to the disease. If they do, they can use those trees to grow more that have the genetic defense, and replant them in the wild. However, that’s a long process. A cure is years away, and until one is found, laurel wilt will spread, staining the tree canopy with death.