A fond farewell to redbay trees and their buddies

February 5, 2009

This op-ed appeared Feb. 1 in the Orlando Sentinel.

By: Francis E. “Jack” Putz
Francis E. “Jack” Putz is a professor of botany at the University of Florida.

It seems as though every time you turn around, another environmentalist is whining about yet another threat to life as we know it. Some seem far-fetched, while others appear inconsequential. I admit to being a whining environmentalist. The threat about which I am most distraught is of the second sort — unavoidable but unlikely to have much impact.

Laurel wilt, a disease fatal to trees in the laurel family including avocado, is caused by an introduced Asian fungus that is transmitted by an introduced Asian ambrosia beetle. Other than the avocado growers in South Florida who will watch the demise of their $30 million per year industry and the estimated 60,000 homeowners with avocado trees growing in their yards, few of the 35 million people living in the path of this killer will be much affected. After all, not everyone can recognize redbay or even sassafras trees, our two natives in most jeopardy.

That said, butterfly fanciers will be saddened by the scarcity of now-common but soon-to-be-rare spicebush swallowtails. And bird watchers might note further declines in populations of cedar waxwings and other fruit-eating species.

Laurel wilt seems unstoppable. It might have been contained in 2002 when it was first detected near the Savannah harbor in Georgia, but authorities decided to wait for more research and not to act. Even if they had tried to contain the infestation, with each tree releasing thousands of fungus-packing females smaller than a pinhead, they might have failed.

I suspect that the avocado growers who now face the demise of their industry wish that they had screamed louder when first warned of the threat. But now this pathogen has fully emerged, and all we can do is sit back and watch the trees die. Researchers can even estimate when and where redbay and sassafras trees are going to die.

I hesitate to draw more attention to laurel wilt. With economies tanking and wars erupting, people already have enough to worry about. Other than a few homeowners who will have to pay to have big bay trees removed, the direct financial costs of this tree disease will be slight outside of South Florida. So why bother providing yet another reason for depression?

My best excuse for writing about laurel wilt is to encourage readers to take a last (or first) look at the redbay and sassafras trees in their environs. Butterfly fanciers might want to photograph the laurel-feeding swallowtails while they still have a chance. Unfortunately, for Jacksonville-area residents, their chance has passed. Folks in Orlando, Gainesville and Tallahassee had better get out there this year if they want a last look. And South Floridians might want to take this opportunity to see some tree islands in the Everglades before they unravel when their redbays die.

Laurel wilt will not be the last of these introduced scourges to follow in the wake of chestnut blight and Dutch elm disease. While hesitating to point fingers at cash-strapped but foot-dragging bureaucrats, I still hope a lesson will be learned from the laurel-wilt experience. When the next biota-threatening exotic emerges, perhaps the reaction will be swift, and there will be one fewer loss to mourn.