Saving the Florida torreya
One goal, two schools of thought on preserving the rare, endangered tree
Bristol, Florida — The Florida torreya was one of the world’s most endangered trees even before Hurricane Michael savaged the remaining wild specimens along the Apalachicola River with 100-plus mph winds in October 2018.
It was also one of the most controversial trees, Exhibit A in a roiling debate over how, and where, to keep alive species facing extinction.
More than 650,000 torreyas once lined the ridgelines or hugged the ravines near the Apalachicola and Flint rivers. Today, maybe 500 stunted and sickly torreyas survive in the aptly named Torreya State Park, victims of a canker-causing fungus that knows no enemy.
“I hate to be pessimistic, but the bottom line is that they’re functionally extinct in the wild,” said Mark Ludlow, the park’s biologist. “They can’t reproduce. They could be gone in 50 years.”
Not if Dr. Emily Coffey has anything to do with it. She is vice president of conservation and research at the Atlanta Botanical Garden trying to save, along with the U.S. Fish and Wildlife Service (Service), the hapless torreya.
“The ultimate goal is to stabilize the population, and monitor it, to really prevent extinction in the wild,” said Coffey. “If we get the resources we really do believe we can save it. We can make things happen.”
Connie Barlow doubts torreya will survive in Florida in a warming climate. She’s the founder of Torreya Guardians dedicated to saving the tree by planting its seeds in the wild, particularly in cooler northern climes where torreya supposedly once thrived.
“It is still limited to a spot where it would’ve survived during the coldest time, 15,000-18,000 years ago, but it hasn’t found a way to move back north,” said Barlow, a science writer who founded the activist group 15 years ago. “If you put the seeds back in Torreya State Park they’ll just produce little saplings and die.”
Vivian Negron-Ortiz, a Fish and Wildlife botanist, says the Service has no official policy on the assisted migration of endangered species.
“We have to look at all alternatives to have the species in situ [in its original habitat] conserved and protected,” said Negron-Ortiz. “Assisted migration could be an alternative given climate change and if there are no other options. But we have to have a plan in place first. It will probably take a lot of resources and a suite of partners to save the torreya.”
“Hanging in there”
Torreya State Park’s topography is more east Tennessee than north Florida. It hugs the eastern flank of the Apalachicola River with steep bluffs affording a commanding view of pine forests stretching miles to the horizon. A handful of Confederate gun pits kept Northern invaders from penetrating upriver to Georgia. A historic home that once stood on a nearby bend in the Apalachicola sits lovingly preserved atop the bluff. The park was named for 19th century botanist John Torrey who declared the tree a new species.
The last Ice Age pushed glaciers south to Florida bringing along a variety of species, including Torreya taxifolia. As the glaciers retreated, the evergreen conifers remained in disjunct pockets scattered across the Panhandle and southwest Georgia. Where they once reached 50 feet high with a multitude of whorled and healthy limbs, the remaining trees look spindly and sickly, rarely growing tall.
Locals used torreya for roof shingles, fence posts, Christmas decorations and fuel for the steamboats that once plied the Apalachicola. Deer rubbed off the tree bark, exposing the underbelly to diseases. Disease and over-harvesting winnowed the numbers to 400,000 or so by the 1940s. It was listed as federally endangered in 1984. By then, though, it appeared as if the torreya was doomed. Hurricane Michael didn’t help matters.
Ludlow, the park biologist, scrambled over and under downed sycamores, black walnuts and yellow poplars in search of surviving torreya. It was a few weeks after the hurricane hit and the trails leading from Rock Bluff to the river were impassable. Wild boar tracks dotted the muddy bottomland. An alligator wallowed in the swamp along the Apalachicola. Leatherwood and needle palms all but obscured the few torreya planted around the ravine’s edge. A 22-footer — the park’s biggest — survived largely unscathed.
“They’re hanging in there,” Ludlow said. “They’re less exposed here than up on the ridge top. That’s where they got really hammered.”
Three-fourths of the tree canopy was savaged by the hurricane which maintained category four strength in the park 60 miles from the Gulf of Mexico. A handful of torreya outside the historic Gregory House were bent into 45-degree angles. But the tree cover that protected them from the blistering sun disappeared adding yet another threat.
Fusarium torreyae, though, is the greatest worry. Jason Smith, an associate professor at the University of Florida, discovered the fungus, most likely an invasive import from China, in 2010. The pathogen causes stem canker with blotchy, brown lesions signalling the tree’s demise. Stunted growth, and an inability to produce seeds, precedes death. At its current pace, Smith says, the torreya will be extinct in the wild in 50 years.
“Let’s give it a chance”
Coffey pushed open the moss-covered greenhouse door at the Atlanta Botanical Garden and ambled between rows of orchids in search of the elusive torreya.
“There are some of our babies,” she exclaimed, with pride, upon discovering dozens of potted specimens no taller than a hardcover book. The garden’s hothouses serve as the torreya’s research and propagation clearinghouse with more specimens in pots, cutting beds and in-ground plantings than exist in the state park. With a $20,000 assist from the Service, Coffey and nearly two-dozen botanical gardens and research institutions across the country preserve the torreya’s genotype and cultivate more than 400 genetically distinct plants.
They’re collaborating with researchers in Florida, including the university’s Smith, on conserving the plant in the wild and investigating possible treatments intended to make torreya resistant to the fungal disease. Seeds have been planted in the botanical garden’s Gainesville nursery and other north Georgia locations where varying doses of sunlight, fertilizer and fungicides have been applied. Some of the trees have produced male and female cones. Still, the torreya replanted in situ in Florida rarely produce seeds or grow beyond stump stage.
A half-dozen experimental torreya rise on the edge of the botanical garden’s property alongside the Piedmont Driving Club in Atlanta. They’ve been there for more than 20 years, descendants of the first batch of cuttings provided by Harvard University’s arboretum in 1989. They’re lovingly tended with fertilizer and lime, yet half of the trees display the cankerous, ulcerous wounds courtesy of the deadly Fusarium pathogen.
“In theory,” Coffey said, “they should all be fine. But, like everything else, sometimes disease kills one and not the other. Currently, there is no known treatment for the disease.”
Connie Barlow says she has a cure for torreya — move them far enough north to escape Fusarium and a steadily warming climate.
The torreya “is in deep trouble in its historic native range, so let’s give it a chance to establish in cooler realms,” Barlow wrote 15 years ago. Her thinking hasn’t changed. “‘Assisted migration’ may be the only stay against extinction.”
Scientists, including Service biologists in their last comprehensive review of the torreya’s condition and prospects, speculate that the tree’s historic range included North Carolina. Most, though, oppose “rewilding” torreya seeds beyond the tree’s current habitat.
“Look at all alternatives”
The Biltmore Estate in North Carolina, and other private entities with mature torreya, donate seeds to the Torreya Guardians who then pass them along to private landowners and botanical gardens across the country. Barrow and colleagues have planted hundreds of torreya seeds in North Carolina, Tennessee, Georgia, Ohio, Michigan and New Hampshire. Their trial-and-error “rewilding” approach has offered valuable insights into how best to grow torreya, they say. Seeds or cuttings planted in sunlight don’t grow well. Those under a canopy of limbs grow slowly, but surely (as they do in Florida), but may reach only a foot tall in five years.
“Climate change is starting to affect everything and other native trees are beginning to migrate north,” she said. “Why not give the same opportunity to torreya conifers?”
The Endangered Species Act doesn’t address assisted migration. Coffey, Negron-Ortiz and other biologists say it’s premature to artificially help the torreya migrate north. Atop their list of concerns: introducing an invasive pathogen into a new environment.
“It could be extremely dangerous for other conifers and hardwoods if it’s put in the southern Appalachians,” Coffey said. “The hemlocks and spruce are sick already. The scientific community is very against spreading disease. You can’t know the consequence until it’s too late.”
Coffey and colleagues surveyed 284 torreya at the state park during a February rescue mission. They “saved” 73 trees covered in hurricane debris. Coffey calculated that Michael killed slightly more than 10 percent of the park’s torreya. She seeks $50,000 in emergency aid from the Service to stabilize the imperiled species. Time, naturally, isn’t on her side.
“Our goal,” she said, “is to make sure it doesn’t end up in a botanical garden only.”
Dan Chapman, public affairs specialist
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