12/24/2019 11:11:00 AM Botanical garden working
to save Fraser Firs
PACIFIC, Mo. (AP) — It’s one of America’s most popular Christmas trees, grown by the millions at tree farms around the country and known for its scent, its long-lasting needles and branches that can support the heaviest ornaments.
But in its only natural range, in the southern Appalachian Mountains, the Fraser fir is endangered, having been decimated in some areas by a tiny invasive sapsucking insect, the balsam woolly adelgid.
Missouri Botanical Garden scientists, however, have been collecting and stockpiling seeds of wild Fraser firs and other threatened or endangered species to preserve them and provide opportunities for research, said Alanna Sanders, the garden’s living collections development coordinator, the St. Louis Post-Dispatch reports.
Sanders said the work is part of a broader effort “that could be critical for the survival” of such species. Researchers collect seeds from a large number of trees across multiple populations so that genetic material is preserved if a population disappears or could be used to reintroduce a species.
They’re either placed in a seed bank at Shaw Nature Reserve, operated by the Missouri Botanical Garden, along Interstate 44 near Pacific or grown to add to the garden’s “living collection.” But Frasers are difficult to grow in the St. Louis area. The garden’s records list their only Fraser as having died in the mid-1990s in the Cherbonnier English Woodland Garden.
After a scouting trip in June to find and map the trees, garden staffers in September visited the only population of the firs that has not sustained widespread damage, at Mount Rogers in Virginia, Sanders said. Five other populations are farther south, she said.
At one of those, in Great Smoky Mountains National Park, garden scientists say that 90% of mature Fraser firs have been killed by the balsam woolly adelgid, which looks like a white woolly spot.
On a miles-long trek to the summit of Mount Rogers, Sanders and others took detailed notes of the tree and its growing conditions before taking photos, and before Travis Hall, a certified arborist, climbed to the top of each tree to collect seeds from cones — the only place they grow, Sanders said.
More than 50 trees were sampled.
“It was tiring work for him,” she said.
Hall took a small amount of seeds, which are slightly larger than a pine nut, from a variety of cones. Sanders said the researchers are careful not to take more than 10% of seeds.
Researchers also collected seeds of other plants including the parasitic piratebush and the Carolina hemlock, another tree threatened by a different adelgid, Sanders said.
Once back at Shaw Nature Reserve, staffers let the seeds sit out, both so they can dry out and so hitchhikers — “little spiders and things that get taken along for the ride” — can make their escape, said Meg Engelhardt, seed bank manager.
Seeds from firs and other conifers need to stay at room temperature or below to allow the embryo to fully develop, as they would have the chance to do on the forest floor or still attached to the tree, she said.
The seeds need to be separated as much as possible from stems, needles and the pitch that gives the tree its characteristic scent.
“It smells like Christmas in the lab right now because we’re working on a bunch of different cones,” Engelhardt said.
Staffers inspect the outside of seeds for damage and cut open a small number to ensure there’s no damage from insects or fungus and that the embryos are fully developed before they’re popped in one of a series of chest freezers.
Engelhardt said the seeds can potentially be stored for decades, and made available for researchers or other institutions that are working to “support the survival of the species in the wild.”