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Agencies join to protect NC climate change-endangered plant

In this July 26, 2019 photo, Louise Barton, a contracted botanist with Archbold Biological Station, looks over a data sheet as she works to find and measure geum radiatum, known more commonly as spreading avens, at Roan High Bluff at Roan Mountain State Park in Roan Mountain, Tenn.The federally and state endangered species is in such peril, botanists from the National Park Service, the U.S. Forest Service and the U.S. Fish and Wildlife Service have been teaming up for more than 15 years to survey and help protect spreading avens, known scientifically as Geum radiatum. (Angeli Wright/The Asheville Citizen-Times via AP)

ASHEVILLE, N.C. — Don’t be deceived by their delicate, buttercup-like petals.

Spreading avens are one tough piece of mother nature, growing out of cracks in the highest mountain cliffs in the Eastern United States, uniquely adapted to the rarified air and geology of the Southern Appalachians.

But although the pretty yellow flowers have weathered about 10,000 years of snow and ice, freezing rain and brutal winds, they are now some of the rarest plants on the planet, due in part to the overzealousness of curiosity-seeking humans, and the slowly choking tentacles of climate change.

The federally and state endangered species is in such peril, botanists from the National Park Service, the U.S. Forest Service and the U.S. Fish and Wildlife Service have been teaming up for more than 15 years to survey and help protect spreading avens, known scientifically as Geum radiatum.

The plant likes cool, humid, high-elevation sites to prevent further decline, as well as to keep another unique part of the Western North Carolina mountains intact.

In 2003, Blue Ridge Parkway botanist Chris Ulrey began working with U.S. Forest Service botanist-ecologist Gary Kauffman to search out the remaining populations of spreading avens and put in place a yearly monitoring survey.

Each July, the two team up with help from other agencies, including Eric Menges, associate research biologist with the Archbold Biological Station in Florida, botanist Rebekah Reid with the U.S. Fish and Wildlife Service, N.C. State Parks, members of the Botanical Gardens at Asheville and volunteers to check on the precious species that spreads across high elevations on National Park Service and national forest land in Western North Carolina.

“I initially wanted to look at sites that were not on National Park Service land to get a better feel for the range of habitats of that species. It’s helpful to see other populations, to put the ones we have in perspective,” Ulrey said.

“It turned into a collaboration where I was able to offer some climbing skills and it’s a way for all of to get together and share information in a field setting. Everyone looks forward to doing it.”

In late July, the team harnessed up to rappel down Roan High Bluff, a popular outcropping on Roan Mountain in Pisgah National Forest on the North Carolina-Tennessee border. The cliff is closed to the public, who come in hordes, especially in June, to view the vast expanse of eye-popping pink and purplish Catawba rhododendrons.

The spreading avens might “pale” in comparison — it takes a trained eye to spot a single flower sprouting out of a mountainside rock — but they are no less spectacular, ecologically speaking.

Spreading avens were first listed as endangered on the U.S. Fish and Wildlife’s Endangered Species List in 1990, said Reid, who is based in the agency’s Asheville office.

Their leaves can be as big as a human hand, bur their delicate flowers measure about an inch across, with three to five flowers to a stem.

At that time there were only 11 known populations of the flowers, with seven populations containing fewer than 50 plants. Thirty-one per cent of historically known Geum radiatum populations had been extirpated, or had gone extinct, she said.

The major reasons for the species’ decline were increase in recreational use, such as hiking and rock climbing, development, including ski slopes and forest succession, or the influx of woody plants, she said.

To remain on the endangered species list, there is a reevaluation of the species every five years to determine if the species continues to meet the definition of threatened or endangered. At the time of the last review in 2013, there were 15 known populations. The are only found in seven WNC counties, and two in Tennessee.

“The threats identified at the time of listing were still present, and the review notes accelerated global climate change as another likely threat,” Reid said, something not noted in 1990. “Recovery criteria had not been achieved, threats remained, and status of some populations were uncertain. The review determined that the species continued to meet the definition of endangered.”

“It’s almost exclusively found in WNC and Tennessee. It has only has 15 populations, most on federal and state lands, so it is protected in that way, but it lives in high-elevation rocky summits, on wet, rocky cliffs that are somewhat shaded,” Kauffman said. “So it’s protected, but it’s in a harsh environment in terms of climate and weather.”

At Roan Mountain’s summit, which sits at about 6,200 feet in elevation, even in summer it can be some 20 degrees colder than in Asheville, 4,000 feet lower, Kauffman said.

“The federally listed species, those are the rarest of the rare, so we should be tracking those to see what’s happening with them,” he said.

The group also tracks Blue Ridge goldenrod, a federally threatened plant, and Roan bluets and rock gnome lichen, both federally endangered, and found on Blue Ridge Parkway and Forest Service lands, but they focus annually on the spreading avens.

There are a few locations they conduct monitoring, including Devils Courthouse and Mount Mitchell. In July at Roan Mountain, Ulrey and parkway interns dangled off the cliffs, saying hello to plants they have come to know for 16 years, or saying good-bye to the fallen.

There are about 500 tagged avens in 15 sites, Ulrey said, about 90 per cent of the population. Each plant is given a number, and tagged with a round, 1-inch-diameter metal stamp placed in the soil next to the plant, or in places with very high winds, drilled and anchored into the rock.

“Each year we find that plant and take some measurements. It’s just like going to the doctor, looking for changes to tell us what’s going on with that population,” Ulrey said.

They look to see if the plants are flowering, if there are any seedlings, or if plants are no longer there.

“The goal is to get long-term data. With this species, there’s not a lot of change from one year to the next. But if there were an event like a landslide or trampling by visitors, if we didn’t do monitoring every year, we could possibly miss that event.”

The visitor trampling had been a big cause of decline, but since fencing was placed around the rock cliffs in the ’90s, that has become less of an issue. The concern now is with the long-term impacts of climate change, Ulrey said.

He co-authored a study about the avens, “Life at the top: Long-term demography, microclimatic refugia, and responses to climate change for a high-elevation southern Appalachian endemic plant,” along with Kauffman, Menges, Pedro F. Quintana-Ascencio and Adam B. Smith.

The study was published in 2015 in the journal Biological Conservation, and found that while the plant populations are currently stable, half of the habitats supporting spreading avens will be lost by 2050.

“This is given the most conservative, smallest amount of change in any of the climate models,” Ulrey said. “It’s definitely a species that is at risk now and probably will be in the future as well.”

The effects of the gradual warming of the Earth due to carbon emissions, sometimes known as greenhouse gases, has been front and centre lately with more extreme weather events such as Hurricane Dorian, record-high temperatures across the country, including Alaska, drought and wildfires in the West and sea-level rising along the coasts.

But the 2-degree Celsius global warming over the past 100 years might also be affecting the seemingly untouchable WNC mountaintops.

Spreading avens are believed to have been around since the last Ice Age, some 10,000 years ago, Ulrey said, and have adapted to the rocky outcrops that remain frozen throughout the winter.

The hypothesis is that with the Earth’s warming, the rocks are starting to warm up sooner than usual, then freeze again, going through multiple freeze-thaw cycles, causing rocks to crack, fall and dislodge the plants, Ulrey said.

Even though the plants are located in rare, isolated environments, that won’t necessarily protect them from climate change.

“These species already exist near their environmental limits and presumably will be greatly affected by changes in climate owing to the limited availability of habitat at higher elevations and difficulty in dispersing to newly favourable mountaintops,” according to the study.

Spreading avens also favour cool and moist environments, so if conditions become much drier than they are now, which is one expectation of climate change, “it can be problematic,” Ulrey said.

He said the monitoring will continue among the different agencies, since it creates a standard protocol for following the plants and leads to data that creates a basis for plant management.

For example, scientists have tried to boost populations by collecting seeds, raising them in a nursery and planting them. They found that a greenhouse in Asheville is too warm for these mountaintop plants, Ulrey said, so they are trying to set up a higher elevation nursery.

One of the best ways that people can help spreading avens, or any endangered plants, is to stay on marked trails.

“They deserve the status to be what they are. They’re the rarest of the rare, so we need to know what’s happening with them,” Kauffman said. “They’re part of the Southern Appalachian culture. It would be good to see our children in the future being able to see these species growing in the same type of habitat we have now.”

___

Information from: The Asheville Citizen-Times, http://www.citizen-times.com

Karen CháVez, Asheville Citizen-Times, The Associated Press






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