Whittier regularly tests seed germination rates in order to evaluate their quality. That’s how he ended up with 1,200 Eastern hemlocks (Tsuga canadensis) in a greenhouse in Waynesville, North Carolina.
The hemlocks were healthy three-year-old seedlings. “They needed a home,” says Whittier.
Jason Rodrigue, silviculturist for the National Forests of North Carolina, had a solution: the Forest Service Genetic Resource Management Areas. These are areas of national forests set aside as seed orchards. They can also function as Restoration Seed Reserves.
The new seed orchards are located on the Beech Creek Genetic Resource Management Area in the Pisgah National Forest in North Carolina, and in the Chilhowee Genetic Resource Management Area in the Cherokee National Forest in Tennessee.
“Rodrigue was instrumental in getting these established,” says Whittier.
So in January, Camcore staff, nearly 20 Forest Service employees, and other partners planted 300 Eastern hemlock seedlings and 168 table mountain pine (Pinus pungens) seedlings in each orchard. “Those are the seedlings from the Camcore collection,” says Whittier. “The Forest Service planted an additional 500 trees.”
Robin Taylor is the seed orchard manager for both sites, and Drew McCarley is the technician for both sites. With support from Camcore, they will care for the seedlings, treating them for hemlock woolly adelgids and mowing around them.
Camcore and the Forest Service have worked closely for years. If all goes well, they will begin sharing seeds from the planted seedlings in a decade or so. Camcore will use seeds for its research and tree breeding projects. Managers in the National Forest System will use them for restoration or conservation projects. And Forest Service scientists will use the seeds in their research.
The seed orchards are a safe harbor for the genes of imperiled tree species like Eastern hemlock. Eastern hemlock was once a keystone species. In the past, an Eastern hemlock tree beside a cool mountain stream — shading the water and providing a home to birds, salamanders, and many other creatures — might have lived for 800 years or more. Now, hemlock woolly adelgids can kill them in as little as two years.
By the 1990s, the devastating potential of the hemlock woolly adelgid was becoming clear.
Foresters, scientists, and tree people from many organizations have coalesced around that recognition.
“Non-profits, States, non-governmental organizations, and many others have funded hemlock conservation projects – things like biological control for the hemlock woolly adelgid, seed production and collection, germination, embryogenesis, and genetics,” says Rusty Rhea. Rhea is an entomologist with the Forest Service Southern Region Forest Health Protection. He began working with Eastern hemlock and Carolina hemlock (Tsuga caroliniana) years ago.
In 2003, Rhea recognized that Carolina hemlock could become imperiled. He reached out to Camcore, a non-profit tree-breeding organization that since 1980 has been saving seeds of imperiled species around the globe. In 2003, they began saving seeds of Carolina hemlock, too. By 2005, they had started collecting seeds from Eastern hemlock. More recently, they’ve begun collecting seeds from:
- Table mountain pine (Pinus pungens),
- Atlantic white cedar (Chamaecyparis thyoides),
- Fraser fir (Abies fraseri),
- Red spruce (Picea rubens), and
- Several ash (Fraxinus) species
Each species on the list is in an unfortunate club: the most imperiled tree species of the South. Their membership in this group is backed by significant science. SRS scientists and partners have developed vulnerability assessment tools that consider the species’ sensitivity to and adaptive capacity for change.
Since 2003, Camcore has collected around 10 million seeds from imperiled tree species of the southeastern U.S., as Robert Jetton has estimated.
Those seeds represent the genetic variation of their species.
“We don’t want to lose hemlock the way we lost the American chestnut,” says Rhea. “We don’t have any seed collections for American chestnut. Most of its genetic and phenotypic variation has been lost.”
Camcore tracks seeds carefully so that information about the mother tree’s location – which represents the seed’s lineage – follows the seed wherever it goes.
To make sure that the seeds represent a local population, they’re usually collected from 10 to 20 trees that are 100 meters apart. “It’s not always possible,” says Whittier. “For example, the Tallulah Gorge site in Georgia only has five mature Carolina hemlocks, and four of these are right next to each other. But those are the southernmost population of the species, so it is important to collect from all of them.”
There are plenty of opportunities to collaborate in the future. For example, a seed orchard for Atlantic white cedar could be established on the Croatan National Forest, as Rodrigue suggested.
“We still have seedlings that need a home,” says Whittier. “We have Fraser fir and red spruce seed collections we could germinate. And we’d like to establish a Carolina hemlock seed orchard in western North Carolina.”
Some of the seed collection was funded by the Forest Service Southern Region.
For more information, email Andy Whittier at firstname.lastname@example.org.