WHATLEY – John Berryhill and Jesse Bellemare wade through a sea of ​​perennials, leaves and goldenrod flowers touching their hips, until their keen eyes spot three six-inch tree saplings barely visible in the thicket of grasses and blackberries.

Berryhill, director of the Smith College Botanical Garden, and Bellemare, an associate professor of biological sciences at Smith College, are thrilled that the small trees they transported from greenhouses on their Northampton campus to the Ada and Archibald MacLeish Field Station in Whately survived the Massachusetts winter.

The men begin removing the grasses and weeds that are overgrowing the delicate mountain magnolia, a species native to the southern Appalachians, and find that the seedlings have grown slightly, with the species’ characteristic double lobes at the base of the leaves still intact.

The three plants are the first steps in establishing a collection of mountain magnolias, known in the scientific world as Magnolia fraseri, in western Massachusetts, a climate similar to the trees’ native habitat in the higher elevations of the Appalachian Mountains in the states of Virginia, West Virginia and Kentucky.

This species and the seven other magnolia species native to North America are not currently a conservation concern, but there are warning signs that all is not well. In these Appalachian states, scientists’ data show that Magnolia fraseri trees that live higher up in the mountains, where it is much cooler than at the base of the mountain, are doing much better than trees lower down the mountain. Climate change could be shrinking their habitat.

The data show that Magnolia fraseri is highly climate sensitive, but the trees did not migrate upslope to cooler regions as scientists might have expected.

“This was the information we expected to find, which would provide an indication of the early stages of large-scale population collapse and fragmentation,” Berryhill said. “If that were to happen, some of the genetic diversity that benefits every species could be lost, especially in a changing climate.”

Berryhill and Bellemare want to protect the mountain magnolia before climate change makes the species even more endangered. But they must act now before the species goes extinct. But the magnolias do not survive the drying and freezing preservation methods normally used to document and preserve a plant. So the pair must grow a living collection of mountain magnolias in their own garden.

That’s where their work at Whately comes in. The conservation project, which will eventually become a large botanical garden for mountain magnolias, is part of the Global Conservation Consertia, a project to protect plant species that cannot survive traditional plant conservation methods. The Consertia organizes and maintains these networks of protected areas for magnolias, oaks, maples and eight other plant families.

Typically, researchers document a plant species by drying and freezing seeds of a species from different areas of the plant’s viable habitat and then storing them in a facility where they can conduct further research, reintroduce the species, or rescue genetic diversity lost due to species population decline. This method is called seed banking.

But magnolia seeds cannot survive this process. The best way to preserve the species and its current genetic diversity is to maintain a collection of living plants, or multiple collections, in case an extreme weather event wipes out one collection.

“This collaborative approach to managing hundreds of trees probably captures the genetic diversity of the species and also encodes enough redundancy so that if something happens at one of these sites, you would have a backup at one or two other sites,” Berryhill said.

Berryhill and Bellemare are responsible for collecting seeds from various populations of mountain magnolia, cataloging the origin of these seeds, growing most of the trees locally, and then shipping duplicates and seeds to other botanical gardens. Smith College also hosts one of these duplicate collections for oak trees.

“These efforts by these different consortia are aimed at creating well-documented collections where the populations of origin are known and where individuals can be traced,” Bellemare said. “This will adopt the model used for endangered species, where you trace lineage and pedigree in a way that has not always been practiced in botanical gardens.”

Bellemare and Berryhill chose to plant the mountain magnolia garden in Whately because the climate in western Massachusetts has many similarities to the high-elevation environment of the Appalachian Mountains. The trees’ survival over their first winter in New England confirmed their suspicions, but the biggest challenge for Berryhill’s team at Smith Botanic Gardens has been growing the young trees in the greenhouse.

“We have some annuals that are only about 6 inches tall and some biennials that are up to 12 inches or more. And it’s difficult to grow this plant as a small tree,” Berryhill said.

Nature conservation is the future of botanical gardens

The project represents a fundamental shift in the philosophy of species collection for botanical gardens. In the past, researchers collected a variety of plant species from different areas around the world and competed with other curators and scientists to create the most unique collection.

“These single individuals, this small handful of specimens, do not bring much benefit to the overall conservation status of the species because they do not represent that much genetic diversity,” Bellemare said.

The new model houses many trees of a single species. Instead of two mountain magnolias, two umbrella magnolias and two southern magnolias, the botanical garden being created in Whately will have only mountain magnolias, but two specimens will be from seeds found in northern Virginia, two will be from Georgia and two will be from Kentucky.

“If you want to preserve the wolf population, you shouldn’t keep a poodle, a dachshund, a beagle,” Berryhill said. “Things that actually have adaptations that were selected by human breeders to serve our interests and desires, and not the traits you would want in a genetically diverse wolf collection.”

Smith’s mountain magnolia botanical garden currently consists of three seedlings, and most of the trees and seeds the researchers have now come from Virginia and Georgia, so their collection doesn’t have much genetic diversity. To change that, Berryhill and Bellemare will travel to western Kentucky and western Virginia with two of Smith’s interns in mid-August to collect seeds for other populations of the mountain magnolia.

“We’re really excited to be able to meet the Smithies of today with this story because it’s really compelling. If I just walk them through the garden and tell them that’s a Perovskia or a Chrysanthemum, that’s beautiful, but it doesn’t spark curiosity. And this story sparks curiosity in a way that a simple walk through a garden doesn’t always do,” Berryhill said.

Emilee Klein can be reached at [email protected].