UMass researchers mull preservation of native plants, in face of accelerating climate shifts

AMHERST – The umbrella magnolia is in full bloom outside Emily Dickinson’s house in Amherst. This stately tree, Magnolia tripetala, sits on the north side of the famous poet’s Homestead, resplendent with large pink and white blossoms.

Though long considered a more southerly tree, the umbrella magnolia has successfully acclimated to New England temperatures. It was previously thought to grow best in mid-Atlantic states, as far south as Florida and as far west as Oklahoma.

However, with warming temperatures due to climate change, the tree is now not only surviving in Massachusetts’ climate zones, but thriving and germinating.

This raises questions: Can native plants survive if moved — and should this be considered for the good of an ecosystem, given that global temperatures are on the rise?

UMass researchers Thomas Nuhfer and Bethany Bradley consider these questions in a recent paper, Balancing Risk and Resilience: Which Plant Traits Should Inform Managed Relocation Species Selection? Nuhfer and Bradley recognize a “growing tension” in climate change ecology on whether action or inaction is the best choice when it comes to moving native plants.

In their research, they developed a way to determine traits that point to successful “managed relocation” of native plant species. They see their work as a first step towards preservation of these plants.

“We’re at the precipice of a mass extinction, of all plants across the East Coast,” said Bradley. “If we do nothing, we do more harm.”

As they continue their work, the Trump administration is clawing back previous government support, including to the U.S. Geological Survey, which funded their study.

In 2023, the U.S. Department of Agriculture updated its Plant Hardiness Zone Map, resulting in about half of the country shifting to a warmer half-zone.

Pace of change

Bradley, a professor of environmental conservation at UMass had been studying the effect of invasive plants for the last 15 years, but in recent work pivoted to focus on the movement of native plants for restoration and adapting to climate change. She is a leading member of the Northeast chapter of the Regional Invasive Species and Climate Change Management Network (NE RISCC)

“We know that even in the last 10,000 years, since the last glaciation, all the plants we see across New England got here on their own,” she said. “And so given another 10,000, 20,000 years, it’s likely that those species could eventually get dispersed here and make it up here.”

Both Nuhfer and Bradley agree, though, we no longer have that kind of time.

Nuhfer, a Ph.D. candidate in the organismic and evolutionary biology program at UMass and the lead author on the paper, said the two are examining the broader picture of what “managed relocation” might look like. It is a case-by-case scenario for each plant species.

To consider any natural progression in the shift of plant locations, Nuhfer and Bradley look to what has already adapted.

“We’re more like what the middle of New Jersey, climate-wise, was like in the 20th century today,” Bradley said of Western Massachusetts. “Which means that all of our plants and animals in Massachusetts that are adapted to what Massachusetts climate used to be, are now experiencing what it was like in northern New Jersey.”

“And that’s only in the last 30 years that that change has happened,” she said.

By the end of this century, Bradley said Massachusetts’ climate will resemble North Carolina’s.

“There’s no way that those species are going to make it that distance on their own,” Bradley said of the pace of change.

For that reason, if humans don’t assist in a managed relocation of native plant species, both Nuhfer and Bradley foresee risk to entire ecosystems that depend on native plants.

“Plants are the foundation of ecological communities,” Nuhfer said. “That’s what we’re talking about. Insects often are specialized to native plant species, and then you need insects to have the birds and to have the little rodents. So you can’t necessarily send all those animals on their way without all the plants that they need to sustain them, which are very specialized.”

Considering what’s ‘native’

The term “native plant” can mean something different depending on who you talk to.

Angela Karlovich has been working at Gardeners in Hadley (formerly the Hadley Garden Center) for 24 years. Some customers come to the center only interested in plants native to Massachusetts. Others look for plants native to New England, while still others are shopping for those native to North America. “There is a range and we get it all,” said Karlovich.

Apryl Sabadosa of Triple Brook Farm in Southampton says their nursery focuses on a broader definition of “native,” as much of the business is mail order to clients all over the United States and overseas. Sabadosa said the nursery focuses on plants compatible to selected climate zones.

Karlovich said much of Hadley and pockets of Amherst were previously in zone 5, but now have bumped up to zone 6.

Sabadosa said that while Southampton used to be 5a/6b, it is now firmly in the 6b range. This slight change in overall temperatures signals a shift in ecosystems, prompting many to wonder what warming temperatures will mean for native plants, if they are left on their own.

Natural adaptation

Some experts are apprehensive about assisting in the migration of native plant species. Uli Lorimer, director of Native Plant Trust, the nation’s oldest plant conservation organization, is concerned that native plants should be “established well” if moved, since entire ecosystems depend on them.

Lorimer said he is often asked about choosing plants based on the changing climate models. He said answers need nuance and consider more than just the climate zone. As an example, he points to the similarities between Cape Cod and Long Island, which provides a similar eco-region plants could do well in.

“Looking to the south to be the solution for what might be coming to us, I think, skips over and discounts the ability of what’s here to adapt,” said Lorimer.

Consider the red oak. Instead of choosing a tree from Virginia, based on future climate models, Lorimer urges gardeners to look for plants that are already in New England and have the ability to adapt.

“We think we’re getting ahead of the game by bringing stuff in, but there’s a broad, very generalized understanding that things from the south are more heat tolerant and maybe more drought tolerant than things that are here,” he said. “I kind of question that assumption.”

Bradley at UMass agrees about working within zones and eco-regions, but believes there is more risk in not assisting plants in relocation.

“I mean climate change is happening, right?” said Bradley. “If a plant ends up no longer being able to survive under these new climate conditions, then you end up with loss of plant populations. You end up with kind of massive disturbances to ecosystems.”

Both Bradley and Lorimer believe that due to human interactions, plants like the umbrella magnolia have already shifted north and been successfully established. To them, that’s an example of what managed relocation can look like.

The point of the UMass research, said Nuhfer, is to help guide land managers and ecological professionals who are “already engaged in taking a landscape that’s degraded or damaged in some way, and trying to create new natural communities to restore ecological function.”