Native species can be a problem for people working to regenerate and maintain natural landscapes.

That was one surprising takeaway from an all-day program on “Native Plant Conservation in the 21st Century” sponsored by the Maine Audubon Society and the Native Plant Trust. (The Trust changed its name just last month from the New England Wild Flower Society).

“Our wild lands can’t regenerate because there is an over-browsing by deer,” Kristin Puryear, an ecologist with the Maine Natural Areas Program, said in an opening panel discussion for the event, held at Maine Audubon’s Gilsland Farm in Falmouth.

The deer population is larger than the land can support, so the deer eat every living plant material almost as soon as it comes out of the ground.

“We have removed many predators of deer, and by that I mean humans as well,” Arthur Haines added during the panel discussion. “Every ecosystem used to have apex predators.”

Haines is a Native Plant Trust employee and the author of “Flora Novae Angliae,” a massive book that describes all the plants found in New England.

He doesn’t support trophy hunting of bucks with big antlers, but hunting of both does and bucks to keep the population down.

Nancy Sferra, director of stewardship and ecological management for the Nature Conservancy in Maine, agrees that keeping the deer population in check would let native plant populations recover more quickly.

During a breakout seminar on conserving ecosystems through management, she said the Nature Conservancy allows hunting on its properties, and would like to allow people to harvest more than one deer per year – but doesn’t see that happening.

In one midcoast Nature Conservancy site, which abuts a land trust parcel where hunting is banned, the deer are smart enough to migrate to the land-trust property during hunting season, she said.

Deer aren’t the only natives she has to worry about.

Sferra said the Kennebunk Plains is threatened by two native plant species that would be invasive to the grassland that the Nature Conservancy maintains with controlled burns.

Kennebunk Plains has the largest population of northern blazing star, Liatris scariosa, in the world and the plant is rare and threatened in Maine. (Sferra said that’s her favorite native plant.) The Plains also is home to rare and endangered birds and animals, including having one of the two populations of black racer snakes in Maine.

If the Nature Conservancy did not do controlled burns – fires would occur naturally fairly regularly if people didn’t work so hard to prevent them – the area would be taken over by scrub oak, pitch pines and gray birches, all of which are native to the area but are not the natives needed to preserve the rare wildlife at Kennebunk Plains.

Haines outlined a couple of changes that people trying to conserve native ecosystems have made in their thinking.

“Our focus used to be to protect that spot where a rare plant used to grow,” he said. “We had believed that ecosystems are static. But succession happens. Climate change has things changing faster, but succession has always happened.”

So the goal shouldn’t necessarily be to protect a specific rare plant in the place it is now growing, but to make sure that the rare plant can find a wild place where it can thrive – and those places are going away.

“We live in an industrial society that sees our natural areas as places to be used,” Haines said.

Heather McCargo of the Wild Seed Project said what she believes is most important is protecting the Eastern deciduous forest, which doesn’t rebound after it is logged the way it once did.

The best way to assist it, she said, is by planting native plants, grown from seed.

In his keynote address, Jose Eduardo Meireles, assistant professor of plant evolution and systematics at the University of Maine and also director of the university’s herbarium, took a wider view of plant succession.

Plants evolve and move over time, and you can compare which plants have common ancestors. The example he used is the tulip tree, liriodendron. DNA analysis shows that the tulip tree native to the Eastern deciduous forest is closely related to a tulip tree in China, and they separated about 15 million years ago.

“We did a similar study for 60 different plant groups, and Eastern Asia is a hot spot for that (shared DNA),” he said. “Most of our diversity came from there.”

So as climate changes, plants will move to find the climate where they can thrive. So if we were able to come back to Maine in a few hundred years, we might not recognize what is growing here.

And it is impossible, at least for me, to think what things might be like in 15 million years.

 

Tom Atwell is a freelance writer gardening in Cape Elizabeth. He can be contacted at: [email protected]


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