When it comes to the growing threat of climate change, the shrinking rainforests of South America get a lot of attention. But one Boston area scientist says we should also be looking closer to home. WGBH Radio's environmental reporter Craig LeMoult spoke with WGBH’s Aaron Schachter about this new research on New England’s trees.This transcript has been edited for clarity.
Aaron Schachter: So what is the problem here? Are a lot of trees being cut down in New England?
Craig LeMoult: Well, that's what Bill Moomaw is worried about. He's an emeritus professor at Tufts University and he says the median age of trees in the northeast is about 75 years old. That’s largely because we have this history of clear cutting forests for agriculture in the northeast. And Moomaw says if you ask foresters when a tree is ready to be cut down, they'll tell you between 9 and 11 inches in diameter, which, for a lot of species, is around 75 years. But his concern is climate change. He says after about 75 years, trees go through a big growth spurt, which means they increase the amount of carbon they're taking out of the atmosphere and converting into wood. In this new paper in the journal "Frontiers in Forests and Global Change," he argues that if current management practices go forward, the world's forests will achieve only about a half of their potential for sequestration of carbon.
"Letting the trees that are about to really start absorbing a lot of carbon continue to grow and absorb that carbon is going to be not only the most effective thing we can do in the next 50 years," Moomaw said, "it is also the least cost thing we could do in the next 50 years."
Schachter: And so Craig, how do the folks who manage forests react to this kind of thing?
LeMoult: Well, I talked with Chris Egan, the executive director of the Massachusetts Forest Alliance, which is a trade association which represents forest land owners, foresters, timber harvesters, and forest product companies in the state. He said they're balancing a lot of things as they manage a forest. And for one thing, he said, cutting down trees can actually help the health of a forest.
“Trees compete for resources, so when a forester does a thinning, they come and remove some trees across a certain area that will actually speed up the growth of the remaining trees because they have more access now to sunlight," said Egan. "They have more access to soil, nutrients and water, and so forth.”
And he points out that we get everything from hardwood floors to magazines from all the forest products that are harvested here in Massachusetts. Of course, Bill Moomaw says the urgency of the climate crisis means that we need to prioritize that over any of the benefits we get from our current forestry practices and our timber here. Egan doesn't agree that the climate impact of cutting older trees is settled science. He says there's other studies that show other things.
Schachter: So this is an issue of competing priorities, obviously. What is the state's policy then on tree cutting?
LeMoult: Well, there's two different kinds of forests that the state is responsible for, first of all. There's about 650,000 acres of state conservation land that they're in charge of. And they also work with private landowners in a stewardship program to manage privately owned forests. In a statement, a spokesperson for the Department of Conservation and Recreation, which is responsible for this, said they're proud of the state's approach to reducing greenhouse gas emissions, which he called creative and aggressive. And he said the forestry projects the state's working on are done to promote the health of forests and the health of habitats and to increase the resilience of forests to climate change. Some activists have been raising alarms about some of the tree cutting practices in the state, especially in places like Wendell State Forest — that's in Miller's Falls, near the intersection of Massachusetts, Vermont and New Hampshire. They're worried about a plan to cut trees there. The DCR says that project is focused on replacing non-native tree species and increasing wildlife habitat.
Schachter: Is there a way, do you think, to really get at these competing interests? Obviously everyone says they're right.
LeMoult: I think it's tough. I think there's very different ways of looking at this issue, and that's what I found in my reporting. One thing that has been proposed that's really on one side of the issue is a bill that would prohibit timber on lands owned by the state or controlled by the state from being sold or removed or destroyed. That bill also says those properties can't be leased or sold or exchanged in any way, to any corporation, and it prohibits any building of pipelines or solar arrays or other energy resources on that land. But Chris Egan, of the Massachusetts Forest Alliance, is no fan of that bill. He says it would end the state's efforts to create habitats for rare and threatened species.
Schachter: And that's done by forest burning and thinning and things like that.
LeMoult: Right, and he says it would also end watershed work designed to protect water quality, and it'll be damaging, he said, to the state's rural economy, as well. Right now, that bill has been referred to the legislature's Environment, Natural Resources, and Agricultural committee. But right now, no hearing has been scheduled.