AYESHA RASCOE, HOST:
Trees are one of nature's best weapons against global warming. They take in the carbon dioxide that would otherwise trap heat in the atmosphere and break the molecules apart. They use the carbon to grow branches, trunks, and roots. Generally speaking, the bigger and older the tree, the more carbon it's captured. That's the logic behind a Biden administration proposal to protect old-growth forests on federal land. Joining us now to explain is Meg Krawchuk, associate professor at the Oregon State University College of Forestry. Welcome to the program.
MEG KRAWCHUK: Hi. Good morning.
RASCOE: First, I want you to define what old growth is under this proposal.
KRAWCHUK: Yeah. This is part of a sequence of initiatives that have gone through a stage of definition making and inventory. So that definition piece came through last year. And the clear piece that comes out of that is there's no one-size-fits-all, sort of clear, easy definition when we're talking about old growth. But we start to think about old as anywhere between - oh, depending on where you are, it could be as low as 80 years old, but sometimes, it's up to 100, 200, even 300 years old - is when you start to get into sort of good, elite, high-quality old growth.
RASCOE: So last month, the U.S. Department of Agriculture said it was planning to add new restrictions on logging in old-growth forests. Can you explain, like, how this proposal would work?
KRAWCHUK: Yeah, this is a really exciting proposal. What we see in this language is no cutting of old trees and old forests. Well, there's some wiggle room there, but there's an encouragement for stewardship within old forest settings. That will likely include thinning and removal of some younger trees and dry forest settings. But we want to keep the old trees. We're not talking at all about removing big old trees.
RASCOE: Why do older trees store more carbon? And are they just storing more carbon, or are they actually capturing more carbon than younger trees each year?
KRAWCHUK: You've hit on exactly the right distinction there in terms of what's already sequestered, what's already there, versus what's being brought in annually. And there is, not surprisingly, a geography to that, as well, in terms of different species and how they grow.
In general, we think about young trees growing fast and putting on a lot of carbon, but old trees, by the nature of being old, are also still putting on substantial carbon. Some of them are slowing down, but you have to balance off that slowdown in association with what's already there in terms of that carbon pool in the live trees and the dead trees in that whole forest stand or forest ecosystem. So again, another thing that's really complex.
RASCOE: And so when it comes to what the federal government is doing, will these new restrictions make a difference in terms of climate change?
KRAWCHUK: So this is one piece of the puzzle that is clear and important in terms of the carbon perspective. I think it's also useful to think about the broader ecosystem services of old growth, not just their carbon contribution. In terms of biodiversity, I would say it's a carbon plus (laughter) in - when we're thinking about old growth.
RASCOE: So the timber industry has raised some concerns because, as they have said - that thinning out these old-growth forests is important because it helps prevent forest fires. Like, are their concerns legitimate, and are they addressed in this proposal?
KRAWCHUK: That is a very good question. In the drier forest systems where stewardship is going to be encouraged, I think there's a win-win between an ecological perspective and a timber perspective. Moister forest settings - we do not have agreement about when, where and why there might be removal from those forest stands, so that's where there needs to be an ongoing conversation about why the timber industry would think that there should be timber removed from those particular stands and those particular geographies. And there will be a disagreement with ecological rationale that's articulated in this plan.
RASCOE: So I know it takes a long time for the federal government to create regulations like this one. When are these rules likely to go into effect if they are finalized?
KRAWCHUK: Ah, well, some of that will depend on public opinion. But I see in the language here that the final environmental impact statement is expected for January of 2025, so that's a year out for that point. Depending on whether there are strong responses from the public or elements that take this into a court environment, things might be slowed down. So it's a little bit of a wait and see, to tell you the truth.
RASCOE: That's Meg Krawchuk, associate professor at the College of Forestry at Oregon State University. Thanks so much for coming on.
KRAWCHUK: You're very welcome. Thanks, Ayesha. Transcript provided by NPR, Copyright NPR.
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