A Once and Future Forest
An Interview with Emily Burns of Save the Redwoods League
By David Loeb
This interview appears in the current Conifer issue of Fremontia magazine. We wish to thank our friends at Save the Redwoods League, who helped sponsor this special issue.
California is home to the largest trees in the world. And none are larger, or more iconic, than the two species of redwood—Sequoia sempervirens (coast redwood) and Sequoiadendron giganteum (giant sequoia)—that grow here and nowhere else (except a small sliver of Oregon). In many ways, the long battle to save these trees has also been iconic, an emblem of the state’s long and proud tradition of conservation.
And speaking of long and proud conservation traditions, last year, Save the Redwoods League celebrated its centennial as an organization dedicated to protecting, and educating the public about, the redwoods. To mark this milestone, the venerable San Francisco-based nonprofit published two important documents. The State of Redwoods Conservation Report is a comprehensive look at the status of these two species after 100 years of both intensive logging and dogged conservation. Then looking forward, Centennial Vision for Redwoods Conservation sets out both an inspiring long-term strategy and a set of ambitious medium-term goals for nurturing the redwood forests of the future. (Both publications are available for free download at savetheredwoods.org.)
One of the authors of these reports is Emily Burns, Director of Science for Save the Redwoods League from 2010 to 2019. In that role, Burns ensured that all the League’s conservation, stewardship, and advocacy programs are grounded in science. She directed the League’s Research Program, and in particular the Redwoods and Climate Change Initiative, the Redwood Genome Project, and the Vibrant Forests Plan. In May 2019, Burns left the League to become Program Director at the Sky Island Alliance in Tucscon. Burns sat down with Fremontia guest editor David Loeb on a rainy winter day to discuss the current state of redwood forests and her hopes for their future.
D: How did you first get interested in redwood trees?
E: I grew up in San Rafael under redwoods my parents had planted in the yard of their house. But my professional interest in redwoods started in the early 2000s, when I heard a lecture by Professor Todd Dawson at UC Berkeley about how redwood trees are able to absorb fog water directly into their leaves, and it blew my mind. I had just graduated from UC Davis with a degree in plant biology, but had never heard anything about this phenomenon that we call foliar uptake. And it made me realize that there is so much about these remarkable trees that we don’t know, so I decided to go to graduate school to study this particular phenomenon. I went to UC Berkeley to study with Todd and in my research learned that about 80% of the plants in the redwood forest can do foliar uptake.
D: Was this not known before you started studying it?
E: For species in the redwood forest, foliar uptake had only been documented in redwoods. I surveyed other trees and shrubs, herbaceous plants like redwood sorrel, ferns, and I found that it’s actually western sword fern that that does the most foliar uptake— absorbing about twice as much moisture as redwoods [per unit leaf area]. My research started focusing on the ferns, and I got to know Save the Redwoods League because it helped fund my research. When the job of science director at the League came open in 2010, it really spoke to me because, while I love basic research, I saw the importance of being able to apply research to decisions on the ground, to conservation.
D: Let’s start with a few questions about the League’s new State of the Redwoods report. What portion of California’s remaining redwood forest is old-growth?
E: We have 1.6 million acres of redwood forest in the state today, compared with 2.2 million acres before the Gold Rush, so we’ve lost about a quarter of the redwood forest overall, due to logging and conversion. Of the remaining forest, about 7%—113,000 acres—is considered old-growth.
D: What percentage of that old-growth forest is protected?
E: About 90,000 acres of old-growth forest is protected through a combination of public ownership, conservation easement, or nonprofit ownership with conservation intent.
D: Looking at all types of redwood forest, what percentage is protected?
E: Protected forest, meaning no logging or development allowed, covers 22%, or 345,000 acres. But there’s another 200,000 acres of what we would call partially protected, where some rights are restricted, with limited logging or development allowed. Conservation is a range, with many different flavors. But that 22% has the highest level of protection.
D: Going beyond protection, there’s the question of the health of the forest. What did you find in comparing the health of the redwood forest today versus the health of the forest 100 years ago.
E: Over the last century, there’s been a race between protecting land and very aggressive commercial logging and conversion. The redwood forest 100 years ago had many more contiguous patches of old-growth redwood forest, but at the same time, much less of the forest was protected. While we’ve had a blossoming of redwood parks, we’ve also seen the landscape of old-growth be largely reset into a very different type of forest, due to clear-cutting. Today we have islands of old growth surrounded by a sea of forests of different ages. The oldest second growth that we have was cut in the Gold Rush era, so it’s now about 170 years old. It’s actually rare to find this kind of mature second growth, and it has recovered many, but not all, of the important ecological traits of old growth—tree size, density of trees—and is beginning to resemble old growth.
These forests didn’t suffer from the same sort of aggressive logging that we had later, like in the 1960s, when tractor logging decimated redwood watersheds and scarred them with logging roads, and the sub sequent high-density restocking with Douglas-fir changed the forests by displacing the historically dominant redwoods.
D: Does a forest replanted in Douglas-fir have potential for recovery?
E: It does. The resilience is captured in the name, Sequoia sempervirens—always green, always living—the trees have this amazing ability to tolerate shady conditions. You can cut them down to the ground and they resprout. But where they have high density of Douglas- fir around them, they may not be able to proliferate without help, and they’re not going to become canopy dominant as easily.
D: Were there any findings from the report that particularly surprised you?
E: Yes, there were a couple. I was surprised that over half the redwood forest today is in the category of youngest, smallest stature forest. That just gives a sense of the scale of the restoration work ahead of us. These are forests that have lost their large old trees, they have lost their carbon storage, they’ve lost their wildlife habitat value. So they have dramatically changed.
And then for me, the other surprising piece was about the impact of the network of roads—both logging and residential roads—that have divided and carved up so much of the redwood forest. It’s not a contiguous 1.6 million acres of redwood forest. There are many hundreds of abandoned logging roads that have unstable sediment that threaten salmon-bearing streams. We calculate that more than a quarter of the redwood forest today—400,000 acres— is impacted by these roads.
D: So we can’t just say we have this much mature forest. The size of the patches matters.
E: Yes, even for what we think of as our best protected redwood areas, we have the “Redwood Highway” running through them. Of course these parks were created intentionally because they were easily accessible for visitors, and that’s still important today. We need roads and we need infrastructure to take care of the forest. We need people to go to and love the redwood forest, but roads do have a natural resource impact. We are trying to figure out which are the nonessential roads, which roads we don’t need any more and can remove.
Redwood forests that have been logged need to recover. They don’t all need restoration, which is an intentional intervention.
D: Another element in the report that was surprising to me was the claim that redwoods have the greatest capacity for storing carbon of any forest type, per acre.
E: That finding came from our Redwoods and Climate Change Initiative that started in 2009 and that established 16 one-hectare inventory plots scattered throughout the redwood region in collaboration with a team led by Stephen Sillett at Humboldt State. All of the aboveground biomass within these plots was inventoried and from that biomass, we can estimate the stored carbon, which was record-breaking at the northern end of the range. For example, at Jedediah Smith State Park, which is in the California temperate rainforest, we have more than 5,000 metric tons of biomass per hectare, which translates to about 1,000 tons of carbon per acre.
D: How do you determine the amount of carbon storage?
E: The team takes core samples and partitions the biomass to see how much is bark, how much is sapwood, how much is heartwood, and estimates carbon within each category. The heartwood is the most important reservoir of carbon. I consider it a carbon sink. Many forests are accused of losing carbon back to the atmosphere, but redwood heartwood is the best at holding on to carbon for many millennia, because it’s decay and pest resistant. Redwoods in older forests have had more time to accumulate heartwood, and the combination of the living and dead trees make up the totality of that biomass. Whereas a young forest is accumulating wood quickly, but the trees are so small, even though the rate of growth is fast, they don’t have many leaves and only a small growing surface to build wood. The ability of young redwoods to sequester and store carbon is just a fraction of what an old tree can do. The younger forests that are recovering will catch up, but it’s going to take generations to reaccumulate that biomass.
D: I read that growth in these old trees is surprisingly fast. That they don’t stop growing when they get old, like we do.
E: Oh right, the fastest growing redwood trees are old and large, unlike people, where we taper off and then start to shrink; that doesn’t happen in redwoods; they continue to grow. As a continuation of our research we’ve been looking at wood production rates in redwoods all over the state. It’s remarkable, old redwood trees are growing faster now than they ever have in their lifetimes, even during the drought that we just had. We’ve seen this growth surge, especially since the 1970s, which is pretty remarkable.
D: So do we know what the impact of climate change has been on the forest?
E: There’s a couple of ways to answer that. One is looking at these growth trends in coast redwoods. In old growth we’ve seen a distinct increase in wood production starting in the 1970s. Why is that? Lots of factors probably. As the climate has been warming, carbon dioxide levels have been going up, which simply provides trees more carbon to fix through photosynthesis. Interestingly, on the coast we’ve seen a reduction in summertime fog and cloudiness, as well as less particulate pollution and improvement in air quality as the timber industry stopped using teepee burners. We can’t say which one of those factors is better able to explain what we’re seeing, but the trees have had more sunlight and we see a very clear and distinct growth response. If redwood trees have enough water and light, their growth rates are unstoppable.
The other way we look at climate change impacts is to compare different redwood forests because they span a really large climate gradient along the coast, with twice as much rainfall up north as in the southern part of the range. It’s sort of a proxy for climate change because we can ask, how do redwood forests grow when they have only half the rainfall and warmer summers? We find more of the drought signal in forests in the south, that are typically dryer and warmer. It may be that these forests have experienced more frequent fire, and when they do burn, the trees have to invest in healing themselves, and this prevents them from having the kind of growth acceleration that you see when they’re uninjured and have lots of resources—like lots of water, lots of growing space. Fire frequency is definitely coupled with climate change, so I think that is one aspect of redwood forest ecology that we need to track closely in the future.
Of the remaining forest, about 7%—113,000 acres—is considered old-growth.
D: Okay, let’s move now to the Centennial Vision report, which lays out a pretty ambitious goal of creating the old-growth forests of the future, with a shifted emphasis from protection to restoration.
E: We realize that our protection work is not over; there is more forest to protect and there’s a need to create a more connected, larger redwood reserve system. But a lot of the remaining old growth has been protected, so the protection work is going to be happening hand-in-hand with restoration, and with long-term sustaining stewardship. And because most of the currently unprotected forests have been logged in the past, we are looking for the critical places where restoration is needed to put those forests on the best recovery trajectory.
This is where the terminology gets funny. Redwood forests that have been logged need to recover. They don’t all need restoration, which is an intentional intervention. I like to say that a doctor wants all of her patients to recover, but they don’t all need surgery. So when we think about the restoration vision, it really is about the broader sense of the recovery of redwood forests and we don’t want there to be just 113,000 acres of old growth. We want there to be at least 800,000 acres of old growth—many generations from now.
D: Can you explain the concept of old-growth forest structure, which is talked about in the Centennial Vision?
E: We can’t run the clock forward and make the trees grow old quickly. But what we can do is help them increase their growth potential to get large as quickly as possible. One of the elements of old-growth structure that we’re trying to recover in logged forests is greater space between trees—reducing the number of trees per acre. If you walk through an old-growth redwood forest you can see between these large columns of trees. There are still small trees in a healthy old-growth forest but most of the biomass is accumulated on individual large trees. A forest recovering naturally, if it was a young redwood forest, not a planted Douglas-fir forest, would self-select through natural competition among young redwood trees. Eventually, emergent redwoods would become the upper part of the canopy, occupy the space, and really build out their biomass over time. When we thin the forest and reduce the density in a young redwood forest, it creates space and additional light that stimulates a growth-release in the redwoods left behind.
In an old-growth forest, we see many elements of complexity that developed over centuries—open patches where more light is getting down to the forest floor; snags—dead standing trees—that are really important for wildlife habitat because birds build nests in the decaying trunks. And when these trunks fall to the ground they become nurse logs, habitat for many animals on the forest floor. So we’re really looking for those elements of big trees, widely spaced trees, standing dead snags, wood on the ground, because when those elements are present the biodiversity increases. We see many more types of understory herbaceous plants and shrubs coming in. One of the things that people don’t realize about the youngest redwood forests is that they’re so dense that little else can grow. They’re the darkest forests I’ve ever been in. The trees are all standing so close together, and they’re certainly not let- ting any light down to the forest floor. But when you get in an old-growth forest, it’s much more open, and it’s that light that fuels productivity and biodiversity.
D: So scientists, like you, have learned how to nudge the forest along—how to give it a hand. Is that an active area of work at this point?
E: Well, yes, we have our project called Redwoods Rising, in Redwood National and State Parks. When that for- est was clearcut, probably in the 1950s, they aerially re-seeded portions of it with Douglas-fir seeds from who knows where. National Geographic has photos of helicopter pilots in aviator glasses dumping out huge barrels of Douglas-fir—and redwood—seeds that were silver, because they were coated in rodenticide! Their goal was to reblanket the slopes, and they did. Now in collaboration with the parks we need to go in and figure out how to help the native coast red- woods reemerge and become dominant again. It does mean removing Douglas-firs—we’re talking about cutting trees here—taking those trees out to reduce the density and at the same time removing the old crumbling logging roads. There are 70,000 acres of logged redwood forest within that park complex that surround the largest patches of old-growth on the planet. So we have a really exciting opportunity to help connect those old-growth islands once again by repairing and recovering the forest that’s separating them.
D: This sounds like sort of a laboratory for the science of redwood forest recovery.
E: Yes, Redwoods Rising is symbolic of the League’s centennial restoration vision. We’ve sponsored research into the efficacy of these treatments in that geography and other places in the redwood forest range to understand what happens when you cut trees for restoration, what is effective, how much of the treatment to do, because we don’t want to remove any more trees than we need to. We’re thinking about how to reduce the fire risk in these heavily stocked forests and we’re thinking about how we can help create interim habitats for species that can only live in old growth.
We can’t run the clock forward and make the trees grow old quickly. But what we can do is help them increase their growth potential to get large as quickly as possible.
Of course, we’re going to need ongoing monitoring where we’re doing forest management and to ask our- selves if we’re seeing the outcomes that we expect. Have we reduced density? Are we increasing growth rates? Is redwood becoming dominant again? Are we protecting the native genetic diversity in these stands? Are we improving habitat quality? And did we stabilize sediment in these watersheds by doing the road removal?
What’s driving us today is not trying to return everything to what it was in the past, but rather to create a for- est that can be robust and vigorous despite the onslaught of future environmental changes. Research has shown that larger redwood trees that are spaced apart not only hold more carbon and are better for wildlife, they’re also less likely to burn and more likely to have greater resilience to fire. Luckily all of these goals align in trying to return old-growth characteristics to our forests.
D: Restoring this old-growth forest is going to require more than just recovering the trees. There are all these other organisms—from microbes to fungi to plants— that comprise an old-growth ecosystem. How will these come back? Are they latent, lying dormant in the forest?
E: That’s one thing we’re studying now: how readily native species can reoccupy recovering forests. I can give you a scientific answer, but I want to start with a personal one. In the Mill Creek watershed in Del Norte Redwoods State Park, which is one of the core areas for Redwoods Rising and one of our longest-running restoration projects, working with California State Parks. And it’s one of the largest salmon strong- holds in California, but it was almost entirely clearcut—some 25,000-acres prior to its acquisition into the park. I went out there with volunteers who were helping collect data; we were comparing which species grow on the forest floor of a logged area with one of the nearby patches of old growth that wasn’t cut, called the Hamilton Grove. I walked away from the volunteers while they were collecting and I was looking around and I noticed a frond of Polypodium scouleri— leather leaf fern—coming down out of the canopy; it’s one of those species that grows on big old redwoods. And it just made me realize, “Wow! Even in a very small patch of old growth the species are there!” That plant in particular, with its windblown spores, will be able to repopulate recovering forests, once we build the structure and help the smaller redwood trees get big and form platforms to hold epiphytes. So I think recovery is possible. If we find out that it isn’t, well, then my successors might have to think about doing transplants, or how else to repopulate.
D: What about all the components that make up the soil of old-growth ecosystems, the networks of mycelliae, etc.
E: Soil is such a frontier! We barely understand what species are growing below ground. But given that we still have redwoods in the logged forests, the ancient root systems are still alive underground, and they’re sprouting new trunks aboveground, so my hope is that the microbial communities are not decimated. They may be changed, but I hope they’ll also come back as the forests grows back as a whole. We would sure love to know more about that.
D: What role does fire—as a tool—play in this restoration vision?
E: Fire was much more frequent, certainly over the last 10,000 years at least, and we know that Indian tribes were burning in the redwood region, often to maintain meadows. And many of the characteristics we associate with old-growth forest are probably a result of that frequent burning. So fire is thought of as an important component of redwood forest ecology. How often a coast redwood forest needs to burn though, we don’t know. Unlike giant sequoias that need fire to release their seeds and for those seeds to get established on the ground, redwood reproduction isn’t dependent on fire. Fire helps create a lot of habitat structure, when it burns into a redwood trunk and creates hollows. That’s when the bats can go in, for instance. And those kinds of structures form from many frequent fires over time. And fire can be a way to reduce tree density, if smaller redwood trees, or trees of other species, are killed with relatively low intensity burning. Though trying to get the exact prescription of tree density removal through prescribed fire is nearly impossible. And there’s more fire risk to redwoods now with Sudden Oak Death. We’ve seen redwood trees being more vulnerable and actually dying during medium intensity fires, if there’s a lot of standing fuels associated with SOD mortality.
Fire management is always going to be unique to a place. In places where there’s no road access or where it wouldn’t be responsible to bring heavy equipment in to do mechanical thinning, fire could be a really good tool. There’s been a lot of discussion, and as we work more with local tribes, I think more and more we’ll be exploring fire as a tool, learning from their experience and history of using fire in the redwood forest.
D: What about logging—conservation logging—as a tool in restoration?
E: Well, to me, logging just means cutting trees. It depends on why it’s being done. So there’s a range of protection levels across the redwood forest range; there’s a range of need and perspectives as to how logging, and any revenue that could come from selling trees, fits into good forest management. Save the Redwoods League in particular is focused on ecological outcomes and wants to make sure that every prescription and any treatment that’s designed in a restoration program, is done with- out being driven by financial concerns. But for many private landowners, the question of how you fund a restoration project, or even a fuels reduction project, is a real one, and I’m aware that the commercial sale of some trees can enable good stewardship practices in the forest overall.
After we design our restoration prescription, if logs are commercial size, and we’ve deployed all the wood we need to meet our ecological goals, including leaving dead snags, building up the woody debris on the forest floor, putting logs back in to streams to help rebuild aquatic habitat—once these ecological needs are met, we do need to deal with the extra biomass, because it could be a fuels risk if it’s just left on the floor. If we’ve met all of our wood needs, and there are logs of a commercial size, then they can be sold to help offset the cost. But restoration, if it’s done correctly, is not a money maker! The cost of removing hundreds of miles of roads, doing tree planting, doing the fuels work, bringing in prescribed fire, and repairing streams that have been decimated is so costly that we’re willing, with the right checks and balances in place, to sell some restoration by-products. But it’s never going to pay for the whole process, though I wish it would!
D: Will the redwood forests at the southern end of the range be able to survive the stresses of a warming planet?
E: I do think those coast redwoods are going to be able to tolerate change, and maybe even thrive, in their native range. But the structure of those trees, the pace at which they grow—those are all subject to change as the environment around them evolves. Redwoods are so incredibly resilient—I look at tiny scraggly red- woods on the ridgetops along the Big Sur coast that burn all the time and they’re still there! And they’re setting seeds, they’re sprouting back, and they’re continuing to grow in a really harsh environment. But is that the kind of forest we think of at Muir Woods? Or up at Humboldt Redwoods State Park? No it’s not; but the redwoods really are the backbone of these forests. So where you have redwood forests now, I feel confident that they will persist, at least for the rest of my lifetime, and continue to provide refuge for other species. And that’s so important.
D: This Centennial Vision is such a massive undertaking: How will you mobilize the resources required? And what role can the public play?
E: Well, I think it requires a recommitment from the public and the private sector to protect and sustain our redwood forest. If I take Redwoods Rising as a discrete example. . . Since 1978, about 6,000 acres of forest restoration have happened within the Redwood National and State Park complex. By 2023, we’re going to do at least another 5,000. So we were going to nearly double, in the first five years of this project, what happened over the last four decades. And to do that, it’s being kickstarted with philanthropy, private individuals stepping up to invest in this recovery. And it’s also building this movement, building new human resources, training the next generation of restoration professionals. We’re bringing Humboldt State students into the parks, teaching them about restoration, building the workforce to do all this forest stewardship. And also inspiring the public with the vision of growing this forest back. It’s so iconic for California; it’s really a legacy project for all of California to be giving to future generations. At the same time we’re investing in clean water for communities on the North Coast, we’re building that global carbon reservoir, we’re growing and sustaining populations of endangered species, and creating a remarkable place for people to go and visit. Getting people out into the forest is actually the third part—the “Connect” part—of the League’s Centennial Vision, making redwood forests inviting and accessible to the people of California. The population is increasing, the diversity is increasing, and thinking about how to provide public access opportunities that both protect redwood forests and are welcoming to people who may see the forest really differently, means that we’ll be doing a lot of investment in interpretation and education and public access, to provide a world-class park experience and help people form that bond with the redwood forest.
D: Could cap-and-trade funds provide support for this work?
E: There are several pools of state funding that have grant programs, like the greenhouse gas reduction fund. Redwoods Rising is a great fit for that and we’re inviting several state agencies to make investments in the project. Redwoods Rising was included in Governor Brown’s budget last January. And the League, as it always has, is working to match with private money to help kickstart these efforts. So I think we’re beginning to turn the tide in getting more public resources going into our public lands. This is critical, because we’re not going to have the habitat needed for endangered species, or bring back those carbon storage reservoirs, if we wait. I think we’ve started a movement that will be successful long term, and we’ll see significant progress in the short term. Every decade, from here on out, we’ll be softening the edge between the old-growth islands and the sea of young forest around them. Every decade, we’ll be hiding old growth back into the landscape, as the forest develops around it. Ten years from now, after an old logging road is removed, people may not know where it was, and the salmon habitat will return in these watersheds. The trees won’t be incredibly tall, but they’ll be larger, they’ll be more spaced out, so I think we’ll be able to walk into these forests and see measurable differences.
D: You’ve climbed into the redwood canopy numerous times. What’s that like? And why would you ever want to come down?
E: Well, for one, the harness hurts when it’s on for a long time! For me, everything about seeing the top of the redwood forest is fascinating, but what strikes me the most is how different the colors are, like the colors of the redwood leaves, when you’re looking from the top down versus looking at them from underneath. They’re actually really different, illuminated by the sunlight. You think of the redwood forest as being so shady, but that’s just our perspective from down on the ground. Redwood forests get an incredible amount of sun. The trees are so remarkable because they’ve stood in the same location for centuries, withstanding all kinds of conditions—hail storms, lightning strikes, you name it, and so the fact that these trees are able to continue to thrive and grow faster now than they ever have, given that entire history through all the changes that California has seen, is pretty remarkable. You can’t help but feel that you’re perched in a being that is not only bigger than you are but certainly much more patient and adaptable. It is really humbling.
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David Loeb is a member of the CNPS Fremontia Editorial Board and served as the guest editor of the Conifer issue. He is the co-founder and publisher of Bay Nature magazine and retired as the publication’s executive director in 2017.