New Growth

Now that 2020's historic fire season is over, the plants at Point Reyes National Seashore are in recovery mode. Jerimiah Oetting speaks with fire ecologists and botanists about what that recovery will look like in the coming months and years, and what we can learn from Indigenous practices of managing the landscape with fire.

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TRANSCRIPT:

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The Natural Laboratory: New Growth

JERIMIAH OETTING: Before we get started, I should mention, once again, that we're recording this podcast in early January 2021. Parts of the park are still closed due to the Woodward fire. There's still a ton you can do at Point Reyes National Seashore. Just be sure to check the park's website and social media to plan your trip. Thanks, and happy hiking.

[INTRO MUSIC]

Hey everybody, this is Jerimiah Oetting with Point Reyes National Seashore. This is the second episode of our new podcast The Natural Laboratory. And we're talking, once again, about wildfire.

Last summer was a crazy fire season in California. There were whole days where it felt like the sun didn't come up at all, the skies just turned this weird apocalyptic orange color. People had to evacuate their homes and many of those homes were destroyed. Through all that chaos, it can be really hard to remember that fire isn't all bad. For the ecosystems in Point Reyes National Seashore—and throughout most of California—fire has its benefits.

In the last episode, we learned about the Woodward Fire, which burned in the park last summer. We also explored how its more destructive predecessor, the Vision Fire, impacted the park 25 years ago.

As Dr. Alison Forrestel, the former Fire Ecologist at Point Reyes, says: even hot destructive fires, like the Vision Fire, can have a silver lining…at least, ecologically.

ALISON FORRESTEL: I want to push back on the idea that the Vision Fire was bad and the Woodward Fire is good. The Vision Fire…it was bad from a human perspective, absolutely, and, frankly, the Woodward Fire was traumatic for the community, too. But just from a purely ecological standpoint, the Vision Fire was just as ecologically beneficial as the Woodward Fire.

JRO: For humans, wildfires are a threat. But for many otherspecies, those same fires can be a vital force. In this episode of The Natural Laboratory, we say goodbye to a historic summer of fire, and look forward to new growth: the plants that will rise out of the ashes of 2020. We'll explore what we can learn from the Indigenous people who managed to coexist with fire for thousands of years, even using it in beneficial ways. And we take a look at what visitors to Point Reyes National Seashore can expect to see over the coming months and years: wildflowers, new growth, a recovering landscape. We all hope for better days ahead in 2021. And at Point Reyes, it's going to be a sight to see.

[MUSIC]

JRO: You're listening to The Natural Laboratory from Point Reyes National Seashore.

JRO: I'm Jerimiah Oetting.

AF: Fire ecology is super complicated,

JRO: Dr. Forrestel is now the Chief of Natural Resources at Golden Gate National Recreation Area. But she was the Fire Ecologist at Point Reyes for nearly a decade.

AF: Almost all of the vegetation in California is evolved to fire in some way. And, you know, in some places, it's species that can tolerate some degree of fire, and in other cases, the plant species actually depend on fire to, you know, persist. And even in Point Reyes that range exists.

JRO: After millenia of fires sweeping through the landscape, plants have adapted to it. They return quickly after a burn.

AF: Many many many species have the ability to resprout post-fire, so coast live oak and bay trees and coyote brush and, you know, probably most of the shrub species.

JRO: On the opposite end of the spectrum are Douglas fir trees, which aren't very tolerant of fire. The Woodward Fire burned primarily in Douglas fir forest.

AF: Those trees are pretty sensitive to fire and it doesn't take that much heat to penetrate the bark and kill the cambium layer and thereby kill the trees.

JRO: Dr. Forrestel says bishop pine are on the extreme end of being fire dependent. Their cones only open with the heat of a flame. And other species, like blueblossom ceanothus and some manzanita species, have a seed bank that's buried in soil. Those seeds require fire or smoke to sprout.

AF: So, those are, you know, the species that really truly cannot persist without fire. If fire is absent from the landscape for too long, eventually, they would blink out. And too long is a very long time, you know, more than a century probably.

And the flip side of it is then if fire were on the landscape too frequently, they wouldn't have time to build up the seed bank for the next generation. I think there's a risk of too frequent fire for those types of species.

JRO: These fire-loving species thrive after a burn. Dr. Forrestel published a study in 2011, showing that ceanothus and bishop pine exploded back onto the landscape after the Vision Fire. The species expanded onto habitat that was once coastal scrub. The extent of bishop pine nearly doubled. Before the Vision Fire, bishop pine forests were only found on ridge tops. After Vision, the bishop pine forest community extended down those ridges all the way to the coast

At some point, after reading so much about the fire that started on Mount Vision in the park, and pouring through all of the studies about the fire's impact on the park's natural resources, I decided I should head up there and take a look at it myself.

[gravel crunching underfoot]

JRO [outdoors]: This is it. The infamous Mount Vision.

JRO: There's a narrow, unmarked trail that leads from a small parking area near the summit of Mount Vision. Actually, it's really more of a hill. It's an easy walk, but I did explore some shrubby offshoot trails here and there.

[gravel crunching underfoot]

JRO [outdoors]: Yaaaaghhh!

JRO: There were a ton of crowded bishop pines up there. That's not surprising. Like Dr. Forrestel said, these trees depend on fire. When bishop pine forests burn, they burn completely. Then, they grow back into a crowded forest. Over time, the forest will self-thin as weaker trees die and those with better genetics—or the seeds that just happened to sprout in a better spot—grow to be more mature.

But what struck me wasn't just that it was so dense—it's that bishop pine just looks like a tree that would burn. The trees on Mount Vision looked especially rough. Most of the living trees were scraggly, but there were also a lot of standing dead trees. These trees weren't burned in the recent Woodward Fire, so I wondered if there was something else going on.

AF: The conditions you see on the landscape now are the result of two factors. One is that the bishop regenerated with extremely high-density following fire.

But then there's another layer on top of it of pine pitch canker, which is a fungal pathogen; it's not native to this region. It spread into the post-Vision Fire bishop pine forest, and it's really having a huge impact on those trees, so there's a lot of dead trees and fuels because of that pathogen.

JRO: Pine pitch canker is yet another curveball thrown into the mix. The fungus is known to infect the bark of certain trees, including bishop pine. It leaves behind lesions, called cankers, that ooze with pitch. It might just kill off some needles, making the tree look sickly. But eventually, with enough of those lesions, it will kill the entire tree.

Before the Vision Fire, the forest would have been a stand of mature bishop pine trees. So, the conditions on Mount Vision today are actually quite a bit different than they were 25 years ago.

Even this scraggly forest of sick trees would eventually self-thin, perhaps leaving behind more robust bishop pines. There's some promising research that shows some bishop pine can become more resistant to pine pitch canker as they mature. But in the meantime, the overcrowded trees make this immature stand of bishop pine volatile. With such a dense and combustible source of fuel, I wondered how the forest ever reaches maturity without burning up along the way.

But fires started by lightning are not that common along the coast, especially compared with the rest of California.

AF: So that lightning event that started the Woodward Fire was, like, exceedingly unusual. We don't really have lightning very often on the coast, except in the winter, rarely, but usually it would be during a wet rainstorm event where it wouldn't start a fire.

JRO: There was a study that showed the fire history in Point Reyes using fire scars on big old redwoods trees and Douglas fir trees. The scientists found that over the last three hundred years, there was an average of two to twelve fires per year.

That's a lot more fires than there are lightning storms. Which only leaves one explanation—the same reasons that a lot of fires start: humans.

AF: You know, when Native Americans were managing the lands of Point Reyes, when the Miwok were managing those lands, they would have been using fire very often. So, there would have been, you know, every year fires burning within parts of the coast.

JRO: The Indigenous people that inhabited the land at Point Reyes for thousands of years before European settlers—they had it figured out. They cleared away the understory so it was easier to hunt. They knew where to burn and how often to support harvests of important food sources, like acorns. And they used it to maintain other stands of plants, ones that weren't necessarily food but were useful.

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