Episode 58: Reconstructing Fire Histories

Episode 58 - Reconstructing Fire Histories

Introduction to In the Woods Podcast

Lauren Grand: From the Oregon State University's Extension Service, you are listening to In the Woods with the Forestry and Natural Resources Program. This podcast brings the forest to listeners by sharing the stories and voices of forest scientists, land managers, and enthusiastic members of the public. Each episode, we will bring you research and science-based information that aims to offer some insight into what we know and are still learning about forest science and management.

Stick around to discover a new topic related to forests on each episode.

Jacob: All right.

Meet the Guest: Micah Schmidt

Jacob: Welcome back to In The Woods Podcast, presented by the Forestry and Natural Resource Extension Program at Oregon State University. I'm Jacob Putney, extension agent in Baker and Grant Counties, and your host for today's episode. I'm very happy to be joined today by my extension colleague in northeast Oregon Micah Schmidt. Micah is the Northeast Region Fire Specialist, as well as an assistant professor of practice at Oregon State. He joined the Extension Fire Program earlier this year in January, bringing a wealth of knowledge and experience in forest management and fire ecology. Micah holds a master's in forest Management from Oregon State University, bachelor’s in environmental science and policy from Southern Oregon University.

Micah, it's really great to have you join us today.

Micah's Background and Current Work

Jacob: Why don't you tell us a little bit more about your background and some of the things you've been working on since you started as Northeast Fire Specialist.

Micha Schmidt: Yeah. Thanks Jake. Really happy to be in the podcast today. and, yeah, like Jake said, joined the Uh, program here in January and, uh. You know, before doing this, I kind of started my career off in forestry consulting for private landowner down southwest Oregon. And then eventually decided to get my master's at Oregon State University.

And during that time, was doing, you know, doing historical, fire research, which we'll talk a lot about today, and kind of reconstructing historical fire regimes, also, you know, uh, working on some, silviculture and silviculture related to fire work and my masters. So. Um, yeah, so since I've been here in January, I've been working on a variety of things.

Prescribed fires. Been a, you know, a big topic for me. We got a lot of landowners wanting to burn out here in northeast Oregon and trying to find ways to make that more accessible to folks. and, uh, liability's a big issue. So, trying to work around a lot of those hurdles. But I'll spend working on some projects to assess private lands, cross large landscapes, and try to get funding and the, you know, hands of landowners to do some fuel reduction work, all that, you know, good. fire prevention and fire preparedness work. I've had a ton of fire this year in eastern Oregon and a lot across my whole region. So that was a little bit of a welcome to extension type thing to have this, uh, you know, record setting fire season this year.

So, been doing a lot on the post-fire thing as well to try to figure out, you know, how do we restore these landscapes, recover and, and help people bounce back. you know, after their lands have been, uh, in a lot of cases really heavily impacted by fire. So. So that's, that's mostly what I've been working on, but there's always new stuff to come and lots of exciting stuff for, next year on board, so, yeah.

Jacob: I know, I can't believe you've already. Been here for 10 months has come by so quickly. I mean, we've already done a number of programs too. It seems like we've had a very busy year.

Micha Schmidt: Yeah, no, it's been really fun, and you know, having, having you to help me kind of get settled in here has been really great. So, we've got a, got a good team out here in the Northeast to work with.

Jacob: Yeah, definitely.

Understanding Historical Fire Regimes

Jacob: So today we're gonna be talking about how we can examine tree rings to give us some insight into the past and reconstruct how forest looked and functioned, including their interaction with fire. Mike has a ton of history and background on this, so I'm excited to dive into this today.

But, to get us started, why don't we talk a little bit more about some of the terms that folks might have heard before. So, let's start with what is a historical fire regime?

Micha Schmidt: Yeah, so virtually just touch on the historical part because that word's used in a whole lot of, different ways in the natural resources world. So, when I'm talking about historical and historical fire regimes, talking about the historical period, as in prior to Euro-American settlement in the Pacific Northwest.

So, we're generally talking prior to, 1850s to 19 hundreds. So, you know, settlement and the suppression of fire started generally in that timeframe and other areas, you know, a little bit more in the early 19 hundreds. but uh, yeah, talking about that period before Euro-Americans kind of started coming in and really altering the environment and the, uh, the fire regimes.

And the word fire regime, also has a lot of, you know, a lot of different uses. But, basically, he's it to describe, you know, how fire would have burned, historically in that period, you know, back when lightning and indigenous people were like, you know, igniting fires.

So, with the historical fire regime, we're generally looking at the frequency. So how often did fire burn 'em on a particular site? How many years in between each fire, the severity? Um, so how many trees were killed and how, how heavy were the impacts on the site? so we general talk high severity fires kill most of the trees in the stand, whereas low severity fires may kill a few trees, but generally aren't gonna kill that many of them.

And those are also related to soil impacts impact on other understory vegetation. But those are a little bit harder to get at with the tree ring work we're gonna talk about today. Um, also looking at seasonality. So, what time of the year did fires burned? and so, you know, spring burning was used in, in some cases oftentimes for grassland and oak burning and such.

But, uh, the majority of our fire in Oregon generally were, you know, in the fall or late summer when fuels were dry and ready to burn. So, seasonality is another part of that fire regime. And then the spatial extent, how large areas did fires burn? And other one's really hard to get at, but we can kind of gain some inferences from some of the work we do.

But it's really nice to have those things there because those can kind of, characterize historical fire regime, we can use that to compare to like what's happened currently. Are fires the same size? Are they happening more frequent, less frequent? [Are] they happening, you know, different times of the year in the wood historically?

And that can, you know, help us inform how to manage our vegetation because a lot of the vegetation, across Oregon is adapted to different types of fire regimes. So, if we change how fires are burning and when they're burning, that can have a lot of implications for how plants grow and how we as a society interact with fire.

Jacob: So, along those same lines then, what is historical range of variation? That's a term we hear a lot, or HRV.

Micha Schmidt: And that can be a loaded term. of course, forest Service uses that a lot, and, and definitions kind of vary, but generally we're looking at, in that historical period, so prior to the 1850s, 1900, the, you know, the range of forest conditions that would've ex existed on the landscape. And so that can be, you know, both within a stand.

So it can be, you know, what were generally the dominant trees, in say a Ponderosa pine forest, versus the mixed conifer forest. It can also be, you know, how was the landscape separated into different vegetation and different age classes. So maybe, you know, 25% of the landscape was old growth Ponderosa pine forest in this area of interest. Maybe 30% was, you know, young mixed conifer, forest or lodgepole, but basically gives you, you know, a whole range of, you know, what existed there and, what stages of development: were they in young, middle age, old? What species were there? All that kind of stuff. And it can be really variable depending on, you know, which natural resources professional is using this term, forest service has some specific ways they use it versus how we use it in the research world. But, uh, but yeah, generally that range of forest conditions and the diversity that existed on the landscape historically.

Tree Rings and Fire History

Jacob: So, kind of given those two terms, I mean, how can we look into the past and kind of get a sense of what, these are by examining things like tree rings.

Micha Schmidt: We are super lucky in the forest line world that we have trees to record things over time. In shrub and grassland ecosystems there's often, you know, not that luxury. So, uh, trees, you know, record an annual ring each year. They have early wood, which basically develops some in the early part of the growing season, so spring, early summer.

And that transitions to a darker wood color, generally it's called the late wood. And that happens in the late summer fall as it's growing season's kind of coming to an end. Um, but these, rings are strongly correlated to climate. So, we can look back and say, you know, in general, larger growth rings, corresponded with a year with a better growing season.

So, more rain, maybe some cooler temperatures on each side of the growing season. Um, but anything that, you know, contributes to trees growing, whereas real thin, skinny rings um, not as much tree growth would be in those harsher drought years or maybe years where you had colder conditions on each end.

Trees didn’t, start growing as fast, but, since these rings are strongly correlated to climate, we can compare rings across different trees and, and over time we can actually, you know designate the actual growing year of each ring on a sample we get, in the vast majority of cases.

And so, tree rings also, you know, a scar due to injury, mechanical damage, cross cracks, or fire. and since we're able to precisely date each ring and put, again, you know, attach a a year to each growth ring on a tree, we can also date these injuries. And we have some I guess indicators will tell you what those may be was actually fire that damaged this, was it a frost crack, was it mechanical damage or injury? And I'll get into that a little bit later. But, basically since we have this record, and in some cases going back thousands of years, if you look in the case of, you know, redwoods or, you know, some of the old Bristol cone pine and such, but for most of our trees in Oregon, we're looking generally in spans of a few hundred years to, you know, around a thousand.

So given that, uh. we can precisely date those, we have this whole record over time, and it gives us, you know, some instances when some fire events or other injuries and stuff, did occur.

Field Sampling Techniques

Jacob: So, if you're interested in a particular area or particular forest type, you know, what is the general process for determining where and what to sample?

Micha Schmidt: That can be a challenge 'cause there is so much diversity across our landscape, especially over here in eastern Oregon. Lots of different vegetation types and such, and lots of different fire regimes within our ecosystems. So, you know, I'd first say it kind of depends on the research objective.

Historically, you know, when, when fire history, research was first starting, someone may have said, I just wanna go out and figure out what's the fire regime of this particular vegetation type or this particular place that's important to me for some reason. So, you had a lot of, fire history happening in a ponderous of pine forest where we can visually see the cat-faces of scars and such. Commonly now, you know, we, we tend to wanna sample across a gradient of forest conditions. Um, you know, to kind of gain inferences on, you know, how fire regimes changed over different vegetation types and different sites, different elevations, precipitation, all that kind of stuff. And so, you know, in some of the recent studies I've been a part of, we've said we're gonna take this landscape where we know there's a bunch of different forest types and we're gonna put a grid of, you know, 16 to 20 sites on there, and we're gonna ensure those grids line up with, you know, a range of forest types so that we can say, at these low elevations where we have this type of forest, you know, maybe they burn more frequently or they have lower severity fire, whereas we move up to a different elevation, maybe there's a different fire regime there. That's kind of how we figure it out. But uh, you know, really again, comes back to research objectives. But, within those research areas, you know, one thing that we found to be the most effective way to reconstruct historical fire regimes is, you know, we need some tree rings to collect.

And tree cores don't really show you, you know, fire scars in a reliable way. You don't always capture the scar when you're coring a tree. And often, you know, you can't tell exactly what year a fire burned. So, we go to old clear cuts where, across the 19 hundreds they were clear cutting like crazy across all of Oregon. So we go to those areas that have, old clear cuts that are also hopefully adjacent to an unmanaged forest that would've been similar to that that stand before it was cut. And so we go to those old stumps that were cut, decades ago.

And a lot of times, especially in Ponderosa pine, but also in other species like Doug Fir, that wood's still intact because, you know, when fire burned, it stimulated a pitch response to the tree. Actually, the resins started flowing in the tree, and that resin hardened and basically, retained the structural integrity of the wood.

So, then we go in and, and we actually, you know, cut samples from those old stumps so that way we don't go out actually cutting down any old growth trees. You know, I wouldn't wanna do that. So, we use that, and we get those and then we, uh, compare that to the current forest and the unmanaged area so we can kind of make some inferences like.

Okay, the historical fire regime was this, this is what kind of fires we caught, and this is what this unmanaged area, the area's never been logged looks like. So, we can kind of say that fire regime, you know, um, probably led to some forest conditions similar to that, of that unmanaged adjacent area.

Jacob: Okay. And so, you manage, you mentioned, um, you know, old clear cuts and um, you mentioned cat-faces as well. Is those kind of the key things you're looking for when you're kind of looking for a stump to sample or a particular area to sample? Is there any other key things you look for when choosing a study site or a sample tree?

Micha Schmidt: Yeah, we, you know, we definitely want to have, have some older stumps, 'cause if we, if we do just have young trees that were cut that, maybe that regenerated after fire expressions, say in the early 19 hundreds, and they cut 'em 60 years later. That really doesn't help us recreate that historical range of variations.

So, in general, you know, larger trees are older, although that is really variable across the landscape. [You] can have small trees that just grew really slow, so we try to look for larger stumps while also, you know, trying to sample some of the smaller ones in there, but depending on, what forest type and species you're looking at, it can be a lot easier or harder.

So, we really like trees with visual cat faces or scars. So, if those cat faces are there, which is basically, you know, at the, at the base of a stump or tree, you'll often see a cavity and often it's blackened from char from actual fires. You can actually even count the fire scars, from the, the outside of the tree there.

So, if we see that, we'll definitely cut into that if we know there's fire scars there. But say you're, you know, in a, in a forest with, you know, maybe it's Doug Fir or spruce or something like that, they don't usually have as many visually available cat faces. So there we just have to kind of go through, look for the stumps that probably have intact wood, which can be challenging, 'cause sometimes, you know, like a Doug fir, stump can have six inches of moss on top of it and you cut into it and it's actually a solid wood, believe it or not, inside there. For those we end up just cutting a ton of stumps open hoping we get lucky. And so, we, you know, we might cut 30 or 40 stumps open outta sight and take 15 or 20 samples from, from just the best trees there.

I don't know how to explain it, but people I worked with kind of feel the same way. You tend to kind of get a feel for where the fire scars are and then you end up, you know, losing that feel as you move somewhere else and such. I often kinda look for, you know, deformities, you know, on the tree.

Maybe there's a, a canker or something else that may have been formed by an injury or a scar or something like that too. But but when it really comes down to it, you just end up cutting up a bunch of stumps within your site and you have a, you know, a radius around that site that you're allowed to cut in.

So, we're not cutting too large of an area where we can't actually make inferences about that historical fire regime. But yeah, you cut a bunch of 'em open, and you get lucky enough times and then, uh, and then you probably end up going back to that site later after you've processed all the samples to kind of fill in the gaps that you may have missed.

Jacob: Yeah. And well, it sounds like, uh, ponderosa pine with the cat face would be like the, uh, best case scenario are, are some species easier to work with than others?

Micha Schmidt: Yeah, you, you hit it with the, the ponderosa pine. They are super easy and there's cat faces all over the place in dry forest. So, it's really fun. And sometimes, you know, like we'll find 25 scars or so on the same tree. I think the record something up in British Columbia, Ponderosa Pine had like 56 fire scars or something like that.

So, a ton on one tree. Some other pines like lodgepole can, can be okay for this if you're in a lodgepole forest that had a lower severity fire regime to where some lodge pine of that bloom and bust cycle where they, you know, destroys all the trees. So, there goes all your evidence, but, um, uh, in lodgepole pine that had more frequent fire, they can be okay for scarring.

Douglas fir is actually more reliable than you'd think. You know, even on the west side with that huge thick bark, we'll find a lot of scars in there. But definitely not as reliable as Ponderosa pine. And there's actually been, you know, a study done, I think it was in Arizona, where they had actual record of where and when fires burned over the last a hundred years or so.

And they went out and, you know, reconstructed the fire regime using ponderosa pine scars as well. And those lined up really well. So, it was kind of giving credit to the methodology that the scars were reflecting what the fires burned. Douglas Fir and other species has not really been a study done like that.

So, we don't know, you know, how many of the fires we're catching, but, you know, if you sample enough trees, you hope that you get, you know, at least most of 'em. And, and, you know, open, keep the door open to there being more fire than you found. But, uh, yeah, Douglas Fir is pretty good. Um, other trees like grand fir, white fir, some of the cedars and such can be challenging 'cause when they scar or get injured, they tend to rock from that scar in.

And so, you know, if you ever are out cutting cedars or you know, true firs and such, you'll notice there's a lot of, a lot of rot in the middle. That was the same thing, you know, back when fires were, were burning more frequently. And so those we try to avoid if possible. They also have a bunch of growth distortions 'cause they tend to, you know, buttress out and have a bunch of different growth, growth patterns.

So those ones are not as, not as great. So, Ponderosa Pine Douglas fir to a lesser extent western large and, lodge pole are, are generally what we try to try to get after.

Jacob: Mm-hmm.

Processing and Analyzing Samples

Jacob: So, let's say you go out and you collect a bunch of samples, you know, what's, do you bring these back to a lab? And how do you process them in order to get, get these data?

Micha Schmidt: Yeah, so the, the processing is, you know, really labor intensive and it's one reason why. You know, these, these fire history studies been going on for some decades now. Um, but we still have a lot of areas where we haven't done these. And it's because it costs so much to do all this work. There's a ton of work after you actually drive all the way to the site, collect the samples.

When we take a cross section, so you know, a piece of stump, with the tree ring sample out from the field, oftentimes they're falling apart, you know, and they're like, where there's fire scars, they might break there because there's a little break in the ring and such. So, we kind of, we wrap those up in plastic wrap and bring 'em back to the lab.

And so, the first thing is we gotta maintain the sample integrity by like having the sample number and the other data that we collect. You know, the location, the species, all that kind of stuff. Um, but we also gotta make sure these samples are gonna stay together and we actually start sanding and processing 'em.

So, we'll take either, um, caulk or uh, or wood glue and we'll glue the samples together. The ones that are. Semi sound, you can just glue 'em to themselves. Other ones, we actually glue 'em down to a piece of OSB plywood, so we can make sure, you know, as we're processing 'em, pieces aren't going flying everywhere, which they still do on some rotten samples.

But then we, uh, you know, we used to just take belt sander and start belt sanding away. And, uh, getting them flat because a nice flat surface is really important for cross dating under the microscope. But now, towards the end of my time, in the treating lab at OSU, uh, we had a, a jointer and a planer.

So, samples that were intact enough, we'd send 'em through the jointer and planer, get 'em flat, and then we just use an orbital sander and sand 'em down to a really fine grit. Often all the way down to 400 grits, you could really see those rings on the microscope.

And so, after we sand them, that's when we take 'em into the tree ring lab. And if you, if you do this a lot, you can often visually cross treat these samples. And if the rings are big enough, you don't need a microscope. If they are too small you do need a microscope and you can actually look at the patterns of, you know, drought years and good growing years over time.

And it's really consistent for trees that are growing nearby each other. And, uh, so we cross state those, and then we measure every single ring on e every single sample, into the computer using this, big accu gauge microscope, measuring deal. It's a really cool piece of equipment.

Um, and so we measure all those. So, gosh, I couldn't even tell you how many thousand rings each of us, you know, in the work treatment lab measured. But once we get those measured in, then we'll actually, you know, visually identify the scars, determine if they're fire or maybe mechanical injury or something else and put those into a database.

And, uh, once we have all those samples, that's when we'll actually start doing the analysis and start describing the, you know, historical fire regimes.

Jacob: So, a little sidebar. I don't know if I ever told you this, but I spent a summer right before I started my master's program, um, collecting tree cores from a watershed study site, uh, on the west side and fifth acre plots, and I cored every single tree. Then hauled across that watershed and then went back and mounted and sanded each one of them.

And man, talk about cores falling apart and just sanding and sanding and sanding and sanding to get 'em smooth enough. And then there was a lot of alder too, which is just so hard to try to date. Uh, 'cause the rings are, are different than some of our conifer species. But yeah, it was, it was fun. But man, that was a lot of work.

Micha Schmidt: No kidding. It's really, really, eye opening when you actually see what goes into some of this type of,

work [laughter'.

Jacob: Oh, and after all that, just trying to count all those rings too, and then just having no idea what I was doing when it comes to dating 'em.

Micha Schmidt: it could be a crazy maker, that's for sure.

Jacob: So, so you mentioned looking at some of the different widths, um, of the rings and stuff to, to, you know, kind of cross state them. How else can you kind of key in on, you know, if you really don't know, um, when this tree was cut or it's, you're not getting kind of, the consistency on the rings to be able to date 'em, you know, what are some other kind of ways that you can try to figure out when exactly this ring was or this fire scar at this particular time?

Micha Schmidt: So, the, the vast majority of, samples we take from stumps, the outer ring is not intact like you mentioned. that's because, you know, they've been sitting there for decades and, you know, oftentimes it's interesting, like for Pine, they tend to rot back to the outer scar because that's where the last pitch response was.

So, you lose, you know, anywhere from a, a few rings from when it was cut to, you know, decades worth. And some of our samples, the outer ring ends up being a few hundred years ago. You know, 'cause we lost all that wood. Or it's a, it's a dead tree that just standing for a long time, you know what we, , do, so if you're in a new area and you don't have a database of like, cross stated samples that you can compare your rings to, we always try to take at least a few tree cores and in, in many studies, you know, this fire history stuff also coincides with kind of reconstructing that historical range of variations. So, you're also coring living old trees and seeing what's out there now. Um, but uh, with tree cores, you know, you, you know, the outer rings. You know, when you, when you cross date 'em, as long as they don't fall apart on you, you don't know where the outer ring is anymore.

So, what you do is you, take those ones. You cross date a bunch of those, or basically just count the rings back from that beginning, maybe you cored it in 2020, so you know that outer ring is 2020 and you try to get some old trees so you can start creating a record going back several hundred years.

So. And, you gotta do a bunch of these tree cores because, you know, especially where there are fire scars or bad growing years sometimes rings kind of disappear and maybe where you cored, you actually didn't see a couple of rings. So, you take a bunch of these, and you start getting confident that you have like a good database of measured ring width.

And, uh, um, we have this really cool statistical software called COPECHA, and it was developed back in the seventies or eighties, you know, a long time ago, and we still use it. It actually takes all those ring measurements, um, that you counted in or measured in. And then, uh, it compares 'em and does a bunch of fancy statistical stuff.

It's way over my head and it basically tells you how correlated those are. You know, if you start off with the, the wrong outer ring on every core, you're not gonna be on the right there, but you know, as long as you do your due diligence, know you're outer ring and such, COPECHA will take all this information and it'll start creating, you know, a record.

And that record is, you know, kind of correlated to climate over time. And so even if every tree didn't respond to climate the same way, you know, in each individual year to like the dry or wet years, good or bad growing seasons, um, it'll start kinda averaging those and normalizing those so that it can have a record that you can compare trees that are similar, rings that are similar but not quite the same.

And so, once you have that whole database, uh, developed, you can use that and measuring your rings from, say, a cross section where you don't know the outer ring, and then COPECHA will give you all of these recommendations for, you know, its this much correlated to this timeframe. And it generally goes in like 50-year segments.

So, it'll say, you know, this 50-year segment is highly correlated to 1850 to 1900, and so be it. And then, uh, using that, as well as just like a, you know, a knowledge of cross dating and a knowledge of, you know, tree-ring science and such, we can basically narrow it down, narrow it down until we feel really confident that we actually have the right rings.

And sometimes this can take a long time. You know, most samples we can do pretty quickly, but there's times when, you know, we've had several of us sit for days, you know, on one single sample and just throw it aside. Bring it out another time, throw it aside, bring it out another time. And the more samples you get,

the more you keep building that database and the more the COPECHA software can tell you, you know, this is probably what you're looking at. So, it's a little, it, it can be challenging. There's still samples out there we haven't cross-dated, but we're able to cross date well over 90% of the samples using, you know, both visual and then COPECHA to help us kinda, rebuild that uh, tree ring network.

Jacob: No, that's super cool. And like you said, I imagine, you know, the more and more data you could collect, you can start to get some really accurate estimates for, you know, a pretty broad region.

Micha Schmidt: Yeah, definitely. And, and they use this, you know, tree-ring stuff going way back in time. They'll take, you know, ancient civilizations and such and they'll take like the wood posts and they'll actually cross state those posts and then combine it maybe with carbon dating other stuff. And so, they can use it to, you know, reconstruct when people were in different places if you have records going back. It's also been used in New Zealand they had a tree they found in a bog, and it actually, I don't know what the evidence looked like, but it had evidence of the last, uh, magnetic pole shift in the tree rings of that tree, because it was,

it was So ancient.

So, it's, it's really amazing what you can do with that stuff.

Jacob: Yeah. No kidding.

Micha Schmidt: Mm-hmm.

Interesting Findings and Future Goals

Jacob: So, um, from the research you've been involved with, what would you say is the, uh, most interesting thing you've found?

Micha Schmidt: There's so many interesting things, but I, I think for me, just like the amount and the frequency of fire is the most interesting thing across all of Oregon, and so like, I've always been a strong believer fire touches, you know, all of our vegetation historically, you know, impact all of our vegetation types in one way or another.

It looked really different across the state and across different sites and, uh of course you have areas that didn't, didn't burn when surrounding areas burned as much, but you know, almost everywhere we've looked, been kind of surprised at how frequent the fire is. Um, even, you know, looking at the Western cascades where, in the coast range where, you know, conventional knowledge tells you it was all standard replacing high severity fire.

Like what, say what we saw on the 2020, during Labor Day fires, you know, the, the story's a lot, um, a lot more nuanced. You know, those big fires were part of it. There are also a lot more load, a mixed severity fire throughout the, the development of those stands and each different type of fire kind of leads to, you know, different outcomes and different development of the stands.

So, I always think as a core of, um, my, uh, mentorship and sub-culture in my career it's like stands can take so many different developmental pathways and such. And fire just mediates those pathways and changes 'em and come out with like lots of really unique, conditions across the landscape, even in sites that are really similar otherwise.

And so, I just think, you know, seeing how much of a role Fire played and communicating that to people and seeing people's eyes light up when they say, wow, this burned that frequently, or this did that, and we can use that to inform our management. I think that's some of the most interesting and fun stuff for me.

Jacob: Yeah, definitely. So. You know, you collect a bunch of samples from, from live trees and from these dead trees in an area. , you start to look at, you know, what that fire return interval might have been and try to get some sense of like the extent and the severity and the seasonality and the things you mentioned, , earlier.

But, you know, how do you take that next step to try to see what the kind of historical structure and composition of the forest might've been?

Micha Schmidt: So, um, so with that, you know, that's generally where tree cores and, uh, you know, some type of research inventory plots come in and. And those generally play a role, you know, in, in those unmanaged, um, areas adjacent to where we collect our, our tree ring samples that I mentioned earlier. So, what we'll do there, is you'll go into a plot and, uh, you know, similar, similar to what you were saying you were doing with coring a bunch of trees.

You'll go in, core all the trees in an area and, uh, we will cross date those and you'll start to get a sense for, you know, how old different trees are and what the, you know, species and age composition was. And then you can actually look at the tree rings and say, okay. These trees, um, that we cored established prior to what we'd say American settlement or fire suppression era.

So, say, you know, this many trees, um, established in the 15 hundreds versus the 17 hundreds, you know, and, and so you can actually talk about, you know, what, what trees and species were there before fire expression happened. And that is definitely true of the large trees and such. You can imagine though, over the course of a hundred or 150 years of fire suppression, some of those smaller trees may have fallen over decomposed, especially in the, you know, in the moisture forest.

So, you don't get the, you know, the full complete picture. But it's, uh, the best we have. And it you know, it, puts together a pretty complete picture by saying, okay, in this area, you know, nowadays after this area's been clear cut and hasn't had fire, it's like an even age Doug fir forest. But historically it had, you know, 500-year-old ponderosa pine

then it had 200-year-old Douglas fir in the, um, you know, in the mid story but, uh, um, you know what I mean? But, uh, you can start to say, you know, which species and which trees were here, um, historically based on when the tree ring said. Then you can often look and say somewhere, something we see on the east side is, uh, grand fir and or white fir, you know, um, you'll see a bunch of those in a stand, but you start tree coring 'em, and, and even if they're big trees, they're often pretty young, you know, relative to, all the older trees.

So they can be, you know, anywhere from 80 to 120 years old or so. And, and that tells you that those trees basically established after fire suppression. And the, you know, the thought is that it's likely that if fire kept burning those trees would not have survived. 'Cause they're, you know, fire intolerant, they don't like fire that much and stuff.

So, um, as we do that, if you do enough plots across the landscape, you can take your broad forest types that we talk about, moist mixed conifer, dry mixed conifer, ponderosa pine and Doug fir, whatever it may be. And you can start rebuilding the range of conditions that occurred in each one of those types as long as you have enough plots.

So, and that kind of gets that, you know, same with the fire history, when we want to do that across a gradient. Because, you know, um, especially on our national forest lands, you know, they, um, they manage across all those different vegetation types in most cases, and even private landowners, they may not have all of 'em on their property, but across whole private land, you know, matrix, all those vegetation, um, types tend to exist except maybe some of the alpine ones in some cases.

But, uh, that kinda helps you, helps you get at that. We can also look at the, increment growth on those, cores. And so, like how much it was growing each year. And that can give you an idea of like historical basal area, historical density. So, you can say, you know, um, there was about this much density at this point in time.

And then as it got older, it went to this density. And that can kind of help inform our, our current management and, you know, what density we might wanna manage for if restoring the historical forest is an objective for a given cycle.

Jacob: No, that's really interesting. I'm always fascinated by, you know, what these forests look like long prior to when we, when we got here, um. And I know you're still involved with some of this research. Um, you know, what would you say are some of the future goals or some of the next steps for this work Is?

Micha Schmidt: So, um, now that I'm in extension role, I don't do quite as much research, but I am still involved, like you said, so still some of my colleagues are working on, you know, um, continuing to reconstruct the fire regimes and historical forests, composition and structure in the moist forest of the Western Cascades and coast rains.

So, um, I'm not quite as much involved in that, but I know there's, you know, a ton of questions since conventional knowledge told us those were long unburned systems that eventually burned down at, at a high severity. So, uh, I know they're, um, trying to reconstruct that because there's a big interest in our society across all forest types, how do we continue to develop, protect old growth forests and acknowledging, you know, a lot of our old forests stay in the dry side, are in pretty rough condition and may not have, you know, a lot of life in some of those old trees. Um, you know, because they've been overcrowded and dense for so long, we wanna figure out, you know, what kind of fire regime develop these type of old growth forests so we, we know how to emulate those with silviculture.

And, uh, you know, acknowledging we're never gonna emulate those historical fire regimes across the whole landscape. We're never gonna, you know, restore historical forest conditions everywhere. Again, it can be a guide and uh, we can acknowledge that, you know, even if we can't have fire, like a lot of our, you know, ecosystems, evolved with say if it's a frequent low severity fire regime, you know, they evolved with a frequent low severity disturbance regime. So, we can emulate that with our silviculture um, and our other things. So, say, you know, maybe we come in here more frequently, disturb it a little bit more often. And it'll, you know, maybe we can get some of those benefits of the historical fire regime.

Um, but I, I think my goal now is just to make this information as practically useful as possible in an extension role. Most, almost all of this work is only presented in an academic context and research, publications, webinars, and such like that. Um, so I'm hoping to, you know, make it a little bit more real.

And, uh, I really like going out field tours and showing people those cat faces on the Ponderosa pine and say, hey, look, this area is super dense with Doug fir grand for now, but historically it was a ponderosa pine forest and look at all these scars. So, I kind of view that as my role now, how to make this practically useful to both landowners, the general public and, and land managers.

Um, so that even if we can't restore those historical fire regimes, we can use it to, you know, kind of help guide our management in a, a more ecologically, sensitive way.

Jacob: Yeah, I think that would be incredibly useful. I mean, there's been a lot of fascinating work that's been done in some of the results. Um, I mean, they surprise me every time I see a new publication come out about 'em. Um, and, you know, I, we really scratched the surface that there's so much more we could talk about too.

Especially some of those interesting results. But, um, unfortunately we're gonna be nearing the end here today, but I don't wanna miss anything important. So, do you have any parting thoughts on some of the tree ring research and reconstructing these fire histories and, um, looking at the historical range of variation?

Micha Schmidt: There's one thing I I like to tell people is that, you know, we, when we walk in the forest, I'm guilty of it, as many of us are. We generally look up and we look at the

trees when we're trying to look at what's going on here, and, uh, not to mention all the understory vegetation and other stuff we're missing.

But the other thing I would just encourage people look towards the ground and, uh, you know, with this information presented today, look to see are there old stumps around here that were cut at some point? Um, you know, if, if you're in a managed forest, um, or are there not stumps? Why aren't there stumps?

Why are there? And I, I find it's really cool because, uh, you start to develop, you know, the stump record can be lost with a, a fire that comes through or a couple fires and burns 'em off, or maybe. For some reason they pulled out stumps historically. But I, I think it's really cool to look around. 'Cause what I often see is the species composition now does not match what it was historically.

And uh, um, in some of these areas you're like, wow, this is really wet and moist feels really cool in here. And suddenly you see a ponderosa pine stump with a bunch of fire. And so how, you know, that can kind of give you some emphasis on like, what did this site look historically? You can kind of rebuild that tree in your mind looking at the stump, that's a big old growth tree.

And just kinda look at that and think of the woods in a little bit different way and think about, you know, if you were walking out here 200 years ago, what, what it might have looked like. And I think it'll give you a little bit different look and idea of, you know, what you're doing out there in the forest land.

And um, obviously we gotta look at what is there now, but looking what was there historically can, can help inform you our management decision. So that's probably the last, the parting thought I'd leave you with there.

Jacob: Definitely I'm guilty of it as well. I spend a lot of time looking up when I'm walking out in the woods. But I do, I do really enjoy, you know, finding these old stumps and especially if they have cool springboard notches in them or things like that. And then kind of looking across the landscape and trying to see, you know, what did this forest look like?

A hundred, 200, 500 plus years ago, you know.

Micha Schmidt: Yeah. Yeah.

Jacob: Well, Micah, thank you so much for sharing your expertise with us today. Uh, like I mentioned, I find this fascinating. I I really enjoy this work. you know, reconstructing the past has challenged some of our previous notions on Fire Ecology can really help inform future decisions and I really liked your point about, you know, how do you make this useful to communicate and, um, kind of tell that story.

Um, I know we discussed a lot today, so if any questions came up while you were listening or if you'd like to learn more, please drop us a comment or send us a message on our website.

Lightning Round and Conclusion

Jacob: And before we wrap up, Micah, we like to do what we call our lightning round, or where we ask a few questions of our guests.

So, kicking off with the first one here, what is your favorite tree?

Micha Schmidt: Well, I gotta give you two. 'Cause I grew up in southwest Oregon and there's no way, I can't say sugar pine, they are just, to me, the coolest tree. Ever. Um, and, uh, you know, something that's le a lot less abundant than it used to be. So, when you come upon an old grow sugar pine, it's like, wow. But the other one, since I'm an Eastern Oregon now and I don't get sugar pine anymore is, is Western Larch, which I know is the favorite a lot of people, but there's just nothing better than, you know, in fall time when you, you know, go driving through the woods or walking through the woods and you just see that whole blanket of gold covering the canopy.

So, I would say those two on the west and east side are probably my favorite.

Jacob: Those good. Those ones are hard to beat. I actually have a couple of sugar pinecones sitting in my office here. They're fascinating species as well.

Micha Schmidt: Hey, maybe that's our next tree to start planting out here. Huh?

Jacob: All right. The next question here is, what is the most interesting thing you bring with you in the field? I.

Micha Schmidt: I don't bring a ton of interesting stuff 'cause I'm one of those people that likes to go as light as I possibly can. But one thing, you know, since I really enjoy prescribed burning, one thing I find really useful is an infrared camera. So, I have this little, it's about the size of a phone and it has a, um, infrared sensor on it.

And so, you can actually walk around and, you know, number one, it's really great for mop up. You can see where stuff's still hot and burning so you can make sure your fire's not gonna escape later. But it's really cool just to show people why fire's burning. You know, sit there with someone who hasn't really watched fire before.

Have 'em look at their eyes and look what the infrared camera's showing and look where that heat's transferred and such like that. So, um, I find that really cool. And then for, you know, for the mop upside, it's a lot more fun using that camera than walking around with your, you know, your bare hand on the dirt, trying to feel hot spots.

So.

Jacob: I always find it interesting too, is like looking at just the vegetation on a hot day is how hot that vegetation could get and how that heat's moving around.

Micha Schmidt: It's amazing, huh? Yeah.

Jacob: All right. And then lastly, uh, what resources would you recommend to our listeners if they're interested in learning more about tinder chronology, historical fire regimes or historical range of variation in some of the research that's come out of the the Tree Green Lab?

Micha Schmidt: Yeah. So, um, you know, the research is where most of it is. You could, you know, if you go into Google Scholar and just type in historical fire regimes. Um, you know, that'll take you to a lot of it. Uh, I really, you know, I worked a lot with James Johnson and Andrew Marshall. They have a lot of good research look up their names, Emil Heyerdahl is another person.

Um, and, uh, you know, lot, lots of great, you know, um, great researchers out there doing this stuff. But outside of the research, you know, there's not a ton of, information. But, you know, you can, you know, most of your, you know, extension Foresters Regional Fire specialist in your region. If you reach out to them, they, you know, all of us have a

pretty good. Um, uh, uh, good knowledge of ecology and historical fire and can point you to resources there. Uh, what we have over here, we, um, put out our spring edition to Life From the Dry Side a few months back. And, uh, if you look on that, I have a writeup on historical fire regimes and range variation.

We're also, you know, we have this upcoming webinar series this winter that you and me, Jake and several other people are gonna be, uh, um, uh, doing, and I'm gonna present on historical fire regimes, how we reconstruct 'em. Then we're gonna have a bunch of experts on specific vegetation types go into those.

So, I'd really encourage, you know, watching that webinar. other than that, uh, you know, there's not a lot of information out there. So, if you have a, you know, a desire to have more of the information for your region, I would say reach out to your local extension person and say, Hey, we might want some of this.

And, and I'm sure we could all work together to put something together there.

Jacob: Definitely, uh, that was a great article you wrote for the Life on the dry side newsletter and, uh, I'm really looking forward to your presentation for that webinar series as well, so we'll make sure to get those linked to the website.

Micha Schmidt: Yeah, thanks. Yeah, should be fun.

Jacob: All right. Well, thank you again for being here today, Micah. so glad to have you in the Northeast and I look forward to continue to work together with you.

We still need to get out and go cut some, samples of our own so we can have something to show folks about, looking at these old fire scars. Well, this concludes another episode of In the Woods. Thank you all so much for listening. Don't forget to subscribe and we will see you all next time. Bye everyone.

Lauren Grand: The In The Woods Podcast is produced by Lauren Grand, Jacob Putney, and Scott Leavengood, who are all members of the Oregon State University Forestry and Natural Resources Extension team. Other members of the team who've been involved in the podcast include Carrie Berger. Jason O'Brien and Steven Fitzgerald. Episodes are edited and produced by Carrie Cantrell.

Music for In the Woods was composed by Jeffrey Heino and graphic design was created by Christina Friedhauf. Funding for In the Woods is provided by Oregon State University Forestry Natural Resources Extension, the Oregon Forest Resources Institute, and the USDA Renewable Resources Extension Act funding. We hope you enjoyed the episode, and we can't wait to talk to you again next month.

Until then, what's in your woods?