Forest Health and Natural Disasters with Carrie Fearer

(music)

Travis

When I was a kid, we had a devastating ice storm that took down quite a few power lines and a whole lot of trees. In the decades that followed, the mark of that storm was unavoidable in the forests around us. So when parts of Appalachia were hit with a devastating hurricane this fall, I became curious what the short-term and long-term impacts of that would be on the forests. And thankfully, Virginia Tech's Kerry Fearer is an expert in forest health and was kind enough to chat with me about it.

Carrie is an assistant professor of forest health as well as an affiliate faculty of the Global Change Center. Her research covers a broad range of topics related to forest health, including forest pathology, early disease detection, and the role of microbes in tree health. Carrie and I chatted a little about what forest health actually means, how these devastating storms impact forests, what it takes for them to recover, and what role humans should play in that process.

She also helped me better understand how a silver lining to these disasters might just be that we have an opportunity to replant our forests in a better way. She helped me understand the role invasive and native species play in that. And she gave me really good excuse, I mean reason, for not picking up all the tree limbs in my backyard. I'm Travis Williams and this is Virginia Tech's Curious Conversations.

(music)

Travis

Before we get on here, we were talking a little bit and we were talking about forest health and that is your expertise. And so I'm curious, what is forest health? I think I told you before, I know a lot of people who study human health, but I don't know a lot of people who study forest health. So what exactly is that?

Carrie

Yeah, actually, that's a great question because it's pretty broad, right? Forest health in general. So my specific expertise is on forest pathology. Tree diseases, so just like humans, trees get sick too with several of the same types of pathogens. So they can be infected with bacterias, fungi, what we call nematodes or like microscopic worms and several other types of pathogens. But then we can think of forest health more broadly. So just in terms of abiotic factor. So these would be things related to weather conditions that impact the health of the forest invasive species coming through. Those could be plant species, those could be insect or arthropod species, and then of course these pathogen species. So I focus on forest health kind of what I call it is the microscopic view. So looking at the pathogens, but how they impact the macroscopic forest. So overall our forest health and how it's able to thrive and be resilient in the face of change.

Travis

So you're kind of like a forest doctor.

Carrie

Yeah, my husband refers to me as a tree doctor.

Travis

You're the tree doctor. I imagine it's almost all home visits though.

Carrie

Yes, you're right. And it's really great because the patients don't talk back, they don't fight. It makes it really convenient.

Travis

That's amazing. Do let us know though if they ever do talk back. We'll do another podcast on that.

Carrie

Yes, I certainly will.

Travis

Well, I know we've had a lot of storms, a lot of hurricanes in this region, particularly Hurricane Helena that came through recently. I'm curious when a storm like that comes through and we see just a lot of destruction and devastations, particularly in forests, what impact can a storm like that have on forest health?

Carrie

Yeah, so really with these kind of catastrophic weather events or disturbances that we see in the ecosystem. What's really happening is we're changing succession. So succession is really the next stage. So progressing through stages of organisms through time. So we have two different stages of succession. Primary, which is that really occurs when we have a non-vegetative landscape. So we can think of that in terms for instance, an area that has never been colonized by trees or plants before. Now, when we deal with disturbances and weather events like this, we're really impacting secondary succession. And that's what happens when we're having, when a major disturbance comes in and kind of changes the vegetation of a current forest or a current ecosystem. And so typically we go through very different distinct stages of vegetation that colonize the area and we get to our forest, which is what we call a steady state. So it's not really changing. We have dominant canopy trees in the ecosystem. So the forest maintains that structure and is able to thrive. So whenever we have these weather events come through, that's when we see this change overall in that steady state. And we're almost reverting back to a previous state of succession.

Travis

And so when we revert back to one of those previous states. What does that look like for me? How might that impact me when I'm looking at the forest?

Carrie

so it's going to be first from visual standpoint, because of course, we're all love just the aesthetics of forest or, or most of us do. I would think that when we go out, we love to these tall canopy trees, the huge diameters and just really beautiful. But so we go back to these earlier successional states, what we're doing is we're essentially eliminating those overstory species and we're getting back into pioneer species, which are our grasses or things that are very fast colonizing in an area. And we're missing some of those very important keystone species. So our keystone species are one that are important for not just ecosystems or not just vegetation, but also for animals too. So we may lose a lot of those animals that on our overstory species for nuts and other habitat production. But then also for people, of course it impacts us actually in ways that we might not see, but through carbon sequestration. So when we lose those larger overstory trees that are really harnessing a lot of the carbon from our atmosphere, all of sudden we lose that ecosystem function that's really important for us.

Travis

Wow, yeah. I guess to your first point, I don't know a lot of people. I don't really know anybody that goes outside and is like, man, I hate the way this forest looks.

Carrie

I hope not. That would break my heart. But yeah, that is fascinating that all the impacts that maybe we see or we don't see.

Travis

I'm curious, what's the best way for us humans to interact with these forests when they're in that pioneer stage?

Carrie

Yeah, so for us, really succession can proceed sort of in two ways. So without humans, so our forests are always going to go through these processes. They're always going to have various species colonizing the area, changing conditions, and then moving through these very distinct phases of succession. Now, for us as humans, of course, I think most of the time what we want to get back to is that steady state that old store, old growth forest that we've come to know and love from that certain area. So for us interacting, really the next after a disturbance, the best, the best case scenario is that we go in there and we look at one specifically the native species diversity. So we're always looking for repopulating with native species because we're trying to keep the species that we don't want in the ecosystem out. And those would be our invasive non-native plant species. So going in there, we can actually facilitate succession to help get us to those later stages. So our overstory forest that we've come to know and love. That's just planting with appropriate species and then also just encouraging their growth and discouraging the growth of species that we wouldn't want to rapidly colonize.

Travis

I was going to ask if when we have a situation like this and maybe if it's even a catastrophic situation, does it give us an opportunity to maybe write some things that were maybe done wrong in the past in our forest?

Carrie

Yeah, actually that's a great question. And I think it kind of turns the light a little bit from this really fad, bleak situation of our forests from these catastrophic disturbances. And we can actually think of it as a really great opportunity to go in and fix some things that have been wrong in forests. So that, yeah, that might be the case that we have a forest that's just colonized in the understory with these non-native invasive species. And hopefully from these flooding events, now invasive species, they're able to survive a lot, but even most of them, have, most of the time they have pretty shallow root systems. So even they can't survive these catastrophic flooding systems. So if we start kind of with a clean slate, it really gives us the upper hand here that we can get in, keep those areas clean of these kind of non-native invasive plant species. and start planting species that are native that we would prefer to have here and increase species diversity. So we really want to keep a diverse forest ecosystem that allows it to be more resilient in terms of these catastrophic events that could happen in the future too. So yeah, we can think of it as a clean slate instead of thinking as a negative thing.

Travis

Yeah, you mentioned some of the invasive species and some of the native species. Where might a person like me figure out what is what because when I look outside I know grass and I know trees and occasionally a flower or two I don't go much further than that. So how can I learn more about that? What's my good reference point?

Carrie

Yes, actually that's great question. So there are a lot of resources online. the Virginia has many different there's a Virginia well maybe I should start I should probably start over with that one. Yeah, let me try again. Sorry. Yeah. So we're looking for native species, there's a lot of resources online and available actually through Virginia Tech Extension as well. publish an invasive, sorry, a native species pamphlet that you can look at and actually goes through shrubs, trees, really anything that you're trying to plant native flora. So non-woody species, they have a whole reference for you there. So those would be good directions to go to.

Travis

Yeah. So short term, those are some of the things I can do. Are there any things long term that we as humans can do to help our forests?

Carrie

Yeah, so for long term, it's really, it's encouraging overall forest health, which I know again, it's kind of a broad term there, but trying to keep these species out, always trying to plant with native species in our surrounding areas. So that's not just even in forest, but even in our backyards too, because What's really critical here is when we have these catastrophic events come through, the first seeds that are gonna recolonize an area are those that are surrounding the area or those that are in the seed bank. So if we start planting in our backyards with native species, then after those catastrophic events, those will be the first one to actually repopulate. In addition to that, also just keeping...healthy the healthy areas in general. So not just in that forest that might be impacted, but just increasing healthy vegetation, trying to prevent erosion or any excess chemicals, which can stress trees. So we're really trying to prevent any sort of stress to our trees. So looking at pollution and other impacts around the area would be important to try to reduce those so we can maintain a very vigorous forest.

Travis

I know I went to the long-term stuff, but to go back to the short-term stuff, is it helpful in an event like this, like a hurricane or even like an ice storm, is it helpful to go in and clean up all that debris and all the stuff that's broken and fallen down? Is that helpful to the forest?

Carrie

So that's a good question and kind of a little bit more complicated than maybe an easy answer. typically the answer would be no, because actually those, the fallen debris is really important for decomposition. And it's actually really important then for nutrient cycling as well, so that we can actually create a healthier soil and increase just nutrients in general for those pioneer species that are coming in and those later successional species. So we actually really encourage decomposition in the forest and it also creates a natural habitat for our animals too. Now, the flip side to that is it does kind of depend on the situation. So, particularly in the southeastern forest, we've had fire suppression for many, many years now. And so when we have a very, a forest full of debris, it can increase wildfires later in the season. So while we want to maintain some decomposition and some woody debris in the forest, it kind of depends on where the ecosystem is and what exactly the species composition now in that understory and the amount of debris down to encourage. But generally I would recommend not going in and cleaning, clearing it because we like those nutrients that they're gonna provide.

Travis

Okay, well I will report back to my wife that I don't need to pick up these limbs that are in our backyard. It's not good for the environment. I'm sorry, I'm not doing it.

(music)

Travis

When I was a kid, we had a devastating ice storm that took down quite a few power lines and a whole lot of trees. In the decades that followed, the mark of that storm was unavoidable in the forests around us. So when parts of Appalachia were hit with a devastating hurricane this fall, I became curious what the short-term and long-term impacts of that would be on the forests. And thankfully, Virginia Tech's Kerry Fearer is an expert in forest health and was kind enough to chat with me about it.

Carrie is an assistant professor of forest health as well as an affiliate faculty of the Global Change Center. Her research covers a broad range of topics related to forest health, including forest pathology, early disease detection, and the role of microbes in tree health. Carrie and I chatted a little about what forest health actually means, how these devastating storms impact forests, what it takes for them to recover, and what role humans should play in that process.

She also helped me better understand how a silver lining to these disasters might just be that we have an opportunity to replant our forests in a better way. She helped me understand the role invasive and native species play in that. And she gave me really good excuse, I mean reason, for not picking up all the tree limbs in my backyard. I'm Travis Williams and this is Virginia Tech's Curious Conversations.

(music)

Travis

Before we get on here, we were talking a little bit and we were talking about forest health and that is your expertise. And so I'm curious, what is forest health? I think I told you before, I know a lot of people who study human health, but I don't know a lot of people who study forest health. So what exactly is that?

Carrie

Yeah, actually, that's a great question because it's pretty broad, right? Forest health in general. So my specific expertise is on forest pathology. Tree diseases, so just like humans, trees get sick too with several of the same types of pathogens. So they can be infected with bacterias, fungi, what we call nematodes or like microscopic worms and several other types of pathogens. But then we can think of forest health more broadly. So just in terms of abiotic factor. So these would be things related to weather conditions that impact the health of the forest invasive species coming through. Those could be plant species, those could be insect or arthropod species, and then of course these pathogen species. So I focus on forest health kind of what I call it is the microscopic view. So looking at the pathogens, but how they impact the macroscopic forest. So overall our forest health and how it's able to thrive and be resilient in the face of change.

Travis

So you're kind of like a forest doctor.

Carrie

Yeah, my husband refers to me as a tree doctor.

Travis

You're the tree doctor. I imagine it's almost all home visits though.

Carrie

Yes, you're right. And it's really great because the patients don't talk back, they don't fight. It makes it really convenient.

Travis

That's amazing. Do let us know though if they ever do talk back. We'll do another podcast on that.

Carrie

Yes, I certainly will.

Travis

Well, I know we've had a lot of storms, a lot of hurricanes in this region, particularly Hurricane Helena that came through recently. I'm curious when a storm like that comes through and we see just a lot of destruction and devastations, particularly in forests, what impact can a storm like that have on forest health?

Carrie

Yeah, so really with these kind of catastrophic weather events or disturbances that we see in the ecosystem. What's really happening is we're changing succession. So succession is really the next stage. So progressing through stages of organisms through time. So we have two different stages of succession. Primary, which is that really occurs when we have a non-vegetative landscape. So we can think of that in terms for instance, an area that has never been colonized by trees or plants before. Now, when we deal with disturbances and weather events like this, we're really impacting secondary succession. And that's what happens when we're having, when a major disturbance comes in and kind of changes the vegetation of a current forest or a current ecosystem. And so typically we go through very different distinct stages of vegetation that colonize the area and we get to our forest, which is what we call a steady state. So it's not really changing. We have dominant canopy trees in the ecosystem. So the forest maintains that structure and is able to thrive. So whenever we have these weather events come through, that's when we see this change overall in that steady state. And we're almost reverting back to a previous state of succession.

Travis

And so when we revert back to one of those previous states. What does that look like for me? How might that impact me when I'm looking at the forest?

Carrie

so it's going to be first from visual standpoint, because of course, we're all love just the aesthetics of forest or, or most of us do. I would think that when we go out, we love to these tall canopy trees, the huge diameters and just really beautiful. But so we go back to these earlier successional states, what we're doing is we're essentially eliminating those overstory species and we're getting back into pioneer species, which are our grasses or things that are very fast colonizing in an area. And we're missing some of those very important keystone species. So our keystone species are one that are important for not just ecosystems or not just vegetation, but also for animals too. So we may lose a lot of those animals that on our overstory species for nuts and other habitat production. But then also for people, of course it impacts us actually in ways that we might not see, but through carbon sequestration. So when we lose those larger overstory trees that are really harnessing a lot of the carbon from our atmosphere, all of sudden we lose that ecosystem function that's really important for us.

Travis

Wow, yeah. I guess to your first point, I don't know a lot of people. I don't really know anybody that goes outside and is like, man, I hate the way this forest looks.

Carrie

I hope not. That would break my heart. But yeah, that is fascinating that all the impacts that maybe we see or we don't see.

Travis

I'm curious, what's the best way for us humans to interact with these forests when they're in that pioneer stage?

Carrie

Yeah, so for us, really succession can proceed sort of in two ways. So without humans, so our forests are always going to go through these processes. They're always going to have various species colonizing the area, changing conditions, and then moving through these very distinct phases of succession. Now, for us as humans, of course, I think most of the time what we want to get back to is that steady state that old store, old growth forest that we've come to know and love from that certain area. So for us interacting, really the next after a disturbance, the best, the best case scenario is that we go in there and we look at one specifically the native species diversity. So we're always looking for repopulating with native species because we're trying to keep the species that we don't want in the ecosystem out. And those would be our invasive non-native plant species. So going in there, we can actually facilitate succession to help get us to those later stages. So our overstory forest that we've come to know and love. That's just planting with appropriate species and then also just encouraging their growth and discouraging the growth of species that we wouldn't want to rapidly colonize.

Travis

I was going to ask if when we have a situation like this and maybe if it's even a catastrophic situation, does it give us an opportunity to maybe write some things that were maybe done wrong in the past in our forest?

Carrie

Yeah, actually that's a great question. And I think it kind of turns the light a little bit from this really fad, bleak situation of our forests from these catastrophic disturbances. And we can actually think of it as a really great opportunity to go in and fix some things that have been wrong in forests. So that, yeah, that might be the case that we have a forest that's just colonized in the understory with these non-native invasive species. And hopefully from these flooding events, now invasive species, they're able to survive a lot, but even most of them, have, most of the time they have pretty shallow root systems. So even they can't survive these catastrophic flooding systems. So if we start kind of with a clean slate, it really gives us the upper hand here that we can get in, keep those areas clean of these kind of non-native invasive plant species. and start planting species that are native that we would prefer to have here and increase species diversity. So we really want to keep a diverse forest ecosystem that allows it to be more resilient in terms of these catastrophic events that could happen in the future too. So yeah, we can think of it as a clean slate instead of thinking as a negative thing.

Travis

Yeah, you mentioned some of the invasive species and some of the native species. Where might a person like me figure out what is what because when I look outside I know grass and I know trees and occasionally a flower or two I don't go much further than that. So how can I learn more about that? What's my good reference point?

Carrie

Yes, actually that's great question. So there are a lot of resources online. the Virginia has many different there's a Virginia well maybe I should start I should probably start over with that one. Yeah, let me try again. Sorry. Yeah. So we're looking for native species, there's a lot of resources online and available actually through Virginia Tech Extension as well. publish an invasive, sorry, a native species pamphlet that you can look at and actually goes through shrubs, trees, really anything that you're trying to plant native flora. So non-woody species, they have a whole reference for you there. So those would be good directions to go to.

Travis

Yeah. So short term, those are some of the things I can do. Are there any things long term that we as humans can do to help our forests?

Carrie

Yeah, so for long term, it's really, it's encouraging overall forest health, which I know again, it's kind of a broad term there, but trying to keep these species out, always trying to plant with native species in our surrounding areas. So that's not just even in forest, but even in our backyards too, because What's really critical here is when we have these catastrophic events come through, the first seeds that are gonna recolonize an area are those that are surrounding the area or those that are in the seed bank. So if we start planting in our backyards with native species, then after those catastrophic events, those will be the first one to actually repopulate. In addition to that, also just keeping...healthy the healthy areas in general. So not just in that forest that might be impacted, but just increasing healthy vegetation, trying to prevent erosion or any excess chemicals, which can stress trees. So we're really trying to prevent any sort of stress to our trees. So looking at pollution and other impacts around the area would be important to try to reduce those so we can maintain a very vigorous forest.

Travis

I know I went to the long-term stuff, but to go back to the short-term stuff, is it helpful in an event like this, like a hurricane or even like an ice storm, is it helpful to go in and clean up all that debris and all the stuff that's broken and fallen down? Is that helpful to the forest?

Carrie

So that's a good question and kind of a little bit more complicated than maybe an easy answer. typically the answer would be no, because actually those, the fallen debris is really important for decomposition. And it's actually really important then for nutrient cycling as well, so that we can actually create a healthier soil and increase just nutrients in general for those pioneer species that are coming in and those later successional species. So we actually really encourage decomposition in the forest and it also creates a natural habitat for our animals too. Now, the flip side to that is it does kind of depend on the situation. So, particularly in the southeastern forest, we've had fire suppression for many, many years now. And so when we have a very, a forest full of debris, it can increase wildfires later in the season. So while we want to maintain some decomposition and some woody debris in the forest, it kind of depends on where the ecosystem is and what exactly the species composition now in that understory and the amount of debris down to encourage. But generally I would recommend not going in and cleaning, clearing it because we like those nutrients that they're gonna provide.

Travis

Okay, well I will report back to my wife that I don't need to pick up these limbs that are in our backyard. It's not good for the environment. I'm sorry, I'm not doing it.

Carrie

Right, you're trying to help the fungi, the microbes, yes.

Travis

Well, how long does it take a forest that's been through a devastating event to get back to kind of that old forest classical look that we're looking for?

Carrie

Yeah. Wow, Travis, that's a yeah, get another hard question to answer here, but actually it's so it really depends on the forest type and where the actual disturbance happens and kind of the. Again, how I mentioned before, the seeds and the seed bank, the trees surrounding it, and the species that are present there. Now, when we're talking about this secondary succession that I've been mentioning here, it can take anywhere probably until we get a steady state forest to be about 50 to 75 years till we see that again. Again, some can be earlier or we can notice a forest ecosystem earlier than that. It just might not be quite what we were used to. And so really about the 50 to 75 years is where we can get back to that steady state forest that we're used to.

Travis

Wow. So these really are like storms of a lifetime sometimes when they hit a forest like that.

Carrie

Yes. And they can look very different too. So I mean, again, depending on the seeds that are surrounding the area and what you're going to get back, it might not ever look the same. We might see a totally different species composition or we might see that within our lifetime, it's totally different than what we're used to in that area.

Travis

Okay, well, I'm curious, do you have a favorite tree? I won't tell the other trees, but what's your favorite tree?

Carrie

Yeah, that's actually a great question. I struggle with it. think I change all the time. I think my favorite tree personally is American Beech. I've worked a lot with American Beech in the past, but then also, It's just such a beautiful tree. It has smooth bark to it and then it has this beautiful canopy that during the fall it turns yellow, like this beautiful gold. It's just, a wonderful tree. We have it native here in Virginia and then also all the other places I work. So I've been in Ohio and New Hampshire and beach trees are able to be in those areas. They provide a great canopy for other organisms and animals too. And they're very threatened by diseases. So again, it's near and dear to my heart.

(music)

Travis

And thanks to Kerry for talking to us about forest health in the wake of natural disasters. If you or someone you know would make for a great curious conversation, email me at traviskw at vt.edu. I'm Travis Williams, and this has been Virginia Tech's Curious Conversations.Right, you're trying to help the fungi, the microbes, yes.

Travis

Well, how long does it take a forest that's been through a devastating event to get back to kind of that old forest classical look that we're looking for?

Carrie

Yeah. Wow, Travis, that's a yeah, get another hard question to answer here, but actually it's so it really depends on the forest type and where the actual disturbance happens and kind of the. Again, how I mentioned before, the seeds and the seed bank, the trees surrounding it, and the species that are present there. Now, when we're talking about this secondary succession that I've been mentioning here, it can take anywhere probably until we get a steady state forest to be about 50 to 75 years till we see that again. Again, some can be earlier or we can notice a forest ecosystem earlier than that. It just might not be quite what we were used to. And so really about the 50 to 75 years is where we can get back to that steady state forest that we're used to.

Travis

Wow. So these really are like storms of a lifetime sometimes when they hit a forest like that.

Carrie

Yes. And they can look very different too. So I mean, again, depending on the seeds that are surrounding the area and what you're going to get back, it might not ever look the same. We might see a totally different species composition or we might see that within our lifetime, it's totally different than what we're used to in that area.

Travis

Okay, well, I'm curious, do you have a favorite tree? I won't tell the other trees, but what's your favorite tree?

Carrie

Yeah, that's actually a great question. I struggle with it. think I change all the time. I think my favorite tree personally is American Beech. I've worked a lot with American Beech in the past, but then also, It's just such a beautiful tree. It has smooth bark to it and then it has this beautiful canopy that during the fall it turns yellow, like this beautiful gold. It's just, a wonderful tree. We have it native here in Virginia and then also all the other places I work. So I've been in Ohio and New Hampshire and beach trees are able to be in those areas. They provide a great canopy for other organisms and animals too. And they're very threatened by diseases. So again, it's near and dear to my heart.

 

(music)

Travis

And thanks to Kerry for talking to us about forest health in the wake of natural disasters. If you or someone you know would make for a great curious conversation, email me at traviskw at vt.edu. I'm Travis Williams, and this has been Virginia Tech's Curious Conversations.