Florida on Fire: Prescribed Fire in the Sunshine State
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Show Notes
Learn more:
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Fire and Habitat - https://sfyl.ifas.ufl.edu/archive/hot_topics/environment/fire_habitat.shtml
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Effects of Fire on Florida’s Wildlife and Wildlife Habitat - https://edis.ifas.ufl.edu/publication/uw132
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Wind and Trees: Lessons Learned from Hurricanes (Mentioned by Shannon) - https://edis.ifas.ufl.edu/publication/FR173
How You Can Help:
Consider Creating a Firewise Landscape
These documents outline actions homeowners can take to better prepare their landscape for a possible wildfire:Support Prescribed Burning Programs
These resources outline prescribed burning efforts throughout Florida:Sources for this Episode:
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Gopher Frogs, Burrows, and Fire: Interactions in the Longleaf Pine Ecosystem - https://edis.ifas.ufl.edu/publication/UW295
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Effects of fire history, tree age, and canopy seed bank size on serotiny of Ocala sand pine (Pinus clausa var. clausa) in Florida scrub - https://www.jstor.org/stable/26477959
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Chapter 9 – Ecological Effects - https://www.fdacs.gov/content/download/39688/file/pft_chapter_09_ecological_effects.pdf
If you enjoyed this episode, please consider sharing it with a friend who might enjoy learning about Florida's natural areas and the wild things that live here!If you're active on iNaturalist, consider joining our iNaturalist project, Naturally Florida's Listener Observations, here: https://www.inaturalist.org/projects/naturally-florida-s-listener-observations -
Episode Transcript:
SHANNON:
On today's episode, we're going to be talking about fire ecology in Florida. You'll learn about the differences between prescribed fire and wildfire and hear about fire adaptations for Florida's wildlife and plant species.
LARA:
Welcome to “Naturally Florida,” a podcast about Florida's natural areas and the wild things that live here. I'm Lara Milligan.
SHANNON:
And I'm Shannon Carnevale.
LARA:
This podcast is brought to you by UF/IFAS Extension in Polk and Pinellas Counties.
SHANNON:
Lara, I was going through some of my old textbooks and, you know, the binders of stuff that we have from past extension programs, and I came across a note from my predecessor. And it's, I think, the perfect leaping off point for our episode today. And that note is: Fire is neither good nor bad. It is a part of our system, and too much or too little of it is a bad thing.
LARA:
Wow. Shannon, that's a good find. That's like a very simple yet somewhat complex statement. And yeah, fire is very complex, and you guys will get a little taste of that today. So we're going to be talking all about fire, both prescribed fire and wildfires today. And so real quick, I just want to define those terms so we're on the same page with that.
When we say “prescribed fire," that's basically a planned fire, simply put. Though, it's planned by land managers who are specifically and uniquely trained to put fire on the landscape. “Wildfires,” on the other hand, are basically fires that occur that are not planned and that can occur from a variety of sources—whether it's naturally caused by lightning or intentionally caused by arson or even accidentally caused by a spark or, you know, somebody throwing out a cigarette butt or something like that.
So just so you guys are clear on that, and what we really want to focus in on today is the value and importance of fire. Again, both wildfires and prescribed fires as it relates to many of the ecosystems here in Florida that actually need fire. So let's dive in.
SHANNON:
I'm so excited.
LARA:
Same. Geez, I love fire and I love pine trees, which are often associated when we talk about fire. So generally speaking, in Florida, when we talk about or define ecosystems, it's often by the most dominant tree species that’s found there. So we often say like pine flatwoods, so they're going to be dominated by pine trees. And then we have other ecosystems called oak hammock, so often dominated by oak trees.
But again, the super cool thing is these ecosystems are really defined by fire. There’s some other components that play a part, but fire is a really big piece of the puzzle. So in these often different there's different types of pine ecosystems. We're not going to get into that today, but anywhere from like two to seven years, these ecosystems will historically will have seen fire started by lightning. And that repetition of fire over these cycles or rotations is what helps to maintain that ecosystem as, say, a pine flatwoods.
SHANNON:
Right. That's true. But we also have some pine ecosystems that are dominated by long-term fire rotations. So they might only have a fire every 10 to 60 years, but it'll burn hotter and more intense.
LARA:
Yeah. And often in those we’ll have different types that might come, like scrub oak species. And if you guys are familiar with oak trees and their leaves, they tend to be really thick and leathery and they are like, not, they don’t burn very easily. And that's one adaptation that they have. But there's all different… I mean Shannon and I could talk about fire forever, but there's reasons that these different ecosystems burn on different rotations.
Unfortunately over time…And I talked about, again, in our urban forestry episode, there was a time when Florida was not as populous as it is today. And in those times, fires would start by lightning and go for thousands and thousands of acres. And people moved in. And then we got into this like “put the fire out because there's people in harm's way.” And got into this idea of what we call “fire suppression.”
And there are some negative effects—this fire suppression.
SHANNON:
Yeah. In the 20th century, we really got behind the idea that fire’s bad—just all the time fire is a terrible thing. And if you think back to what society looked like, especially in the early 20th century, most of our cities and towns were made of wood. So it made a lot of sense that fire was something that people were afraid of.
So we began this thing called fire suppression and fire prevention efforts. There were all sorts of education programs about how only you can prevent forest fires. There was a lot of fire prevention and suppression. And what we mean is, if anything lit a fire naturally—like lightning—those fires were extinguished ASAP. “Just as soon as possible put the fire out. Make it safe again.”
LARA:
Mm hmm.
SHANNON:
Like Lara alluded to, though, this had a lot of unintended consequences. So when we suppress fire, we stop it from burning off fuels. “Fuels” are what we in the business use to describe sticks and leaves and downed woody debris, which is, you know, more dead vegetation, fallen trees, big branches, things that burn, things that you might put in a campfire if you were trying to light one. And it also allows the overgrowth of understory species.
And when you have a lot of overgrowth of understory species, you also get a decrease in species diversity. So all these unintended consequences came up when we decided to stop fires.
LARA:
Yeah. Yeah. And I mentioned that earlier. And, right, we don't get the title of Lightning Capital of the World or the United States for no reason. We have a lot of lightning here. So generally speaking, when we talk about Florida's wildfire season, when fires would occur on the landscape due to lightning, that's like mid-April through July. Again, anything in the natural world we can't really set these like timeframes and it's always going to happen then. So we also have our dry season that can factor in, right? If we're in a drought and we have a storm, we can also have fires, wildfires outside of that timeframe.
I think the key thing that we want to point out here is these fires were occurring regularly, naturally, right. We're getting these thunderstorms every year and lightning would start these fires. And because those fuel loads are…You know, the fuels are eaten up by the fire one time, lightning strikes again, it might burn again. But because their fuel has been knocked down by the fire before, it's not going to be super intense. So these wildfires that were happening were very low intensity, like kind of the good fires if you go back to that post-it note that Shannon mentioned earlier.
So we often hear the term “wildfire” and think this big, bad, negative thing, but it's not always the case. Now, in the case of 1998—if anyone was around during that time and remembers the big, bad wildfires that happened that did occur during wildfire season—and that was kind of a big eye-opener for the state of Florida.
SHANNON:
And if you aren't familiar with the 1998 wildfires in Florida, you probably are familiar with the more recent intense wildfires that California has been experiencing and other of our western states. And whilst I cannot speak to the fire rotations that are natural for those ecosystems, in Florida most of our ecosystems were used to having fire every handful of years.
LARA:
And one other thing I want to mention is you might have also heard the term “controlled burn” or “controlled fire.” And we've really gotten away from that. It is technically like it would be like synonymous with “prescribed fire.” But really, fire is, you can't really control fire. We can do the best—you know, put in our best efforts—but it's ultimately Mother Nature. So we really worked in kind of the fire world to stress and just only talk about “prescribed fire.”
SHANNON:
Right. Because those wind conditions can change. A forecast…I mean, think about how many times we have a forecast for rain. I mean, if we planned our lives around a 50% chance of rain in Florida, we would never leave the house. (LAUGHTER) But the forecast, it just changes. And so all the science in the world can still occasionally lead to a bad outcome.
And so that's why we've gotten away from the word “controlled." But prescribed fires are really important in Florida. And they help us avoid those wildfire results that you're seeing out West. Just as a point, Florida up until—this is year to date for this year up until November—Florida had burned over 1,600,000 acres of prescribed fire in the state of Florida.
The next closest state was Georgia at 1,300,000 and followed up by Alabama with almost a million acres. After that, it drops off significantly. So it's always the Southeast that has the most prescribed fire acres because we are trying to mimic a natural fire rotation that is pretty frequent compared to other parts of the country. So the Southeast is for the most part going to burn more prescribed acres with fire than anywhere else in the country.
But that is starting to change. California is looking to Florida for lessons on how they can reintroduce fire to their ecosystems. And it’s just an evolving science which is so cool and why we love talking about prescribed fire.
LARA:
Yes. Yeah. Again, Shannon and I could talk forever. So we're going to rein it in. Rein it in! (LAUGHTER) Yeah, and we encourage you guys, you know, we'll include links in the show notes if you want to learn more. And there's tons of resources out there on fire in general in the Southeast, Florida specifically. So definitely check that out.
But the amazing thing is, right, this lightning’s been happening in the state for as long as the state has been around. And the plants and animals have adapted to this force of Mother Nature. And so Shannon and I wanted to highlight some of these because it's super cool. And be prepared because I'm probably going to nerd out..
SHANNON:
(LAUGHS) They’re so cool, though. It's worth it.
LARA:
(LAUGHS) So I think that if we start with longleaf pines because they're my favorite. Let's get that out of the way. They have really thick bark. If you guys are familiar, this really goes for most pine species, but it tends to be kind of like flaky. I'm sure if you were a kid at some point you have pulled off a piece of pine bark.
But that pine bark is its own basically form of insulation. And within each layer of that bark there is moisture, right? There's air. And so by the time a fire gets to the core of the tree, it's typically gone past the tree and it's able to thrive and survive. And studies have looked at the temperatures of fire and how it relates to the surface of the bark. So at the surface, the temperature can be as high as 1500 degrees.
But when you look at what we call the “cambium” or kind of the internal living tissue of the tree, the temperature there is only 180 degrees. So that's like crazy!
SHANNON:
It’s amazing.
LARA:
Yeah. I said it's like kind of like when you put on a little oven mitt, right. The pan that you're touching in there—well, we'll say it's probably like 400 degrees. You put that on, like the pine bark. You go and grab the pan, right, it’s not going to be that hot. But the longer you hold that pan, the heat is going to seep through.
So the same is true. There's something called “fire residency time.” We won't get into it today, but it's basically like how long the fire sits in an area. And so the longer the fire sits there, the more damage it can cause.
SHANNON:
Lara, can I talk about my favorite fire adaptation of our pine trees?
LARA:
Yes.
SHANNON:
Okay. It is the serotinous pine cones that many of our pine species have. And “serotiny,”which is that trait that allows pine trees to store their seeds in their cone and then it will open with extreme heat or in most cases, fire.
What this means is when their pine cones fall and they're on the ground, when the fire comes through and burns up all the stuff on the ground, the cones will pop open and the seeds will fall out into that bare soil. And it just gives them a perfect little nursery to raise their little baby pine trees. And I just think that is the coolest thing.
LARA:
Yeah. And yeah, and you mentioned like the bare soil, which is also caused by the fire. So it's like this perfect set up for these little baby pine seedlings.
SHANNON:
Yes. And our listeners, if you guys are in an area where you see a tightly bound up pine cone when you're out at a park or in your backyard—don’t take anything from like a national park, that's not allowed—but if you're somewhere where you can grab a tightly bound up pine cone that is serotinous (it’ll feel kind of waxy on the outside).
You can pop it in your microwave for like 20 or 30 seconds. Watch it very closely. The cones will open and then you can see the seeds inside them—one of my favorite activities to do with kids.
LARA:
That's awesome. Yeah. If you guys know you have sand pines or pond pines—or want to ask somebody who you know that might know—those are two species that have serotinous cones. So that could be… I mean, you can do that really with any pine species what Shannon is talking about, but in terms of the waxy coating, sand pines and pond pines are known for that.
So we also want to talk about some cool animal adaptations too. And one species that is really well known for this is the gopher tortoise, which maybe we'll do a whole episode on one day because they’re super cool. But they create something called a “burrow.” You probably heard of gopher tortoise burrows. The number one statistic that's thrown around with that is that 350 species find refuge in their burrows.
And that's not only in the case of fire, but obviously for today's episode, that's what we're going to be talking about. So, right, we can probably imagine that some larger mammals like coyotes or deer can just see or smell a fire and dart away. But there's a lot of other smaller species—and think, right, like a gopher tortoise is probably not moving that fast.
Although they can book it. I've seen that, but they're going to find refuge in their burrows and other animals are going to take advantage of that as well. And so it's kind of this constant temperature underground. And they can just all go in there, hang out, party, wait for the fire to pass and then come out. And they have survived. So that's one really cool benefit that the gopher tortoises provide. We might call that like an “ecosystem engineer."
SHANNON:
They are the coolest. So outside of those gopher tortoise burrows, they also have something called an “apron.” And that apron is just like a big sandy welcome mat to their burrow. And on that apron there are no plants. It is just a big sandy area. So the gopher tortoise will meticulously maintain this area, removing anything that tries to grow there.
And this serves as a great firebreak. A firebreak is just an area where the fire slows down or cannot burn. And so that area is protected. This is something that we can learn from the gopher tortoise and we call it “fire-wise landscaping.” So if you live in an area that's not super urban—right, you’ve got a lot of vegetation around your house,
you live in an area maybe in the forest or adjacent to a wild area—“defensible space” and “fire-wise landscaping” are something that might be of interest to you.
And all you need to do is create an area of defensible space. An area of defensible space is about 30 feet from your home in any direction. And you're just trying to create a firebreak, just like the gopher tortoise. So you would want to remove some vegetation, make sure it's not overgrown. Choose some species that are lower flammability.
And we have some lists that we can provide to you in the show notes as recommendations. Another thing you'll want to do is make sure that you don't have a bunch of trees that are really, really branchy all the way up from the ground and then overhang over your house, because transferring the spark from the ground to your roof is one of the things we're trying to avoid with defensible space.
The other great reason to enact a defensible space on your property is it helps protect the firefighters who are out there fighting the wildfire So when we have a neighborhood with good defensible space and fire-wise landscaping, it's less dangerous for our wild-land firefighters who are out there trying to protect our homes and our neighborhoods from that wildfire that's in the area.
So if you don't want to do it to protect your home, maybe think about doing it to help protect the lives of our emergency responders.
LARA:
Yeah, Shannon, that's really helpful information. And we know not all of this might be relevant to everyone depending where you live. But there are things we can all do to help support prescribed burning programs, whether that's writing your elected officials or just simply helping to share accurate information about the benefits of prescribed fire. So we really appreciate you guys all tuning in today to learn a little bit about the big world of fire.
SHANNON:
Thanks for listening to “Naturally Florida,” a podcast about Florida's natural areas and the wild things that live here. Stay updated on new episodes by subscribing on your favorite podcast platform. If you enjoyed today's episode, consider sharing it with a friend. “Naturally Florida” is produced by your hosts Shannon Carnevale
LARA:
and Lara Milligan.
SHANNON:
If you have questions or suggestions, submit them online at naturallyfloridapodcast.com. This podcast is brought to you by the University of Florida's Institute of Food and Agricultural Sciences Extension, an Equal Opportunity Institution. Thank you for listening.