are already wrecked by massive fires every year. So setting any fire on purpose doesn't

exactly sound like a good idea. But these people here pouring fire on the ground. They're

actually saving these forests from those devastating out of control fires we see on the news, because

over time we've learned that forest management isn't always about saving trees. Sometimes

it's about burning them. Indigenous communities studied the effects of natural periodic fires

and they've been practicing controlled fires for centuries. Before colonizers learnt from

these communities, forests were managed in ways that were ultimately harmful and made

the fire problem even worse. While many indigenous communities embraced fire as part of the forest.

US government took a different approach. After a massive fire, known as the Big burn of 1910

destroyed huge swaths of land in and around Northern Idaho. The US Forest Service launched

an aggressive fire suppression campaign. That campaign has lasted and persistent in many

forms over the decades and has basically removed natural fire from the landscape. And since

then, we've learned about the many benefits of natural fires and forests so this campaign

was straight up a huge problem. Before this whole fire is bad movement, fires were super common

and can be categorized in three ways: low, moderate and high severity. Most natural fire

was low and moderate, with occasional high severity fire that created gaps in forest which was actually

good. Fires created patchy forests with a diversity of conditions. We got open meadows and sections

with large fire resistant trees. Following that period with European settlements, there

was a large scale logging of the forest. So much of the old growth forest was cut down

in big swaths. For over 400 years though, loggers had chopped down thousands of acres of trees until

the 1970s when Forest Service lands were marked for preservation. What the Forest Service

inherited in many cases was very unhealthy forest full of lots of young trees, overcrowded,

very dense conditions. Those conditions have played themselves out and resulted in large

severity wildfires of the kind of witnessing in recent years. When you picture a healthy forest,

you might think of something that looks like this, a bunch of very similar looking trees

all bunched together, but this isn't quite right. Healthy trees need much more space

than this. Before the forest was cut down and then fire suppressed we typically had somewhere

between 30 and 50 very large trees per acre today and what we have is tree densities that

are more like 300, 500, and even 800 trees per acre. Amid so much competition the trees that

can't get the resources they need die and fall over turning into ground fuel. So today's forests have

way too much of this ground fuel. So when a fire sparks it can burn through more than three feet of fuel

on the forest floor, which can then quickly escalate into a high intensity fire and high

intensity fire ruins forests. The trees need a much longer time to go back and soil quality

is just wrecked. Huge fires this size are also dangerous for humans burning homes and

causing evacuations. They also produce disease causing smoke and contaminated water sources.

So we need not too much fire not too little fire but just the right amount. The Sierra Nevada

as a whole is a fire adapted forest. It needs good fire. But when we look back at

the scientific literature, reconstructing some of the deep history of these forests,

what we learned is that most of the fires were what were classified as low or moderate

severity wildfires. There was actually a very low percentage of wildfires that were in that

high severity class prior to the clear cutting and the fire suppression that we talked about.

The Big Burn of 1910 caused a campaign that literally extinguished all kinds of helpful

low intensity fires. But now experts are working to put those low intensity fires back into

the forest. Enter the Nature Conservancy, the US Forest Service, and their partners who

have been working to restore the natural state of these forests. through what's known as

prescribed burns or controlled fires. So we went to check out one of these prescribed fires

in the French Meadows area of the Sierra Nevada. The goal of the prescribed fire first and

foremost is to reintroduce beneficial fire to landscape and we want to simulate a low intensity fire.

To meet that objective, there's a prescription that is planned ahead of time that our firefighters and our

fuels officers have to meet. Literally a prescription to help the forest heal. Ideally all forests

that need it would get this treatment but in this case, the Forest Service chose the

Fresh Meadows area to protect the local reservoir and water source from a major fire. In addition

to choosing a good location, a lot goes into making sure that conditions are perfect to

burn off that ground fuel but not let the fire get out of control. One of the ways that

we can measure if we're in ideal conditions to initiate ignitions on a prescribed

fire is through the fuel moisture of the sticks out here in the forest, the fuel moisture, how

much actual water is in these, how easily they can snap and break. Let us know if they're

ready to burn to meet our objectives. You want there to be some moisture so the fire won't burn too

hot, but not so much that it doesn't spread at all. So the firefighters have to both start

the fire and keep it from spreading out of control. We always first try to use roads

or ridge lines or rocky outcroppings and if necessary, firefighters will prep an area

they'll actually build containment liners like the line behind me with removing all

the hazardous fuels all the burnable material to stop that progression of the fire. There

are all kinds of benefits to these prescribed fires burning off that excess ground fuel

protecting communities and water sources from high intensity fires and just upping the overall

forest health by restoring nutrients to the soil and bringing carbon from those excess

trees back into the soil. But not everyone is a fan of lighting fires intentionally especially

after all those fire. nearby communities also worry that these Burns will decrease air quality.

Smoke is an ever present part of prescribed fire planning in advance of doing a prescribed

fire. There are professionals to actually model the different environmental conditions

that will help lift the smoke up and disperse it out and away from populated areas. I will

say this in a large high intensity wildfire, the amount of smoke is magnitudes greater

than if we kind of nickel and dime our way through the smaller prescribed fire Each prescribed

fire has a measurable amount of smoke that is far less smoke input and carbon released into

the atmosphere than those high intensity fires. And again, more prescribed fire now equals

less high intensity wildfire later. One more time. More prescribed fire now equals fewer

high intensity fires later. In this world where the climate crisis is very much a reality.

We have more frequent and more devastating wildfires. Even though setting forest fires

might not be intuitive, prescribed burns have worked for millennia and are still one of

the best solutions for managing our forests well into the future. So this portion

of his watershed is now going to be more resilient to drought, disease, beetle infestation, and

what's important maybe it's gonna be more resilient to high intensity wildfire that's

the wildfires that we see in the news. My name is Niba of NotesByNiba and this has been

Seeker's Impact of Everything. Let us know if there's an episode topic you want us to

cover and we'll see you next time. Thanks for watching.