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I think what happened in those years,
the foresters thought they were doing the right thing
by keeping fire out of these ecosystems,
because they were trying to protect the trees.
The result was losing that resource,
and I can think of several examples of fires
around Yosemite
where they kept fire out, kept fire out,
and the fire that eventually came through burned down
all the trees that were there.
So by doing what they thought was right,
they ended up losing what they were trying to protect.
We were creating a situation
that we're setting the stage
for potentially catastrophic wildfire,
for fires that are going to become much larger,
much more intense,
and threaten the communities
that we decide to settle into and live in,
and so what do you do about that?
Who is willing to take on and shoulder the risk
of applying fire to a landscape
when it's been pumped into you from day one
that fire is bad?
I think when you're dealing with something
that is as potentially dangerous as fire,
and has its place in history of human civilization
as being a destructive force,
you can't forget,
you can't forget those stories.
You can't forget that fire is an awesome force of nature.
The only image I've ever seen on TV of a wildfire is,
this big crown fire
that's racing up the [inaudible] hill,
200-foot flame length,
homes burning up,
you know, just mayhem and chaos,
whereas in actuality, like 90% of the time,
it's just really creeping,
you could outcrawl a fire,
it's low flame lengths,
not doing anything but good.
Beautiful day to be gathered here in the Park.
I'm Taro Pusina.
I'm the prescribed fire and fuel specialist
here in Yosemite National Park.
I'll be the burn boss for this incident today.
Mariposa Grove is a very special place.
It's one of the main reasons
that Yosemite Park was originally founded.
And the reason that we do burning up here in the Grove
is to try to mimic
what natural fire would have done here historically,
and by natural I mean lightning-caused fires.
In the fourth year of America's bloody Civil War,
few people took notice
when the President signed a bill
preserving 60 square miles of California wilderness.
In signing the Yosemite Grant,
Abraham Lincoln marked the first time in Western history
that a government set aside land
purely to protect its scenic beauty
for everyone to enjoy.
The Yosemite Valley,
along with this Grove of Giant Sequoias,
suddenly belonged to all Americans,
and it was our government's responsibility to protect them.
This was a new idea
and with no precedent to guide them,
Yosemite's early managers did what made sense.
Their job was to protect
some of the largest living things on earth,
and that meant keeping one obvious enemy
well away from what was now a national treasure.
Well, I think the first Park Managers honestly felt
that fire would destroy this gem,
this gem of the sequoias,
the whole reason we founded
Yosemite National Park or one of them,
so by keeping fire out of the Sequoia
and the rest of the Park,
we were essentially protecting the Grove,
saving this gem, this treasure.
Because they felt the best way to protect the Grove
was to build a road around it,
so that they could keep fires out of the Grove,
and that was pretty much the Park Service's view
for decades after that,
that they wanted to keep all fires out of the Grove
to protect the trees.
In 1899, a USGS report declared
fire's effects were always evil,
without a single redeeming feature.
Looking at the effect wildfires had on communities,
this made sense.
As for the health of the forest,
the logic seemed obvious.
Everyone knew fires destroyed forests.
So protecting our public lands
meant stopping fire whenever possible.
As more Americans moved West
and larger fires got more attention,
the battle against wildfire grew into one all-out war.
On the front lines were thousands of firefighters
and backing them
was a nation quick to label fire as the enemy.
That was the beginning of the Fire Prevention Program
that eventually evolved into Smokey Bear,
one of the most identifiable ad icons that exists.
I think more people know Smokey the Bear than Ronald McDonald.
My dad had the Smokey the Bear picture book and, you know,
he was reading me the story,
and I would see...
as a kid I'm looking and all I'm seeing
is a little bear cub with his paws bandaged
from hanging onto the tree and being burned,
and shows the desolate pictures of the burned-out forest.
Fire was evil.
We had to stop it before it destroyed our precious forests.
By mid-century,
America's fire crews
were working to put out every reported wildfire
before 10 a.m. the next day.
The fight was on,
and at least in some places
we appeared to be winning.
In the Mariposa Grove of Giant Sequoias,
looking back through the centuries,
lightning strikes had started fires in the Grove,
every few years until the mid-1800s,
when Yosemite's Managers began stopping these fires
in order to protect the trees.
What happened next, was not what those Managers expected.
Today, after more than a century of keeping fire
away from these trees,
why are Yosemite's Managers intentionally starting a fire
in the middle of the Mariposa Grove?
Well, this is a test fire;
we do this before we commence any prescribed fire,
and that's mostly just a ground truth
to see if we're actually going to get
kind of what we expect.
If we conducted this test burn and noticed
that the fire was starting to creep up
and get into the ladder fuels
and carry up into the canopies,
we would probably have to shutdown,
because we know it's only going to get warmer and drier
as the day progresses.
By the 1960s, a century had passed
since Abraham Lincoln first set aside this Grove.
During that time the National Park Service
kept all fires away from these precious trees,
but looking around the Grove
it was clear that something was wrong.
All the ancient Sequoias remained as we had found them,
but young Sequoias were few and far between.
Despite our protection,
or perhaps because of it,
the next generation of trees was largely missing.
What Yosemite's early Managers failed to realize
when labeling fire as the enemy
was that the Sequoias, like many other species,
actually depend on fire.
Wildfire wasn't threatening the trees;
it was the opposite.
By keeping fire out of the Grove,
we were actually making it harder
for the trees to reproduce.
Giant Sequoias are particularly well adapted to fire.
The cones at the top of the tree will open on a hot day,
so if you get a fire that burns underneath the stand,
most of the cones will open and the seeds drop out.
Once the seeds fall out,
they need to land on mineral soil
in order for the seedling to become established.
So the combination then of the fire burning through,
burning the fuels from the ground,
creating the mineral soil,
having heat go up into the canopy of the tree,
opening the cones,
the seeds then fall down on the mineral soil.
The fire kind of acts more like a vacuum cleaner,
if you will.
It helps kind of clean up the forest floor
and actually reduces some of the smaller trees as well.
Well, if you look at before and after pictures of the Grove,
it used to be much more open
in the understory, on the ground,
you could see and walk for much greater distances
without all of what we call dog hair thickets
of dense understory, underbrush.
With fire, fires would come through
and take out the smaller trees,
would reduce the fuels that were on the ground,
and would generally clean up the forests,
so the fire that did come through was not as intense.
Certain areas in the Park you can't even walk,
you know, it's just choked with so many little cedars,
like you can't get through them, you know, and...
tons and tons of ground fuels.
Suddenly the problem stood up like a sore thumb.
Without fire to open their cones and clear the forest floor,
Yosemite Sequoias were fighting an uphill battle.
By excluding fire,
we had fundamentally altered
the forest we were trying to preserve.
The Sierra Nevada probably looked,
and these are words that the early explorers used,
open park-like is a cliché.
You could ride a horse through the forest
for days without having any problems at all,
and that's a result of the fires
that burned through there regularly.
And we have several methods we use to determine that,
and one of the primary ones is to look at fire scars
in cores of trees.
And from the core,
then you'll see fire scars in the tree rings,
and from that you can tell how often the particular area
would have burned naturally.
So we can say,
if fire burned here every ten years historically,
and we've been putting fires out for a 100 years,
that's probably ten fires
that this particular system has missed.
As it turned out, the plight of Yosemite Sequoias
was only the tip of the iceberg.
By the time foresters realized what was going on,
America had been excluding fire across the country
for almost a century.
The result was, and in many areas still is,
a tinderbox just waiting to burn.
We were shooting ourselves in the foot.
If you leave all that fuel on the ground
and increase the density of the understory,
a fire will come through and actually rage through
and take out the trees
that the previous fires protected.
This goes back to the suppression
for the last 100 years,
just because, you have all of these different layers,
vertical layers in the forest now,
from the ground up to the tops of trees.
And so once,
you know, you get a little flame on the ground,
and it can crawl up a little seedling,
and end up higher and higher,
and once it gets wind and heat on it,
and it has that available fuel from different layers,
it just starts ripping.
A-Rock,
Steamboat,
Ackerson;
these and other unusually destructive fires
ripped through Yosemite
as recently as 1996,
fueled by the very trees
we had so carefully protected.
By excluding fire from our forests,
we broke a natural cycle.
On its face, the problem looks relatively simple,
the solution however is not.
We've stacked the deck against ourselves.
Our forests are now choked with fuel,
deadwood, brush, tightly packed young trees,
all just waiting to burn,
and burn far more intensely than they would have
had we never intervened.
Continuing to exclude all fires
only makes the problem worse.
On the other hand,
after a century of excluding fire,
if we simply walk away
and let all lightning fires burn uncontrolled,
the results could be catastrophic.
I don't think the question is to burn or not to burn;
I think the question is pay me now or pay me later,
is another cliché,
because it will burn,
we know it will burn,
and there is nothing we can do about that.
As foresters begin to see the problem
we had created by excluding fire,
one thing became clear,
we needed to figure out a way to live with fire
instead of fighting against it.
There was no simple solution that could turn back the clock,
but by using what we had learned from fighting fire,
perhaps we could slowly dig ourselves
out of the hole we had created.
Starting in the 70s,
Yosemite's managers broke stride
with traditional firefighting practices
and began carefully allowing some natural wildfires to burn.
Today in much of the Park's designated wilderness,
fires like this one,
started by a lightning strike near Frog Creek,
are allowed to run their course within careful limits.
Right, we're working in an area now where your safety zone
is probably going to be this black,
for the Wapama Fire over here.
It's very important that this fire continue to be a success.
Again, I think we're getting a lot of good ecological benefit.
We're still planning level five.
When July thunderstorm started this fire,
Yosemite's managers looked at the fire history
for the Frog Creek area
and saw the benefits that would result
from allowing a natural fire to burn.
Its location was away from developed areas
and the weather parameters were all right inline
with the type of a fire effects
that we wanted to see in the wilderness.
This section right here is your safety zone.
Safety.
The idea is to carefully use lightning fires
to slowly piece back together Yosemite's natural fire cycle.
Though the goal here is not to stop this fire,
the tactics firefighters use to control it
are the same tactics learned from suppressing fire.
Technology makes the job safer,
and at times easier,
but the most effective ways to control fire
are still the same as when Yosemite's first managers
began protecting Mariposa Grove.
Clearing a strip of ground or fire line
in event of a fire creates a break,
hopefully stopping the fire where we want.
Many such breaks already exist;
rivers, trails, roads, open granite,
and most important, areas that have already burned.
When you have that patchwork mosaic,
a natural fire is out on the landscape,
subsequent fires can't go as far,
they can't build up as much intensity.
They're going to be smaller in size.
They're going to be less intense,
because they're going to run into a recent burn,
and either stop altogether
or drop down all the crowns
and essentially go to ground
and just clean up the dead and down material
from the last burn.
They'll burn for four or five months,
four or five months,
that's your normal fire
is it doesn't move very fast in low intensity.
It's not like this whole uniform just wipe out everything,
it's kind of a mosaic.
You'll have patches,
within the perimeter of the fire that hasn't burned,
it still has the leaves and the litter,
and you'll have areas
that have like totally torched out the canopy,
you know, it's just this nice little patchwork.
Using these patchworks of naturally burned areas
as a collection of firebreaks,
today's fire managers are slowly piecing back together
the natural balance that we originally altered.
This process is slow however,
and it involves the challenge of herding the fires
away from some areas and toward others.
We made a conscious choice
to actually hold the fire to the North side of Frog Creek
and not let it burn to the South side of Frog Creek.
It's really great that the fire is moving in here
and cleaning up a lot of this dead and down material,
but the fire up in these snags
is creating a spotting source
and we're getting spotting across the line.
What we're trying to do is to take this line
just on down to Frog Creek
and then the fire can make its way up North unimpeded.
Some people think that
just because we have a wilderness fire,
we're not out there,
and we're not managing it.
Yes, we are managing it,
and in this particular case,
we wanted to make sure we've managed it
to reduce smoke impacts to communities.
Smoke;
it's the way most of us experience wildfire.
Rarely do we get to see the actual flames of a forest fire,
but one fire can affect thousands or millions of people
with its smoke.
If our goal is to allow natural fires to run their course
and allow these ecosystems to function naturally,
we butt up against some other society values.
We live in a bigger world.
There are other values that are important to society
that conflict with that goal of achieving total naturalness,
and society has deemed that smoke is bad,
and therefore if you are allowing fires
to burn and producing smoke,
then you're responsible for the effects that,
that smoke might have on other communities.
Surprisingly,
I have only had one constituent call and complain
despite the fact that this is going on
for weeks and weeks and weeks now.
Even the low level intensity smoke
is causing people to get irritated over a period of time.
The dilemma that we're in
is trying to balance the ecosystem needs
of having fire on the landscape along with the human needs,
of the desire not to be impacted by smoke.
Naturally there would have been smoke all summer long,
and we're maintaining this artifact of no smoke
for public health reason,
but also for visibility reasons.
And people complain
when they can't see Half Dome on a smoky day,
but they don't complain
if they can't see Half Dome on a foggy day.
We pick on fire because we can.
It is a force that we've thought we could control.
Should we bring in big fans and blow out the fog
so people can see half Dome?
No, you know, should we put out fires
that are burning naturally
so people can see Half Dome?
I think not.
I think we need to accept the natural world
as it presents itself,
particularly national parks,
which are supposed to be places
where people can see their natural heritage,
not a cultural artifact.
Public health,
air quality,
forest health,
safety,
cost,
politics;
the questions faced by today's fire crews
they are far more complex
than those that faced Yosemite's first managers,
but looming behind this balancing act
is the simple truth that ignoring the problem
will only make matters worse.
Four months after lightning struck this tree
and started the Frog Creek fire,
it continues to slowly move Northward.
Restoring this area back to what it might have looked like
before we began putting fires out.
Using lightning fires in this way to ensure our forests
back toward a more natural state
makes sense in a wilderness setting,
but in more developed areas or new landmarks
we're not willing to jeopardize,
allowing natural fires is often just too risky.
These areas still need to burn,
but we want them to burn on our terms.
Jim, the results of the test burn are favorable,
we're going to continue on.
We've got about half a maker.
When Yosemite's managers realized in the 1960s
that they should not have been excluding fire
from this Grove of Giant Sequoias,
they faced a dilemma.
Fire would benefit the Grove,
but the trees were too precious
to risk allowing natural fires into the area,
especially now that the Grove was overgrown
after a century without fire.
One idea was to clear the overgrown forest ourselves
or mechanically thin the understory.
Where fire is just too dangerous to allow,
fire crews still use this option,
but it can be extremely expensive,
and in the end it's only a partial fix.
From an ecological standpoint,
what these forests need is to actually burn.
The solution came from a group of scientists
who were willing to push an idea
that went counter to everything firefighters were used to doing.
We light the Grove on fire ourselves.
This is a prescribed fire.
Some people call it controlled fire.
We just have a set area that we want to burn
and we want to keep the fire in that area.
So the main thing, you want to usually just start
at the upper end of the unit,
establish a black,
what they call black line,
across the top,
let that cool down,
and then you kind of run strips below that
and just keep deepening it
and taking it all the way down to the bottom.
If you light from the bottom,
it's going to race up,
fire likes to race uphill
and then you'll get...
it will torch out the trees and canopy.
There is a rhyme and reason,
it's almost an art form.
The idea of prescribed fire
is based on our need to find a compromise.
There are some areas that we know need to burn,
but we want to control exactly how they burn
and under what conditions.
Yosemite's fire crew has been planning this burn for months,
waiting until this fall day
when conditions are just right for a safe,
but still effective burn.
Leading up to the fire,
crews kept careful track of weather patterns,
watching and waiting for the right opportunity
or window in which to light the fire.
The temperature has to be within a certain range.
Relative humidity and winds also have to be in a certain range.
The wind direction is very important,
that determines where the smoke will go
and how the fire will behave,
and only when all of those parameters are met
and within our narrow windows can we go ahead and proceed
to light the match.
And the winds are light,
one to two from the Southwest.
So the idea is to have the best chance for success
as opposed to a fire
during the worst times of the summer,
when it's too hot and dry.
Once the fire is lit,
by monitoring weather conditions
and carefully containing the burn,
Yosemite's crew strikes a balance,
allowing the Grove to benefit from a much needed burn,
while enabling us to rest assure
that our national treasure won't be harmed.
Throughout the day, crews continue lighting
different sections of the Grove,
slowly working fire through the Giant Sequoias
at a pace that we determine.
All of these plants in this type of forest system rely on fire,
so we're trying to help clean up a little bit of this understory
and bring it back to its normal natural, healthy state.
Unlike the Frog Creek fire,
which burned for over four months before fall rains
finally put it out,
this prescribed fire burns for only a few days,
then quietly smolders for barely a week,
before predicted showers start the winter season.
Next year, Yosemite's fire crew
will ignite another section of the same Grove,
slowly restoring the natural fire cycle
with which these Giant Sequoias originally evolved.
Some of the early Park managers
maybe didn't have the benefit of science
to base their decisions on when it came to managing fire.
The only thing they knew was fire suppression,
and they felt honestly that,
that was the right thing to do.
They were saving the forest.
They were saving lives and property and whatever else,
and honestly felt they were doing the right thing.
Ironically, by lighting these burns
Yosemite's fire crew is continuing the effort
first started by those who fought to keep fire
out of this Grove.
They were doing their jobs
with the best of intentions
and now after learning from their experiences,
we are continuing to do the same.
As much as we know about fire systems in the Sierra,
we realize that there is still a lot to learn,
and part of science is profiting from mistakes,
that in itself guides us
and informs our scientific method,
that we have to keep coming back
and revisiting the assumptions that we've made.
So there's never an end to this.
It's a process that makes you understand
that you have to come out it with a humble curiosity.
The alternatives could be catastrophic.
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