Tropical rainforests are among earth's great drivers of climate.

They are producers of oxygen and absorbers of greenhouse gases.

Part of expanded researchinto how our planet operates... are two different sites dedicated to expanding our understanding... of these huge reservoirs of life.

The Biosphere in Arizona and the rain forest of Costa Rica.

Funding for In the Americas with David Yetman was provided by Agnese Haury ♪ Funding for In the Americas with David Yetman was also provided by the Guilford Fund.

♪ ♪ In the Americas with David Yetman theme ♪ This is the Biosphere located north of Tucson, Arizona.

It's the world's largest earth scienceresearch center.

It focuses especially on water and its effect on human habitation... and natural habitation, ranging from tropical rainforest... To deserts... To oceans.

The world is increasingly running out of fresh water, and this is one place where we're finding out what is really... happening with water and the places where we live.

One of the earth's most important habitats is tropical rainforests.

This largest building is completely dedicated to a study... of how those operate, how water affects the plants, and how everything else enters into that water cycle.

The original Biosphere was established in the late 20th century... to study how humans could survive in space or on other planets.

In the early 1990's after a long series of experiments... a small group of researchers were sealed inside the facility... to see if they could survive in a self-sustaining... closed environment.

Those early experiments ran into complications... and that concept was abandoned.

Columbia University assumed ownership in 1995... and used the facility for research.

In 2007, the University of Arizona took ownership.

And now operates it strictly as a research facility... studying climate change.

Biosphere 2.

We're trying to cause a water cycle in a rainforest.

Recognizing that in Brazil and in other rainforests... probably there'll be drier times and hotter times and we want to know what's going to happen to them.

As the Amazon dries out, as roads are put in through the Amazon... All of that will affect the health of the Amazon... and how much C02█ it can bring in or worse yet if it's going to start pumping C02 out... and we can do that of course by the death of the Amazon.

Come in.

Oh, wow, my god.

The humidity.

What do you think of this?

Oh, my goodness.

Look at that.

Wow!

I think climber's vines do very well in here.

Isn't this beautiful?

When Colombia was running the Biosphere, their main interest... was the reaction of various biomes to C02.

They were able to show that this rainforest sort of topped... out at 800 bpm C02.

So if we ever get to above 800 bpm CO2 in the earth... then the rainforests are not our allies anymore.

They start emitting gases that are greenhouse gases... like isoprene.

So, it reverses the benefit?

Yeah, it reverses the benefit.

We can actually create droughts... and we can create hot droughts or colder droughts.

That's the beauty of the Biosphere as a whole.

We can basically change the variables that control... the health of these biomes.

In addition, what happens when the plants go out through the roof?

Know that we always have to cut them.

You have to cut them back?

We have to cut them back.

They like to grow in here.

They like to grow.

And you know there's an enormous variance in temperature... up by the top.

It's really, really hot.

So we can actually even see how they do... but no we cut them back continuously... and the other beautiful thing about this rainforest... that we have here is that although it... it really is not identical to any rainforest out there... it is an equilibrium.

When they started this rainforest, they had about 400 species... now there's about 150... but these 150 are doing quite well and... we can then do research in here.

And of course, it's not completely natural, right?

Because the pollinators are different.

We do have ants and we have cockroaches... but we don't have birds, and we don't have monkeys... so the way that things pollenate are slightly different... but we can see that the plants that exist here look quite healthy.

...we found things like snails, round worms, flat worms... Scientists at the biosphere are studying rainforests... but in a controlled environment.

Now it's time for the real thing.

We travel to northern Costa Rica... where scientists there are studying rainforests... and their struggle to survive as the world's climate... is undergoing rampant change.

The biosphere is located in the Sonoran Desert.

The closest accessible rainforest is about... 2,500 miles to the southeast, in Costa Rica.

You can fly into the airport in San Jose... get into a vehicle and in an hour to the northeast... be in dense, old growth rainforest.

La Selva preserve is part of the Costa Rican rainforest.

It contains nearly 4,000 acres of old growth rainforest.

We stay within the preserve for a few days... to immerse ourselves in a real ancient rainforest.

...This is the last frontier...

Visitors come from all over the world to La Selva.

Because it is old growth forest and it has accommodations.

Scientists, students and just tourists show up.

There is a lot to see.

♪ Until 1995, the crossing of the river here was almost at great.

It's good this bridge was installed.

It's a suspension bridge and it does rock a lot... but it crosses the river well above the current.

Its capacity is 15 persons.

And there's a warning, swim in the river at your own risk... because there are crocodiles.

These piranha relatives are not dumb fish.

Not at all.

Not at all.

And like most piranha relatives they are vegetarians.

They are waiting for this seeds and fruits... that fall from the trees that grow along the stream.

Certainly are able to immediately assess if there's something... edible or not and then if it continues to fall they will lose interest.

♪ Carlos de la Rosa is in charge of La Selva.

And he oversees the myriad scientific projects... that are going on at all times.

He is an expert on rainforests.

The rainforests is an incredibly rich assemblage of species... that are in this band across the world.

You have the Tropic of Cancer.

And the Tropic of Capricorn.

and within that band are the conditions... for the creation of these assemblages... of very, rich, very unique type of species.

and you have them rainforests in the Americas, rainforests in Africa, rainforests in Asia, in Australia, even China has rainforests.

But all of the species have formed this package of species... are going to be different in those different continents.

And now we are zooming into Costa Rica.

What you see here is all the main rainforests... and dry forests and types of forests that are left in Costa Rica.

Here is La Selva where we are right now.

We are attached to the Braulio Carrillo National Park, which is one of the large national parks in Costa Rica.

We are 1,600 hectors of land and attached to 44,000.

So we have a continuous forest in this whole region that is protected So we have a continuous and is a laboratory regi for studies.

ected and is a laboratory for studies.

But all of these have few generations ago, 30, 40 years ago, this was all rainforest and it was all covered.

We have lost a lot of the forest somewhere in the process... of trying to bring some of the forest back.

So, if we zoom into this little bit and this region, then you get a kind of a 3D view of where we are here.

Here is La Selva.

This is called a Barba corridor and then the bralica region.

35 meters above sea level and a continuous forest... through almost 3,000 meters in here.

This is one of the last, if not the last remaining... forest corridors, rainforests left in Latin America.

In central America, at the very least.

And we have a trail that goes up there... and shows us where researchers can study... what's happening at different elevations.

Because elevation is the other factor... that changes the rainforest.

♪ This is my office and this is my lab as well.

This is where we do all the work for 300 scientists that are working here at the station every year.

And many of those scientists have turned their projects... into climate change, climate science projects... because that's the big topic that is impacting all of us.

because that's the So the temperatures increasing, we know that.

So the temperatures increasing, we know that.

That's data, we have that data here.

We have generated it.

So we're monitoring what is happening to the trees, what is happening to the birds, the amphibians, he mammals as the temperatures change... and you notice that they over time in t hese are decades... that things are going to start moving upwards.

Moving upwards, where it's cooler.

Yeah.

Exactly.

So what happens to the ones that live on the top?

They have nowhere to go.

Exactly.

So you have cloud forest species that are accustom... to having a ball in this very specific conditions... at the top of the mountain.

They are going to get squeezed out.

We don't have the Avatar floating mountains for them to jump into.

So they are going to disappear so we need to know this.

We need to be able to predict what level changes... and what temperatures are going to happen so we can... design strategies to deal with it.

So part of the lab's work is to tie the work of the scientist... to the citizens, into a citizen's science project... and what we do is we measure this tree, we know these trees like children.

This is where we always measure this tree... at that particular height and then we use this tape that is designed for this.

They tie it so there is no air and we can tell... exactly how wide this tree is and this is done over decades and then l onger the database is, the more interesting it gets with the story of this plants... and what makes them tick literally and what makes them grow.

This is important for us to predict... what is going to happen to them... as the temperatures and the precipitation patternschange over time.

During that last wet season, the more rain we get... the trees grow more over time.

And that seems like an obvious thing but now we have data.

The other thing we didn't expect, here's where it ties to the whole big picture... and it's a scary picture.

If we know that the temperature overall... continues to increase over time... then there's a point where this trees are going to grow... less and less and they are going to stop growing... and when they stop growing then they might start dying... and if they start dying, this forest in 20, 30, 50 years is going to change.

The scientific moral of this, is the species that are in mid-range, not at the bottom or the top, they can move one way or the other.

But those at the bottom have nowhere below to go.

Those to the top have nowhere up to go.

And they're the ones that are going suffer the most... or they're going to see the most dynamic in change... for better or for worse.

Even those that can move still have to have the place to move.

If we can continue to reduce the amount habitat... available for them, not even the most adaptable ones... can change and survive if they don't have the habitat to live in.

♪ Look at this, look at that.

A beehive.

Yes.

Let's get closer.

Alright, I'm trusting you Carlos.

Yes, yes.

Because these are bees.

Yep.

And apparently you're not afraid of them.

No, because they're stingless bees.

So the nest is down there... and in their nest they have marble size chambers... made out of wax... some of which are filled with pollen... and others are filled with honey.

And it's the sweetest, sweetest honey that you will ever taste.

Uh-huh.

And look up here.

We have a land snail and this right next to it is an oothecal... this is the egg case of a praying mantis.

Just hear you know in this square meter of forest... you can find life histories and stories to tell... about plants and animals.

♪ I have probably walked into this trail a thousand times... in the last few years and every time I walk in the trail...

I will see something that I've never seen before.

A species that showed up and we've never seen it... or an interaction, a moment that I've never seen... like butterflies drinking the tears of caimans,and on and on.

All the species have a unique story.

♪ And then the noise, you're going to pick up all of this, cicadas and birds and the rustling of life.

This is the perfect recycle machine, a hundred percent of everything... that this forest produces gets recycled.

Most of the biomass, most of the carbon... and the tissue is above the ground.

It's above the ground.

So with all the heat here and the moisture this recycles really quickly.

Very, very quickly.

♪ La Selva employs a number of guides, people who grew up in the area and are intimately familiar... with this forest and many of its creatures.

Here is this little, little viper.

This tiny little thing.

What is it?

And how dangerous is it?

This is called the hognose viper, one of the four types of vipers we have here.

Hognose viper, I've never seen one.

This is really camouflaged they can have different colors.

Some of them... this is a beautiful light one, but there are some darker ones that are more difficult to see.

Little viper, could give you a fatal bite.

That could kill you.

The name of this one is the poison-dart frogs or poison-arrow frogs.

It is actually poisonous and it's poisonous enough... to be protected from some possible predators.

The family, within the family there are species just in Colombia... would maybe put the poison in the arrows and darts... for hunting animals, like monkey for example.

It's only an inch long, and still even at that size... they can produce that much toxin.

This is a species just a little, just for protection.

But the other species in Colombia are very dangerous.

Where is the poison?

It's all over the skin.

This palm has very strange roots on it... and man they're covered with spines.

Yeah.

Yeah.

They're very sharp-y.

Ouch.

Yeah they are.

Yeah.

They coming from this plant growing from here... down to the ground and this plant keeps growing higher... then this root system is going to be higher and higher, and this one is broken so you can see before it has been eaten... and these are eaten sometimes by the peccary...

So the outriggers of this huge wassimo tree have made... a hole here where water can collect in soil.

And this tree has taken root.

And you're telling me it's a relative of the nutmeg?

Yeah, this is one of the trees in the nutmeg family.

And that's wicker, that they make furniture from.

And that's wicker, that they make furniture ....That's wicker... ....That's wicker...

So just in that little extra part of this tree two other fascinating aspects.

You call these bullet ants?

Bullet ants, yes.

Why are they called bullet ants?

They're huge.

Some people believe that it's like being shot, if you get stung by one of these.

Really?

Yeah, these ants are found everywhere through the forest... they have their colonies in the base of the trees... like this, you can see the hole right there.

You warned me when we came up to not get to close to the bottom.

Yes, because that's where they live.

Yes, because that's where Yeah.live.

Yeah.

They move mostly up and down the tree... and they go on the vines and these ants can be found anywhere else, solitary in the forest.

Sometimes when you move the branch or the tree... they can just stop the mouth and you put your hand on them.

Oh my goodness.

And that's a way to discover them.

Yeah.

And you remember them for quite a while.

Yes, that's right.

So, these ants are very common here.

According to some scientists, they are only about... every 50 square meters in the forest.

So, they're quite common.

You know, you are lucky today.

Because these animals are not found all the time... so okay, what they do is they pick a leaf like this... and they cut it along the midriff, like you can see here.

See they cut it and to make the tent, that's why they're called tent-making bats.

Tent-making bats.

Yeah.

So, we have a big diversity of bats in these forests, so they have been around in different situations.

The difference are using this kind of leaf as a place for resting.

They're so tiny, that's a full-size.

That's a full adult-size?

Somebody believes that when they light comes through the leaf, they look green and that makes them more difficult to distinguish.

Well they do.

That's correct.

They actually look like green fruits in there.

So, one of those projects that deals with the changes, is the camera trap project.

We set up cameras....

Camera traps (laughs).

Yep.

Called Camera traps.

You don't touch them animal you just take the picture.

You know, the selfies.

Animals selfies.

They set cameras on the floors... and paths in the different areas, and as the animals cross█ this infra-red camera they trigger the camera, so they take their own pictures.

Or their own videos.

Over time you can not only document what species... are moving around those areas, their densities, their persistence, their number are increasing or decreasing.

This is a little experiment that we got right here.

Because we have been smelling the animals underneath the bridge, so we know that there has been an ocelot coming here.

Then we have in total, eighty cameras on three different study sites.

Okay...so this is the, this is the gold, right here.

This is what we want.

It's a lot of fun to go through these pictures.

Because you get so much interesting behavior too.

So, when an animal passes the camera... they will start recording or start taking photographs.

So, here we are at one of the sites, where we put up the camera.

So, we have a mother puma walking by... and you see a juvenile coming out after her.

So, that's her cub?

That's her cub, yes.

See we got a very beautiful tapir too the other day.

Oh my goodness.

That's pretty exciting.

Because we haven't had a lot of tapirs, in La Selva recently, they seem to be increasing a little bit.

We have a lot of puma pictures here and what we get most here at La Selva, are these guys.

They are everywhere.

So, when I'm sitting heregoing through, sometimes thousands of pictures of them.

Peccary, peccary, peccary, peccary.... Something other very interesting that we have never... gotten here on camera at La Selva before is the jaguarundi.

So, right here we have him walking or her, walking on the trail...

This is very exciting; so, this is one of the other...

They are elusive animals.

They are very elusive.

So, over time, you will be able to see the trend... and you can say well the pumas are decreasing... in numbers or the predators.

You can do it at a species level and a group level, and then be able to see the changes, how it relates to the environmental measurement... that you're making, after regular face and be able to predict.

The ability to make predictions, is critical... for us to find the solutions.

♪ Carlos and I see the forest from the ground.

To get a more complete picture, we need to see it from above.

Above the canopy.

A hundred feet high.

La Selva has a tower for just that purpose.

People still need to go up on trees to do research, so they use ropes, they go up on the trees... and they move along the branches, where they need to.

Where they establish some data and some cases to do research.

(laughs) From here you can look down and almost not see the ground.

So already you have that influence of the huge rainfall... and realize that the ground, they will never get direct rain.

Right?

It hits the leaves first.

Eventually gets the rain down there, but the light is scarce down there, too.

Yeah.

That's why you mostly see palms in the understory.

And they are a lot big broad leaves.

So, a part of a rainforest is an... everlasting battle for life.

Now we're up, canopy level, at least here and most of the trees, not all of them, are below us.

Yes, it's a different world.

Wow, it's like looking over a sea of green.

If you're in a tower like this, at this level... you can see some birds moving in the canopy, sometimes you get to see the monkeys very close to you, you can better understand their behavior.

♪ La Selva Biological ResearchStation is a pristine example... of the great Atlantic, Caribbean rainforest.

Four years ago, that forest extended with its canopy, almost unbroken up into Nicaragua and south of the city of San Jose, since that time it has been greatly compromised by the... expansion of pastures and agriculture.

One of the challenges, of La Selva and the biosphere... is to find ways that we can accommodate the growing... needs of the population that is hungry and the... need to protect rainforest, in way that does not undermine the very basis for human life.

Join us next time in the americas with me David Yetman When the Spaniards arrived in the America's They chose a large island to █construct their first capital city.

They call the island Hispaniola.

Today, the Hispanic part of that island maintains a strong heritage of Spain.

But over the centuries its European ethnologies has mixed Hello everyone, we are from China.

And we will spend the day taking pictures of the birds... and now we have spent several days here now.

And we have taken about 160 types of bird photos here.

Funding for In the Americas with David Yetman was provided by Agnese Haury Funding for In the Americas with David Yetman was also provided by the Guilford Fund.

Copies of this and other episodes of In the Americas with David Yetman are available from the Southwest Center to order call 1-800-937-8632 Please mention the episode number and program title Please be sure to visit us at intheamericas.com or at intheamericas.org