All language subtitles for E02 - Water Worlds_Track7

Plants cover

much of the land surface
of our planet.

But there is another
extraordinary green world

that is often hidden from us.

It's one where plants
have overcome huge challenges

in order to survive.

The world of freshwater.

At first sight,

a lake like this
would seem to have

everything that life needs
in order to thrive -

clear, oxygen-rich water,

plenty of dissolved nutrients
and minerals

and lots of sunlight.

But in fact, life in freshwater

presents plants
with huge problems.

To succeed, plants have had
to abandon

many of the adaptations

that have served them
so well on land

and evolve something quite new.

And in doing that,

they have created
some of the most beautiful

and bizarre and important
habitats on Earth.

There are few places
where it's more difficult

to make a permanent home

than a freshwater torrent
like this one.

Violent currents
rip across the riverbed,

scouring it clean...

...ripping land plants
from their margins...

...and drowning them.

How could any plant survive
in a place like this?

Yet even here, some do manage
to, quite literally, hold on.

They can grasp the bare rock
with remarkable strength.

This ability
allows plants to thrive

in these otherwise
hostile environments.

This is
the Caño Cristales river

in Colombia.

These plants are red macarenia,

sometimes called
the orchid of the falls.

They cling to the riverbed
not with their roots

but with their stems,

glued to the rock surface

by one of the most powerful
adhesives in nature.

The rock itself will break

before these anchors
lose their grip.

These feathery filaments
are their modified leaves,

and they do what roots
normally do -

gather the minerals
and nutrients they need

that are dissolved
in the water.

With such spectacular colours,

it's hardly surprising

that the Caño Cristales
is sometimes called

the most beautiful river
on Earth.

But being rooted to the spot

is not always the best strategy

for living in a water world.

This is a water lettuce,

and it has
some remarkable adaptations.

Its roots hang freely.

So it's not anchored
to the ground.

And its leaves
are thick and spongy

and covered in fine hairs,

so the plant itself is,
more or less, unsinkable.

This combination
of characteristics

enable the water lettuce
to do something

that almost no land plant
can do -

it can travel.

It is an ability
that becomes invaluable

when, during the wet season,

flooded rivers
become great highways,

as they do here,
in South America.

This is the largest inland
water world on Earth,

the Pantanal.

For a few months every year,

it provides water plants
with ideal conditions.

But all too soon,

it becomes a battleground.

Plants are racing to claim
their space on the surface.

The water lettuce
rapidly expands

its network of hanging roots

so that it starts
absorbing nutrients

before
other competitors arrive.

Water hyacinth appears.

Its leaves
are carried on stalks

filled with air

that also make it
virtually unsinkable.

The race for space intensifies.

A new competitor arrives -
ludwigia.

It spreads by developing
a chain of tiny rafts...

...and jostles for space

with the densely packed leaves
of mosaic plants.

All are racing to claim
as much sunlight as possible.

They flower quickly,
before the floodwaters recede.

And these surface dwellers
also have competitors.

Including one
that has been waiting

in the depths...

...and is now stirring.

It's a monster.

It's well armed.

It clears space for itself...

...by wielding
one of its buds...

...like a club.

And now...

...it dominates the surface.

This is a leaf
of the giant waterlily.

It expands
by over 20 centimetres a day

and eventually measures
more than two metres across.

Its immense leaves
are supported

by a network
of air-filled struts

and protected by spines
two centimetres long.

The leaves float high
in the water,

and their surfaces are dotted
with tiny holes - drains -

that help them ensure

that rainwater doesn't
accumulate and sink them.

Nutrients from the fertile mud
below

are carried up by tubes
in its stem

to fuel the leaf's expansion.

Over the next few months,

the lily will produce
some 40 or so

of these gigantic leaves.

And as each one reaches
the surface and expands,

more and more light is taken

from those plants

that are trying to grow
beneath.

Competitors are pushed aside.

Some are crushed...

...or skewered.

Eventually, its immense leaves
press their margins

against one another,

totally cutting off the light
from the plants beneath them.

The battle is over...

...and victory is total.

The frozen water world
of Lake Akan,

in northern Japan.

Home to one of the strangest
and most primitive of plants.

It's an alga,

like those that appear
so mysteriously in our ponds.

But this one
is truly extraordinary.

Each spring,
the melting ice releases

soft, velvety balls
of interwoven threads

called marimos.

This one is small,
no bigger than a walnut.

But there are
lots of them here.

They attract the attention
of visiting whooper swans.

But there is one way
for the marimo to escape

from the danger,

and it depends on
a change in the weather.

Fortunately, in the spring,

winds sweep across the lake...

...creating currents
that carry some of the marimos

beyond the reach
of hungry swans.

It's the start
of a remarkable journey.

They are gently carried
back and forth

by the currents

so that the marimos become
more and more spherical.

And slowly,
they travel into deeper water.

Here, there are
great numbers of them,

certainly many millions.

Some are the size
of basketballs.

They are safe from swans

and the water
is still shallow enough

for some sunlight
to reach them.

It seems a perfect home.

And so it is.

Almost.

The snag is that these waters
also carry a fine sediment

that can clog
the marimos' surface,

cutting off
the all-important light.

But the marimos
are not entirely immobile.

They dance.

The winds blowing
over the lake's surface

create currents beneath

that are sufficiently strong
to move the marimos.

They rub against each other.

And, in just a couple of hours
of gentle movement,

they're all clean once more.

As they spin,

every part of their surface

gets enough time
in the sunlight

to keep growing.

This is the heart
of the Amazon.

There are water worlds here
that are so remote

that, even today,
few people have ever seen them.

This barely explored tributary

is Rio Claro.

And here,

when conditions are just right,

it's possible to witness

a rare
and remarkable spectacle.

The river is so crystal clear

that its bed is bathed
in sunlight.

A magical landscape
of miniature mountains

and valleys.

It's carpeted by pipewort,

fanwort and star grasses.

As the sun climbs in the sky...

...bubbles of gas appear.

Evidence of photosynthesis.

Deep inside the plant cells,

tiny structures
called chloroplasts

move towards the light.

They absorb carbon dioxide

and use the sun's power
to synthesise the sugars

that the plant needs to grow.

And, as a by-product,
they release oxygen...

...the gas that we

and all other animals

must have
in order to breathe.

Now, in late afternoon,

bubbles of oxygen
make the river water fizz

like champagne.

The plants can become
so buoyant with gas

that they rise
to the surface...

...even carrying the bedrock
with them.

Only in this remote water world

can this spectacular
natural wonder be seen.

Eastern Venezuela.

Here, rectangular
table mountains known as tepui

stand above
the tropical forest.

There are more than 50 such

isolated mountain plateaus
here,

each home to
a unique community of plants.

Downpours are so torrential
that no soil can accumulate

on their broad, rocky summits,

and some plants living up here

have to find their nutrients
from another source.

These are bromeliads.

Their leaves are shaped
like a funnel

and collect rainwater,

which accumulates
in the centre.

This small pond is colonised
by all kinds of tiny animals.

And it is their bodies,
when they die,

that provide
some of the nutrients

the bromeliads need.

This makes a good partnership,

in which both parties
can thrive.

But it can be exploited...

...by a plant predator.

This probing stem

belongs to a plant called
a bladderwort.

It too is in need of nutrients.

And a well-stocked
bromeliad pool

is just the place to find them.

This one is full
of aquatic animals.

The bladderwort
begins to change...

...into a hunter.

It develops bladders

and removes sufficient
of the water within them

to create a partial vacuum.

Each bladder has a trap door
beside it with trigger hairs.

And now all the bladderwort
has to do...

...is to bide its time.

It only takes one touch

for the trap door
to snap open...

...and suck in its prey.

It's all over in a millisecond.

And after it has fed,

a bladderwort has enough energy

to produce another tendril,

to search
for another bromeliad pool.

Swamps and bogs
are also poor in nutrients.

So several plants
that live in such places

catch insects too,

if they can.

The leaves of sundews

are covered
with long red hairs,

each tipped with a droplet.

These glistening globules
are in fact glue.

Once the sundews detect

the taste
of their victim's body...

...they flood it
with digestive enzymes.

The little body disintegrates.

And the sundew gets
the nutrients it needs.

Another plant has
an even more elaborate way

of catching a meal.

The Venus flytrap has leaves

that are lined
with interlocking teeth.

It attracts insects
by producing a sweet perfume,

just as a flower does.

It too has a hair trigger.

And another insect is caught.

But the technique
is more complex

than it might seem.

The Venus flytrap
has a problem.

It needs to avoid
false alarms -

snapping shut
on something inedible,

like a raindrop
or a little bit of twig.

That would be a waste
of both time and energy.

So how does it avoid that?

Well, it does it by counting.

If I touch this one
sensitive hair just there...

No reaction.

That could be a false alarm.

But the plant remembers that
for 20 seconds.

And if I touch it a second time
within that time...

...then that's much more likely
to be worth eating.

And so...

...it closes!

So far, so good.

But now it needs to be
absolutely certain

that it's got something
worth eating,

so it continues counting.

Only after it has totted up
five separate touches

to those hairs

will it give the final squeeze

and then begin to produce
the liquid

from the surface of the leaf

which will dissolve the body
of its unfortunate victim.

The flytrap now has
enough energy

to produce flowers

and attract
pollinating insects.

Wind and insects,
between them,

pollinate
virtually all land plants.

But neither method can be used

by plants that live
entirely underwater,

so some lead double lives.

At York Stream,
in southern England,

and swaying in the current

is a plant for which
these rivers are famous.

This is water crowfoot,
a kind of aquatic buttercup.

For most of the year,
it is underwater.

And if I take
this underwater camera...

...you can see its floppy stems
grow horizontally.

That reduces the risk

of being swept away
by the current.

But each spring,
when it's time to flower,

it produces something
crucially different.

A stem that is stiff enough
to resist the current...

...and lift its flowers
into the air above.

And now, of course,
they can get help from insects.

So, every year,
in part at least,

water crowfoot
becomes a land plant...

...and provides us

with one of the loveliest
natural spectacles

of the early English summer.

Water crowfoot is not
the only water plant

to lift its flowers
above the surface.

Plants do so
all around the world.

From the swamps
of the Pantanal...

...to the lakes of Thailand...

...they all burst into
spectacular bloom.

Once they've been pollinated,
they produce seeds.

And now their flowers
have done their job,

some return to a life...

...underwater.

Now they must ensure

that some of their seeds

will find suitable places
in which to germinate.

Bulrushes, every year,

produce these long,
brown, velvety objects.

Look what happens
when I break one open.

It contains almost
a quarter of a million seeds.

Each seed is attached
to a delicate parachute.

Even the slightest breeze
will lift it

and may carry it
for very long distances indeed.

So even though suitable
stretches of freshwater

are few and far between,

there's a good chance
that at least one

will end up in a place
where it can grow.

Much bigger seeds, of course,
can't travel by air.

A river can provide transport,

but it's a one-way journey -

downstream -

that often ends up in the sea.

And that's not ideal.

So how can any riverside plant
avoid this

and travel upstream?

Here, along the Bonito river,
in Brazil,

a variety of trees
manage to do exactly that.

They embed their seeds

in the middle
of soft, sweet fruit.

Monkeys,
such as these capuchins...

...make a meal of them
just as soon as they're ripe.

But monkeys
are very wasteful feeders.

And what's not eaten...

...ends up in the river
and is washed away.

But not all.

In the fruiting season,

hundreds of piraputanga fish

gather beneath these trees.

But the piraputanga want more
than the monkeys' leftovers.

The brightly coloured fruits
are clearly visible,

even to the fish
in the water below.

And some manage to claim them

even before a monkey does.

This isn't a skill mastered

by just one particularly
successful acrobatic fish.

Many of the piraputanga
can do this.

Nor is this a disaster
for the tree.

Far from it.

These piraputanga
are migratory,

heading many miles upriver
to spawn.

The trees, by enticing the fish
to eat their fruits,

have a perfect means of
transport for their seeds.

With luck, the seeds
will be deposited

many miles upstream.

The ability to colonise
new habitats

has allowed one group
of flowering plants

to venture out of freshwater

and into a world that may look
the same to us...

...but for a plant
is crucially different.

The much greater,
saltier world -

the sea.

This is a fruit from one
of the most important plants

on the Earth today.

Sea grass.

This particular one is floating
off the coast of Formentera,

in the Mediterranean.

100,000 years ago,

a sea grass seed like this

sank to the sea floor
just here.

And eventually, it produced...

...a great meadow.

A meadow that is still
flourishing today.

It did so by cloning itself.

Now over ten miles across,

it's not only
one of the largest

living organisms on Earth...

...it's also one of the oldest.

And it supports
a rich community

of many kinds of animals.

It's become
a kind of marine savanna.

Over a thousand species
now live here.

Some, like these elegantly
camouflaged pipefish,

live nowhere else
but amongst the sea grass.

Sea grass fringes
many of the world's coasts.

Turtles depend upon it, too.

And so do dugong,

animals
that are sometimes called,

very appropriately, sea cows.

Today, sea grass
plays a critical role

in maintaining the health
of our planet.

It creates stores of carbon
around its roots

at an enormous rate -

35 times faster, in fact,

than plants that live
on the floor

of a tropical rainforest.

Here, off Formentera,

it's possible to see
beneath the living sea grass

layer upon layer
of trapped carbon

that the plants
have accumulated

over the past 2,000 years.

Sea grass, however, is easily
destroyed by human disturbance.

A third of the world's
underwater meadows

have already been lost,

and many more
are in decline.

Biologists are now striving

to not only protect
the remaining meadows

but to restore them.

One plant at a time.

Sea grass could be
a valuable ally

in our fight
against climate change.

Today, water worlds everywhere
are under threat.

Many of their inhabitants
are disappearing

without us even being aware
of their existence.

The plants that grow in water

are probably
the least noticeable.

They're certainly
the least studied.

But the more you know

about the problems
of living in that way,

the greater the wonder
of their success.

Surely, they deserve
more of our attention

and, most importantly,
our care.

This vast wetland
is the Pantanal.

The Water Worlds team

are heading
to a plant battlefield -

the home
of Brazil's giant waterlily.

This is like seeing
the end of a war -

there are leaves growing
on top of each other,

flowers going through leaves...
Unbelievable.

To capture this story
in all its detail

would take over a year

and require a unique
Green Planet approach,

both filming here

and in a parallel
mini Pantanal,

in deepest, darkest...

...Devon.

This is the unique world

of specialist time-lapse
cameraman Tim Shepherd.

Tim has the reputation

of being able
to think like a plant.

It's absolutely crucial

that you get the plant
really happy.

And to make the giant lily
feel totally at home,

Tim must build a little piece
of Brazilian wetland.

First, a 10,000-litre tank.

Hundreds of bricks,

almost a thousand kilos of soil

and countless cups of tea
later,

the foundations are complete.

So far, so good.

Now time to prepare

for the new Green Planet
camera system.

That way.

We're trying to assemble
the main gantry framework

so that we can mount
the moving rig on top of it.

So it's a bit of a fiddle
to get all the screws

in all the right places,
basically.

After a few weeks,

the building works
are complete.

The flood can now begin.

Tim needs to be sure
everything in the room

is heated
to tropical temperatures...

Ah!

...before the star of the scene
can move in.

Carefully grown
at the Royal Botanic Gardens

at Kew, especially for us.

Everything depends
on this one plant.

There will be no time
for a second attempt.

And even more important
for Tim,

to keep his guest
happy and healthy.

This big monster
needs a lot of feeding.

We've found we need
about five sandbags

full of compost
every two or three weeks.

So we just sort of
lower them in

and stick them
down by the roots.

Whoa! There we go.

Whilst the Devon giant
settles in...

...the Pantanal crew

are continuing
to get their shots.

Time to see

some giant waterlilies
underwater,

and I hope there's no anaconda.

Oof!

Mission accomplished.

The pressure is now on Tim.

After months of pampering,

the giant lily
is ready for action.

First thing to film
is a leaf spike rising up

from the depths.

Luckily,
there are no anacondas here.

The special camera
weighs over 40 kg.

It's suddenly become
less heavy, which is good.

The new rig

means Tim will be able
to follow

the emerging plant
in any direction.

Whoa! Fancy!

The technology is working well,

but nature is starting
to derail Tim's plans.

Getting really tangled up
with all these weeds!

What happens is,
we've got

a bit of an ecosystem
developing here.

Before you know it,
you get masses and masses

of algae growing
in amongst it all.

Eugh!

Gah!

I think I've just released
some anaerobic gases there.

No, not me, the...

...the algae.

State-of-the-art tools
help keep the algae at bay.

Eugh!

Just in time
for Tim to film liftoff.

Well, that's quite nice,
coming out of the water.

Look at that!

Tim's focus can now shift

to the battle that's starting
to take place on the surface.

Well, I'm trying to film

this new bud
coming out on this lily leaf.

It's going to take
about three days

to grow from where it is now

to somewhere in this zone,
between these two other leaves.

I want that to last
about ten seconds.

Ten seconds
is about 250 frames.

That works out to about
one frame every 20 minutes.

But plants don't read scripts.

It's nature -
it doesn't always do

what you think
it's going to do.

We've had a few false starts,

where the leaf has swung out of
shot and gone somewhere else.

Or it just grows a lot quicker
than you thought.

It's a challenge
to get things right,

but with the combination
of Tim's expertise

and the new camera system,

results are starting
to look good.

I think the difference now
with this series

is we can bring the plants
much more to life

as characters

and tell their story
in a much more dynamic way.

It's great to be able
to follow them around,

much more in the way
you'd film an animal behaving.

These rigs have given us

a whole new realm
of possibilities.

After over a year of filming
and recording

100,000 separate images,

the secret life
of the giant waterlily

and the battle of the Pantanal
has been revealed.