- 2 days ago
Explores bizarre and beautiful water plants, which use nature's super-glue, counting, and killer spikes to get a leaf up...
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00:04The
00:33Plants cover much of the land surface of our planet,
00:37but there is another extraordinary green world
00:42that is often hidden from us.
00:57It's one where plants have overcome huge challenges in order to survive.
01:11The world of fresh water.
01:27At first sight, a lake like this would seem to have everything
01:33that life needs in order to thrive.
01:37Clear oxygen-rich water, plenty of dissolved nutrients and minerals,
01:43and lots of sunlight.
01:46But in fact, life in fresh water presents plants with huge problems.
01:56To succeed, plants have had to abandon many of the adaptations
02:02that served them so well on land and evolved something quite new.
02:07And in doing that, they have created some of the most beautiful
02:12and bizarre and important habitats on Earth.
02:22There are few places where it's more difficult to make a permanent home
02:27than a fresh water torrent like this one.
02:30There are few places where it's more difficult to make a permanent home
02:43than any of the developers for the last year.
02:45In the province, the scientists have found a big part of their own
02:46Two other people are following the land in the land.
02:47While the and those people are in the land
02:48are active and beginning to grow.
02:51And when they are being liberated,
02:53to the land in the land,
02:54the rest of their land are not subtle.
02:58You can act like this.
02:59You can not only understand the land.
02:59Well, what are the land?
03:03Ripping land plants from their margins and drowning them.
03:12How could any plant survive in a place like this?
03:28Yet even here, some do manage to, quite literally, hold on.
03:38They can grasp the bare rock with remarkable strength.
03:49This ability allows plants to thrive in these otherwise hostile environments.
04:00This is the Caño Cristales River in Colombia.
04:20These plants are red Macarenia, sometimes called the orchid of the falls.
04:37They cling to the riverbed not with their roots, but with their stems, glued to the rock surface by one
04:45of the most powerful adhesives in nature.
04:55The rock itself will break before these anchors lose their grip.
05:10These feathery filaments are their modified leaves, and they do what roots normally do.
05:18Gather the minerals and nutrients they need that are dissolved in the water.
05:28With such spectacular colors, it's hardly surprising that the Caño Cristales is sometimes called the most beautiful river on Earth.
05:45But being rooted to the spot is not always the best strategy for living in a water world.
05:54This is a water lettuce, and it has some remarkable adaptations.
06:02Its roots hang free, so it's not anchored to the ground.
06:08And its leaves are thick and spongy and covered in fine hairs, so that the plant itself is more or
06:17less unsinkable.
06:27This combination of characteristics enable the water lettuce to do something that almost no land plant can do.
06:35It can travel.
06:40It is an ability that becomes invaluable when, during the wet season, flooded rivers become great highways, as they do
06:50here in South America.
06:57This is the largest inland water world on Earth, the Pantanal.
07:04For a few months every year, it provides water plants with ideal conditions.
07:12But all too soon, it becomes a battleground.
07:25Plants are racing to claim their space on the surface.
07:30The water lettuce rapidly expands its network of hanging roots, so that it starts absorbing nutrients before other competitors arrive.
07:56Water hyacinth appears.
08:07Water hyacinth appears.
08:15Water hyacinth appears.
08:32It's INTENSIBLE
08:42or are racing to claim as much sunlight as possible.
08:56They flower quickly before the floodwaters recede.
09:12And these surface dwellers also have competitors,
09:18including one that has been waiting in the depths and is now stirring.
09:34It's a monster.
10:04It's well-armed.
10:21It clears space for itself by wielding one of its buds like a club.
10:36And now it dominates the surface.
11:00This is a leaf of the giant water lily.
11:25It expands by over 20 centimeters a day and eventually measures more than two meters across.
11:37Its immense leaves are supported by a network of air-filled struts and protected by spines two centimeters long.
11:51The leaves float high in the water, and their surfaces are dotted with tiny holes, drains, that help them ensure
11:59that rainwater doesn't accumulate and sink them.
12:17Nutrients from the fertile mud below are carried up by tubes in its stem to fuel the leaf's expansion.
12:33Over the next few months, the lily will produce some 40 or so of these gigantic leaves.
12:49And as each one reaches the surface and expands, more and more light is taken from those plants that are
12:57trying to grow beneath.
13:12Competitors are pushed aside.
13:38Competitors are pushed aside.
14:13Competitors are pushed aside.
14:20Eventually, its immense leaves press their margins against one another, totally cutting
14:27off the light from the plants beneath them.
14:32The battle is over, and victory is total.
14:57The frozen water world of Lake Akan in northern Japan.
15:06Home to one of the strangest and most primitive of plants.
15:14It's an alga, like those that appear so mysteriously in our ponds.
15:22But this one is truly extraordinary.
15:32Each spring, the melting ice releases soft, velvety balls of interwoven threads, called
15:41marimos.
15:46This one is small, no bigger than a walnut.
15:51But there are lots of them here.
15:59They attract the attention of visiting hooper swans.
16:30This one is small, no bigger than a walnut.
16:32But there is one way to get rid of their own animals.
16:33for the marimo to escape from the danger and it depends on a change in the weather.
16:44Fortunately, in the spring, winds sweep across the lake,
16:51creating currents that carry some of the marimos beyond the reach of hungry swongs.
17:01It's the start of a remarkable journey.
17:22They are gently carried back and forth by the currents
17:25so that the marimos become more and more spherical.
17:36And slowly they travel into deeper water.
17:53Here there are great numbers of them, certainly many millions.
17:59Some are the size of basketballs.
18:08They're safe from swans and the water is still shallow enough for some sunlight to reach them.
18:16It seems a perfect home.
18:19And so it is.
18:22Almost.
18:25The snag is that these waters also carry a fine sediment that can clog the marimo's surface,
18:33cutting off the all-important light.
18:38But the marimos are not entirely immobile.
18:52They dance.
19:02The winds blowing over the lake's surface create currents beneath that are sufficiently strong
19:09to move the marimos.
19:18They rub against each other and in just a couple of hours of gentle movement,
19:24they're all clean once more.
19:33As they spin, every part of their surface gets enough time in the sunlight to keep growing.
19:40They're all clean.
19:58This is the heart of the Amazon.
20:18There are water worlds here that are so remote that even today few people have ever seen them.
20:27This barely explored tributary is of Rio Claro.
20:34And here, when conditions are just right, it's possible to witness a rare and remarkable spectacle.
20:51The river is so crystal clear that its bed is bathed in sunlight.
21:02The magical landscape of miniature mountains and valleys.
21:22It's carpeted by pipewort, fanwort, and star grasses.
21:39As the sun climbs in the sky, bubbles of gas appear.
21:49Evidence of photosynthesis.
22:03Deep inside the plant cells, tiny structures called chloroplasts move towards the light.
22:14They absorb carbon dioxide and use the sun's power to synthesize the sugars that the plant needs to grow.
22:26And as a by-product, they release oxygen.
22:33The gas that we, and all other animals, must have in order to breathe.
23:01Now, in late afternoon, bubbles of oxygen make the river water fizz, like champagne.
23:08The gas start to breathe.
23:08Brian?
23:10So.
23:15Yeah.
23:34I mean, no, we're so excited.
23:37I'm John.
23:37I'm John.
23:38I'm John.
23:56The plants can become so buoyant with gas that they rise to the surface, even carrying
24:05the bedrock with them.
24:17Only in this remote water world can this spectacular natural wonder be seen.
24:32Eastern Venezuela, here rectangular table mountains known as Te Puy stand above the tropical forest.
24:50There are more than 50 such isolated mountain plateaus here, each home to a unique community
24:56of plants.
25:02Downpours are so torrential that no soil can accumulate on their broad rocky summits,
25:08and some plants living up here have to find their nutrients from another source.
25:21These are bromeliads.
25:28Their leaves are shaped like a funnel and collect green water which accumulates in the center.
25:40This small pond is colonized by all kinds of tiny animals.
25:54And it is their bodies when they die that provide some of the nutrients the bromeliads need.
26:02This makes a good partnership in which both parties can thrive.
26:06But it can be exploited by a plant predator.
26:24To dole the land, which turn the green water.
26:26Now we will get to the outer supply of water.
26:29In this cold water, we have to get the water to the ground.
26:35We have to get the water to the ground.
26:36We can serve the water to all the fields, and keep the water.
26:42When we are getting out of water in the morning, we have to get the water to the water.
26:45This probing stem belongs to a plant called a bladderwort.
26:51It, too, is in need of nutrients.
27:02And a well-stocked Promeliad pool is just the place to find them.
27:11This one is full of aquatic animals.
27:41The bladderwort begins to change.
27:43The bladderwort begins to change.
27:46into a hunter.
27:50It develops bladders
27:54and removes sufficient of the water within them
27:57to create a partial vacuum.
28:04Each bladder has a trapdoor beside it with trigger hairs.
28:11Now,
28:12all a bladderwort has to do
28:18is to bite its time.
28:39It only takes one touch.
28:42For the trapdoor to snap open
28:47and suck in its prey.
28:56It's all over in a millisecond.
29:09And after it is fed,
29:12a bladderwort has enough energy
29:13to produce another tendril
29:15to search for another bromeliad pool.
29:34The swamps and bogs are also poor in nutrients.
29:41So several plants
29:42that live in such places
29:44catch insects too, if they can.
29:59The leaves of sundews
30:02are covered with long red hairs,
30:05each tipped with a droplet.
30:27These glistening globules are, in fact, glue.
30:49once the sundews detect
30:50the taste of their victim's body,
30:53they flood it with digestive enzymes.
31:07The little body disintegrates.
31:14And the sundew gets the nutrients it needs.
31:24And the sundew gets the nutrients it needs.
31:35The Venus flytrap has leaves
31:38that are lined with interlocking teeth.
31:46It attracts insects
31:48by producing a sweet perfume,
31:50just as a flower does.
31:55It too has a hair trigger.
32:09And another insect
32:11is caught.
32:25But the technique
32:27is more complex
32:28than it might seem.
32:33The Venus flytrap
32:35has a problem.
32:36It needs to avoid
32:38false alarms.
32:40snapping shut
32:41on something inedible,
32:43like a raindrop
32:45or a little bit of twig.
32:47That would be a waste
32:49of both time and energy.
32:51So how does it avoid that?
32:54Well, it does it by counting.
32:58If I touch this one,
33:00sensitive hair just there,
33:05no reaction.
33:06That could be a false alarm.
33:09But the plant remembers that
33:11for twenty seconds.
33:12And if I touch it a second time,
33:15within that time,
33:16then that's much more likely
33:19to be worth eating.
33:20And so,
33:24it closes.
33:28So far,
33:29so good.
33:31But now,
33:32it needs to be absolutely certain
33:34that it's got something worth eating.
33:36So it continues counting.
33:39Only after it has totted up
33:41five separate touches
33:43to those hairs,
33:44will it give the final squeeze
33:48and then begin to produce the liquid
33:50from the surface of the leaf,
33:52which will dissolve the body
33:54of its unfortunate victim.
33:58the flytrap.
34:00The flytrap now has enough energy
34:01to produce flowers
34:02and attract pollinating insects.
34:16Wind and insects, between them, pollinate virtually all land plants.
34:22But neither method
34:24can be used by plants
34:26that live entirely underwater.
34:28So some lead
34:30double lives.
34:34A chalk stream
34:35in southern England,
34:37and swaying in the current
34:39is a plant for which these rivers are famous.
34:43This is
34:44water crow fruit.
34:46A kind of aquatic buttercup.
34:48For most of the year
34:50it is underwater.
34:52And if I take this
34:54underwater camera...
34:58You can see
35:00its floppy stems grow horizontally.
35:03That reduces the risk
35:04of being swept away by the current.
35:09But each spring,
35:10when it's time to flower,
35:12it produces something crucially different.
35:17A stem
35:18that is stiff enough to resist the current
35:22and lift its flowers into the air above.
35:46And now, of course,
35:48they can get help
35:49from insects.
35:50And now, of course,
36:06water crow foot
36:07So, every year,
36:08in part at least,
36:10water crow foot becomes
36:11a land plant.
36:15And provides us
36:16with one of the loveliest
36:18natural spectacles
36:19of the early English summer.
36:27water.
36:31Water crow foot is not the only
36:33water plant to lift its flowers above
36:35the surface.
36:42Plants do so
36:43all around the world.
36:50from the swamps of the Pantanal
36:58to the lakes of Thailand.
37:01They all burst
37:03into spectacular bloom.
37:15Once they've been pollinated,
37:17they produce seeds.
37:31And now their flowers have done their job.
37:34Some return to a life
37:37under water.
37:44Now, they must ensure
37:47that some of their seeds
37:49will find suitable places
37:50in which to germinate.
38:06Bullrushes, every year,
38:08produce these long
38:10brown, velvety
38:12objects.
38:14Look what happens when I break
38:16one open.
38:20It contains
38:21almost a quarter of a
38:23million seeds.
38:32Each seed is attached to
38:34a delicate parachute.
38:42Even the slightest breeze
38:44will lift it, and may carry it
38:47for very long distances indeed.
38:51So, even though suitable
38:53stretches of fresh water
38:55are few and far between,
38:57there's a good chance
38:58that at least one
38:59will end up in a place
39:01where it can grow.
39:11Much bigger seeds, of course,
39:12can't travel by air.
39:22A river can provide transport,
39:25but it's a one-way journey
39:28downstream
39:29that often ends up
39:31in the sea.
39:35And that's not ideal.
39:40So, how can any riverside plant
39:42avoid this
39:43and travel upstream?
39:48Here, along the Bonito River
39:50in Brazil,
39:51a variety of trees
39:53manage to do exactly that.
40:02They embed their seeds
40:04in the middle of soft, sweet fruit.
40:07And that's not ideal.
40:24Monkeys such as these capuchins
40:28make a meal of them
40:30just as soon as they're ripe.
40:36But monkeys
40:37are very wasteful feeders.
40:40And what's not eaten
40:44ends up in the river
40:45and is washed away.
41:20in the fruiting season,
41:23hundreds of Pirraputanga fish
41:27gather beneath these trees.
41:37But the Pirraputanga
41:39want more than the monkey's
41:41leftovers.
41:44The brightly colored fruits
41:46are clearly visible
41:48even to the fish
41:49in the water below.
42:00And some
42:01manage to claim them
42:03even before a monkey does.
42:18This isn't a skill mastered by
42:20just one particularly successful
42:22acrobatic fish.
42:24Many of the Pirraputanga
42:26can do this.
42:32Nor is this a disaster for the tree.
42:42Far from it.
42:49These Pirraputanga
42:51are migratory
42:53heading many miles
42:55upriver to spawn.
43:04The trees,
43:05by enticing the fish
43:07to eat their fruits,
43:08have a perfect means
43:09of transport
43:10for their seeds.
43:13With luck,
43:14the seeds
43:15will be deposited
43:16many miles
43:17upstream.
43:36The ability to colonize
43:38new habitats
43:39has allowed one group
43:41of flowering plants
43:42to venture out of fresh water
43:44and into a world
43:46that may look the same to us,
43:48the plants.
43:49But for a plant
43:50is crucially different.
43:55The much greater,
43:57saltier world.
43:59The sea.
44:04This is a fruit
44:06from one of the most important plants
44:08on the earth today.
44:11Seagrass.
44:20This particular one
44:21is floating off the coast
44:23of Formentera
44:24in the Mediterranean.
44:37A hundred thousand years ago,
44:40a seagrass seed like this
44:42sank to the sea floor
44:44just here.
45:00And eventually,
45:02it produced
45:04a great meadow.
45:09a meadow
45:10that is still flourishing
45:12today.
45:17It did so
45:18by cloning itself.
45:23Now,
45:24over ten miles across,
45:26it's not only
45:27one of the largest
45:28living organisms
45:29on earth,
45:31it's also
45:32one of the oldest.
45:41and it supports
45:42a rich community
45:44of many kinds
45:45of animals.
45:51It's become a kind
45:52of marine savanna.
45:59Over a thousand species
46:01now live here.
46:03Some,
46:04like these
46:04elegantly camouflaged
46:06pipefish,
46:06live nowhere else
46:08but amongst the seagrass.
46:20Seagrass fringes
46:21many of the world's coasts.
46:31turtles depend upon it too.
46:37And so do dugong,
46:40animals that are sometimes
46:41called,
46:42very appropriately,
46:43sea cows.
46:53Today, seagrass
46:55plays a critical role
46:56in maintaining
46:57the health
46:58of our planet.
47:01It creates stores
47:02of carbon around
47:03its roots
47:04at an enormous rate.
47:0635 times faster,
47:08in fact,
47:09than plants
47:10that live on the floor
47:11of a tropical rainforest.
47:16Here,
47:17off Formentera,
47:18it's possible
47:19to see beneath
47:20the living seagrass
47:21layer upon layer
47:22of trapped carbon
47:24that the plants
47:25have accumulated
47:26over the past
47:27two thousand years.
47:36seagrass.
47:36Seagrass, however,
47:37is easily destroyed
47:38by human disturbance.
47:40A third
47:41of the world's
47:42underwater meadows
47:43have already been lost,
47:44and many more
47:45are in decline.
47:55biologists are now striving
47:57to not only
47:58protect the remaining
47:59meadows,
48:00but to restore them.
48:04One plant
48:06at a time.
48:14seagrass could be
48:16a valuable ally
48:17in our fight
48:18against climate change.
48:24Today,
48:25water worlds
48:26everywhere
48:27are under threat.
48:33Many of their
48:35inhabitants
48:35are disappearing
48:36without us
48:38even being aware
48:38of their existence.
48:48The plants
48:49that grow in water
48:50are probably
48:51the least noticeable.
48:52They're certainly
48:53the least studied.
48:55But the more
48:56you know about
48:56the problems
48:57of living in that way,
48:59the greater
49:00the wonder
49:00of their success.
49:04Surely,
49:04they deserve more
49:06of our attention
49:06and,
49:07most importantly,
49:09our care.
49:26this vast wetland
49:28is the Pantanal.
49:30The Waterworld's team
49:32are heading to a plant battlefield,
49:36the home of Brazil's giant water lily.
49:42This is like seeing the end of a war.
49:45There are leaves growing on top of each other,
49:47flowers going through leaves.
49:48It's unbelievable.
49:52to capture this story in all its detail would take over a year and require a unique green planet approach,
50:00both filming here and in a parallel mini Pantanal in deepest darkest Devon.
50:11This is the unique world of specialist time-lapse cameraman, Tim Shepard.
50:20Tim has the reputation of being able to think like a plant.
50:26It's absolutely crucial that you get the plant really happy.
50:30And to make the giant lily field totally at home,
50:33Tim must build a little piece of Brazilian wetland.
50:39First, a 10,000 litre tank.
50:45Hundreds of bricks, almost a thousand kilos of soil,
50:49and countless cups of tea later,
50:52the foundations are complete.
50:55So far, so good.
50:58Now, time to prepare for the new green planet camera system.
51:03That way, we're trying to assemble the main gantry framework
51:07so that we can mount the moving rig on top of it.
51:10So it's a bit of a fiddle to get all the screws in all the right place, basically.
51:16After a few weeks, the building works are complete.
51:21The flood can now begin.
51:30Tim needs to be sure everything in the room is heated to tropical temperatures.
51:40Before the star of the scene can move in.
51:46Carefully grown at the Royal Botanic Gardens at Kew,
51:49especially for us.
51:56Everything depends on this one plant.
51:59There will be no time for a second attempt.
52:04And even more important for Tim,
52:06to keep his guests happy and healthy.
52:10This big monster needs a lot of feeding.
52:13We found we need about five sandbags full of compost every two or three weeks.
52:19So we just sort of lower them in and stick them down by the roots.
52:23There we go.
52:33Time to see some giant water lilies underwater.
52:37And I hope there's no anaconda.
52:51The pressure is now on Tim.
52:57After months of pampering, the giant lily is ready for action.
53:04First thing to film is a leaf spike rising up from the depths.
53:11Luckily, there are no anacondas here.
53:16The special camera weighs over 40 kilos.
53:20It's suddenly become less heavy.
53:23The new rig means Tim will be able to follow the emerging plant in any direction.
53:34Whoa, fancy!
53:37The technology is working well.
53:40But nature is starting to derail Tim's plans.
53:44Really tangled up with all these weeds.
53:48What happens is we've got a bit of an ecosystem developing here.
53:53Before you know it, you get masses and masses of algae growing in amongst it all.
54:02We kind of just need some anaerobic gases there.
54:06They're not me, the algae.
54:10State-of-the-art tools help keep the algae at bay.
54:25Just in time for Tim to film lift-off.
54:41That's quite nice coming out of the woods.
54:42Look at that!
54:43Tim Stokers can now shift to the battle that's starting to take place on the surface.
54:52I'm trying to film this new bud coming out on this lily leaf.
54:56It'll take about three days to grow from where it is now, somewhere in this zone between these two other
55:02leaves.
55:02I want that to last about ten seconds.
55:04Ten seconds is about 250 frames.
55:08That works out about one frame, maybe 20 minutes.
55:12But plants don't read scripts.
55:16It's nature, it doesn't always do what you think it's going to do.
55:26We've had a few full starts where the leaf has swung out of shot and gone somewhere else.
55:36Or it just grows a lot quicker than you thought.
55:43It's a challenge to get things right, but with the combination of Tim's expertise and the new camera system, results
55:50are starting to look good.
55:52I think the difference now with this series is we can bring the plants much more to life as characters
55:58and tell their story in a much more dynamic way.
56:05It's great to be able to follow them around, much more in the way you'd film an animal behaving.
56:19These rigs have given us a whole new realm of possibilities.
56:24After over a year of filming and recording a hundred thousand separate images, the secret life of the giant water
56:31lily and the battle of the Pantanal has been revealed.
56:42Next time on the Green Planet, the ever-changing seasonal world, full of hunters, tricksters and unlikely alliances.
56:57Plants here are in a race against the clock.
57:02Timing is everything.
57:06The Open University has produced a poster that explores the vital role that plants have for our planet.
57:15To order your free copy, call 0300 303 4200 or go to bbc.co.uk forward slash green planet and
57:27follow the links to The Open University.
57:32You can hear David's guide to The Green Planet with music from the series, a mindful mix on the BBC
57:38Sounds app now, and including one of the finest classical actors, Anthony Cher, who died last month.
57:45Henry IV over on BBC Four now.
57:48Next here, a homeless man in desperate need of help on Call the Midwife.
57:54Trust the
57:54The Green Planet is a
57:55The Open University
57:55The Open University
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