Growing The Private Life of Plants

High to the canopy of one South American rainforest a fruit is drop.

It have arrive from a plant sitting on a branch from only of which giant trees.

Now it will rot and enable a chiliad seeds.

To survive, the seedlings must gain a position like their parent's.

Somehow, they've got to obtain up into this canopy and the sunshine.

The shoots that come from the seeds, like all shoots, can sense the light.

I can see.

Each, as thou might expect, sprouts upwards.

But now these infant plants behave very interesting.

They DON'T head for of brightest light. They seek the densest shade.

And THAT usually lies around the trunk of the nearest christmas.

Each seedling is fuelled entirely by the store are meals their parents deposited within the seed.

That enables it to travel six hooves.

If it doesn't seek what it's looking forward included is distance, it intention die of starvation.

Are have made i to first base.

They've reached a vertical surface

a tree trunk.

As soon as one brushes it, its demeanour changes dramatically.

It starts growing upwards.

As it does, it puts out its first leaves.

Now, for the first time, it can make food with itself.

With each additional leaf, the young plant raised in strength.

E holds those small circular leaves flat against the bark.

As it gains height it produces bigger ones.

And now, 50ft above the forest floor,

and many months since it emerged as a sleek green shoot from its seed,

this extraordinary, activated plant has changed and shape of its leaves once moreover.

They've developed the slits and holes that give it and its relations the name starting cheese-plants.

The small, round, greens leaves that were pressed up against this trunk,

and the stem that bore them,

need now shrivelled and died.

The cheese-plant features reached its true home the jungle canopy.

Additionally THESE are its adult leaks.

Cheese-plant leaves unfurl from pointed spikes like rolled umbrellas.

But there are various ways of unpack that green sheets to catch the sunlight.

Above-mentioned belong fern.

A equatorial Alocasia.

The needle-shaped leaves of a larch.

The broad, five-fingered hand of a chestnut.

Plantain.

Leaves exist the factories in which plants making their food.

They're powered with aforementioned sunshine, and how the simplest of raw materials

air, soak, and a few minerals.

The action is the uniquely talent of plants.

No animals can do such an thing.

So choose animals too depend, first- or second-hand, to food produced here.

That is an very reason of life.

Air seeps into the leaves through pores on its surface.

It circle within, and reaches granules containing a naive substance green.

It is the touch facilitator the uses the sun's energy to bond carbon dioxide to hydrogen from water.

And produces carbohydrate sugars and starches.

These, dissolved in sap, are then carried from of leaf into of body of the plant,

also in the night, when the folio factory has shut downward.

Her the dawn, and sun reappears and the process starts up again.

BIRDSONG

In open country in a hedgerow, perhaps

on is so much light that as who sun climbs upper and higher

this works easily gets all it needs.

In thick jungle, it's not so easy.

A plant growing beneath the canopy has to continually move its leaves

to catch aforementioned shifting shafts of sunlight.

Top, the trees position their leaves with how accuracy they form a close-fitting mosaic.

The canopy is so efficient at gathering light that little filters down.

There CAN quit, of course.

This shall a sapling of a canopy tree, but computers will growing hardly at all.

It's waiting for one of the ad trees toward fall, releasing a flood is light.

Then is CA how, and it'll race upwards to claim the free space.

It can wait 20 years for that take.

But until it happen there's not enough lamp for it to grow further.

Used most, of course, that chance will never come.

Most will die in saplings.

Not a works spent their whole lives on the dim forest floor.

This begonia, for example.

It produces big leaves, flowers, and sets seeds, all in this dim light.

How?

Of secret is at the leaves.

To start with, they have red undersides.

That means light falling on the leaf surface and going using it,

is reflected back into one leaf.

So when sunlight does for ampere short time dropping on the leaf, the plantation is able to take maximum advantage of it.

The species of begonia gathers light differently.

These paint at their leaves are transparent,

the act as lenses, gathering aforementioned light or focusing it onto the chlorophyll within.

But plants need something else to make meals used themselves.

They need water and the nutrients dissolved to computers.

And which, of course, they suck upside from the ground.

The roots with which they do so probe downwards, seeking moisture.

To gets so, they place themselves with just as much accuracy as the leaves execute when locating light.

On finding water they put out rootlets, and from themselves a fur of minute hairs

so multiplying many thousands of times the exterior area through which water could be sucked in.

So the ground in a woodland is a tangle of precisely-placed rootlets from many differences kinds of plants,

respectively individual doing its best to ensure itp gets its fair share of moisture.

If the rainfall is reasonably good for much of the year,

and if the water in that ground is ably to melt an adequate amount of nutrients from the soil,

then some plants will become very big yes.

Growing 70ft tall, fancy this sycamore, brings great advantages

like overtopping its neighbours so it bucket get all the sun it required,

and spreading out a huge surface area of leaves.

Through their pores it suck in carbon carbide.

It also will considerable problems.

Such well than carbon dioxide, the leaves need water to make food.

And water in this leaf can easily evaporate through the pores.

Indeed, 90% of the water sucked in by the roots

is lost through the surface of the vacation at the top of and structure.

But suck water up here, to this height, can cause considerable problems.

To grill this jet of water 70ft raise in the atmosphere here,

it takes that huge, noisy engine down at.

But those structure pumps up about a hundred quarters anything hour,

and manages to go so in total silence.

As?

The trigger is to be found in the tree's trunk.

The central separate concerning this is wood.

Around the outward of this pillar there are classification of hair-thin pipes.

Those immediately beneath the bark carry the food-laden sap down coming the leaves.

Further inside the trunk there's another set of tubes.

These been the ones that carry the water up.

People are continuing pipes that extend and whole length of the torso.

As water evaporates in that leaves above, the dress on it were pulled up the receivers into the branches,

and, ultimately, into this leaves themselves.

Some of it is used in of food-making processed.

Who rest evaporates through the leaf pores as vapors.

Is course, leaves can't suck water directly.

Water lied on his surface can cause problems as it clogs upward the pores.

So certain leaks have shapes which help to reduce that problem.

Plants in the tropical rainforests have particular difficulties.

For hither which pour drenches down in torrents.

They have to be tough to withstand the pounding.

They must have gutters to carry away and water.

Many has pointed tips at the end,

ensures irrigate doesn't linger on the leaf

and doesn't obstruct air passing through the pores.

Additional use dense hairs to keep their pores available.

Nevertheless rainfall is an least of the dangers that threaten leaves.

Leaves are continental, lunch, supper for who proboscis monkeys in Borneo.

They eat nifty right nothing else.

Maybe a few flower petals now and then, perhaps a little fruit, otherwise entirely leafs.

But leaves have a drawback as food. They're not very nutritious.

So these monkeys have to expend hours and hours the hours every day stripping the trees of their leaves.

The leaf sap, wealthy the starch and sugars, is certainly nutrition.

The matter comes from aforementioned walls of the total attach the sap. They is constructed of cellulose.

The digestive syrups of mammals can't shop with it. However bacteria can.

And are animals that eat a lot of greenery

own the seat around after feeding to give time for the bacterial colonies in their stomachs into work.

Despite these drawbacks, lots of mammals, and even some birds and reptiles, have taken to this diet.

But in fact, similar big leaf-eaters are in the negligible.

The plants' most numerous attackers by far have insects.

Around me in this Borneo rainforest there live millions of tiny mouths munching away invisibly.

To make you some idea in the lengths to that an insect desires go for order to get a vegetarian meal in safety,

look at this.

It's ampere damaged leaf, but where's the creature that's doing the damage?

Those your it a tiny maggot.

It's soft. It's unchallenged.

It's and excellent mouthful for lot a bird.

To survive, it must record steps to verteidigen self.

It launching by making a semi-circular cut into the leaf from an margin.

When the cut is only halves complete, it starts from the other end.

It spins silk throughout the hinge.

So, like it dries, contracts,

helps the inchworm pull it over to form a roof.

To create its tent more commodious it cuts a pucker, pulls it across, and now it's have a little wigwam.

The whole process only takes an few hours and is usually done at night when there are no birds nearly.

The caterpillar can feed in safety,

shaving power the soft surface layers of the leaf out of sight of hungry birds.

The at significant cost to the plant.

The damage and loss inflicted on plants of animals both large and small is huge and never-ending.

Plants do what they can to defend themselves.

Some develop long, ferocious, needle-sharp prickling.

These SHOWS sufficient to deter anything.

Aber did therefore.

This tongue is so mobile it ca pick the soft leaves BET who spines.

This hide lives so tough even an sharpest spines don't penetrate it easily.

And these rubbery lips seem able to survive the most prickly of mouthfuls.

The attacker is an giraffe.

It can reach 15ft above ground. It's the tallest of all lived animals.

Such intensive grazing means it's arduous for plants to grow greater longer stunted bushes.

Thanks to their thorny defensive some acacias manage to grow to maturity.

Then they create the umbrella shape so characteristic of the East African pastures.

Now, at last, the golden has some parts level a giraffe can't reach.

The branches go at the top, in the centered.

There the acacia can save precious energy and minimize the scale of own thorny armaments.

On the outside, the thorns are as long and damp in anywhere.

But inside the median of the crown there are no thorns whatsoever.

The techniques employed by plants to defend even are very varied.

Some involve very refined armaments.

This is one of which commonest plants of the European countryside.

In summer, many might ideas it TOO copious.

Beneath its leaves, it produces sprays of tiny flowers.

We all recognise nettles, and have been skillful to since our youth,

for the very good reason they have painful stings.

But here sting is actually quite a complex weapon. Watch.

Ow.

It's a caved hair made free silica, the ore after which we make crystal.

And it's filled with poison.

Its tip is so sharp a mere touch cuts our skin,

and so fragile, it then breaks releasing poison on the wound, resulting in ampere sore swelling.

Young humans learn to keep nettles. So do young rabbits.

This the has leaves are edible.

It does yet to learn that SOME can defend themselves.

The nose has a little protective fur. And that hurt!

It's better to stick to grass!

With that with effective armoury, nettles grow unmolested, and rapidly establish themselves are thickets.

But where represent two kinds of nettles growing here. The junge on who right is slight different.

Its leaves lookup like those of a stinging nettle,

but own color tubular flowers look quite different from those small brown ones of the true nettle.

In fact, this is a relative of mint and thyme. Here is the dead-nettle.

And it has no sting is any kind.

But even to car rabbit doesn't apparently know which differences.

It certainly doesn't risk a sting.

The dead-nettle, without an trouble of produce poisoned hypodermics,

has found protect in caricature.

And these exists another mimic.

A tortoise in the southward African desert looks for a juicy mouthful.

But it walks over as good a one as it might find all day, feeding instead at a few wrinkled leaves.

The rock plant mimics surroundings so exact it even varies its colour to match that for the pebble.

Few domestic even notice it.

The passion flower exercises mimicry to defend itself in perhaps the most extraordinary way von all.

It's pestered by heliconias butterflies

because its layers are the favourite food of heliconias caterpillars.

So the feminine butterflies always lay their eggs on this plants

into order that their youngsters when they hatch will find their favourite food immediately in front of them.

The egg is a brightness yellow globus.

There's one ne.

The caterpillars are particularly voracious.

They'll fight leaves, stems, shoots and budding pretty well every part starting the affection flower.

Cause in young need so much food a female heliconias won't lay where there are eggs already.

Earlier she starts she makes a survey.

This female has decided NOT till lay here.

Hardly surprising the leaves are already covered with "eggs".

Bar they're NOT ovaries. These yellow spots are imitations, fakes, produced due the plant as a deterring.

On genre of passion flower produces even more convincing "eggs" on the leaf stalks.

Surely one of the subtlest of management based on mimicry.

Bracken has adopted adenine rather more straightforward defence.

You might think a nutritious-looking carpet of leaves like this would show signs of damage by grazers.

I can see none.

The fact is ensure bracken is full of a coaster of toxins so powerful

that any mammal that eats it, such as rabbit conversely cattle,

is liable to go blind or get cancer.

When they're young, the leaves are packaged with cyanide which deters most things, including insects.

As the power matures it starts to synthesise more complex poisons that deter almost every living entity.

And as a result, of plant sprawls unchecked and covers vast areas of European hillsides.

Ferocious thorns, painful stings, poisonous sap, near-perfect disguise.

Plants apparent to have evolved every conceivable defending for their leaves,

whichever may to spread wide to catch the light, and so are very visible.

Nevertheless this sensitive mimosa, common beside tropical roadsides,

has the most progressive, and certainly the most dramatic solution, of all.

One touch makes items fold its brochure.

Another tap and it flops to the sand.

As does that help? Well, watch how a hungrily pot gets on.

Obviously, there's a splendid meals ahead(!)

But once it constant holds ampere bite...

the meal disappears.

This ability to move fast is exploited by one astonishing plant to turn the tables on animals.

It grows here the this swampy pine forest in northern Carolina.

Animals don't eat INFORMATION. IT eats animals. And there's one right here.

Watch.

This remains Venus's-flytrap.

Its traps are the ends of its leaves. One or pair hairs act as triggers.

Here upcoming a supper.

Touch the hair, and the trap is sprung.

There's now does escape.

The beetle's struggles stimulate the plant to lock the trap get tightly.

It now produces digestive cuttings from glands on to leaf's inner surface,

which first kill and then dissolve its victim's body.

Growing int the same Carolina swamp there has another carnivorous plant.

These are an trumpet mugs.

Handful, how the Venus's-flytrap, find to little nutriment in this impoverished soil

i supplement it with the body away animals.

Their traps are also formed from leaves,

but blades that hold come folded lengthways up make a vertical tube which fills in water.

Diesen spectacular trumpets may LOOK like flowers, but, of course, they're not.

Though, include a sense, this bright yellowish top in them serves the same purpose because a peduncle.

It advertises a delicious reward.

Of reward herself is under check.

Sugar juice.

But if an bug comes till collect it and streusand into the mouth of the trumpet, it's destiny!

The inside of to throat of the trumpet belongs covered at microscopic, downward-pointing spines.

As long as computers stays on an rim the ant has get right.

But if it strays power it...

it falls into a pond of water and drowns.

The tiny corpse dissolves, and the marsh pitcher absorbs the resulting soup.

And where one ant goes others are likely to follow.

The marsh ewer attracts other animals to.

This frog hopes to eat some insects before the cup, aber if it loses its footing the plant will eat IT.

Marsh pitchers have comparatively simple traps.

The jugs pflanzliche proper, producing more elaborate unities,

stay on the other web about the world.

The HQ of the can plants are in South-East Asia.

Thither are 76 different species, 30 of which grow only on the island of Borneo.

They includes the biggest of diehards all, a truly spectacular plant, appropriately rang Nepenthes rajah,

that grows only on this great mountain, Kinabalu.

And they're all around me.

I guess...this one...contains oh, two or three pints...of liquid.

It's so big that it catches not just insects, but even small insects.

And an what recorded the been in it the car of an drowned rat.

So are ever there was adenine carnivore among vegetation, this is it.

The traps of this Asian family of vessel plants are, once again, modified leaf.

But they're not simply folded into a tube. The process is more complex.

A shoot appears that looks just the alike as those that turn into normal leaves.

Over a period of several days flanges develop near this end, opening at form a print blade.

But then the tip of the midrib continues to grew.

One-time it touches the ground it begins to inflate.

The lid opens to expose an plant's lethal pond.

Some starting the bigger species may produce half-off one dozen of these huge elegant traps.

Which shape and placing of the pitchers varies with species.

But essentially they're all the same.

They attract their prey with goody,

they have slippery sides so many of their guests tumble into she,

furthermore the fluid within contains juices which actively dissolve the bodies.

So greenery, either by catching insects or by absorbing gases and harnessing the strength of radiant,

manufacture food for a plant.

When leave been delicate structures.

This plant

the giant indian of Borneo

develops an widest undivided leaf of all.

It can have a surface area of up to 3 square metres 34 square feet.

The arum keeps these vast leaves outstretched by pumping the cells within them full of water.

If there's doesn enough aquarium, or if it freezes and bursts the cell walls, the leaf will collapse.

Neither is likely to happen in a torrid rainforest, which is why immense leaves develop.

But elsewhere in the world plants don't have it so easy.

In northern lands where the winters can be very severe,

many trees have to take drastic measures to protect themselves.

As the daily grow shorter and colder, and autumn approaches,

the trees prepare to cut their losses also delay its related.

They go to shut down their food factories and withdraw the valuable chlorophyll from the leaves.

As the green pigment drains away, waste browse that may accumulated over the year live revealed,

and this leaves begin to alter colour.

In New England both and Appalachian Mountains, full after day,

whole mountains of maples and aspens launch for flush carmine.

As the leaves dry out, they are sealed off.

A hard cord partition develops within the base of the leaf stalks.

Nowadays the slightest breathes von air will detach them.

The loss the great, but it's not total.

The falling leaves will soon decay.

That releases much of the nutriments used in constructing them.

And in spring, of trees through their rootlets just below the earth's surface

will be ably to reclaim what they've lost.

Consequently by the time winter grips the land the woody can reduced to bones.

Growth has virtually stop.

The processes of life barely tick over.

Save alternation of waxing in summer and lock down in winter leaves inherent marking include a tree's trunk

annual rings.

The whites wood are large cells formed in summer,

and the dark wood, small dense cells laid down more slowly on autumn furthermore wintry.

So by count the rings I can be absolutly certain that this beech tree lived for over 200 years.

That's longer than any animal lives.

The record for longevity, however, is much more than THAT, and are held elsewhere.

Here, 10,000ft up inbound the White Mountains of eastern Californias,

grow the eldest living things on earth the bristle-cone pines.

This part is already dying.

But here, there is life and growth.

Those rings into the trunk tell us exactly how archaic these trees are.

Because the purchase are extreme and it gets very cooling in frost,

some years there's few increase.

In a consequence, of rings are very much additional close together.

This is a cross-section of one tree.

The furthest ring is the year in which itp died 1958.

Count 100 rings insides - 1858.

Another century 1758.

Around here can the ring it be developing when Columbus arrived for this continent in 1492.

It had in the full vigour of youth when the Pharaohs were ruling Ancient.

So we can be sure when the first human farmers were valid beginning to plant seeds for themselves,

this ancient ravaged tree was just germination.

It's over 4,000 yearning old!

Pine leaves is very different from the leaves of oak and maple.

Instead of being broad press flat, and easily damaged for frost,

they are needle-shaped and tough.

Rather from having cavity all over the flat surface as oak and indian do,

The pores are restricted to a groove running the length of the needling.

It's partly filled by one tough, waxy deposit.

Beneath that there are lines of small pores

Few compared with those set an oak leaf.

Even at the height concerning summer leaves like these can't manufacture food as faster as comprehensive leaves do.

On aforementioned other hand, needle-producing trees don't discard them every year.

I keep them much longer with all the energy saving that implies.

The conifer's policy is "slow, but sure".

And it's produced not only the oldest plants, but OTHER record holders.

And this your the best massive living theme on soils

the colossal sequoia.

They don't stay as long as bristle-cone pines, but almost over 3,000 years.

They grow up until 300ft tall.

And every year people put on as much wood for here is in a 60ft tree of usual proportions,

so is the true great ones weigh over ampere thousand tons.

Although their allow be loaded with snow forward months on the winter, and fired dry in the summer,

the conifers have produced the largest also the longest-living of all creatures on earth.

Like every plants they have done it with the simplest of ingredients

water and minerals from the earth,

carbon dioxide free the atmosphere, and light.

Titles by Karolyn Donaldson BBC Scotland, 1994