How do these scientists walk on the canopy ? | GEDEON DOC

If I had to make a diagnosis of a forest in a quarter of an hour, I would rather do it from up above than down below. I understand the forest much better from above than from below. Both are instructive, but I really think it's better from above. This is Madagascar, and the forest that covers the Machoel Peninsula, one of the last primal forests still intact on this huge island. A scientific expedition has come up with a way of deciphering its secrets from the skies. To do so, they will land on the treetops themselves. There's some fruit, there's some fruit here. But it's the same thing there. Well, I've tried to get it. OK, we got it, let's go. This research mission may be one of science's last. The Madagascan forest is in the process of disappearing. As long as man was unaware of its existence, Madagascar was a veritable paradise. The fauna and flora have flourished here since the dawn of time. Cut off from the rest of the world for 80 million years, the island was once covered with tropical forest. This isolation favoured the emergence of unique animal and plant species. The lemurs, that have almost disappeared from the rest of the planet, still move freely through the trees of the Machoel forest. But for how much longer? In cutting down the trees for firewood or burning them to cultivate the land, man has endangered the rare species that the primal forest nurtured and cherished for so long. The Machoel National Park is now all that remains. It is an irreplaceable ecosystem. A sixth continent for the biologists, who now explore it with a sense of urgency. October 2001. A base camp has been set up between the forest and the sea. The expedition has an extensive range of study resources. The most spectacular of which is this observation platform. It is a treetop raft, designed to be lowered onto the forest itself. Francis Allais, renowned throughout the world for his knowledge of primal forests, is in charge of this new scientific mission for the treetop raft. He is a botanist at the University of Montpellier in France. A full-scale on-site laboratory completes the operation's impressive infrastructure. A hundred people have been mobilised, including 70 scientists from 12 different countries. These botany experts and specialists in insects, frogs and toads will each play their part in the three-month project to explore the Madagascan ecosystem. They are the first to study Madagascar's treetops, or canopy, the least known but most luxuriant part of the forest. The canopy is the layer where the light's energy is captured in vegetation. If the vegetation is an enormous 40-metre high forest, then the canopy will be 40 metres above ground. But if the vegetation is only 2 or 3 metres high, then the canopy is 2 or 3 metres up. If there is almost no vegetation, with simply moss on the ground, then the canopy is the moss itself. But we'll always have the same definition, it's the surface that captures the solar energy. Before observing the canopy, the scientists will explore the undergrowth. As the edge of the forest here borders the sea, the team decides to approach its heart by boat. The food's in that blue thing, enough for everybody for two days. There we go, it's waterproof. Let's go, all aboard! The tropical forests contain almost 70% of the planet's living species, a host of animals and plants, many of which are still unknown. All right, all right! Do you know what it is? Look at this guy. I don't know, but he's got an eye spot. Yeah, eye spot. There's the other eye spot on both sides. Burrowed in the dirt. No holes in it. At first sight, a tropical forest is a seemingly chaotic place. But in reality, plants and animals live here in perfect symbiosis. A tightly knit network of dependence and alliance, dominance and submission. Each life form is both prey and predator, host and parasite, food source and waste product. But the forest is a giant with feet of clay. The balance is sophisticated but precarious. It relies on the interaction of a vast number of links between microscopic organisms, huge trees, humble insects and highly developed mammals. Man can so easily destroy it. For Francis Allais, it is a constant source of wonder. What seems to be particularly interesting in the case of the liana is that they are by far the least known plants in the forest. With the grasses, anyone can pick them, or the epiphytes and the treetops. People are fascinated by them. And there are worldwide collections. Even with the trees, one can cut them down and collect the leaves. But how are you going to cut down something like that? First of all, we don't even know which part of the ground it comes from. And even if we could find the base, it's clear that cutting it would not make it fall. We can imagine that this liana is attached to that tree there, but most likely it's also attached to this one, and that one, and that one, and that one. And so to cut down something like that, you'd have to cut down a hectare of forest. That's why we know so very, very little about the liana. Their trick is that they live without a trunk, so they climb very quickly and with a reduced metabolism. This enables them to be very active up above. They have a considerable leaf surface and enormous sexual activity, because liana are plants with an overabundance of flowers, as is the case with Madagascan jasmine, for example, or bougainvillea. Flowering plants appeared on earth relatively late, but they adapted so well that they colonised almost every natural milieu on the planet. The expedition's expert is Jean-Noël Labatte, from the Natural History Museum in Paris. We don't see many flowers, but often there are a lot of species that have really small flowers. And it's only once you're in there that you can see them. Like here, look, there's a little Dioscorea climbing up here. It doesn't have many flowers. This strange metal structure, perched 30 metres above ground, is an ideal observation platform for the scientists. They will move in here for a few days. The logistics of the overhead camp are entrusted to professional climbers. Dante Fanoli is looking for tree frogs. Much less at home in their natural habitat than they are, it takes him a good 15 minutes to reach the metal nest. Yes. Ah, this is great. 35 feet higher than the canopy, looking down on the Bay of Antonjou. This is incredible. Yeah! Chameleon, right here. Oh, this is great. Did you get it? Marc, we have a bag for you, hold on. Wait. OK? OK. Demonstrating that chameleons can live in the canopy quite successfully. There you go. Let's see what it is. Yes, it's a rubyacea. In order to take samples, Jean-Noël Labatte has to move from one tree to another. But it's too dangerous. Jean-Yves Serrin, a tree trimmer with 15 years' experience, does it for him. Jean-Yves' agility enables him to move among branches no thicker than his arm, at a height of 10 storeys above the ground. He's completely mad. It's unbelievable. No, no, no, I wanted to take lessons, but I could never manage to do that. It's not possible. The expedition's first goal is to make an inventory of the vast array of animal and plant life. The scientists are also looking for unknown plants that could be useful to man, without damaging the forest. With Madagascar, we have programmes for working with chemists. They work on research into active principles, and we help them by determining the plants and indicating similar species, which may contain the same active constituents, but perhaps in larger quantities or with a slight chemical difference that could perhaps be more effective. We're something of a plant dictionary for the other scientists, but along with being a dictionary, we try to provide a life history with the whole phylogeny. Where the various species come from, what are their closest relatives, what their ancestors were in terms of fossils, or at a very ancient level. We're not just a dictionary, but more an encyclopaedia. Today is a special day for the team, as the raft is going to be lowered onto the canopy. The giant 400-square-metre pretzel is a new prototype redesigned by technicians from the Ocean Vert Association. It has never been tested before. This is its first treetop landing. Thanks to the distribution of weight over a large area, the treetop raft can literally float on some of the forest's most fragile branches. Francis Allais can now take over the raft, assisted by a climber. The great botanist has often said that a raft allows the true face of the forest to be revealed. Here it lies before him like an extended, luminous offering, the exact opposite of the image it presents to those who explore by foot. There, there's something I don't know. For Francis Allais, the forest becomes an open book. It seems unbelievable, but it's a kind of flax. Plants that back home in Europe are small grasses like flax. Here they take the form of huge, lignous plants like this liana. We'll have to identify that. I think that people who really love these forests are extremely rare. In any case, there aren't any in governments or in the circles of decision-makers, certainly not among the economists. Consequently, the equatorial forest is in the hands of people who don't appreciate it. So in these conditions, how can we hope to save it? In the makeshift laboratory, botanists identify the plants as soon as they're collected. Out of six orchids discovered since the mission began, three are totally unknown. In order to provide an accurate ID, Francis Allais dissects the flowers and fruit. What interests me is the structure of flowers. The protective part, represented by the green sepals, and the most visible part, what we can call the advertising part, represented so clearly by the large white petals. These yellow sacks that I'm removing, in technical terms, are called stamens, and they represent the male function of the flower. Why do they represent the male function? Because they're filled with spermatozoa. Or to be more precise, I should say they're filled with pollen grains, and each grain of pollen contains two spermatozoa. So we remove them, and inside, right in the centre of the flower, the most important part, because it will transform into a fruit, we can see the ovary appear. Most plants are hermaphrodites, which means they are both male and female. But genetic principles prevent the male part from fertilising its own female part. The pollen is often transferred from one plant to another by insects. Over millions of years, plants and animals have developed close working relationships. Certain plants can only be pollinated by one specific insect, which feeds solely on its flowers. But this exclusivity has a downside. If one of the partners disappears, the other perishes. Henri-Pierre Aberlanck is an entomologist, an insect specialist. What's going on? Are you pulling a rope down there, or what? Almost all the flowers in the forest are found in the canopy, so Henri-Pierre has to climb up to examine them. Plants send out airborne chemical signals called keramones, which attract insects. One of Henri-Pierre's tasks is to determine which plant attracts which insect. Wait a minute, let's not make a mistake. One H is at the top in the open, so this is one H, yes? To find out, Henri-Pierre asks one of the team's climbers to set out containers on the edge of the raft with keramones to trap the insects. This has never been done before. The traps have always been tested at ground level. It's clear that the forest we have here, compared to the forest on the ground, is not the same milieu. For a start, there's a diffusion of the molecules. Here we're in the open air, with the wind, and if you look down, we're in the undergrowth, where it's dark and humid with very little air movement. They are two completely different milieus. We have a whole series of molecules to test, one after the other. We'll be able to see the results, but right now we're heading into unknown territory. The canopy is the most innovative chemical laboratory on the planet. For about ten years now, we've shown that biochemical activity in canopies is much greater than in the undergrowth. The biochemical activity is what makes a plant potentially useful for medicine. Research for medicinal plants until now has been done on the ground. People take a leaf and do a test, and when the result is negative, they say, OK, this species has no interest for us. We have demonstrated that the biochemical interest is not on the ground, but in the canopy. During their growth period, trees use most of their energy to increase in size and to move toward light. Once they reach the sky, they are colonized by fauna that feed on their leaves, such as saturnite caterpillars, that are only found in Madagascar. The plants under attack begin to develop chemical defences, like pesticides, herbicides and antibiotics. They create active molecules which, in part, protect them from the leaf eaters. Exploiting these molecules in the pharmaceutical industry could provide commercial opportunities, and a good reason to preserve the forest. For even if hundreds of kilos of leaves are required to produce medication, they will grow back again, as surely as the wool on a sheep's back. Prolonged stays in the tropical forest are exhausting, so each week a fresh team of scientists arrives to relieve the previous group. But today, the conditions at sea are not making things easy. The dirigible is taking off this morning in a new attempt to reconcile man and the forest, by gathering molecules that could make conservation and cost-effectiveness compatible. Dave Apple and Roman Kaiser are what the perfume industry calls noses. Thanks to the sled, a very light inflatable structure suspended from the dirigible, they will surf over the treetops in search of new fragrances. The smell of certain flowers disappears when they are cut, so it's important to take cuttings directly from the tree. To capture the scent, Dave and Roman enclose the flowers in a glass jar. Using a small air pump, the perfume molecules are then drawn out and fixed into an absorbent material. As the mission progresses, it becomes clear that the tropical forest is an inexhaustible reservoir of new molecules. Some plants, such as the Madagascan periwinkle, already make up 70% of the formula in the production of certain cancer treatments. And the exploration of the canopy has only just begun. After each flight, the dirigible's 8,500 cubic metres of air have to be emptied out. The canvas is then folded under the watchful eye of David Bowen, who has also assumed the role of the team's official taster. It's like latex. David Bowen is the director of the Perfume Lab, but fortunately, tasting doesn't mean swallowing, as Madagascar is home to a number of highly toxic plants. David looks for new flavours that could be used in sorbet or yoghurt, or unknown fruits whose aromas could delight our palates, much like the kiwi or lychee in recent years. It's interesting. I think this one is not quite ripe yet. It needs a little longer. This is another one we found. It's really very interesting because it's dry and it's not very juicy, but it actually tastes more like dairy than fruit. It's very creamy, milky, but also has quite an interesting fruity taste. So this one's interesting. We might find some different materials in this. One problem is the industrialised countries are perfectly capable of making synthetic substances. To protect tropical countries where original molecules were identified, a document acknowledging their rights over their natural resources was approved in 1992 at the Rio Summit. No firm commitments have yet been made, but it's in the spirit of this agreement that the non-governmental organisation Pro Natura has solicited the help of the RAF's scientific mission. The goal? To encourage the durable exploitation of biodiversity in tropical countries, including Madagascar. I think it's very important that all the industrialised countries continue to buy tropical wood. I protest very strongly against the attempts to boycott tropical wood that take place in some northern European country on badly understood ecological pretext. You have to understand that if these tropical forests produced nothing at all in economic terms, the governments of the countries concerned would only have one solution, to cut everything down and replace it with peanuts, palm trees or rubber. All the same, we have to stop exploiting primal forests. This has become unbearable. The wood has to come from plantations or agricultural forests. Take it easy. If you get too much momentum, you'll hit the tree at full speed. Another invention of the members of Ocean Vert, the treetop bubble. Don't use all your energy at the start, Hector. Thanks to this moored balloon, the entomologists can quite happily levitate above the canopy, guided by a rope. Collecting insects from the treetops becomes child's play. They merely have to tap the trees to make them fall into a net. The undergrowth provides an eternal hunting ground for butterflies, a pursuit that Henri-Pierre enjoys whatever the weather. Here we're looking for cocoons, the big triangular cocoons that are spun collectively by a number of caterpillars for the chrysalis formation. That takes place here, on the liana that hang under this big tree. Hey, I can see one. There it is. So, as usual, there are a lot of ants. You can see here, these granules each correspond to a cell in a butterfly's individual cocoon. And there we have a collective cocoon, which always ends in a point like that, suspended from a branch. Inside, there is a cushion of silk, which must be a good insulator. Obviously, the cocoons are completely sheltered from the weather until the butterflies emerge. I think that the butterfly there doesn't have to eat. In fact, I'd be curious to know if, by any chance, it has a proboscis. The butterfly mates, lays eggs, and then dies. And some butterflies don't even eat. They live on the reserves collected by the caterpillar. What's remarkable is the variety in the size of the cocoons. Look at this one. It's bifid, because of the leaf that was in the middle. And then you have cocoons, which are absolutely enormous. It depends on the size of the community of caterpillars that spin them, down to a small community of a handful of caterpillars that make mini cocoons. There's a butterfly in the cocoon. It just came out as we were looking for some others. So, four butterflies have come out today, and two came out yesterday. This is an old nest. It's abandoned. The butterflies have all come out, and inside we can see all the individual cocoons. If we open up a cell like this, an individual cocoon, we can see all the debris inside from the exuvia of the chrysalis that emerged. So that's very interesting, because, in fact, it's not a butterfly that came out here. Here you can see a pupa, which means that the butterfly had a parasite and was killed by the larva of a fly. But the funniest thing is that the pupa, in turn, has been killed by a microhymenopteran, and that hole was made by the parasitic microhymenopteran. So there's a whole chain. The chrysalis was killed by a fly larva, which ate it. The fly larva became a pupa, but it was then killed by a parasite hymenopteran, and the hymenopteran emerged at the end of the chain instead of the butterfly. In the warmth of the Madagascan night, the scientists share their observations and show the treasures harvested during the day. This is one of the remarkable things one comes across, or, indeed, treads on, in fact, in the Malagasy forest. Look at this little fellow. It's a hawkmoth caterpillar, which was discovered today by my colleague David Lees. What's absolutely extraordinary are these two protuberances here on the thorax. It's completely unknown, but should correspond to a previously described species. But we don't know which one, because the caterpillars are not nearly as well-known as the adults. Did you know that chameleons are smaller than caterpillars? It's living proof. There we go. Tonight, the entomologists have decided to catch nocturnal insects, and they are curious to see the results. About 20 years ago, a scientist had the rather unorthodox idea of spraying a tropical tree with an insecticide. The insects he found were so abundant that to estimate their total number on the planet, he factored to the power of ten. Hidden in the canopy, they had gone unnoticed until then. A second light trap has been installed 40 metres up on the treetop raft. Henri-Pierre Abberlank is on board. Welcome in the highest canopy light trap. Mr David, I presume? Livingstone. Yes, yes, indeed. These are your animals. There's already quite a few things arrived by the looks of it. Yes, yes, indeed. Voila! Yep, this is a micro, but a very large one. A large micro? A large tortoisid. Quick, quick. No, no, you mustn't. You'll damage it. Have you got a large tube? This kind of tube is good? Yes. White and black pyralids. Is it interesting for you? Yes, but at the moment, I'm just completely wrapped up in this cord, trying to disentangle myself. Pyralids, huh? A family of butterflies. Where is my net? Your net, your net. OK, so this is just a convenient little net for this kind of situation. It's made in Britain. I don't know whether you can get this in France. Pocket spring net. Very useful in these kind of conditions when something is just flying off. Time passes, and the insects are noticeably absent. That's a cockroach. There's almost nothing. You'd expect to get more in a sheet hung in a garden in a suburb of London or Paris on a summer's night or even on a winter's night. This is the extraordinary thing about tropical forests. It comes in huge cycles, and we're at the bottom of one of these cycles. It's probably connected with the moon. I've never seen anything with this colour pattern before. I don't even know what genus it's in, but this is his tongue. Have a look here. It's just unrolling. You just get an idea. In fact, Madagascar has the hawkmoth with the longest tongue in the world. It's called Darwin's predictor. We've caught some creatures tonight that we've never had the chance to catch down below, so that's some consolation. Down in the undergrowth, the catch is much better. It's a leaf bug, you know, a bit like a giant tingedus or a hybrid. Is it in the soil there, the organic matter? No, it must have flown away. The lack of insects high above the ground could be explained by the presence of the moon above the canopy, the light of the trap seeming pale and less attractive. You were wet. Yes, I was wet, but only for maybe about ten minutes. It's not a problem, David. You're English. I'm now completely dry again. One of the things that we'll be interested to look for is just some crepuscular skipper. There's one flying just behind you. Where? It was just flying around somewhere. I'm going to catch it. Just show me it. A spider caught in its own web while hunting for insects is not a common sight, but it can happen to an entomologist. You have to push on top of the ring. There's a little catch, like a ring. There's a pulley. You open it up and try to fasten it. That's it. As soon as you can grab the rope, put the block against the white rope and then pass the rope inside. Go on, grab the handle. Henri-Pierre, we're coming to get you. In the lab, it's now time to record all the data. Dante Fanoli and Mark Wilford of the University of Oklahoma are making a preliminary analysis. This is a nice little mantella. There are some convergences between this particular group of frogs, the mantellas, and the poison frogs of Latin America. In some frogs, there's a defensive mechanism or behavior called the unken reflex where they'll arc their back and point upwards the undersides of their hands and feet. What happens is a defensive mechanism and we think that the sudden revealing of bright colors or the sudden display of bright colors would scare predators. Bright colors typically warn of toxins and that's the whole idea behind aposematic coloration. This one perhaps is a new species. One of the interesting characteristics are these two white spots that are on the back. Hopefully, we'll look through the literature, look through papers, and see if anybody else has described a frog like this and if not, then we'll be able to describe this as a new species. Nectar first green on which the anthers are fixed then the anthers fade and open up. More than 550 plants have been identified. Jean-Noël Labatte now has to classify and preserve the samples. Only then can they begin the scientific analysis and this may last for several months or even years. We work for ourselves and for future generations who will be able to study what we've gathered perhaps with new methods of exploration or new technology that maybe we don't know about today. When Jussieu or Lamarck studied plants, they didn't know that one day we could study plant DNA and yet we do that now based on the work they did before. So all of this is a continuum. It's only the technology that evolves and enables us to explore nature in a different way. In the tropical zones, we're at the stage where we're learning to read nature and to decode it because here this is really about deciphering. The expedition draws to a close with a case study of paramount importance to the geneticists. A single tree appears to possess several genetic lineages. To verify this, Francis Allais selects the largest tree in the forest. Every tree trimmer is on hand. But before the scientists can study the tree's DNA, they have to identify the specimen and discover its name. The flower here is not well known. We really need flowers and fruit. For example, the tree we're on here, I only know the family. I can't say any more until we have the flowers and fruit. Perhaps I can see some floral buds there. Can you see just in front of you? There, you see the leaves? Opposite, yes, right there. Yes, there are bunches. Just below the leaves. Very interesting. Take a bagful, please. Yes, it's full of them. We'll be able to find the species now. Biology today is entirely focused on the human being, and only secondarily on animals. It's completely out of the question for a tree to be an individual, even if it's part of our vernacular. But individual means indivisible. A cat is an individual. If I cut it in two, it's all over for the two halves. But a tree isn't like that at all. If I take a pair of cicadas, I can make hundreds, even thousands of trees by cutting this one. And so it's not indivisible, and therefore not an individual. There are genetic arguments, but there is also that one, that cloning is perfectly simple. We know that trees like this one don't have immune systems. We know that mutations are common, as with any animal or plant organism. But the absence of an immune system means that the mutations stand every chance of not being eliminated. As a result, the mutated cells correlatively have a chance of providing mutated lines, which means branches with variations of the genome. To evaluate how significantly DNA varies from one branch to another, the scientists will take about a hundred different samples from the whole crown. This study might allow them to understand how certain plant species that live more than a thousand years manage to adapt to their changing environment. So here, on the same branch, you can take from a bit to the left there. That will be number one through five. No, to your left. I've already taken that one. I put one to three on that one. Ah, OK. This is one to three. All right. See you later, Francis. Easy, easy, Francis. You'll burn your hand. Primal forests are a diminishing resource for our civilization, shrinking as rapidly as scientists gather the proof of their significance. How can we preserve them from man's thoughtlessness? There are several languages used today concerning the preservation of the equatorial forests. Some say, don't cut them down because they don't belong to us. They are a treasure of humanity for our children and our children's children. That's the language of civilization, and no one gives a darn. Nobody listens. Then there's the language of threat. Don't cut the forests down because they're a vital pump for carbonic gases, so they protect us from the greenhouse effect. And if we cut them, the climate will heat up and the ice caps will melt. The language of threat has no effect on our leaders either. They don't hear it. The new language I would favor, that I would like to be given credit for, is, don't cut down the forests because we can all make a lot more money by exploiting the canopy without harming it than we can by cutting wood. And this language seems to interest our governments. But I fear, and I don't say this lightly, that if the solution doesn't work, we have to resign ourselves in the very short term to the disappearance of the last primal forests in our tropical zones.