Mata Atlântica | Biomas do Brasil | Ep.7

In 1993 a group of American scientists discovered the world's largest biodiversity of trees in south Bahia, around 450 species found in just one hectare of forest - a forest that's part of the biome we will study in this videoclass, so put some blood in that eye because today there's Atlantic Forest for you. ♪ To shoot the classes about Atlantic Forest, I traveled almost 320 miles, going from <i>Florianopolis</i> to the state of <i>Sao Paulo</i> where is located the tourist state park of <i>Alto Ribeira</i>, or <i>PETAR</i> for the intimate. However, it poured with rain and I had to finish up filming in the state park of <i>Serra do Tabuleiro</i>, which is located in <i>Santa Catarina</i>.

The Atlantic Forest is the Brazilian biome that received this name exactly because of its proximity to the Atlantic Ocean. It occupies about 15% of the Brazilian territory. It extends from <i>Rio Grande do Norte</i> until <i>Rio Grande do Sul</i> and from the coastline straight inland.

Passing through the coast mountains, going into the Parana basin on east Paraguay, as well as <i>Misiones</i> county in Argentine. The Atlantic Forest goes throughout 17 Brazilian states and almost 3 thousand cities, but not continously, rather fragmented, in other words, we have pieces of Atlantic Forest scattered all over Brazil. Many species found here in the Atlantic Forest, are endemic, in other words, you only find them in this biome.

In no other place in the world, you will see the golden lion tamarin for instance, it only exists here. Today you only will be able to find around 3200 of these individuals in the whole Brazilian Atlantic Forest. <i>"- Gee Jubijubao, that's too few!

"</i> It is too few, but it has been worse. During the '70s, there were only around 200 golden lion tamarin in the whole Atlantic Forest here in Brazil, that's why this biome is classified as a hotspot. Why?

It's got a high biodiversity - just so you know, 8 thousand species of plants are endemic of the Atlantic Forest, 500 species of vertebrate are endemic of the Atlantic Forest - so there's quite a high diversity. And this biodiversity is seriously endangered - Nowadays, the Atlantic Forest is one of the 5 most endangered biomes of the world. That's why it's classified as a hotspot - What's a hotspot?

" It's a region with high biodiversity that's seriously at risk of disappearing. In Brazil, the Atlantic Forest and the <i>Cerrado</i> are regarded as hotspots because they have a high biodiversity and both are seriously at risk of vanishing from our planet. ♫ Let's talk about the climate that rules the Atlantic Forest, as long as it's quite important to define the type of vegetation found in a given biome and here is a hot place and quite moist as well, in other words, it's a tropical climate.

The average temperature is around 22 degrees Celsius, and the rainfall index, in other words, the amount of rain per year is around 2500 mm, bear in mind that the Atlantic Forest spreads throughout a large portion of Brazil and there are variations - there are places where there's more or less rain, where the temperature is higher or lower. But I'm giving you an average preview. The most important is that you keep in mind, first off you have a boom of life where you have heat and high volume of fresh water.

So this is what defines the high biodiversity of this biome. The type of vegetation can change from a northeast Atlantic Forest to a south Atlantic Forest exactly because of the wide geographic distribution. That's why some authors defend the idea that the Atlantic Forest is not a single biome, rather, is a set of biomes.

Hence it's called Atlantic Domain. In this videoclass we will only talk about the ombrophilous dense forest, in other words, the traditional big Atlantic Forest you are familiar with. But what does characterize this basic Atlantic Forest, this ombrophilous dense forest?

It's ombrophilous because of moisture, these are plants that like moisture, they are adapted to moist places. These are perennial type of plants, in other words, they won't lose their leaves during the year, they always keep them. Why?

Because there's no drought season here, when you need to lose leaves to save energy. No, there's a lot of moisture here, keeping their leaves the whole year, with no problem at all. This is also a vegetation in which we find predominance of arboreous plants, trees.

Big trees that can reach up to 130 feet in height. Besides being ombrophilous, besides liking moisture, besides keeping their leaves, this is also a dense forest. Take a look, there's plenty of vegetal biomass here, check this out, I just can't get in here, it's too hard.

This is all closed! This is a dense vegetation, this is Atlantic Forest. Now, why does it rain too much in the Atlantic Forest?

Let's understand this educational process! We have the coast on this side, there's the Atlantic Ocean, where the formation of rain clouds take place. These rain clouds are brought to mainland, and when they arrive in this region - notice the amount of hills I have here.

This is characteristic of Atlantic Forest, this is a biome that develops in this type of lansdcape. This is what we call a "sea of hills" - you can see how it looks like a sea with several hills. These clouds that come from the ocean, are captive in these hills, they can't follow ahead, then the water cointained in these coulds condenses and all the rain falls here.

♪ As you know, the climate defines the type of vegetation, but the soil will also work on it, they act as a team. And the first characteristic of Atlantic Forest I want you to keep in mind, is that the soil is shallow. In other words, if I start to dig here, I quickly reach a hard rock, so this is not a deep soil Other characteristic is that the soil is little fertile.

Then you might ask me this <i>"- But Jubijubao, how come a soil that has few</i> <i>mineral nutrients will be able to support such a</i> <i>big vegetal biomass like the one I'm seeing? "</i> The secret is in this superficial layer. This residue of leaves we call litterfall, plus remains of animals, animal waste, will suffer a decomposing action by fungi and bacteria.

Then they will form a nutritious structure we call humus. Bear in mind that humus is fertilizer for the forest, take a look: This superficial layer you see here, is not the soil, the soil is underneath it, this is organic matter in decomposition. Forming our friend humus.

This humus has nutrients that permeate the soil and are absorbed by the roots of the plants. An interesting detail is that these plants will also suffer the action of decomposing agents when they die, and turn into humus that will nourish the other plants that exist in this region. That's why we say the organic matter is cyclical inside an ecosystem, because it falls here in the soil and goes to the plant, which in turn will give back the organic matter to the soil, which will be utilized by other organism.

Another detail is that there are two groups of animals that help a lot with the infiltration of nutrients in the soil, in other words, with the infiltration of humus in the soil, which are worms and ants. These animals dig tunnels and when it rains, this humus starts to penetrate the soil, then it's easier for the plants to absorb this humus nutrients through their roots. ♫ An interesting details is that the Atlantic Forest soil is at natural risk of collapsing.

That's because the rocks underneath the forest, are often impermeable, so when it rains too much they don't absorb the excess of water and end up soaking the soil, which ends up sliding because this is a hill, and gravity will make it happen. This is a natural risk, now imagine if you remove the vegetal coverage. This risk becomes bigger and of course, this associates to all the hills of the Brazilian coast where you have human occupation.

People build their houses, they destroy these forests and put their buildings on top of a heavily unstable soil then when the rain season comes, it's like what you see on the news, landslides and people dying, all the time - people should be forbidden to build their houses in this type of Atlantic Forest terrain, because it's a naturally unstable soil. If you cause deforestation, it becomes worse. ♪ Now let's talk about plants of the Atlantic Forest, which has one the biggest vegetal biodiversities of planet Earth.

About 7% of the plants that exist in our planet are located in the Atlantic Forest, that's a lot of plants. Just so you know, 80% of 2300 catalogued orchid species of Brazil, live in the Atlantic Forest. You guessed it!

The bromeliad is a very common plant in the Atlantic Forest. Just so you know, about 74% of bromeliad species found here, are endemic, in other words you only see them in the Atlantic Forest - check this out, there's not only one species of bromeliad, there are various species. And 74% of the species you see here, you only see here.

So very likely this is a species you can only see here. If you go to the <i>Caatinga</i>, if you go to the <i>Cerrado</i>, you no longer see this species. Do you see the importance of preserving the Atlantic Forest?

Then you ask <i>"Ok but what's the point of preserving Bromeliads? "</i> Pineapple is a bromeliad and you eat it - besides, bromeliads store rain water inside the forest. Their shape allows it, and they end up creating some kind of micro-habit that's quite appreciated by various animals that come here to use them as a source of shelter, to lay their eggs, to mate.

Various insects, anurans, love bromeliads to do something, to build a part of their lives inside these plants. Plus, bromeliads flowers produce a nectar, a honeycomb that's appreciated by various birds, such as hummingbirds, bees and even bats. So notice the importance of these plants to various other species, then I ask you this: What do you think would happen to the Atlantic Forest, in case bromeliads were destroyed?

Notice the domino effect of impacts. Other interesting detail is that bromeliads are epiphyte plants, which are quite common inside the Atlantic Forest. What are epiphyte plants?

They are plants that live on top of other plants, without parasiting them. This bromeliad is an epiphyte plant, it lives on top of this tree here. But it's not damaging this tree, this bromeliad isn't removing nectar from this tree, it doesn't have a structure to do that.

So epiphyte plants are not parasites. They simply utilize plants as a support. Besides bromeliads, we find other epiphyte plants here in the Atlantic Forest, such as ferns and orchids as well.

♫ Check out this nice example of how a single vegetal species is important to support several others. So here you have the main tree and let's observe how many other species of organisms live with this tree, better yet, thanks to this tree: Here we have a bindweed, here you have another species of plant - an epiphyte plant - another species here - there's small bromeliad up here, you have association with algae and fungi which are lichens, you have also moss, you have this tree right here, which is thriving under the shadow cast by this other tree, so notice the abundance of species I have within half a square meter, take a look - here you are able to see the biodiversity of the Atlantic Forest - How many species do I have in my arms with a single hug? ♪ Now let's analyze the vegetal organization of the Atlantic Forest.

We basically find three vegetal strata, in other words, three layers of vegetation. A higher one, which is the arboreal layer, a median one, which is arbustive and the lower one, which is herbaceous. The higher layer of the forest is formed by big trees, such as this one here - actually this is not that big because I'm in a secondary Atlantic Forest, in other words, this place was deforested and now you have a new vegetation thriving in here, so it's still young, but if you have the opportunity, better yet, the luck to find a more preserved Atlantic Forest, with a primary forest, in other words, untouched, was always that same way, you will find bigger trees that this one here - such as <i>ipe</i> trees, rosewood, cinnamon trees, which can reach up to a 100 feet in height, and they form what we call canopy, the "forest roof", these are the plants that most receive sunlight exactly because their top stays higher, then the sunlight hits their leaves.

♪ We have the arburstive layer living underneath the arboreous layer, in other words, the one formed by median plants that reach 32 feet in height, they could be either shrubs or young trees like this one here. What this one here is doing? It's not increasing its volume, it's investing on its height to quickly reach the top and have access to the sunlight, now this plant should stay in this same median layer during its whole life.

Surely it will have less volume of light, that's why it has to be adapted to be able to survive and do photosynthesis in the darkest part of the forest. You may be observing how dark is underneath the Atlantic Forest, exactly because the upper layer prevents the sunlight from entering, so everything that's below the upper layer needs to be adapted to be able to live in an environment with very little light. Case in point, the jussara palm tree, which lives in the arbustive layer of the Atlantic Forest and can reach over 30 feet in height, almost went extinct over the extraction of its trunk apex from which the palmetto is extracted.

Another plant that lives in the arbustive layer and was almost extinct is the <i>samambaiacu</i> fern, a pteridophyte that reaches up to 16 feet in height, this plant was killed because its stalk is utilized to manufacture xaxim vases, a practice that has decreased nowadays. Then we have the lower layer of this forest where you have the herbaceous layer, with smaller plants like these, you have also the litterfall in this layer, which are these remains of leaves with various animals living on it, mainly invertebrate and that's cool because the lowest part of this forest righ here, gets even less sunlight. An interesting characteristic, is that the leaves of plants that thrive in this lower layer are larger, they are broadleaft plants.

The bigger the leaf, the larger the surface to catch a little sunlight coming from above, so that this plant manages to do photosynthesis. ♪ Now we have to bring up a "philosophy of life" regarding some characteristics of Atlantic Forest plants. Because this is a very moist place, so these plants need to be adapted to be able to survive in a place with a lot of moisture, because when you have too much water in a place, you're at risk of rotting your tissues.

One of these characteristics is the shape of the leaves of Atlantic Forest plants, take a look! This is quite pointy, which allows for better rain water flow, it runs down here and quickly drops with easy, then <i>pow</i>, it easily drops so you don't have water accumulating here. Another detail is that these plants are flexible, so this also helps when the water hits here, the weight quickly makes it run and no water will accumulate and cause trouble to the tissues.

Another adaptation they have, is to keep their stomata open the whole time - stomata are those little buttons located in the leaf, to make gas exchange - it opens and closes these buttons. But they keep them open the whole time in the Atlantic Forest, so they lose water by transpiration. <i>"- Will they run out of water?

"</i> No, it's an environment with a lot of water, so a plant that thrives in a moist place can do that, can snub and let its stomata open all day long. That's snobbish! Like <i>"today I will open my stomata all</i> <i>day long"</i>, because there's a lot of water here They make the <i>Caatinga</i> plants very jealous.

Another adaptation regarding moisture, is that plants of the Atlantic Forest have glands known as hidatodes. These glands are located in the leaves and eliminate the excess of water in a phenomenon known as "gutting". Sometimes it doesn't rain for a long time and you see small droplets on the tip of their leaves, that's gutting, it's simply eliminating the excess of water through their leaves.

Another adaptation to resist Atlantic Forest high moisture, is trees that have roots that increase their support base, such as tabular roots that help to keep the plant fixed in these moist soils. Another strategy is to stick to the nearest plant. If you observe inside the Atlantic Forest, we have an elevated vegetal density, that's also a way of protecting yourself against the unstable soil, by the way, the Atlantic Forest fauna will be the great theme of our next videoclass.

All in all, needless to say that was a treat to be here with you, a great hug, bye! <b>Subs: <i>msfreelancer</i></b> http://tinyurl.