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I'm into that kind of music.

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I'm into that kind of music.

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I'm into that kind of music.

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Good morning.

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We are starting a new topic today.

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We are going to see the relationship that living beings have with their environment.

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We are going to see the biosphere.

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What is it?

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What is the biosphere?

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Well, the biosphere is the set formed by all the living beings that live on Earth.

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Here, remember that living beings, we are not only talking about animal plants,

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but we include many more organisms.

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What does the biosphere consist of?

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Well, we have a series of organisms, producers, consumers and decomposers,

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that are going to take advantage of the energy of the sun and are going to expel heat.

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That is, our system is energetically related,

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acquiring solar energy and releasing heat.

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It also acquires a series of materials,

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such as oxygen, water, CO2, phosphorus or nitrogen.

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All that is going to enter the system and it is also going to come out in the form of oxygen,

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because, for example, producers take CO2 and expel oxygen.

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It is going to come out as water, many metabolic reactions,

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because its final derivative is water.

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CO2, because here consumers take oxygen and expel CO2.

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And also as phosphorus and nitrogen, but it may come out in another way.

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If one is oxidized, it comes out as a reducer or the other way around.

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Everything is going to be related to the atmosphere, the hydrosphere and the geosphere,

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which we have already studied all three of them.

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Keep in mind that the biosphere is an open system.

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Remember that we saw the systems in topic 1 a long time ago.

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We said that the open system was when it exchanged matter and energy with the outside.

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There is always a recycling of all that matter.

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None of the elements is going to be lost at any time.

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The ecosphere, another term that we have to know,

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which are all the organisms of the biosphere and the relations that are established between them and the environment.

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With that, we are going to focus mainly on this topic,

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on all those relationships that occur between organisms.

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Within the ecosphere, we have to talk about ecosystems.

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The term ecosystem, although we all know it,

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we may not be sure how to define it.

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We are going to take the definition of Eugene Odom,

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who was a great ecologist, who wrote the book Fundamental of Ecology

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and is the one called the father of ecological ecologism.

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He says that it is a unit that includes all organisms in a certain area interacting with the physical environment,

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in such a way that an energy flow leads to a clearly defined trophic structure,

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biological diversity and cycles of matter within the system.

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That is, we have a community of living beings, which we also call biocenosis,

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a physical medium, a physical environment, which is what we call biotope,

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and among them they are interacting through a relationship of matter and energy.

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This gives rise to the fact that in that system we have, as it says here, a trophic structure,

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producers, consumers, decomposers, a great biological diversity,

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and that some cycles of matter appear, for example, the phosphorus that enters has to leave in another way,

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or the nitrogen that enters also has to leave, etc.

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Biomes, when we talk about ecosystem, let's say that we are referring to something smaller.

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Biomes are large ecosystems that extend across large regions of the planet,

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but in similar climatic conditions.

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We are going to see some of the main biomes, I have made a classification,

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but there may be others, because depending on the book we choose, we take one description or another.

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We have terrestrial and aquatic biomes.

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We are going to distinguish between terrestrial biomes mainly due to temperatures and rainfall.

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Those climograms that you may have seen when you did geography,

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when you did geography and history,

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in which you could see the amount of rainfall that there was after a year,

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the minimum and maximum temperatures,

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all that is what we take to make that classification of terrestrial ecosystems.

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And then the aquatic ones, which we are going to classify according to whether they are marine or freshwater.

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Let's go with the terrestrial ones.

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We have the equatorial jungles, also known as tropical forest or plurisilva.

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Here we have a large amount of rainfall throughout the year and a constant temperature.

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We are in the area of ​​the equator where there are no differences between winter and summer.

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The savannah is an area where we already have two seasons, the rainy season and the dry season,

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so one season it is going to rain a lot and another season it is going to rain little,

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although the temperatures remain more or less constant.

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And the desert, we already saw when we were talking about how convective cells were distributed,

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where the large deserts appeared, which appeared mainly in the tropical areas,

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because of that convergence of air in the tropics that made the anticyclones descend

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and that heated the air and on the other hand dried it up.

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Here we have the large deserts where the rainfall is very, very scarce

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and the temperatures vary a lot between day and night.

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In the temperate climates, we have the temperate forest,

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which would be a forest where the rainfall is relatively abundant throughout the year,

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there is not much variation between winter and summer,

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but the temperatures do vary, in winter they are colder and in summer they are a little warmer.

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It is the typical forest, as we speak of the Atlantic forest, for example in the area of Galicia, Asturias,

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or if we go to Central Europe, almost all of Central Europe has a temperate forest,

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or in the areas of the United States, Mediterranean forest.

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Although we call it Mediterranean, it is not only in Europe, in the Mediterranean region,

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we also find it, for example, in South Africa, we find it in the area of Chile and Argentina,

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we find it in Australia.

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It is a forest characterized by very high temperatures in summer,

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a little cold in winter, not excessively cold, but a little cold,

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and a rainy season in spring and autumn, and quite dry in summer.

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The meadows and steppes would be those places where we have two very marked seasons,

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also a rainy season and a dry season.

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They are large areas where there are practically no trees,

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with conditions of life that are generally harder,

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it may be because they are areas where the wind blows a lot, where it is not favoured that trees appear.

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There are large areas of the planet where those meadows or steppes appear,

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for example, the Pampa Argentina, we find the large meadows of the United States.

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We have already moved on to the cold climates, here we distinguish two,

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the taiga, which are areas where forest still appears, where trees appear.

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We have a very cold season, which is quite long,

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and a slightly warmer season, which allows these trees to survive.

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The precipitation is generally in the form of snow in winter,

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and then in summer it also rains, it is also a humid season.

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And the tundra, we are already going further north,

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and we find an area where trees can no longer grow.

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The vegetation will always be low because practically all year it is covered with snow,

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which does not allow these trees to appear.

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In the aquatic ecosystems, we said that we distinguish between the marine and the freshwater,

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in the marine we distinguish two areas, the neritic or coastal area.

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We take it from the coast up to 200 metres deep,

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which depending on the area of the planet will be more water inside, more towards the coast.

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For example, on the Chilean coast, the depth immediately drops,

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because we are close to a tectonic pit.

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But, for example, in the areas of Australia,

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we have many, many kilometres of this neritic area,

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that is why these large coral barriers appear in Australia,

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because they are areas where there is little depth,

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the water passes very well and large formations such as coral barriers can develop.

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And the pelagic area would be the one where the depth of the seabed is more than 200 metres,

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and certain floating organisms appear that are not settled on the bottom.

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For example, here the pelagic area is based, its main organism is the phytoplankton,

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although we cannot see it, but they are the ones that determine all the trophic chains of the pelagic area,

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those microscopic algae that will feed the rest of the trophic chain.

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Well, within the aquaculture, we distinguish two, for example, the lotic area or running waters,

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here we would include the rivers, streams where the water moves,

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and the Atlantic areas, which are stagnant waters,

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we include lagoons, lakes, swamps, even if they are of artificial origin,

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we also include it here in the aquaculture.

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Within these ecosystems, how do organisms relate to each other?

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Organisms will relate to each other by a series of trophic relationships.

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I have posted a video that is in English, but you can put it with subtitles,

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and you will find out that it is called Ecology of Ecosystems,

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so that you can get a first idea of ​​what these trophic relationships are like.

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Do you see it? And we continue.

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Well, once we have seen the video, we go with those relationships,

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we distinguish between producers, consumers and decomposers.

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Let's see the different types.

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Within the producers are the autotrophic organisms, which are the ones that feed themselves.

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Here we have two types, we would have the photosynthetic,

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which are those that depend on light to carry out their chemical reactions and to feed themselves,

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and the kinesynthetic, which obtain energy from the oxidation of organic substances,

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for example, this one that we have here, sulfulobus,

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is an archaea that uses sulfur to make its chemical reactions.

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We have other types of archaea, for example, which are methanogenic,

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which generate methane in their chemical reactions.

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That is, not everything will depend on light,

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but there may also be producers that depend on other chemical substances.

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Consumers are going to be those who are going to eat the producers or who are going to eat each other.

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We have herbivores, which are going to be the primary consumers, those who eat the producers.

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Carnivores, we have secondary consumers, who are the ones that are going to eat the herbivores,

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or tertiary consumers, which are those who eat the herbivores.

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For example, what example have I put here?

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I have put a tomato plant.

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For example, we have a producer, we have the tomato plant,

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we have the flea that sucks the sap from that tomato plant, that is, it is a herbivore.

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We have the fly that eats the flea, which would be a secondary consumer.

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In case you don't know, flies are great and wonderful to get rid of fleas.

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And we have this little bird, which is a carbonero,

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that eats the fly that eats the flea, and that would be a tertiary consumer.

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Among the consumers we have two other types.

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We have, for example, the carnivores or necrophages.

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Something dies, something eats it directly.

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They are the carnivores, which does not mean that we do not have, for example,

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a secondary consumer that is also a carnivore.

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If I find free food, I will take advantage of it.

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And we also have the saprophytes or detritivores.

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These are in charge of eating decomposing material,

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but not so much of the dead animal, but of the remains that remain.

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Imagine a corpse that is left abandoned in the field of a sheep.

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For example, the sheepdogs start eating it,

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and the remains of that sheep, of the wool, of the meat, of the bones,

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they eat it on the ground, little by little, the saprophytes,

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or in the water, it falls to the bottom of a lake,

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and the detritivores also eat it.

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All these organisms, producers, consumers, and decomposers,

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are related by a series of trophic networks.

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From what was said before, from the trophic chains,

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the herbivore eats this, the other.

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It's not that simple.

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Normally, there are many relationships between each other.

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A consumer can also be a carrion at a certain time,

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or even a secondary consumer can be a herbivore.

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So, what is a trophic network?

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They are food chains of an interconnected ecosystem,

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through food relationships.

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And at the last stage of the chain, we have the decomposers.

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What are decomposers?

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They are a special type of detritivores

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that are responsible for transforming organic matter into mineral salts.

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Here, we close the cycle.

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We already have a series of bacteria, a series of fungi,

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that are going to eat the remains of what is left

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and transform it into mineral salts

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so that they return to the ecosystem again.

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And this is all for today,

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starting with our topic of the biosphere.

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Until the next day.

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Transcription by ESO. Translation by —