david alercia
Bachelor of Biology
The biosphere is the subsystem of the Earth, the “sphere” in which all life on the planet develops. If you have ever seen an image of our planet, you will have noticed a green and blue sphere. The blue, evidently, corresponds to the oceans, and the green to the emerged land. Thus, the Earth can be subdivided into “spheres”, or subsystems, in order to study it better.
There are living organisms on the planet from the bottom of the oceans, where darkness is complete and there are no plants or algae, that is, there are no producers. There, ecosystems develop in which the trophic web is different from the rest of the known ecosystems, and their food source is what “falls” from the illuminated surface of the oceans. In the areas of submarine volcanoes, very particular ecosystems develop, whose energy source is not the sun but the gases produced by this volcanic activity. All of these life forms are known as deep-sea organisms. “Strange” is a way of saying, it is not that they are essentially different from the rest of the living organisms on the planet, but because they live at such great depths, it is not often seen.
On the surface of the earth, the biosphere, that is, the inhabited “layer” of our planet, extends up to about 10 kilometers in height (about ten thousand meters) which is the maximum height at which some birds can fly, although there are many other organisms capable of flying and floating in the air –insects, microorganisms, among others) and it is also necessary to take into account the organisms that live on top of the mountains.
There are no organisms that live 100% in the air: they all descend to the ground, either to feed, rest or reproduce (although many birds and bats feed while in flight hunting flying insects).
The biosphere, therefore, designates the “sphere” or subsystem of the Earth inhabited by living beings; but it is an abstract concept, because we cannot see the whole “biosphere”: to do so we would have to be able to see all the organisms that are alive at the moment on the whole Earth, and that is clearly impossible. What we can see, although not completely, is the set of living organisms that inhabit a place at a given time. That is, we can know the particular biosphere of a place, a country, a region. This set of organisms from one place is called biota. To summarize, the biota is the local manifestation of the biosphere. For example, talking about the biota of Mexico (or any other country) makes perfect sense, and would be equivalent to talking about the biosphere in Mexico, but talking about the biosphere in Mexico would be incorrect.
Flora, Fauna and Funga
Biota encompasses all living organisms, but large groups of organisms have been identified since ancient times: plants and animals stand out.
The set of plants is called Flora, and is one of the components of the biosphere. The importance of plants in ecosystems lies in the fact that they are the producers of all the trophic chains of all known ecosystems (with the exception, as we have said, of some abyssal ecosystems). Plants are the organisms that convert inorganic matter (water and carbon dioxide) into organic matter using the sun’s energy for the reaction; that is to say, they constitute the base of all food chains and trophic webs, because they provide all the matter of which living beings are made. Another very important function of plants is that they are responsible for configuring the landscape, that is, it is the place where the rest of the organisms live. The appearance of the landscape is called physiognomy, and it is largely determined by the geology and climate of the place (mountains, deserts, rivers, plains) and by the flora of the place (forests, jungles, meadows). Another of the large components of the biosphere are animals, and the set of animals is called Fauna.
Until the 18th century, plants and animals were the only large groups of recognized organisms. Since then, more and more forms of life have been discovered that did not fit the pattern of plants and animals. There is a great variety of unicellular organisms (formed by a single cell, invisible to the naked eye) and multicellular (formed by many -up to billions- of cells) that are clearly different from plants and animals. By tradition, and due to lack of sufficient technology to see that they really were neither plants nor annals, they were classified as “lower plants” and most microorganisms and fungi entered there.
Fungi, in particular, are very important organisms in ecosystems, just as important as plants because of the role they play in trophic chains: if plants are the producers, taking inorganic matter from the environment and converting it into organic matter, fungi are Fungi are decomposers: they decompose the organic matter of the corpses of living beings into inorganic matter, thus closing the cycle of matter in the biosphere. The recognition of this importance in ecosystems has led to the group of fungi in a place being called Funga.
This grouping into Fauna, Flora, Funga is an informal classification of living things and refers to the large groups of “recognizable” organisms. Intuitively we can recognize and distinguish an animal from a plant and a fungus, although sometimes it is not that simple, on many occasions it is. The formal classification of organisms is much more complex and is called taxonomy, and the discipline of biology that makes that taxonomy is called systematics. The complexity of the formal classification of living beings deserves several articles of its own, but with this simple grouping of the components of the biota we can get an idea of the immense diversity of life, known as biodiversity.
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