Introdução a ecologia

#Biology #Ecology #ENEM Lesson aimed at high school and ENEM students on basic ecology concepts. Video outline: Ecology is a branch of biology. It studies the interaction between living organisms and their environment. In this lesson, we will clarify some very common concepts in this area, which you will see quite frequently. Starting with spatial concepts, such as the biosphere, which is the broadest level of ecology, it is literally the entire planet Earth, all habitable and non-habitable regions, containing all the biodiversity of the planet Earth. Now we have a second concept, biodiversity, which is quite popular, but have you ever stopped to think about what it means? In short, biodiversity, or biological diversity, is the variability among living beings, only through natural modifications, that is, the richness of forms and shapes of all living organisms, both in relation to the number of species that exist and in relation to the variability of these species. Also, we have to mention that in total we estimate that the species richness on planet Earth is over 10 million species, although we have only found around 1.5 million so far, which is already quite a lot. The second concept of space is habitat, which is the physical location where an organism lives, for example, a city for humans, or the treetops for monkeys. Therefore, we can also introduce the ecosystem as the next concept, which is the interaction of the environment with the various species that inhabit it, that is, the interaction of abiotic factors (such as rain, sun, wind) with the inhabitants of that environment, the biotic factors. The biosphere is made up of all the ecosystems we know. In addition, the ecosystem can be divided into three categories: the epinocycle, which are ecosystems on land; the thalassocycle, which are saltwater ecosystems; and the limnocycle, which are freshwater ecosystems. We also have to point out that ecosystems can be defined by how they arose, with natural ecosystems being those that arise naturally (like a forest) and artificial ones being those formed by humans (like a large city). Now that we have defined the spatial issue, let's understand who the agents that live in this space are. Starting with the term organism, which is nothing more than a living being, a unit, like you or me. Several similar organisms are considered a species. But of course, species is a rather complicated term; there's a video on the channel talking about the subject, it's worth taking a look at it before continuing with this video. So, if ecology studies the interaction between organisms, we can put two concepts here: interspecific and intraspecific. Both mean some interaction with another organism; the difference is that in the interspecific interaction, it is an interaction between organisms of different species (like hyenas competing for a carcass with vultures), and the intraspecific interaction is the relationship between organisms of the same species (like hyenas competing for a carcass with other hyenas). When several organisms of the same species live in the same habitat, we can say that we have a population, that is, a group of organisms of the same species living in the same environment. However, when several populations live together in an environment (which is the most common thing to happen), we have a community. Therefore, a community is the interaction between several populations in the same environment. Another concept widely used in the media and textbooks is biomes, which are a set of similar ecosystems in a given region. It is a very controversial subject in the scientific community, as many authors dislike this definition and have other ways of classifying it. However, since we are focusing on the entrance exam, in Brazil we have 5 biomes: the Amazon, the Caatinga, the Cerrado, the Atlantic Forest, and the Pampas. Later we can make a video on the channel talking more about each of them. We must emphasize that in many places you will find the Pantanal being considered a biome, but it is not; it is an ecotone. Think of it this way: the Amazon borders the Cerrado, right? But it's not a defined border; one doesn't end and the other begins out of nowhere. There's a kind of gradient, a transition zone from one biome to the other, with characteristics of both biomes. This transition zone is called an ecotone. The Pantanal is an ecotone of several biomes, both Brazilian and from other countries. We have other ecotones throughout Brazil, such as the coconut palm forests, the semi-arid region, or the coastal restingas. I must emphasize again that the subject of biomes and ecotones is not a consensus in the scientific community; in fact, it is something quite debated, not only in its classifications but also in the very use of the term biome.