Earth's organisms do not live in isolation, interact with each other and the environment. By studying these interactions we call Ecology.
The word ecology comes from two Greek words: Oikós which means home, and logos which means study. Ecology literally means Habitat Science.
Some important concepts
SPECIES - is the set of similar individuals (structurally, functionally and biochemically) that reproduce naturally, giving birth to fertile descendants. Ex.: Homo sapiens
POPULATION - is the set of individuals of the same species living in the same area in a given period. Ex .: rat population in a manhole on a given day; bacteria population causing tonsillitis for 10 days, 10,000 people living in a city in 1996, etc.
COMMUNITY OR BIOCENOSIS - It is the set of populations of different species that inhabit the same region in a given period. Eg beings from a forest, a river, a lake from a swamp, fields, oceans, etc.
ECOSYSTEM OR ECOLOGICAL SYSTEM - is the set formed by the physical environment, ie, the BIOTOP (formed by abiotic factors such as soil, water, air) plus the community (formed by biotic components - living beings) that relates to the environment.
HABITAT - is the specific place where a species can be found, that is, its "ADDRESS" within the ecosystem. Example: A plant can be the habitat of an insect, the lion can be found in the African savannas, etc.
BIOTOP - Physical area in which a particular community lives. For example, the piranha habitat is freshwater, such as the Amazon River or the Pantanal Complex rivers. biotope Amazon River is the place where all living organisms live on this river, among them the piranhas.
ECOLOGICAL NICHO - is the role that the organism plays, ie the "PROFESSION" of the organism in the ecosystem. The niche informs at the expense of what it feeds, who serves as food, how it reproduces, etc. Example: The female Anopheles (transmits malaria) is a blood-eating insect, the lion acts as a predator devouring large herbivores such as zebras and antelopes.
ECOTONE - is the transition region between two communities or between two ecosystems. In the transition area (ecotone) we will find a large number of species and therefore a large number of ecological niches.
BIOSPHERE All life, whether animal or plant, occurs in a range called the biosphere, which includes the Earth's surface, rivers, lakes, seas and oceans, and part of the atmosphere. And life is only possible in this range because there are the gases necessary for terrestrial and aquatic species: oxygen and nitrogen.