Ecosystem (Meaning and Explanation)

We explain what ecosystems are and what types exist. Also, how they are composed, their characteristics and various examples.

ecosystem polar example — There is a great diversity of ecosystems on the planet.

What is an ecosystem?

In biology, an ecosystem is a system that is made up of a set of organisms, the environment physical environment in which they live (habitat) and the biotic and abiotic relationships established between them. The species of living beings that inhabit a certain ecosystem interact with each other and with the environment, determining the flow of energy and matter that occurs in that environment.

There is a great diversity of ecosystems on the planet. They are all made up of biotic factors (living things) and abiotic factors (non-living elements, such as soil or air). There are also different types of ecosystems: there are marine, terrestrial, microbial and artificial, among other examples.

An example of the relationships that take place between living beings in an ecosystem are food relationships. Trophic or food chains are simple representations of the feeding relationships that exist between the species that are part of a given ecosystem. Generally, in ecosystems, food chains are interrelated, forming food webs.

It is said that there is a trophic relationship between two organisms when one of them is consumed by the other. In turn, The consuming organism can be the food of another that is part of the same ecosystem. Thus, a connection is formed between several links and a food chain is formed. Each link in a chain represents an organism that “eats another” or “is eaten by another.”

Within food chains there are different trophic levels, which are based on the position that an organism occupies in the flow of matter and energy. In other words, the trophic level groups all the species that share the origin of their food within the ecosystem. There are three trophic levels:

Producers They are autotrophic organisms, that is, they are capable of producing organic matter (their own food) from inorganic matter, through photosynthesis or chemosynthesis. Producers are the first trophic level, that is, they constitute the first link in food chains. This group is represented by plants, algae and phytoplankton and some bacteria.
Consumers They are heterotrophic organisms, that is, they feed on other living beings to obtain the matter and energy they need. In turn, consumers are classified into different groups, according to the organism that constitutes their food. The primary consumers are herbivorous organisms, that is, those that feed on producers. Secondary consumers, on the other hand, are carnivores and feed on primary consumers. There are also tertiary and quaternary consumers, which feed on secondary and tertiary consumers respectively.
Decomposers They are organisms that feed on decomposing organic matter, that is, they obtain the matter and energy they need from the remains of other living beings. Although they are not usually represented in food chains, they are essential in nature as they allow the recycling of nutrients. Among the decomposing organisms are fungi, worms and some bacteria that recycle organic matter.

Components of an ecosystem

An ecosystem is made up of two types of elements or factors:

Biotic elements They are those elements of an ecosystem that have life, that is, all the living beings that inhabit it. For example: flora and fauna.
Abiotic elements They are those non-living factors that are part of an ecosystem. For example: climatic conditions, relief, pH variation, presence of sunlight.

It is very important to keep in mind that the relationships established between biotic and abiotic elements are also considered one more element that forms a specific ecosystem.

Ecosystem types

There are various types of ecosystems that are classified according to the habitat in which they are located:

Aquatic ecosystems They are characterized by the presence of water as a main component and are the most abundant type of ecosystem: they constitute almost 75% of all known ecosystems. This group includes the ecosystems of the oceans and those of fresh or salt continental waters, such as rivers, lakes and lagoons.
Terrestrial ecosystems They take place on the earth's crust and out of water in various types of relief: mountains, plains, valleys, deserts. There are important differences in temperature, oxygen concentration and climate between them, which is why the biodiversity of these ecosystems is large and varied. Some examples of this type of ecosystem are forests, shrublands, steppe and deserts.
Mixed ecosystems They are ecosystems that are located in “intersection” areas of different types of land, for example, in which the aquatic and terrestrial environments are combined. Mixed ecosystems, also called hybrids, share characteristics of both terrestrial and aquatic ecosystems, and are considered transition zones between both types of ecosystems mentioned. Living beings that inhabit this type of ecosystem (such as amphibians) spend most of their time in one of the two ecosystems but require the other to rest, feed or procreate. Some examples of this type of ecosystems are mangroves, estuaries and coasts.
Microbial ecosystems They are ecosystems formed by microscopic organisms that inhabit practically all environments, both aquatic and terrestrial, and even within larger organisms, as is the case of the intestinal microbial flora.
Artificial ecosystems. They are those ecosystems created and/or intervened by humans, which is why they are also known as anthropic ecosystems. Some examples of these ecosystems, which are increasingly common on our planet, are urban ecosystems, reservoirs and agricultural ecosystems.

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Characteristics of an ecosystem

ecosystem - food chain — In each ecosystem, multiple interactions occur such as food chains.

are formed by biotic and abiotic factors that are dynamically interrelated through food chains, that is, the flow of matter and energy.
They vary in size and structure depending on their type.
can be terrestrial (in reliefs such as the desert, mountains, prairie), aquatic (fresh or salt water) or mixed (such as those that can be found in wetlands).
can be natural or artificial (created and/or intervened by humans)
There is great biodiversity in many of them.
are dynamic and variable environments that undergo natural or artificial changes and a constant flow of energy and nutrients between the factors (both biotic and abiotic) that constitute them. The transition zone between one ecosystem and another is called “ecotone”.
The main source of energy in ecosystems is the one that comes from the solar radiation. This energy is used by producers (who are the first trophic level of food chains) to fix inorganic matter into organic matter.
are complex systems due to the interactions between its members. The greater the biodiversity, the greater the complexity of the ecosystem.
can be altered naturally (such as natural disasters) or by human action (such as deforestation, pollution and indiscriminate fishing). Alterations by human action can cause irreversible damage to ecosystems, since many times the species that live there cannot adapt to the changes produced in the environment.
are studied by ecology branch of biology that studies living beings and their relationship with the environment they inhabit.

Examples of ecosystem

ecosystem example coral reef — Coral reefs present a great concentration of life and biodiversity.

Coral reefs They are one of the largest concentrations of life in the underwater world and occur in and around the coral structures that form a natural barrier. Due to the abundance of organic matter that lives in them, numerous species of fish, crustaceans and small mollusks serve, in turn, as food for predators.
Submarine abyssal zones They are extreme ecosystems, with little animal presence and no plant presence, since the absence of sunlight prevents photosynthesis. The living organisms that live there adapt to the enormous pressure of the water and the low amount of nutrients.
Polar ecosystems They are ecosystems that are characterized by very low temperatures and little atmospheric humidity. Despite this, they have a sea rich in plankton and an animal life adapted to icy waters: the animals have hairy bodies and dense layers of fat.
Lotic ecosystems. They take place within and on the margins of rivers, streams or springs on the earth's surface. Life in them adapts to the flow of water, which carries with it nutrients, chemicals, living species or highly oxygenated water in its movement.