BIOTOPE: COMPONENTS, TYPES AND EXAMPLES - ENVIRONMENT - 2024

The biotope constitutes the abiotic (non-living) component of the ecosystem. It is a geographical area with physical-chemical characteristics that allow the development of a community of living beings. The components of the biotope are the environment, the substrate and the environmental factors; of the latter, climate, soil and water are the fundamentals.

Some of the determining factors in the conformation of a certain biotope are light, temperature, humidity and the physical-chemical properties of the medium and substrate.

Biotope lake. Source: pixabay.com

Biotopes can be terrestrial, aquatic and mixed or transitional. Examples of terrestrial biotopes are tropical rainforests, temperate forests, and savannas.

Among the aquatic there are marine and freshwater biotopes. Mixed or transitional areas are located in contact areas of land areas and bodies of water; These include the various types of wetlands such as marshes, swamps and mangroves.

Definition

The biotope is the abiotic component in which living beings in the ecosystem interact. It can be said that it is the geographical place that houses a certain biocenosis (community of living organisms in the ecosystem).

In addition, the biotope is characterized by having defined physical and chemical properties. These conditions are necessary for the living beings present to develop properly.

Components

The biotope is made up of the complex interaction of a large number of abiotic factors, which serve as a matrix to support life in the ecosystem. The fundamental components are the medium, the substrate and the environmental factors.

Scheme of the biotope of a lake. Source: pixabay.com

The middle

It is the matter in which the biocenosis is immersed. In this the living organisms move and perform their functions.

The main media are air and water. However, there are very particular environments, such as the intestine of a mammal. This forms an ecosystem with a biocenosis of bacteria, fungi and protists, and the medium is the pericellular and cellular content of the intestinal tract.

The substrate

It is the matter on which living beings in the ecosystem are based. The most common is soil, but in the case of many aquatic biotopes, water is medium and substrate at the same time.

Environmental factors

Life can only exist within a defined range of environmental conditions and each organism has an optimal functioning adapted to each abiotic factor. Thus, a given biotope has a dynamic equilibrium of abiotic factors that allows the existence of a given biocenosis.

Among the environmental factors we have the following:

Solar radiation

The incidence of solar radiation and its quality influences the community of living beings that can exist in a biotope. A deficit of solar radiation limits bioproductivity and affects the food web.

Water

If humidity is limited in a given area, only one particular biocenosis can develop. On the other hand, an aquatic environment determines a different biocenosis than a terrestrial environment.

Temperature

The temperature range in which living beings are capable of performing their basic functions is restricted. Above a certain limit, most proteins are denatured.

At high temperatures the number of species that can be part of the biocenosis is very low (only thermophilic archaebacteria). At the other extreme, when temperatures are very low, living beings capable of survival are also scarce.

Chemical composition of the medium and substrate

Plant species and soil biota respond to chemical compositions and physical and pH characteristics of the substrate in a defined range.

In water, salinity and pH are determining factors. Another important element is the proportion of gases that make up the air in a given biotope.

Weather

It is decisive to define the variety of species that can inhabit a given area. In a temperate zone biotope, subjected to a four-season regime, the biocenotic characteristics are very different from those of a warm tropical regime.

Relief

The physical conformation of the terrain influences other environmental factors. Temperature decreases with altitude, while runoff and underground water availability vary with slope.

For example, air masses rise when they collide with a mountain and condense as they rise, generating cloudiness and orographic rain. This defines very particular environmental factors, such as high humidity that favors the development of a particular biocenosis.

Types

Terrestrial biotopes

They are characterized because the biocenosis settles on the earth as a substrate and is immersed in the air as a medium.

They have a latitudinal variation, so when we move latitudinally we will find tropical, temperate and cold biotopes. In turn, in each area there will be as many biotopes as possible combinations of soil types, relief, altitude and climate are present.

Aquatic biotopes

In this case, the fundamental medium in which the biocenosis that occupies it is immersed is water in a liquid state. There are marine and freshwater aquatic biotopes, which differ in depth gradient (vertical) and horizontal zoning.

It is in the marine environment that the greatest variety of biotopes is reached. The conditions vary depending on whether they are located in the pelagic environment (open sea), in the benthic (ocean floor) or in the abyssal region (deep sea trenches).

Marine currents, depth and temperature are determining factors in the biocenosis that is established in these.

Transitional or mixed biotopes

The physical environment of these biotopes includes terrestrial and aquatic elements. Wetland or coastal zone ecosystems fall into this category. The biocenosis that occupies this type of biotopes has evolved adapting to this mixed condition.

Organisms can fulfill part of their cycle in one or another area of ​​the biotope. They generally depend on the flow of matter and energy that occurs between the aquatic and terrestrial environment. Among these biotopes we find estuaries, swamps, marshes, deltas and coasts.

Differences with habitat, biocenosis and ecological niche

All areas of the planet occupied by living beings constitute the biosphere. This works as an integrated system, but from a practical point of view it is divided into smaller units.

The largest units are biomes, defined by general climate characteristics. In turn, biomes are divided into ecosystems with different communities made up of populations of different species.

The ecosystem is the interaction of a biotic community (a set of living beings of various species) with its abiotic environment.

There are various concepts linked to an ecosystem that are related to the different levels of organization. In some cases the terms can be confused, so it is necessary to establish the difference between them.

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Habitat refers to the geographical area occupied by one or more populations of a certain species. Although in some cases the term biotope has been used as a synonym for habitat, they are different concepts.

The concept of biotope refers to the geographic area where a community (set of populations of various species) develops. That is, the biotope includes a variety of habitats.

For example, in a tropical rain forest we can find a species of monkey whose habitat is the treetops, in the upper canopy of the forest, while a jaguar has the understory (the floor of the jungle) as its habitat. Both species exist in different habitats, but they coexist in the same biotope, which is the rainforest.

Biocenosis and biotope

Ecosystems are formed by the community of living beings, the relationships between them and their relationship with the physical environment.

Biocenosis is the living part of the ecosystem. It is made up of all the species that form populations that, in turn, are grouped into communities. This includes the symbiotic relationships between different populations within a community and between communities.

Instead, as mentioned above, the biotope is the physical environment in which these communities develop.

Biotope and ecological niche

Another term that is confused with that of biotope is that of ecological niche. However, this category applies to species and not to communities.

It refers to the functional relationship of a species with the community of which it is a part. It includes all the adaptations of this species to its environment, especially in relation to the place it occupies in the food web of the ecosystem.

Examples

Terrestrial biotopes

Mountain Cloudy Rainforest

The biotope of this ecosystem has a determining influence on latitude and relief (altitude). They are areas located in the intertropical strip at altitudes between 800 and 2500 meters above sea level.

They are exposed to moisture-laden air masses that condense and form cloudiness as they rise. They have a high relative humidity and, due to the altitude, the temperatures are relatively low. Another characteristic associated with the relief is the presence of steep slopes, so the substrate is shallow.

This biotope supports one of the most diverse biocenoses on the planet. There is a large number of species with different habitats and occupying abundant ecological niches. Furthermore, there are numerous complex symbiotic relationships between organisms.

The warm dry thorn

In contrast to the cloud forest, the thorn or warm thorn scrub is made up of a fundamentally flat biotope in relief.

It generally has sandy soils, with little organic matter and low fertility. Daytime temperatures are high and nighttime temperatures are low, and there is only a short rainy period with low precipitation.

This biotope is home to a very different type of vegetation and fauna, much less diverse than that of the more humid tropical forest.

The páramo or tropical alpine tundra

This is a dry ecosystem subjected to high radiation; however, due to the altitude (2700 to 5000 meters above sea level), low temperatures occur mainly at night. The winds are dry, cold and strong.

They are high mountain areas with rocky substrates and low fertility. All of this conditions a biocenosis with various specialized adaptations to withstand these conditions.

Aquatic biotopes

Coral reef

It is an aquatic biotope located in warm seas in the photic zone less than 100 meters deep (sunlight is received). Generally the waters in which they develop are shallow, sunny and rough, with a low content of nutrients.

In this ecosystem there is the peculiarity that the fundamental part of the substrate (calcium carbonate of the barrier) is generated by the main component of its biocenosis, which are corals. The biocenosis that sustains this biotope is very diverse.

Hydrothermal vents

The Galapagos Trench is a deep crevice in the ocean floor. There are a series of hydrothermal vents or vents of water heated by the underlying rock.

Upon penetrating the interior of the earth, water is loaded with mineral compounds such as hydrogen sulfide, which is toxic to many species.

The pits are located at great depth (2500 meters), where sunlight does not penetrate. Photosynthesis cannot occur in these areas, but they host a large amount of life.

The biocenosis that supports this biotope includes giant tubeworms, clams, crabs, and mussels. In addition, there is the presence of chemosynthetic autotrophic bacteria that are capable of oxidizing hydrogen sulfide, providing the necessary energy to fix CO ₂.

References

1. Glynn PW (1973) Ecology of a Caribbean coral reef. The Porites reef-flat biotope: Part II. Plankton community with evidence for depletion. Marine Biology 22: 1–21.
2. Odum EP and GW Warrett (2006) Fundamentals of Ecology. Fifth edition. Thomson Publishing. Mexico. 614 p.
3. Purves WK, D Sadava, GH Orians and HC Heller. (2001) Life, The Science of Biology. 6th Edt. Sinauer Associates, Inc. and WH Freeman and Company. 1044 p.
4. Udvardy MFD (1959) Notes on the Ecological Concepts of Habitat, Biotope and Niche. Ecology 40: 725–728.
5. Whittaker RH, SA Levin and RB Root. (1975) On the Reasons for Distinguishing "Niche, Habitat, and Ecotope." The American Naturalist 109: 479–482.