What is a Biosphere? Examples and Meaning in Biology


What is the biosphere?

The biosphere is the global entirety of all ecosystems, which includes all life forms and their interactions with the elements of the atmosphere, hydrosphere, and lithosphere. Simply put, the biosphere is the area of the Earth’s surface where land, air, and water connect to sustain life. It extends from 12500 meters above sea level to at least 8000 meters deep in the ocean. The biosphere is one of the characteristics that distinguish the Earth from the other planets.

Definition of biosphere

The biosphere is a term that refers to all of Earth’s ecosystems, which includes both nonliving factors (such as sunlight and water) and living things. In layman’s terms, the biosphere means a global ecosystem made up of living organisms (biota) and the abiotic (nonliving) factors from which they derive energy and nutrients.

Biosphere definition in biology

In biology, the biosphere is made up of the areas of the Earth where life can be found. The biosphere encompasses everything from the deepest tree root systems to the dark environment of ocean trenches, lush rain forests, and high mountaintops.

Biosphere definition in geography

The biosphere is a relatively thin layer that supports life on Earth’s surface. This thin layer extends from a few kilometers into the atmosphere to the deep-sea vents of the ocean. The biosphere is not the only sphere on the Earth, there are 3 other spheres, namely; the atmosphere, lithosphere, and hydrosphere, and not all of them are inhabited by living things as regards the biosphere. This definition of a biosphere is that of geography.

Components of the biosphere

The biosphere is made up of three parts, the lithosphere, atmosphere, and hydrosphere; however, not all of them are thriving or inhabited by living things. Only the areas where life can be found and sustained are considered to be parts of the biosphere. This includes the area of the sky where birds can be seen flying, the depth of the ocean where life forms can be seen, and the depth of the ground where bacteria are observed.

Since all living things must interact with their environment to function properly, it is then fair to say that there is a need for abiotic and biotic components to be briefly discussed as part of the components of the biosphere.

Abiotic component

  1. Lithosphere
  2. Atmosphere
  3. Hydrosphere

The lithosphere is the biosphere’s terrestrial part. It contains solid landmasses such as our continents and islands. Its lower mantle and core are the only parts that do not support life and thus are not a part of the biosphere. Apart from this, all the other parts of the lithosphere support life, from the smallest bacteria to large mammals and tall trees, by providing shelter and food.


The atmosphere is the gaseous layer that exists above the Earth. It contains various gases such as carbon dioxide, oxygen, and other gases that aid in the survival of living organisms such as plants, animals, and humans. However, the upper region of the atmosphere has a low oxygen composition, which is why flying birds are found within 200 meters above the Earth. Apart from providing gases for respiration, the atmosphere which is part of the biosphere plays a specific role in protecting living organisms from the sun’s harmful ultraviolet radiation.


The hydrosphere encompasses all of Earth’s water also referred to as the aquatic region of the Earth and it covers the solid form of water that is found in the glaciers (cryosphere). The hydrosphere, which supports life, is crucial in regulating Earth’s temperature. Furthermore, it provides all living things with water.

Biotic component

  1. Plants
  2. Animals
  3. Microorganisms

Plants, animals, and microorganisms are examples of biotic components. These biological components are also the foundation of the ecosystem’s food chain.


Plants are known as primary producers or autotrophs in the biosphere that manufacture their food through the process referred to as photosynthesis. These plants help the biosphere through their participation in the recycling of waste and more importantly through the provision of food for every other living organism which includes animals and humans.


These are the consumers (heterotrophs) that are unable to produce their food from inorganic sources but rely on other sources, such as plants or small animals. They use the food they eat to release energy and store it for later use and the energy obtained from the food is used for development and growth.


Microorganisms for example fungi, algae, bacteria, viruses, and others play an important role in the ecosystem. Their function in the biosphere is to act as decomposers by decomposing waste or dead materials and through the process of decomposition, they get their food.

Examples of biosphere

  1. The Earth/biosphere 1
  2. Biosphere 2

The above listed are the examples of a biosphere and these examples will be discussed below.

The Earth (biosphere 1)

This biosphere example is made up of living organisms and their surrounding physical environment. The non-living components of this example include the rocky substance of the Earth’s crust, water, light, and atmospheric gas. The living components of the Earth are primarily defined by the reference to all life and living organisms on Earth. It has a five-tiered organizational structure.

  1. Biomes
  2. Ecosystems
  3. The species community
  4. Populations
  5. Organisms


The vast biosphere is divided into numerous biomes classified into 5, namely; tundra, grassland, forests, deserts, and aquatic biomes. A wide range of plants and animals live in rivers, lakes, seas, and oceans, as well as other aqueous habitats. While desserts, on the other hand, are the driest places on the planet, with the least amount of rain per year. Grasslands cover the Earth’s green areas and it receives moderate rainfall, but not enough to support the growth of large trees and forests are areas that are dominated by tall trees. Whereas tundras are vast areas of treeless Arctic land where the subsoil is permanently frozen.


A biological community and the physical environment of the Earth constitute the ecosystem which includes both biotic and abiotic factors working together as a unit. The terrestrial, freshwater, marine, and artificial ecosystems are the four types of ecosystems. The terrestrial ecosystem is the ecosystem that occurs on land, and it is exemplified by the grassland and forest ecosystems and the freshwater ecosystems are aquatic ecosystems that include lentic and lotic ecosystems. Because the marine ecosystem is a saltwater ecosystem, it can only be found in seas and oceans and a man-made ecosystem, such as a terrarium, which is an artificial ecosystem.

The Species Community

Because the biosphere is so diverse, different species contribute to the community’s composition. These species thrive in environments where abiotic factors such as temperature, pH, and nutrient levels are tolerable or optimal. A biological community, on the other hand, is defined as an assemblage of interacting organisms (of the same or different species) coexisting in a specific location and time.


The population of species is defined as all members of a specific species living in a single habitat. The population size can range from a few hundred to thousands of organisms. There can be an overpopulation of specific species and it occurs when a species’ population exceeds the carrying capacity of an ecological niche. A population decline, on the other hand, is one in which the size of the population decreases.

A population overabundance may result in a struggle for survival in which species will compete with one another for limited resources. This struggle has led to the emergence of various symbiotic relationships and those who give and take in a relationship are said to be in a mutualistic relationship, whereas those who cause or bring harm to other organisms are said to be in a parasitic or predatory symbiosis. This is also where natural selection enters the picture and in this case, species with useful or beneficial variations are “favored,” and thus have an advantage in terms of survival and reproduction over those with less favorable traits.


Organisms are the biosphere’s living entities and one of the characteristics that distinguish them from non-living material is the presence of a cellular organization (cells) and system that allows for various life processes. Genetic material inside the cell carries the code for all biological activities and reproduction. These organisms can be either eukaryotes or prokaryotes. Humans, plants, and animals are all eukaryotes, whereas bacteria are prokaryotes and they are distinguished by the presence of an endomembrane system and internal compartmentalization that results in the formation of various organelles. Eukaryotes have these characteristics, whereas prokaryotes do not.

Biosphere 2

Humans have created an artificial biosphere known as biosphere2 as a result of their curiosity. In Oracle, Arizona, Biosphere 2 is known as the man-made laboratory and the project’s initial goal was to research various factors of the biosphere and collect relevant data.

This was created between 1991 and 1994 and in terms of structure, it is similar to a large greenhouse with various groups of people who have simply attempted to live and work beneath the facility.

Biosphere 2 was supposed to be a 100-year mission, but it failed after only four years. Over the course of the four years, the five biomes have been dispersed throughout the biosphere 2 projects, and scientists have encountered difficulties in the project and, sadly, have had to abandon the project. Although it is still available for research and tours meaning one can easily take a tour of the area and learn about the various parts and factors of the biosphere.

The Biosphere Facts

  1. The term “biosphere” was coined in 1875 by geologist Eduard Suess. He defined the biosphere as the area of the earth’s surface where life exists.
  2.  It is thought that the biosphere evolved and the evolution began at least 3.5 billion years ago with a process known as biopoiesis or biogenesis. Biopoiesis is the process by which life emerges naturally from non-living matter, whereas biogenesis is the process by which life emerges from living matter. Up to this point, the biosphere is the only place in the universe where life exists.
  3. There are many elements that are essential to the biosphere’s survival and they include the tilt of the Earth, the distance of the Earth from the Sun, and the seasons.
  4. Scientists estimate that the earth is about 3.7 billion years old and this implies that the biosphere is approximately the same age.
  5. Determining the biosphere’s exact outer boundary is difficult and it is due to the fact that some birds, such as the Ruppell’s vulture, can fly as high as 11,300 meters.
  6. The depth of the biosphere is also difficult to determine because some fish have been discovered living as deep as 8,300 meters in the Puerto Rico Trench.
  7.  The biosphere is divided into biomes, which are home to largely similar flora and fauna, and the latitude of the Earth is found to be the primary factor that distinguishes biomes on land. Plant and animal life are scarce in the biomes of the Arctic and Antarctic Circles and the majority of densely populated biomes with more plant and animal lives are found near the Equator.
  8. The biosphere contains more water than land with an estimated 70% to be water.
  9.  In addition to the Earth’s biosphere, there are artificial biospheres such as Biosphere 2 and Biosphere 3 but the Biosphere 1 is the biosphere of the Earth.
  10. Biosphere 2 is located in Oracle, Arizona, in the United States and it is a scientific research facility, as well as the world’s largest artificial, closed ecological system. Its original goal was to test the viability of such a system for sustaining life in space. Biosphere 2 was only used twice due to oxygen and food challenges, as well as management issues.
  11.  The Biosphere 3 project is located in Russia and it is a closed ecosystem that consists of an underground steel structure that can house three people and the longest experiment lasted 180 days.
  12. Scientists are still working on developing an artificial biosphere capable of supporting life on other planets such as Mars.
  13. The existence of extraterrestrial biospheres is still speculative. It has yet to be established if there are other biospheres besides the Earth.
  14. Throughout the world, there are numerous biosphere reserves especially, where there are concerted efforts to preserve the environment. In fact, there are 669 biosphere reserves in 120 countries worldwide.
  15. The biosphere is approximately 21,500 meters deep in the ocean from the Earth’s surface.

The above-listed facts of the biosphere will help in the understanding of what is a biosphere and the definition of a biosphere.

Biosphere reserve

What is a biosphere reserve?

Biosphere reserves are referred to as learning places for sustainable development.  They serve as testbeds for addressing the challenges related to the function of the biosphere and are tasked with understanding and managing changes and interactions between social and ecological systems, such as conflict resolution and biodiversity management.

Biosphere reserve definition

Biosphere reserves are defined as locations that provide local solutions to global problems such as terrestrial, marine, and coastal ecosystems. With each reserve promoting solutions that balance biodiversity conservation with long-term use.

An example of biosphere reserves is; The Yangambi biosphere reserve located in the Democratic Republic of the Congo which is known to be the first biosphere reserve.  However, there are now 563 different biosphere reserves worldwide, with further discoveries of new biosphere reserves such as the Yayu reserve in Ethiopia. Some of these reserves are used for agriculture.

Here are some examples of UNESCO biosphere reserves;

  • Gran Arenal in Australia
  • Fuerteventura in Spain

the above listed are some of the international biosphere reserves or biological reserves that are known in the world.

Types of biospheres

The biosphere is distributed into biome regions and the biome is the most extensive of the five organizational levels. Hence the biomes are divided into five categories by scientists namely aquatic, desert, forest, grassland, and tundra. These 5 types of biomes are classified as the types of biospheres.

Importance of biosphere

  • Promotes life on Earth
  • Production of organic matter
  • Provides raw materials
  • Cleans the Earth of toxic substances
  • Provide pharmaceutical compounds
  • serve as a pollution marker
  • Help to track pollutants

The biosphere is an important reservoir in the carbon cycle, water cycle, and nitrogen cycle and it is critical to the survival of organisms and their mutual interactions and it is also a critical component of climate regulation. A change in the biosphere causes a change in the climate. Hence the above-listed importances are easy to understand.

Promotes life on Earth

Various environmental conditions, such as favorable temperature and moisture, are required for organisms to survive on Earth. This implies that energy and nutrients are also required by the organisms to function and grow. The Earth’s biosphere contains all of the mineral and animal nutrients required to sustain life. The nutrients found in the waste products of dead organisms or living cells are converted back into compounds that other life forms can use as food. This nutrient recycling or biogeochemical cycle is critical because there is no food outside of the biosphere.

Production of organic matter

The biosphere generates oxygen and nitrogen through oxygen photosynthesis. These substances are involved in almost every biogeochemical process that results in the formation of organic matter. The carbon cycle, which includes both terrestrial and organic substrates, produces organic matter.

Provides raw materials

The biosphere’s living components, also known as the biota, play an important role in providing us with the raw materials we require to survive such as food, fuel, and fiber.

Cleans the Earth of toxic substances

The biosphere’s natural cycles of decomposition and biological modification assist the planet in expelling toxins and other components that could be hazardous to life. Carbon dioxide, for example, is used in photosynthesis, and organic wastes are recycled by the biota.

Provide pharmaceutical compounds

Almost all of the substances used in the pharmaceutical industry today are extracted from natural compounds found in the terrestrial biosphere. Continuing biological research in biologically dense areas such as the Amazon in South America and Southeast Asia has provided scientists with new elements that have been used in pharmaceutical applications ranging from chemotherapy to beauty treatments.

Serve as a pollution marker

The study and control of biosphere composition can serve as an effective marker for keeping levels of terrestrial pollution in check. This will also aid in determining whether international treaties and public policies have had a genuine impact on current levels of global pollution. From the result of the information derived from research, one can draw historical and interregional comparisons that show changes and variations in pollution levels in various ecosystems.

Help to track pollutants

One might be able to tell what the pollutants that are caused by humans are and how they act by studying the composition of the biosphere. This would assist states and the international community in initiating research and policies aimed at reducing pollutants and preserving the physical environment.

Evolution of biosphere

Around 3.8 billion years ago, early prokaryotes thrived in an oxygen-depleted biosphere and some of these creatures eventually evolved to the point where they could use light, water, and carbon dioxide to produce chemical energy-rich compounds while also producing oxygen molecules as a byproduct.

Photosynthesis is the process of producing food using light energy, and the creatures that can do it are known as autotrophs and as a result of this photosynthesis, more species, ranging from single-celled algae to multicellular autotrophs like vascular plants, were able to consume atmospheric carbon dioxide and eventually provide oxygen to the environment. The diversity of aerobic creatures that lived and developed evolved in tandem with the amount of oxygen in the atmosphere and more sophisticated life forms such as vascular plants, animals, and humans, can thrive in the presence of oxygen because of this.

Autotrophs are the producers of the food chain while heterotrophs serve as natural biological controls because they are unable to generate food in the same way that autotrophs do and thus must consume other species.

Herbivores are plant-eating heterotrophic organisms while carnivores are animals that only eat animal flesh, whereas omnivores eat both plants and animal meat.

Another important ecological niche is that of decomposers and these organisms decompose dead animals or decaying tissues, as well as convert organic materials into simpler chemicals or molecules that feed the Earth. Fungi, for example, decompose dead plants and animals’ cells into simpler compounds that the environment can use as organic nutrients.

Factors affecting biosphere

  1. Tilting of the Earth
  2. Natural disasters
  3. Other factors

The biosphere that surrounds the Earth is constantly changing as a result of living and non-living entities. A variety of variables influence it and the actions of the living creatures that comprise the ecosystem. The three variables listed above have varying effects on it.

The tilting of the Earth

The Earth’s tilt has a significant impact on the biosphere. This is because it causes one side of the Earth to cool over time while the other side remains warmer. This tilting creates seasons which are one of the physical factors that influence the types of organisms that thrive in a given area.

Natural disasters

Natural disasters have the potential to have a large and long-term impact on the ecosystem. For example, volcanic eruptions, earthquakes, floods, and other natural disasters have a negative impact on the ecosystem.

Other factors

Other minor variables, such as temperature change, water, soil erosion, or any other type of change, have an effect on the biosphere and threaten the survival of many species.


What does biosphere mean?

The biosphere means the global entirety of all ecosystems, which includes all life forms and their interactions with the elements of the atmosphere, hydrosphere, and lithosphere. The simple meaning of biosphere is that it is the area of the Earth’s surface where land, air, and water connect to sustain life.

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