Functioning of environmental system: role of biotic and abiotic elements

What Is Environmental System?

The term “environment” refers to anything that surrounds or has an impact on an organism over the course of its lifetime. In the beginning, early man’s surroundings was limited to the planet’s physical elements, physical components, such as the lithosphere, atmosphere, and hydrosphere, as well as biotic groups. However, as civilization advanced over time, man expanded his environment to also include his social, economic, and political duties. All of the biotic and abiotic components are a part of the environment. Environmental System is a system with interconnected biotic and abiotic elements that are based on the natural environment. And the local environmental systems are known as ecosystems.


On the basis of basic structure, the environment may be divided into

>Abiotic environment

>Biotic environment

Types of Environment
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Abiotic or physical environment is split into the following categories based on physical characteristics and conditions:
i. Solid i.e. lithosphere (solid earth)
ii. Liquid i.e. hydrosphere (water component)
iii. Gas i.e. atmosphere (gaseous component)

These environments can be classified as lithospheric, hydrospheic, and atmospheric environments, which can then be further divided into smaller units based on various spatial scales, such as mountain environments, plateau environments, plain environments, lake environments, river environments, glacier environments, desert environments, etc. The physical environment can also be seen in terms of the climate, which offers different habitat types for biological groups, such as tropical, temperate, and polar environments, etc.


The biotic ecosystem is made up of vegetation and wildlife, including man as a significant component. Consequently, the biotic environment can be separated into:
iv. Floral environment
v. Faunal environment

Additionally, all creatures collaborate to create social groups and organisations on a variety of levels, creating a social environment in which the organisms cooperate to obtain nutrients from the physical world for survival and development.

The word lithosphere originated from a Greek word mean “rocky” + “sphere” i.e. the
solid outmost shield of the rocky planet. The Earth is an oblate spheroid. It is
composed of a number of different layers.

The lithosphere, which consists of rocks and soil, the hydrosphere, which consists of water, and the biosphere, which consists of living things, are the basic elements of the environment.


  • Atmosphere is like envelop of thick gaseous surrounding the earth.
  • It extends up to 300 km above the surface of the planet.
  • In addition to gases, the thick gaseous layer that surrounds the globe also contains water vapour, industrial gases, dust and smoke particles in a suspended condition, microorganisms, and more.
Layers of the Atmosphere
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  • At the centre of the Earth is the Core, which has a radius of 3500 kilometres and a diameter of roughly 7000 kilometres.
  • The mantle, which surrounds the core and is 2900 kilometres thick.
  • The crust, which is made up of both granitic- and basalt-rich continental and oceanic crust, floats on top of the mantle.
Lithosphere Illustration:
(Image source: polarpedia)


  • 71%of planet surface is covered with water
  • Freshwater- 2.53%
  • Freshwater in glaciers-1.74%
  • Water as water vapour in atmosphere-12,900 km3 living organism contain- 1100 km3
  • All water on or near the surface of the world is considered to be a part of the hydrosphere, which also includes clouds, soils, subsurface rock layers, lakes, rivers, wetlands, oceans, and ice caps.
(Image source:

The environment includes both the abiotic (non-living) and biotic (life) elements of the earth. Therefore, the elements of the environment can be divided into two basic types based on their basic structure:


Abiotic variables are the most essential determinants of where and how effectively an organism exists in its environment. Even though these factors interact with one another, only one of them has the power to restrict an organism’s range, making it the limiting factor.These variables can be divided into the following categories:

1.PHYSICAL FACTORS: -The four main factors are temperature, water (rainfall), light (energy), soil, and atmospheric pressure.

TEMPERATURE: -The most important environmental aspect from an ecological perspective is temperature. It is a well-known and well-established fact that the average temperature on land varies seasonally, dropping gradually from the equator to the poles and from plains to the tops of mountains, with summer temperatures in tropical deserts and polar regions ranging from sub-zero to >50 C, respectively.But there are also special ecosystems with temperatures over 100 °C, like thermal springs and deep-sea hydrothermal vents. A small number of organisms, known as eurythermal organisms, can tolerate and thrive in a wide range of temperatures without having an impact on their internal environment. However, the vast majority of organisms only function in a small temperature range (such organisms are called stenothermal).

WATER (RAINFALL): -Water is the second most crucial factor affecting the life of organisms after temperature. In truth, water is responsible for the origin of life on Earth, and without it, life cannot exist. Deserts are not a good place to find it. Because of this shortage, only unique adaptations by local plants and animals allow them to survive in such unique environments.

Water has a significant impact on plant productivity and distribution. The quality (chemical makeup, pH) of water becomes essential and one of the most important factors in determining the survival of aquatic organisms. Less than 5% of inland waters have a saline concentration (calculated as salinity in parts per thousand), whereas the sea has a salinity of 30–35% and some hypersaline lagoons have a salinity of >100%. Some species (known as euryhaline) can tolerate a large range of salinity, whilst others are constrained to a much narrower range (referred as stenohaline).Due to osmotic issues, many freshwater animals cannot survive in salt water for very long, and vice versa. This eventually results in their death.

LIGHT (ENERGY): – Since autotrophs produce/manufacture food by photosynthesis, a specialised process that is only possible with the availability of sunlight as a source of energy, it is simple and easy to appreciate the significance of light and energy for living organisms. Additionally, many plants rely on sunlight to fulfil the photoperiodic needs for flowering. Light is crucial for many animals as well because they utilise the diurnal and seasonal fluctuations in light intensity and duration (photoperiod) as cues to time their feeding, mating, and migrating behaviours. Since the sun is the source of both, the availability of light and temperature on land are closely related.

SOIL: – The type of soil and its characteristics vary greatly from location to location depending on the climate, which includes temperature and humidity, the weathering process, whether the soil is transported or formed sedimentarily, and how the soil was developed. Several physical traits of the soil, including its composition and grain size. The soil’s ability to percolate and hold water depends on its size and aggregation.

The vegetation in any location is greatly influenced by these characteristics, chemical factors like pH, mineral composition, and topography, as well as other factors. This, in turn, shows or rather specifies the type of creatures that can live on a specific soil region. Similar to this, the qualities of the sediment in an aquatic environment frequently dictate the kinds of benthic creatures that may live there most successfully.


Proteins, carbohydrates, and lipids are examples of essential organic compounds, where water, oxygen, carbon, nitrogen, sulphur, nitrates, phosphones, and ions of various metals are examples of essential inorganic substances.


It consists of the living components of the environment, such as the relationship of numerous interconnected populations from various species coexisting in the same environment. Populations of the microbial, plant, and animal communities make up the three groups.

The biotic community is divided into following

AUTOTROPHS (derive from Greek word: auto – self, trophos – feeder) are referred to as producers, transducers, or convertors. The process of creating a high-energy complex organic compound (food) from inorganic raw materials with the aid of the sun is known as photosynthesis, and it is carried out by photosynthetic plants, which are typically chlorophyll-bearing. The foundation of every biotic system is an autotroph. Typically rooted plants are considered autotrophs in terrestrial settings. The primary producers in aquatic ecosystems are the floating plants known as phytoplankton and the shallow water rooted plants known as macrophytes.

HETEROTROPHS (from Greek: heteros – other; trophs – feeder) are the consumers, which are typically creatures that feed on other organisms. While macroconsumers are typically herbivores and carnivores, consumers are also known as phagotrophs (from the Greek phago, meaning to swallow or ingest). The reason why herbivores are referred to as first order or primary consumers is because they eat only green vegetation. For example, consumers of the terrestrial environment include cattle, deer, grasshoppers, rabbits, etc. Consumers in aquatic ecosystems include protozoans, crabs, etc.
Carnivores are creatures that hunt or consume other creatures. consumers in the second or Creatures that eat herbivorous animals are considered primary carnivores. For instance, fox, frog, smaller fish, hawks and other raptors, snakes, etc.
The animals that consume primary carnivores are known as third order consumers or secondary carnivores. a wolf, an owl, a peacock, etc. Secondary carnivores are preyed upon by certain larger carnivores. Animals that consume secondary carnivores are referred to as quaternary consumers or tertiary carnivores. For instance, the tiger, the lion, etc. There is no other animal that consumes those. The term “top carnivores” also refers to larger carnivores that cannot be further preyed upon.

SAPROTROPHS (from Greek again: sapros – rotten; trophos – feeder) are referred to as the osmotrophs, decomposers, or reducers. They breakdown the intricate chemical components in dead stuff (dead plants and animals). The food is not ingested by decomposers. rather, they  release an enzyme that will break down the organic matter in the dead, decomposing plant or animal remnants. The complex organic molecules in the dead matter are reacted by the enzymes. Decomposers use some of the byproducts of decomposition as food for themselves. The residual material is absorbed into the substratum as minerals during the mineralization process. Plants, who are the producers, use released minerals as nutrients or recycle them.

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  • Balasubramanian A., ECOSYSTEM AND ITS COMPONENTS,2008.
  • Mukherjee S. P., Environmental Geography Notes, CONCEPTS AND COMPONENTS OF ENVIRONMENT,

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