Balance of Ecosystems

Balance of Ecosystems

The Sun: Driving Force of Ecosystem

The Sun is the primary sustainer of life on Earth. Energy from the sun flows through materials and living organisms and eventually goes back into space in the form of heat. Only a tiny part of the Sun's energy falls on Earth, but that is enough to keep the ecosystem going.

• The Sun is the driving force of an ecosystem.

• The Sun is the main source of energy, which causes changes in the environment.

• We are very familiar with the day-to-day changes in weather and seasonal changes in climate.

• These changes are the result of differences brought in the heating of the Earth and its atmosphere by the Sun.

• Similarly, other environmental changes occurred due to solar energy.

• A field of wheat, a herd of cattle, a crowd of people, and a shoal of fish represent examples of solar energy stored in various forms.

Types of Ecosystem

There are two types of ecosystems—Natural/Noncultivated and Artificial Cultivated systems.

1. Natural/Non-cultivated Ecosystem

Natural ecosystem is subdivided into two categories—Terrestrial (land-related) and Aquatic (Water-related).

• (a) Terrestrial (land-related): For example, Forest, Grassland, Desert, etc.

• (b) Aquatic (water-related): For example, Salty water (marine, estuary, etc.), Fresh water (Stream, Lake, Pond, etc.).

Pond Ecosystem

2. Artificial/Cultivated Ecosystem

Human activities may modify or convert a natural ecosystem into an anthropogenic or man-made ecosystem. Generally, natural forests have been cut, and land has been converted to an agricultural system or a plantation. Often, dam construction involves the submergence of forests and the conversion to water reservoirs.

For example: 

• Crop field

• Park

• Spacecraft

• Swimming pool

• Well

• Aquarium etc.

Aquarium Ecosystem

Components of the EAN cosystem

An ecosystem consists of both abiotic/non-living and biotic/living components-

1. Abiotic/Non-living Component

Abiotic components of an ecosystem consist of lithospheric, hydrospheric, and atmospheric components, which are generally considered as land/ soil, water, and a, respectively.

Chemical substances (whether organic or inorganic) found in land, water, and air, and other climatic elements (such as light, temperature, rainfall, etc.) make up together abiotic components of the ecosystem.

Categories of Abiotic Components:

(i) Inorganic Materials:

• For example, water, oxygen, carbon dioxide, and minerals like phosphate, nitrate, etc.

(ii) Organic Materials:

• For example, carbohydrates, fats, proteins, vitamins, etc.

(iii) Climatic Elements:

• For example, light, temperature, rain, etc.

The amount of abiotic components that are present at a particular time in a given area is known as the standing state.

In an ecosystem, abiotic matter keeps changing into biotic matter and biotic matter into abiotic matter continuously. This process is called the biochemical cycle.

2. Biotic/Living Component

• Plants, together with animals, constitute the biotic/living component of the ecosystem.

• The biotic components are broadly divided into two major groups—the producers and the consumers.

Producers

• The producers are organisms that produce their food from the physical environment. These are called autotrophic [auto (= self) + trophic (= nourishing) = self-nourishing] organisms.

• Green plants are Primary Producers, as they take simple inorganic substances from their abiotic environment and make complex molecules utilising the Sun's radiant energy.

• These are the only organisms in an ecosystem that can trap energy from the Sun and make new organic materials.

• All other organisms in this world are directly or indirectly dependent on the producers for their food.

• The process used by the producers to convert inorganic materials into organic matter is called photosynthesis.

• The green plant takes water from the soil, carbon dioxide from the atmosphere, and energy from the sun to make a kind of sugar molecule. In the process, it gives out oxygen.

• The presence of green pigment called chlorophyll in the leaves of plants makes photosynthesis possible. Hence, we can say that photosynthesis takes place in the leaves of the plants.

Photosynthesis Process

• In ocean waters, phytoplankton are primary producers as they produce their food using solar energy.

Note: During the photosynthesis process, 50% of the total energy is absorbed by the plants, and at most 5% (i.e., 10% of the energy absorbed) of that is converted into organic energy under the most favorable conditions. Under adverse conditions, the rate of energy conversion decreases.

This means 1-10% of absorbed solar energy is converted into organic energy by plants through photosynthesis.

Consumers

The organisms that depend on other organisms for their food are called Consumers or heterotrophic [Haetero (- other) + trophic (= feeding) = other feeding] or Phagotrophs (phago = to devour). Consumers of an ecosystem are categorized into four categories.

a. Primary Consumer:

• An organism that feeds only on plants is called a Herbivore or Primary Consumer — For example, rabbit, goat, deer, cow, buffalo, etc.

b. Secondary Consumer:

• An organism that feeds on primary consumers is called (primary Carnivore (meat-eater) or a Secondary Consumer. For example, an insect-eating frog, a mouse-eating cat, a deer-eating fox, an edible meat-eating man, etc.

Omnivore (Herbivore + Carnivore)

• Some organisms may be omnivores, i.e., both herbivores and carnivores.

• Omnivores can eat both plants and animals (e.g., cockroach, rat, pig, fox, bear, human being (man), etc.).

• Whenever they eat plants, they are treated as primary consumers.

• Whenever they eat animals, they are treated as secondary consumers.

Example: Human Being

• It can be seen in the case of a human being (man):

  • When he depends only on plants (such as vegetables, seeds, fruits, etc.), he is a herbivore or vegetarian and considered a primary consumer.

  • When he depends only on animals (such as chicken, mutton, etc), he is a carnivore (meat-eater) or non-vegetarian and considered a secondary consumer.

  • When he depends on both plants and animals, he is an omnivore (vegetarian + non-vegetarian) and is considered a primary consumer, together with a secondary consumer.

Note: A human being (man) may also be a tertiary consumer when he eats the big fish that eats the smaller fish that eats the algae.

c. Tertiary Consumer:

• A consumer that feeds on a secondary consumer is called a tertiary consumer.

• Tertiary consumer includes top/secondary carnivore (e.g., tiger, lion, etc).

• Which can not eat plants but depends only on meat.

• The top carnivore stands at the top level of carnivores, and it can not be eaten by other animals.

d. Decomposer or Quaternary Consumer:

• A fourth group of consumers feeds on dead or decomposed tissues of plants and animals. They are called Quatemey Consumers or Decomposers or Saprotrophs (Sapro = to decompose) or Detritus feeders / Detritivore.

  • Example: 

    • Bacteria

    • Fungi (Hindi fafund)

    • Termite (Hindi Deemak)

    • Maggot

    • Ant earthworm (Hindi jonk)

    • Millipede (Hindi Kankhafura)

    • Crayfish etc.

• Apart from getting energy and nutrients from the plants and animals, the decomposers convert organic materials into inorganic substances.

• They release simple substances to the environment as by-products of their metabolism.

• These are taken up by green plants and help in completing the cycle of soil nutrients.

• In this way, the indefinite cycle goes on.

If decomposers are removed from the biosphere, the Earth will become an immeasurable dump of dead organisms. Life on the biosphere will stop as the nutrients for life will remain in the dead organisms that eventually will break the cycle.

Note: Bacteria are both decomposers and producers. A virus is not considered a decomposer because it is neither alive nor dead.

Ecological Classification of PlantBased onof ecology, Danish botanist Eugenius Warming (1841-1924) classified plants into five classes as follows: Hydrophytes (Hydro (- water) + phytes (= plants)], Mesophytes (Meso - middle), Xerophytes (Xero = dry), physiologically dry plants in soil, and functionally dry plants in soil.

Some Specialised Plants

Final Thoughts

The Sun is undeniably the primary driving force behind all ecosystems on Earth, providing the essential energy that sustains life. Through processes like photosynthesis, solar energy is converted into organic matter, forming the basis for the entire food chain. The delicate balance between abiotic and biotic components in ecosystems ensures the continuous cycling of nutrients and energy.

Consumers, from herbivores to decomposers, play crucial roles in maintaining this balance by transferring and recycling energy. Human influence has transformed many natural ecosystems into artificial ones, but the fundamental reliance on solar energy remains unchanged.

Understanding the importance of the Sun’s energy and the roles of various ecosystem components is vital to preserving biodiversity and ecosystem health for future generations.