Energy flow in an ecosystem: (introduction)
The ecosystem, where organisms are found, where each living things has their role to play. But with all
these living things present in an ecosystem, you might ask, what is the primary requirement for an
ecosystem to be sustained and not collapse? For all living things present to survive? This all leads to one
answer, energy.
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All living organisms require a source of energy to live, the chemical energy which is found in
foods is the main source of energy in the ecosystem, this source is found in the different trophic levels of
the food chain where organisms eat others and vice versa.
What is the food chain and food web?
The food chain is essentially the order or sequence of what each animal and organisms eat, from single
celled organism to as big as the blue whale needs foods to survive. Food chain explains which organism
eats another organism the energy transferred by doing so.
The food web is a collection of several food chains therefore it is in a larger scale than a simple food
chain. While in food chain, a single organism is consumed by a predator or it consume an organism, in
food web, a single organism is consumed by many predators or it consumes several other organisms.
Food webs are more complex and leads to a more sustainable ecosystem.
Energy flow in an ecosystem
- The energy flow in an ecosystem is one of the greatest factors that supports the survival of a
great number of organisms. Almost all organisms on Earth uses the sun as their primary source
of energy, they absorb sunlight and get the energy from it and use it in different ways, plants
absorb a specific type of solar radiation known as Photosynthetically active radiation for
photosynthesis.
All living organisms can be classified as producers or consumers, and those producers and
consumers can then be classified as part of a food chain. Energy flows within ecosystems
because the organisms in those ecosystems are highly interdependent.
What are the trophic levels of the energy flow?
Also known as the feeding level, the Trophic levels consists of multiple producers and consumers forming
several layers, where the organisms of a chain are classified into different levels based on their feeding
behavior. This is illustrated by a pyramid consisting of four main layers, these are:
1st layer: Primary producers
Consists of Autotrophs, these are the green algae and plants, primarily utilizing solar
energy using photosynthesis other than relying on other animals.
2nd level: Primary consumers
-Consists of herbivores, animals and organisms that requires autotrophs to fulfil their
food requirements.
3rd level: Secondary consumers
-Consists of carnivores, they consume other living organisms or animals to meet the
food requirements.
4th level: Tertiary consumers
-Eats primary and secondary consumers. This means that meat is the main source of
their energy and is what they need to meet their food requirements.
-in nearly all layers of the trophic levels, 10% of the energy is lost. In an ecosystem, energy flows not in a
singular direction but in a unidirectional pattern, this is due to the fact that the energy that is lost during
energy flow cannot be reused in later stages of the energy flow.
Direction of Energy Flow
The trophic layer’s energy transfer/flow involves multiple steps. There are four main steps of
energy flow in an ecosystem, these are:
1st step: Production of energy
- Primary producers utilize solar energy to produce organic material through photosynthesis at
the first trophic level.
2nd step: Consumption of primary producers
- Plants are used as food by herbivores at the second trophic level of energy flow in the
ecosystem, which provides them with energy. Metabolic operations have considerable effect on
the energy transfer as it consumes a large portion of energy.
3rd step: Carnivores consume herbivores
- Carnivores will eat other herbivores to obtain energy for their survival and growth. If giant
predators are present, they represent a higher trophic level, and they get energy by feeding on
carnivores.
4th step: The decomposers
- Bacteria, fungi, and insects are examples of decomposers, which break down wastes and dead
creatures and return nutrients to the soil. Then, the producers then take up this decomposed
waste. Decomposition does not recycle energy; instead, it releases it.
Laws that support energy flow in an ecosystem:
There are two primary laws that supports the energy flow in an ecosystem, these are the first
and second law of thermodynamics where:
-the first law states that energy cannot be created nor destroyed, energy can only be transferred
from one state to another.
-the second law states that a chunk of energy is emitted to the environment as heat during any
conversion.
