What is ecology? Definition and examples

Ecology is the study of how living beings interact with their physical environment and also with one another. It is a branch of biology that studies the relationship between organisms, their environment, and their associated energy flows. We can study ecology at many different levels. For example, we may study organisms, populations, ecosystems, and the biosphere.

The biosphere is the zone of life on Earth, i.e., the global sum of all ecosystems.

In politics, the term refers to a movement that aims to protect the environment. Most ‘green’ parties across the world focus on ecological issues and protecting our environment.

Green party politicians talk a lot about our ecological impact. Our ecological impact is the effect that we are having on the environment.

The British Ecological Society has the following definition of the term:

“Ecology is the study of the distribution and abundance of organisms, the interaction between organisms, the interaction between organisms and their environment, and structure and function of ecosystems.”

Ecology is the study of how things that live interact with each other and their surroundings.

Ecological indicators

People who study ecology often focus on specific organisms to determine an environment’s health. For example, the presence of lichens may suggest air pollution.

In this context, lichens are ecological indicators, i.e., they give us information about our ecosystem.

Ecology vs. ecosystem

Even though the two terms are closely related, their meanings are quite different.


This is the study of how organisms relate or interact with one another and their surrounding environment.


An ecosystem consists of two factors: the biotic and abiotic factors.

The biotic factor includes all living things, such as microorganisms, plants, and animals.

The abiotic factor includes everything in the environment that does not live. Water and soil, for example, are abiotic, i.e., they have no life.

The term ‘ecosystem’ is a sub-part of ‘ecology.’ Just like a banana is a sub-part of fruit.

Regarding the difference between the two terms, PEDIAA writes:

“Ecology is the study of ecosystems whereas ecosystems are units that are formed by the interaction of a community of organisms with the environment.”


Many companies across the world have become ecologically aware. There is today a management philosophy we call ‘eco-efficiency.’

An ‘eco-efficient’ company is one that strives to make a profit but at the same time consume less energy.

In other words, eco-efficient businesses try to be efficient but environmentally friendly at the same time.

Etymology of ecology

Etymology is the study of the history and origin of words. It is also the study of how the meanings of words have evolved.

The term ‘Oecologyemerged in 1873 with the meaning “branch of science dealing with the relationship of living things to their environments.”

German zoologist Ernst Haeckel coined the German term ‘Ökologie.’ It comes from the Greek word ‘Oikos‘ which means “dwelling place, habitation, house.” The Greek word “Logia” means “study of.”

It was not until the 1960s that we started using the term ‘ecology’ for anti-pollution activities.