Wednesday, April 6, 2022

Introducing Ecology

Biology Index

Where are we going with this? The information on this page should increase understanding related to this standard:  Understand the environment and how each organism fits in.

Article includes ideas, images, and content from Troy Smigielski (2022-03)

Introducing Ecology
(Hey! This sounds familiar!)

is the study of interactions amongst organisms and between organisms and their environment.

It is the branch of biology that deals with the relations of organisms to one another and to their physical surroundings (Source, 2022-03).

Ecology includes the whole spectrum of things related to and essential for living creatures and their interactions. It starts small… very small… and expands to include more and more things. 

Ecology is tiered using several levels of organization.

Let's go for a little context…

A species is a group of organisms so similar that they can successfully breed. A population is a group of individuals that are in the same species and the same area; they can also successfully breed. 

A community is a group of different populations in one area.

An ecosystem is made up of all living and non-living organisms in an area.

A biome is a group of ecosystems that have the same climate and dominant communities.

Within any of these collectives, there are two types of things. The term biotic refers to all living factors; all of the things that are alive or were once alive.  The term abiotic refers to all non-living factors, such as the physical features of an area.

So, if we were to view it more fully, it would look something like the illustration below:

Now, within an ecosystem, there are different types of organisms. From bacteria up to apex predators, there are many different organisms… from all of the kingdoms… but we will most readily see and identify plants and animals.

Organisms of a species can either be autotrophs or heterotrophs.

These words are not new to this conversation. We have talked about these concepts in previous articles.


Autotrophs are organisms that can capture energy from sunlight and use it to produce their own food. Autotrophs are also called producers.

Naturally, we will think of plants as being autotrophs. They use photosynthesis to produce their own food!


are organisms that must get their food from an outside source. Heterotrophs are also called consumers.

There are several kinds of heterotrophs.

Herbivores, such as cows and rabbits. are heterotrophs that only eat plants

Or giraffes.  

Carnivores, such as lions, snakes, and owls, are heterotrophs that only eat animals.

Omnivores, such as bears, crows, and many humans, are heterotrophs that eat both plants and animals.

Detritivores,  such as mites, earthworms, snails, and crabs, are heterotrophs that feed on dead or decaying plant and animal material.

A decomposer is a heterotroph that breaks down organic matter. Examples of decomposers include bacteria and fungi.

Energy Flow Through and Ecosystem

Life depends on energy. Within an ecosystem, there is a flow of energy, often in the form of chemical energy that is transferred from organism to organism. However, the energy in an ecosystem begins as energy from the sun!

Energy comes from the sun or inorganic chemicals and goes to producers (autotrophs).

From there, it goes to consumers (heterotrophs).

Sun > Producers > Consumers

It is important to know that energy flows through an ecosystem in one direction.

We do not give energy back to the sun when we eat a salad.

In other words, energy moves in one direction down a food chain or food web.

Each step in a food chain or food web is called a trophic level.

Trophic levels begin with producers and move to consumers. A producer can either make its own food through photosynthesis or chemosynthesis.

Photosynthesis is when an organism uses sunlight to make food. This requires light.

Chemosynthesis is when an organism uses chemicals to make food. This does not require light.

Both types of synthesis make food.

What type of food does it make? Carbohydrates or other sugars

Consumers are organized based on the order they receive energy.

The first consumers are called primary consumers.

And… so it follows that…

The second consumers are called secondary consumers. The third consumers are called tertiary consumers. The fourth consumers are called quaternary consumers.

Notice how the 2nd trophic level is the 1st consumer.

Trophic levels are often displayed in an ecological pyramid, which is a diagram that shows the relative amounts of energy in each trophic level.

As we move up the trophic levels, the amount of energy passed on goes down. A lot.

Only 10% of energy in one trophic level can be passed on to the next level.

This is because organisms use much of that energy for life processes.

No comments:

Post a Comment