The Basics of Ecology & Flow of Nature on Earth

The flow of energy in nature

Ecology is the complex study of the flow of energy & resources through an ecosystem.

Understanding ecology can be tough because of all the variables in nature. In today’s article, we will be covering the basics of ecology and how it keeps ecosystems balanced for your entertainment!

The Sun & Plants

The cycle of energy in an ecosystem begins with the sun. Without the sun, life on Earth would not be possible. Some bacteria and small organisms may be able to live in the ocean near heat from the core of the Earth, but complex life as we know it could not exist.

The sun warms up the Earth for life to be possible, and it also provides energy to what are called “primary producers.”

Primary producers include plants, algae, and some micro-organisms that can use the sun’s power to self-generate food. They are called photoautotrophs, and use a process called photosynthesis to turn solar power into food!

Plants may need water from the soil as well to survive, however their “food” comes from the sun. They need nothing else besides air, water, and sunlight to thrive.

Primary Consumers

Primary consumers are usually animals that eat the primary producers. This could be a squirrel, rabbit, or a bug for example.

These creatures are typically herbivores, which mean that they only eat plants. They do not eat other animals so they are not carnivorous.

These animals are usually not too big; however there are some noteworthy exceptions to this case. Primary consumers usually are defensive, and not aggressive, meaning that they have adaptations that help them run away from predators & dangerous rather than fight.

Secondary Consumers

Secondary consumers eat the primary consumers. For example, snakes eat rabbits, making them a secondary consumer.

These creatures can be carnivorous or omnivorous. Carnivores eat other animals, whereas omnivores eat both plants and animals.

The key takeaway behind secondary consumers is that don’t just eat other plants- they eat other animals too. They may not always need to eat other animals or plants; however they can eat both and get energy from both.

These animals are generally more aggressive than defensive. They have offensive adaptations such as sharp teeth and a fast sprint.

Wolves, crocodiles, and eagles are all examples of secondary consumers because they hunt other animals to survive regardless of whether or not they also eat primary producers (plants, etc.).

Tertiary Consumers

Tertiary consumers are creatures that are not usually hunted by other animals. Sometimes tertiary consumers are also classified as secondary consumers, depending on which ecosystem you are looking at and how specific you want to get.

A snake could be both a secondary consumer and a tertiary consumer. If a snake eats a rat (secondary consumer) that eats a grasshopper (primary consumer), then in this case the snake is a tertiary consumer.

Tertiary consumers may also be “apex predators.” For example, the lion in Africa is an apex predator because it is strictly carnivorous and not hunted by other animals. It is on the top of the food chain!

Another example of a tertiary consumer would be a bear. A bear has no natural enemies, so therefore it is a tertiary consumer.

Decomposers & Scavengers

Decomposers are creatures that help decompose dead matter. They clean up waste in the environment.

These creatures also feed off of the tertiary consumers when they pass away. For example, when a bear dies, scavengers (such as certain birds or insects) may eat the tertiary consumer for sustenance.

Micro-organisms such as bacteria will also feed off of the bear that passed away. The energy of the tertiary consumer is completely recycled as their nutrients go into micro-organisms that will be eat by larger creatures & go in the ground to make the soil more nutritious for plants.

The Flow of Energy

As you can see, the flow of energy begins with the sun. The sun allows plants to thrive. Plants (primary producers) are then eaten by primary consumers (such as a grasshopper). The primary consumers are then eaten by secondary consumers (such as a rat). The rats are then eaten by a snake (tertiary consumer). When the snake expels waste and passes away, decomposers & scavengers recycle the energy back into the ecosystem!

Generally speaking, the more plants there are in an environment, the more abundant the ecosystem will be. Proper sunlight & several plants are the foundations for a thriving ecosystem.

The more plants there are the more primary consumers that can eat them. The more primary consumers there are, the more secondary consumers there can be to eat them.  This cycle goes on forever.

In areas such as the arctic that receive too little sunlight in the winter, or are too cold, or simply unstable for allowing for plant life, there will be fewer animals and a not-so-thriving ecosystem.

Imbalance in Ecosystems

Complex ecosystems are self-regulating and always moving towards better balance.

For example, if there are too many secondary consumers, then they will over-eat on the primary consumers. The primary consumer populations will then reduce.

This reduction in primary consumers will do two things. First, it will allow for more plant life (assuming the secondary consumers are not omnivores). Second, a decrease in food population for the secondary consumers will prevent them from growing to be too big.

With too little food for the secondary consumers and lots of food for the primary consumers, the secondary consumers population will begin to decrease while the primary consumers begin to increase again.

This cycle continues on forever and forces ecosystem to remain balance. If there is too many or too little of a certain type of creature in an ecosystem, the effects will force the ecosystem to re-balance.


Ecology is a much more complex study, but this is the basics. We hope you enjoyed reading this article, and make sure to leave a comment if you have any questions. Thanks for reading!

-Wildlife X Team International

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