What is an Ecosystem?

Think of a farm. Rain falls, organisms in the ground produce nutrients and the farmer gets to eat the delicious fruits and vegetables the farm produces – this is an ecosystem.

An ecosystem is a group of plants and animals that live in the same place and continuously interact with each other. It can include plants, animals, and microorganisms, as well as many non-living elements like rain, sunshine, and minerals in the soil.

There are two basic types of ecosystems: terrestrial and aquatic. Terrestrial ecosystems are based on land. Aquatic ecosystems are found in ponds, lakes, streams, oceans, and other bodies of water. The elements of each ecosystem are divided into living elements called “biotic elements” and nonliving elements called “abiotic elements”.

What is an Ecosystem?

Biotic Elements of an Ecosystem

Biotic ecosystem elements can include microbes, fungi, plants, and animals.

Living organisms are connected through the food chain. For example, a mouse might eat the seeds from wild grasses. The mouse could be eaten by a larger animal such as a skunk. The skunk may become a meal for a coyote.

The energy first stored by the grass slowly moved up the food chain through the mouse, the skunk, and eventually into the coyote – that is a food chain. Plants are the basis of food chains. They use sunlight to create sugar, and the energy in that sugar fuels the entire ecosystem.

But, the food chain doesn’t stop there!

The coyote could be eaten by a larger predator such as a mountain lion. The predators at the top of the food chain are called apex predators. However, the energy and nutrients in apex predators do not get trapped there forever.

When an animal dies, its body can become food for vultures, flies, beetles, and tiny microscopic organisms like bacteria. Over time, a dead animal is broken down into microscopic pieces. This is called decomposition. These microscopic bits become part of the soil and add nutrients to it. This rich soil helps nourish plants, and the cycle begins again.

Food Chain

Abiotic Elements of an Ecosystem

Abiotic elements in an ecosystem include all of the non-living components of the ecosystem that make life possible. Things like the temperature, the amount of rainfall, the altitude, the minerals in the soil, and the amount of sunlight are all abiotic elements of an ecosystem. These nonliving elements have a big effect on the biotic parts of the ecosystem.

For instance, consider an ecosystem that usually gets ten inches of rain each year. The plants in that ecosystem are adapted to about ten inches of rain. They won’t grow as well if they only get three inches of rain. Likewise, if the ecosystem gets a hundred inches of rain, the plants will all drown.

If the plants die off because the abiotic elements change, this means less food for plant-eating animals. Those animals will have fewer babies, so meat eating predators will have less to eat. Changes in abiotic elements can lead to less food all the way up the food chain.

The Ecosystem in Your Backyard

The Ecosystem in Your Backyard

Some ecosystems are large but many are very small. You can find them wherever you look, even in a crack in the sidewalk.

Take a few minutes to watch what’s going on in your yard or garden or even a public park.

Put your face near the ground. You will probably see an ecosystem at work: ants, crickets, worms, and beetles – all eating, surviving, and trying to reproduce. You might also see bees, butterflies, birds, and other creatures. The soil, the plants, the insects, and the other animals rely on each other for survival. They also rely on abiotic elements such as sunlight, wind, and rain.

Together, all of these biotic elements and abiotic elements create an ecosystem.

Written by Laura McCamy

Edited by Gabriel Buckley, MS Professional Natural Sciences

Illustrated by Meimo Siwapon