An ecosystem is network of relationships among and between biotic (living) and abiotic (nonliving) things. Energy and nutrients cycle through the ecosystem. Ecosystems can be any size.
"Ecosystem" can be broken down into "eco" and "system." Eco means habitat, or environmental. System means a group of interrelated parts working together.
Science communicator Emerald Robinson explains what an ecosystem is and why they are important in this video.
Science expert Emerald Robinson explains what an ecosystem is and why they are important. Source: YouTube
Ecosystems Cycle Energy and Matter
Ecosystems are very important to us because ecosystems cycle energy and matter. Energy is defined as the capacity to do work. Work can mean many things. Reading this text is work. Standing up is work. In fact, everything you do is work and requires energy. We get our energy from the food we eat, but how does food get that energy to begin with?
The ultimate source of energy is the Sun. The sun's rays hit Earth, and many organisms, like plants, are able to convert the sun's energy in to something called "chemical energy" for animals to use. In simple terms, that chemical energy is what we know as sugar. All animals use that energy to build other molecules in their body, such as proteins and fats. All animals use that energy to move around and do things. You will read more about the cycle of energy and matter on the Food Webs page.
There are many kinds of ecosystems.
There are aquatic (water) ecosystems and terrestrial (land) ecosystems. These can be categorized further into different types of ecosystems: