Read About Food Webs: Cycling of Matter and Flow of Energy

Producers Make Their Own Food

A simple diagram called a food chain represents how energy flows in an ecosystem. A food chain starts with producers. These are the plants at the bottom of the chain. Next, a first order consumer eats the plants to obtain energy. Next in the chain is the second order consumer, followed by a tertiary consumer. Food chains typically have 4 levels, though this can vary.

A food web is the overlapping of food chains within an ecosystem. Living things don’t eat the same thing all the time. Just like people, animals like variety in their diets. This results from living things eating from multiple food chains, which creates a food web. Some living things may eat from different levels of a food chain. Bears for example, consume plants, but also consume fish.

Ecosystems Rely on Chemical Processes

Living things undergo chemical processes that are essential to the living things in an ecosystem. Plants are the producers of an ecosystem and they undergo a process called photosynthesis to make food. This chemical process uses energy from the sun to turn carbon dioxide and water into sugar and oxygen. Likewise, when animals take in food, their bodies undergo a process called cellular respiration. This chemical process takes sugar and oxygen and forms carbon dioxide and water while releasing energy.

Energy Flows Through an Ecosystem

All ecosystems start with energy from the sun. Without sunlight, plants cannot undergo the process of photosynthesis. Using sunlight, water and carbon dioxide, plants make sugar and release oxygen. When a consumer comes along and eats the plant, it g