The food chain is a series of organisms each depending on the next as a source of food. It is a quick way to explain the energy (food) exchange that occurs in an ecosystem. The food chain begins with sunlight and water as essential elements necessary to create plant life. Plants take energy from the sunlight, and nutrients from water and decaying elements in the soil. Herbivores consume the plants and gain that energy from the plants they eat. When a carnivore eats the herbivore, it gains energy from that animal. When animals die or create waste, decomposers like molds, fungi, and all kinds of invertebrates break them down into nutrients that plants can use, thus completing the cycle.
What Is A Producer?
A producer is an organism capable of producing its own energy, or food. In our ecosystem, this means plants. Plants gather carbon dioxide from the air through their leaves and water and nutrients through their root system. They use sunlight through a process called photosynthesis to create the food, or energy, needed to grow and reproduce. Coincidentally, the waste products of photosynthesis are oxygen and water vapor. It is this vital first step of energy creation that allows for all life on our planet to exist.
What Is A Consumer?
A consumer is an organism that gains its energy by consuming, or eating, other organisms. Animals like grasshoppers, lizards, snakes, hawks, and humans are all have different diets, but are all consumers. These consumers are classified in a few simple categories. This includes, Primary consumers, secondary consumers, tertiary consumers, and final consumers. Animals like the grasshopper that feeds on the grass would be the primary consumer. A lizard that eats the grasshopper is a secondary consumer. When a snake eats the lizard, it is a tertiary consumer. Lastly, when the hawk eats the snake, that hawk is the final consumer as it doesn't have any natural predators. When that hawk dies, it will be decomposed by the decomposers and restart the cycle.
Who's At The Top?
In the end, everything rejoins the food chain through decomposition. But in every ecosystem, there are different final consumers that top the food chain. These are called, "apex predators" and you can read more about them, here! If you want to meet an apex predator, you don't have to do anything but look in a mirror!