Understanding the 7 Trophic Levels
Living things need energy to survive and grow, and in the natural world, that energy is transferred through food webs and trophic levels. These trophic levels are most often pictured as a pyramid, and all of the other organisms in each level depend on the organisms in the levels below. Let’s learn more about the 7 trophic levels and how they work.
What are the 7 Trophic Levels?
The 7 trophic levels are categorized based on how organisms obtain their energy, and who they rely on for it. The 7 trophic levels, starting from the bottom, are as follows:
1. Primary Producers (Autotrophs)
- Producers in this category, also known as autotrophs, typically use carbon dioxide, nitrogen, light, or water to create their own energy source.
- Examples: plants, algae, and photosynthetic bacteria
2. Primary Consumers (Herbivores)
- Consumers in this category, known as herbivores, feed directly off of the primary producers.
- Examples: deer, insects, and rabbits
3. Secondary Consumers (Carnivores)
- Consumers in this category, known as carnivores, feed off of the primary consumers.
- Examples: frogs, lizards, and snakes
4. Tertiary Consumers (Omnivores)
- Consumers in this category, referred to as omnivores, feed off both the primary and secondary consumers.
- Examples: bears, humans, and pigs
5. Quaternary Consumers
- Consumers in this category are the highest-level carnivores and feed off of the tertiary consumers.
- Examples: wolves and hawks
- Organisms grown in this category are known as detritivores, they break down organic material.
- Examples: fungi, earthworms, and bacteria
7. Primary Detritivores
- Organisms in this category feed off of the decomposers directly.
- Examples: millipedes, woodlice, and dung beetles
What is the Function of the 7 Trophic Levels?
Each of the 7 trophic levels plays an important role in the transfer of energy from one organism to another. The primary producers are the base of the pyramid and are used as a food source for the other trophic levels. Consumers in each level feed off of the level below it and then use that energy to survive and grow. Finally, the decomposers and detritivores break down the organic matter of the organisms that had been living in the previous levels.
The 7 trophic levels allow us to understand how energy is transferred in nature, and how organisms rely on each other in order to survive and thrive. By learning about these 7 trophic levels, we are able to appreciate the complex and beautiful way that all living things in the natural world are interconnected with one another.