February 12, 2025

Naz Keskin 

10th Grade

Yahya Akel Science High School

Take a moment to close your eyes and imagine walking through a lush forest. The sweet wind softly floats the leaves, birds chirp, and fast squirrels run around. These occurrences are manifestations of a delicate rhythm of energy around us. From the smallest blow of wind to the sun rays peaking through the forest, every one of them has a role in this system. This intricate system which has a sense of play in itself is always around us but to be honest, have you ever sat and wondered how much and in what ways energy travels through the ecosystem? 

We have some rules to keep in mind while we dive into the phenomenon of energy. First of all, it is essential to know that matter and energy are never created or destroyed, they only change forms, to understand the way these two flow through ecosystems. The best example of this would be photosynthesis. Photosynthesis occurs when sun rays provide light energy that hits the leaves and is converted into glucose, a chemical energy. This conversion process is invisible to us, leading many to mistakenly believe that energy is lost. However, it’s simply changing its form, continuously flowing through the ecosystem. Second of all, each time energy is transferred some of it is lost as heat. Applying this to the food chain, we can say that the usable energy decreases as we go up. 

To fully grasp this movement and transformation of energy, we turn to the concept of “trophic levels”—a clear representation of where an organism fits within a food web. Trophic levels accelerate the process of understanding the energy transfer in ecosystems and you might be surprised to hear this but only %10 of energy travels from one trophic level to another, shaping the entire ecosystem that surrounds us. 

Let’s do a mathematical example. If a plant gets 10000J of energy from the sun 9900J is lost in the environment and 100 J is used as food then let’s say there is a deer, a crocodile, and a lion. The deer gets 100J energy from our plant 90J is lost to the environment and 10J is used as food. Next in line is the crocodile. It takes 10J from the deer 9J lost to the environment and 1J is used. Lastly, we have our lion. It takes 1J from the crocodile 0.9 lost to the environment and 0.1 is used. This illustrates the ten percent rule.

We use a pyramid visual to represent trophic levels since energy decreases as we move up the food chain. The base represents “Producers” (primarily plants), followed by “Primary Consumers” (herbivores), then “Secondary Consumers” (carnivores), and at the top, “Tertiary Consumers” (apex predators). Each of these levels can and does consume the level(s) below them as food.

Energy is effectively transferred through the various trophic levels, adhering to the well-established ten percent rule. To illustrate this concept, let’s revisit our previous example. The plant serves as a clear "Producer," harnessing sunlight to create energy through photosynthesis. Next, the deer represents a "Primary Consumer," feeding on the plants to obtain the energy stored within. Moving up the food chain, the crocodile functions as a "Secondary Consumer," preying on the deer to gain energy. Finally, at the top of this ecological pyramid, the lion reigns as the apex predator. Each level relies on the one below it, showcasing the intricate interdependence that defines our natural world.

Understanding the rhythm of energy between trophic levels is essential for appreciating the balance of our ecosystems. The ten percent rule draws attention to the fact that while energy can flow through this system, much is lost, which provides natural selection between species and the different segments of the food chain. This loss of energy is a key reason why ecosystems can only support a limited number of top predators and underscores the importance of producers, who serve as the foundation of the food web.

The next time you find yourself in a quiet corner of nature, take a moment to observe the interactions around you and fall into the rhythm. Consider how energy flows, how each organism contributes to this rhythm, and the vital importance of maintaining the health of our ecosystems. By doing so, we can ensure that this delicate dance of energy continues for generations to come.