How do energy and biomass decrease at higher trophic levels?

Energy and biomass decrease at higher trophic levels due to energy loss through metabolic processes and inefficient energy transfer.

In any ecosystem, energy flows from one trophic level to the next, starting from producers (like plants) and moving up to various levels of consumers (like herbivores and carnivores). However, not all the energy that is absorbed by an organism is passed on to the next level. This is because organisms use a significant portion of the absorbed energy for their own metabolic processes such as growth, reproduction, and maintenance of body functions. This energy is then lost as heat and cannot be passed on to the next trophic level.

The transfer of energy between trophic levels is also inefficient. On average, only about 10% of the energy consumed by an organism is transferred to the next trophic level. This is known as the 10% rule. The rest of the energy is lost during digestion or through waste products. As a result, as we move up the food chain, the amount of available energy decreases significantly.

Similarly, biomass, which is the total mass of organisms in a particular area or volume, also decreases at higher trophic levels. This is because, as mentioned earlier, a large portion of the energy is lost at each trophic level. Since energy is required for growth and reproduction, less energy means less biomass. This is why there are fewer organisms at higher trophic levels and why these organisms tend to be larger - they need to consume more to gain the necessary energy to survive.

In summary, both energy and biomass decrease at higher trophic levels due to the energy losses that occur during metabolic processes and the inefficiency of energy transfer between trophic levels. This is a fundamental principle of ecology and is crucial for understanding the structure and function of ecosystems.