What are the key reasons for biomass loss between trophic levels, such as incomplete absorption, waste production, and respiration?

SouravNovember 12, 2024

Answered step-by-step

The loss of biomass between trophic levels in an ecosystem is influenced by several key factors, including incomplete absorption of energy, waste production, and respiration. Here’s a detailed overview of these reasons:

1. Incomplete Absorption

• Digestive Efficiency: Not all biomass consumed by an organism is absorbed and utilized. For example, herbivores may not fully digest plant material due to the presence of tough fibers like cellulose, leading to significant portions being excreted as waste. This means that a portion of the energy and nutrients from the primary producers is lost before it can be transferred to the next trophic level.
• Non-consumed Biomass: In some cases, predators may not consume all parts of their prey. For instance, bones, fur, or other indigestible materials are often left behind after consumption, representing additional biomass that does not get transferred to higher trophic levels.

2. Waste Production

• Excretion: Animals excrete waste products such as feces and urine that contain unabsorbed nutrients and energy. This waste represents a loss of biomass that could otherwise contribute to the next trophic level. For example, herbivores produce feces that contain undigested plant material, while carnivores may excrete parts of their prey that are not digestible .
• Metabolic Waste: In addition to solid waste, excess energy consumed by organisms is often lost as metabolic waste products during processes like nitrogen excretion (urea) when animals break down proteins .

3. Respiration

• Energy Use for Metabolism: A significant portion of energy obtained from food is used for metabolic processes such as respiration. During respiration, energy is released for cellular functions but is also lost as heat. This heat loss represents a major inefficiency in energy transfer between trophic levels, as it reduces the amount of energy available for growth and reproduction .
• Maintenance of Body Functions: Organisms require energy for various life processes beyond just growth, including movement, reproduction, and maintaining body temperature (especially in endothermic animals). This additional energy expenditure further reduces the biomass available for transfer to the next trophic level