What term describes the total mass of living matter at each trophic level, which decreases as trophic level rises?

What term describes the total mass of living matter at each trophic level, which decreases as trophic level rises?

• A. Biomass
• B. Energy
• C. Sediment
• D. Joules

Answer: (A)

Biomass is the total mass of living matter at a trophic level. In most ecosystems, the amount of living material available decreases as you move up the food chain because energy transfer between levels is inefficient: only a fraction of the energy captured by organisms at one level becomes new biomass at the next, while the rest is lost as heat, used for metabolism, or excreted. This creates a biomass pyramid that typically narrows with each higher trophic level. Biomass is usually expressed as dry mass per area (for example, g/m^2). The other terms refer to energy or non-living material, so they don’t describe the mass of living matter.

Biomass is the total mass of living matter at a trophic level. In most ecosystems, the amount of living material available decreases as you move up the food chain because energy transfer between levels is inefficient: only a fraction of the energy captured by organisms at one level becomes new biomass at the next, while the rest is lost as heat, used for metabolism, or excreted. This creates a biomass pyramid that typically narrows with each higher trophic level. Biomass is usually expressed as dry mass per area (for example, g/m^2). The other terms refer to energy or non-living material, so they don’t describe the mass of living matter.