In order to determine how many kilograms of plant matter would be needed to support the other trophic levels in a biomass pyramid, we would need to know the biomass for each trophic level. Generally, in a pyramid of biomass, the amount of biomass decreases as you move up the trophic levels from producers (plants) to primary consumers (herbivores) and further to secondary consumers (carnivores).
If, for instance, in a given ecosystem, the biomass pyramid showed:
- Producers (plants): X kg
- Primary consumers (herbivores): Y kg
- Secondary consumers (carnivores): Z kg
You would usually find that the amount of biomass of producers is much greater than that of primary consumers, and similarly, the biomass of primary consumers is greater than that of secondary consumers.
A general rule of thumb is that approximately 10% of the biomass is transferred from one trophic level to the next, which means:
- Y kg of primary consumers = 10% of X kg of producers
- Z kg of secondary consumers = 10% of Y kg of primary consumers
If you do the calculations:
- To support Y kg of primary consumers, you would need X = Y / 0.10 kg of plant matter.
- To support Z kg of secondary consumers, you would need Y = Z / 0.10 kg of primary consumers, and consequently calculate how much X would be required to support Z.
Please provide the specific amounts of biomass from the pyramid for accurate calculations. Otherwise, the exact kilograms of plant matter needed cannot be determined.