Suppose that heterotrophs ingested 1,560 kilograms of plant biomass over a month's period. Respiration of these heterotrophs was the equivalent of 900 kilograms, and they egested 420 kilograms. What is the net secondary production?

240 kilograms

Explanation:

The productivity is the rate at which energy is added to the bodies of organisms in the form of biomass (amount of matter in the body).

The total biomass in the body of a heterotroph = 1560 kilograms

Biomass used in the respiration = 900 kilograms

Egested matter = 420 kilograms

Net secondary production = 1560 - 900 - 420

Net secondary production = 240 kilograms