Which term refers to the total gain by consumers in energy or biomass per unit area per unit time?

The term that refers to the total gain by consumers in energy or biomass per unit area per unit time is known as gross secondary productivity (GSP). This metric reflects the amount of energy or biomass that is accumulated by primary consumers, such as herbivores, as they consume plant material.

GSP is significant as it indicates the efficiency with which consumers convert the energy and biomass they consume into their own biomass. It includes all the energy that is not lost due to respiration or other metabolic processes, meaning it measures the total input of energy available to consumers in the ecosystem from what they eat.

Other terms related to productivity have distinct meanings. Gross primary productivity, for instance, refers to the total energy captured by photosynthetic organisms (like plants) in an area before accounting for energy used in respiration. Net primary productivity, on the other hand, calculates the energy remaining after respiration in primary producers, indicating the energy available to support the entire food web above them. Net secondary productivity measures the energy stored by consumers after accounting for their respiration, giving insights into the energy available to higher trophic levels.

Therefore, understanding gross secondary productivity is crucial for analyzing energy flow and biomass accumulation in ecosystems, particularly in relation to consumer populations.