Productivity
The rate at which an ecosystem accumulates energy or generates biomass is known as productivity. Locations with high productivity have more energy available at the base of the food chain. So they can also support more biomass at higher levels of the food chain.
Productivity can be measured in units of mass per area per time—for example, grams of carbon (C) produced per square meter (m-2) per year (yr-1).
Gross productivity is the rate at which energy is obtained or captured — for example, the rate at which producers capture light energy and convert it into chemical energy through photosynthesis. Net productivity is the rate at which energy is converted into biomass specifically.