Final answer:
Gross primary productivity (GPP) is the total amount of energy captured by photosynthetic primary producers, while net primary productivity (NPP) is the energy remaining in the producers after accounting for their own respiration and heat loss. In a desert ecosystem, GPP and NPP would describe the amount of energy captured and available in plants, respectively.
Step-by-step explanation:
Gross primary productivity (GPP) is the rate at which photosynthetic primary producers incorporate energy from the sun. It represents the total amount of energy that producers capture through photosynthesis. For example, in a desert ecosystem, GPP would be the total amount of sunlight energy captured by photosynthetic organisms.
Net primary productivity (NPP) is the energy that remains in the producers after accounting for their own respiration and heat loss. It represents the energy available to the primary consumers at the next trophic level. In a desert ecosystem, NPP would be the energy remaining in the plants after they have used some energy for their own growth and maintenance.