Question

At a minimum, primary producers require water, carbon dioxide, and light. These are things that are readily available in most ecosystems. However, we do not observe the same rates of net primary productivity in every region of the globe. Which of the following statements BEST reflects one reason why rates of productivity are not the same everywhere?

A.) Rates of net primary productivity are actually the same everywhere; scientists just need to calculate the rates relative to plant biomass in a given ecosystem.
B.) Although water is limited in certain ecosystems, nutrients that are scarce actually limit net primary productivity because they are necessary for growth.
C.) Rates of net primary productivity are actually limited by the amount of solar radiation. If net primary productivity were calculated as a yearly average, then this would show that ecosystems have the same rate of productivity.
D.) Although water is limited in certain ecosystems, irrigation would solve the problem and equalize rates of net primary productivity in every ecosystem.

Answer 1

B) option is correct

Step-by-step explanation:

Primary productivity measures the rate at which solar energy is stored by plants as organic matter, and is therefore a measure of the rate at which solar energy is captured and made available to the rest of the food chain

Gross primary productivity (GPP) is the total amount of carbon assimilated by plants within a given area over a specified time-frame

Net primary productivity (NPP) is GPP minus the flux of autotrophic respiration of assimilate used for the plant's own metabolism (R), can be represented as:

NPP= GPP-R

Rates of productivity are not same everywhere because if amount of nutrients are scarce then it will decrease net primary productivity because they are necessary for growth