Learning Objectives

20.2.1 Contrast the direct and indirect influences of climate on the amount of terrestrial net primary production through its influence on photosynthesis and resource supply.

20.2.2 Describe how plant allocation and growth rates can influence the relationship between climate and net primary production.

20.2.3 List the nutrients that commonly limit the net primary production of freshwater and marine ecosystems.

As we have seen, NPP varies substantially over space and time. Much of this variation is associated with differences in climate, such as the latitudinal gradients in temperature and precipitation discussed in Concept 2.3. In this section, we explore the factors that constrain rates of NPP.