Answers to Figure Legend Questions

FIGURE 20.5 Greater allocation of NPP to belowground tissues can be an adaptation to disturbances, such as fire, or to herbivory. Allocation of NPP to storage compounds allows more rapid recovery and higher survival rates following disturbance or loss of tissues to herbivory.

FIGURE 20.7 Estuaries also have high NPP due to the inputs of nutrients brought in by rivers. These nutrient subsidies include organic matter from both terrestrial and aquatic ecosystems as well as agricultural runoff.

FIGURE 20.9 Cacti are CAM plants (see Chapter 5), which open their stomates and take up CO₂ during the night when air temperatures are cooler and humidities are higher. The daily pattern of atmospheric CO₂ concentrations would be reversed from what is shown for the boreal forest, with lower concentrations at night and higher concentrations during the day.

FIGURE 20.12 The proportional allocation to belowground NPP would be greater in the more nutrient-poor community, the dry meadow. Greater allocation to roots enhances the uptake of the resources that most limit NPP, whereas light is more likely to be limiting in the more nutrient-rich wet meadow. Allocation to belowground NPP would decrease in response to fertilization.