Question

Trophic efficiency (proportion of GPP going to NPP) is highest in Select one:

a. coniferous forests

b. common agricultural crops in the U.S. Midwest

c. desert plants

d. tropical rain forests

e. temperate deciduous forests

Answer 1

Correct answer: d. Tropical rainforest. Gross primary productivity (GPP) is the total rate at which organic matter is produced including the energy which is used for respiration per unit area in unit time. Net primary productivity is the total amount of energy converted from solar energy to chemical energy. Tropical rainforest have highest biodiversities of any terrestial ecosystem. The plants here have constant high levels of water and light (at canopy level). The nutrient supply is as high as possible due to rapid decomposition. In tropical rainforests water, sunlight and high temperature are consistent which favors vast photosynthetic output and high growth rate. Biomass increases due to high level of productivity. Thus tropical rainforests have highest trophic efficiency.