Part C - How does animal bioenergetics help explain the net production pyramid?
ID: 39867 • Letter: P
Question
Part C - How does animal bioenergetics help explain the net production pyramid?
As you just learned, in real ecosystems, trophic efficiencies usually vary from about 5% to about 20%. As a result, net production diagrams for ecosystems have a pyramid shape. Two key factors explain why trophic efficiencies are relatively low, and thus why net production diagrams are shaped like pyramids.
First, not all the organisms at one trophic level are eaten by organisms at the next trophic level. For example, not every plant is eaten by herbivores, and not every herbivore is eaten by carnivores.
Second, because of the bioenergetics of animals, not all the food an animal eats is converted to new biomass. As you learned in Part A, significant amounts of energy are lost in feces, used in cellular respiration, and lost to the environment as heat.
Suppose you could change some of these variables in an experimental ecosystem. How would the pyramid of net production change? Remember that in a typical ecosystem, the shape of the pyramid is similar to the one in Part B, and a maximum of 4-5 trophic levels are supported.
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ecosystem in which... shape of net production pyramid Height or net production pyramid less steep every animal has 50% of its energy from food going into biosynthesis more steep every animal has 3% of its energy from food going into biosynthesis fewer trophic levels a greater percentage of organisms at each trophic level are eaten by the more trophic trophic level above levels plants have better defences against herbivores, and animals have better defences against predatorsExplanation / Answer
1) more steep more trophic levels
2) less steep with fewer trophic levels as only few more organisms will be reproduced thus, lesser food for the next trophic level.
3) more steep with more trophic levels
4) since plants can defend themselves thus, lesser consumption by primary consumers which inturn will be comsumed lesser by secondary consumers. thus, less steep with fewer trophic levels due to less overall energy production.