When the pond ecosystem is represented in the pyramid of numbers , then it's upright. But when it's represented in the pyramid of biomass , it's inverted. How it's possible?
Answers
It's easy to understand. Firstly, you should know that the producers are kept at the bottom of the pyramid.
Now think about the number of producers (phytoplanktons) and the number of secondary consumers (big fishes) in a pond. Obviously, the number of phytoplanktons exceeds that of big fishes. Hence, the base of the pyramid which represents the producers will be wider than the apex which represents the consumers. Thus, it results into an upright pyramid of number.
Now, let's think about the weight of tiny phytoplanktons and huge fishes. Undoubtedly, the fishes (secondary consumers) weigh much more than the phytoplanktons. Hence, the base which represents the producers will be narrower than the apex which represents the consumers. Thus, we get an inverted pyramid of biomass.
Hope this helps!