One Response to “What is the difference between a Pyramid of biomass and a pyramid of numbers which relates to ecosystems?”

• 
  misti

  March 12th, 2009 at 11:43 am

  Here’s the way to remember it: bigger animals need more energy to sustain them. That means that whatever they’re feeding on has to be more abundant than they are. the basic rule of energy conversion is that whatever you consume, you get to keep 10% of the energy it contains. The rest is excreted or secreted by your body. So if a lion wants to put on a pound of weight, it has to eat 10 pounds of zebra. If a zebra wants to put on a pound of weight, it has to eat 10 pounds of grass. Therefore, for every pound of lion, 100 pounds of grass must be consumed. This is the biomass pyramid.

  The numbers are very similar. The closer to the bottom of the pyramid an animal or plant is (plants are producers and are generally at the very bottom of the pyramid with a few exceptions), the more numerous they may be. Because there is more below them to consume. Top predators are fewer because they are limited by their food sources.