The things that I am most confused about in this unit are the biomass pyramid, pyramid of numbers and the energy pyramid. I know it's kind of ironic how the only things I am confused about are all pyramids! But I hope you can help me understand these concepts better! Thanks!
Bottom line with pyramids... they show the relative amount of something. Usually the largest amount is at the bottom... the lower
ReplyDeleteSo.... in a pyramid of BIOMASS, the organisms at the BOTTOM of the pyramid (ie: the ones at the bottom of the food chain like the producers) will have the largest biomass.
Biomass is nothing more that the total mass of the organism. So if you took a HUGE scale... the mass of all of the krill in the ocean would be larger than the mass of all of the whales in the ocean.
Pyramid of numbers is just a count of the ACTUAL number of individuals at each level. Soooo, maybe there are 2 million grass plants, 300 grasshoppers, 40 sparrows, and 2 hawks in a given ecosystem. Usually there are more producers that anything else, but when the producer is something large like a tree... one individual tree can support many primary consumers and so on.
For the energy pyramid... this is showing how energy moves through an ecosystem. At each trophic level, 90% of the energy originally obtained by those organisms is NOT passed on to the next trophic level. Only 10% is passed along. This is because of how energy is used by living things. When they use energy, the energy gets converted from CHEMICAL energy to HEAT energy. Heat gets released from the organism and it disappates into the air. It is kinda like it just 'disappears' but technically it doesn't. Energy cannot be created or destroyed... SOOOO... when it gets released as heat, it isn't destroyed. It just can't be reharnessed and used again.
Bottom line with energy pyramid... 90% of energy is lost as HEAT. Only 10% gets passed to the next trophic level.