Ecology: Day 3 notes Photo by http://www.flickr.com/photos/druclimb/56763994/in/photostream/

Ecological Pyramids: Another way of showing relationships in ecosystems, Three Types: 1. Energy Pyramid 2. Biomass Pyramid 3. Pyramid of Numbers

Energy Pyramids Energy pyramid shows how energy is spread out among different trophic levels: They compare energy used by producers and other organisms on different trophic levels

Energy Pyramids Energy used: Between each level of an energy pyramid about 90% of the energy is used up in the organism’s life processes (growing, repairing, moving, getting food, having kids, etc.) . All of these use heat, which is then lost to the environment. 90% of the energy of a trophic level is lost as heat to its environment at that level energy transferred 90% energy lost 10%

Energy Pyramids 10% Energy transferred: Only 10% of the energy at each level is transferred from one trophic level to the next energy transferred 10%

Energy Pyramids How much energy do the secondary consumers get? How much energy do the top consumers receive? 0.1% 1%

Biomass Pyramids Biomass is  a measure of the total dry mass (weight) of organisms in an area. tertiary consumers secondary primary producers 75 g/m2 150g/m2 675g/m2 2000g/m2

Pyramid of Numbers A pyramid of numbers shows the number of individual organisms at each trophic level in an ecosystem tertiary consumers secondary primary producers 5 5000 500,000 5,000,000

Pyramid of Numbers- Generally, a large number of producers are required to support even a few top level consumers

Pyramid of Numbers But not always: very large producers, like large trees in forests, can produce a non-“pyramid” shaped pyramid of numbers. One tree can support hundreds of other life forms (insects, birds, squirrels, etc.). This type of pyramid can actually be inverted or diamond shaped. Many insects A few very big trees

Different shaped Pyramid of Numbers

Energy vs. Numbers Pyramid