8. Keeping the balance in an ecosystem Water plant Small fish Salmon Bear What would happen if the population of the salmon increased?
9. 3 types of pyramids Pyramid of Numbers Shows the relative number of individual organisms at each trophic level. Pyramid of Biomass Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid. Pyramid of Energy Shows the relative amount of energy available at each trophic level. Organisms use about 10 percent of this energy for life processes. The rest is lost as heat.
Ecological Pyramids of Energy Energy in ecosystems flows from producers (photosynthetic organisms) to consumers (herbivores and carnivores). Ecological pyramids of energy usually depict the amount of living material (or its energetic equivalent) that is present in different trophic levels. In this diagram, energy is depicted in kilocalories. Primary producers convert only about 1% of the energy in available sunlight. The average amount of energy that is available to the next trophic level is about 10%. Because so much energy is utilized in building and maintaining organisms, food chains (series of feeding relationships) are usually limited to just three or four steps. Pyramids of energy can not be inverted. References : Campbell, N.E., & Reece, J.B. (2002). Biology ,(6th ed.). San Francisco: Benjamin Cummings. Holligan, P.M., Harris,R.P., Newell, R.C., Harbour, D.C., Head, R.N., Linley, E.A.S., Lucas, M.I., Tranter, P.R.G., Weekly, C.M. (1984). Vertical distribution and partitioning of organic carbon in mixed, frontal, and stratified waters of the English Channel. Marine Ecology Progress Series , 14, 111-127. Raven, P.H., & Johnson, G.B. (2002). Biology , (6th ed.). McGraw-Hill. Image Reference : Baylor College of Medicine, Center For Educational Outreach. (2004). Martha Young, Senior Graphic Designer.
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