lit review
Abigail Schaefer
Dr. Chad Scholes
Biology II
February 24, 2014 Aquatic Ecosystem Function Aquatic ecosystems account for the majority of the earth, and affect not only the organisms living within them, but all other organisms as well. Because these ecosystems are so vast, and have such impacts, it is important to understand how they function. To determine how an ecosystem is functioning, the stability of the ecosystem is taken into consideration. Stability is defined as the tendency of a system to return to equilibrium after being disrupted (DeAngelis 1980). Three factors affect the stability of an ecosystem: energy flow, nutrient cycling, and biodiversity. All three factors are directly related. Increased biodiversity in an ecosystem makes more paths for nutrients and energy to move through, and the more nutrients and energy moving through the system, the more biodiversity. The two main concerns of ecosystem functioning are energy flow and nutrient cycling. When talking about these two topics, the terms open systems and closed systems are used. Most ecosystems are open to energy. Energy enters systems mainly as light energy from the sun, but sometimes as detritus (Vanni 2002). The light energy is used by photoautotrophs, organisms that can use solar energy to make food, in a process called photosynthesis. In photosynthesis light energy, water, and carbon dioxide are used to make sugar; a form of energy that non-photosynthetic organisms can utilize (Knox 2001). In an aquatic ecosystem, the flow of energy can be described using trophic dynamics, or the transfer of energy from one part of an ecosystem to another. Once energy has entered the system, primary producers, such as phytoplankters, take the light energy and, through photosynthesis, convert it into usable energy. Primary consumers, like zooplankters then eat the primary producers and obtain energy from them by breaking the chemical bond of the sugars. In turn secondary consumers, such as
Dr. Chad Scholes
Biology II
February 24, 2014 Aquatic Ecosystem Function Aquatic ecosystems account for the majority of the earth, and affect not only the organisms living within them, but all other organisms as well. Because these ecosystems are so vast, and have such impacts, it is important to understand how they function. To determine how an ecosystem is functioning, the stability of the ecosystem is taken into consideration. Stability is defined as the tendency of a system to return to equilibrium after being disrupted (DeAngelis 1980). Three factors affect the stability of an ecosystem: energy flow, nutrient cycling, and biodiversity. All three factors are directly related. Increased biodiversity in an ecosystem makes more paths for nutrients and energy to move through, and the more nutrients and energy moving through the system, the more biodiversity. The two main concerns of ecosystem functioning are energy flow and nutrient cycling. When talking about these two topics, the terms open systems and closed systems are used. Most ecosystems are open to energy. Energy enters systems mainly as light energy from the sun, but sometimes as detritus (Vanni 2002). The light energy is used by photoautotrophs, organisms that can use solar energy to make food, in a process called photosynthesis. In photosynthesis light energy, water, and carbon dioxide are used to make sugar; a form of energy that non-photosynthetic organisms can utilize (Knox 2001). In an aquatic ecosystem, the flow of energy can be described using trophic dynamics, or the transfer of energy from one part of an ecosystem to another. Once energy has entered the system, primary producers, such as phytoplankters, take the light energy and, through photosynthesis, convert it into usable energy. Primary consumers, like zooplankters then eat the primary producers and obtain energy from them by breaking the chemical bond of the sugars. In turn secondary consumers, such as
Cited: 1. Covich, A. P., Austen, M. C., Barlocher, F., Chauvet, E., Cardinale, B. J., Biles, C. L., et al. (2004). The Role of Biodiversity in the Functioning of Freshwater and Marine Benthic Ecocsystems. BioScience , 54, 767-775. 2. DeAngelis, D. L. (1980). Energy Flow, Nutrient Cycling, and Ecosystem Resilience. Ecology ,61, 764-771. 3. Downing, A. L. (2005). Relative Effects Of Species Composition And Richness On Ecosystem Properties In Ponds. Ecology,86(3), 701-715. 4 5. Giller, P. S., Hillebrand, H., Ulrike-G, B., Gessner, M. O., Hawkins, S., Inchausti, P., et al. (2004) 6. Hooper, D. U., Vandermeer, J., Inchausti, P., Hector, A., Ewel, J. J., Chapin, F. S., et al. (2005). Effects Of Biodiversity On Ecosystem Functioning: A Consensus Of Current Knowledge. Ecological Monographs, 75(1), 3-35. 7. Knox, R. B. (2001). Biology (2nd ed.). Roseville, N.S.W.: McGraw-Hill. 8. Lindeman, R. (1991). The Trophic-dynamic Aspect Of Ecology. Bulletin of Mathematical Biology, 53(1-2), 167-191. 9. Reece, J. B., & Campbell, N. A. (2011).Campbell biology Jane B. Reece ... [et al.]. (9th ed.). Boston: Benjamin Cummings :. 10. Srivastava, D. S., & Vellend, M. (2005). BIODIVERSITY-ECOSYSTEM FUNCTION RESEARCH: Is It Relevant To Conservation?. Annual Review of Ecology, Evolution, and Systematics, 36(1), 267-294. 11.Vanni, M. J. (2002). Nutrient Cycling By Animals In Freshwater Ecosystems.Annual Review of Ecology and Systematics, 33(1), 341-370.