This exploration exercise will allow students to examine the interaction of organisms within the environment. Where they will see how the interaction and development of a stable ecosystem is dependent upon the flow of energy within the environment. There are two ways that we can view this interaction. The first is the commonly used food chain. This food chain provides an organization of organisms based on who consumes whom for food. The second and more complete view is that of a food web. The food web is the interaction of multiple food chains that involve the same organism or organisms. These food webs and food chains are the simplest means by which to follow the flow of energy through the environment. Where the amount of energy drops as the food chain or food web adds organisms into the higher levels of the trophic level of energy.
Each local ecosystem has its own food chains and food webs. And the structure of the trophic pyramid can vary across ecosystems and across time. In some instances the amount of organisms (called biomass) can be inverted to the energy flow pyramid. This pattern is often identified in aquatic and coral reef ecosystems, and is attributed to different sizes of producers. As producers that are smaller in mass than the consumers, yet will still dominate aquatic communities as the producers have a high growth rate. A second inversion may exist due to population structures, migration rates, and environmental refuge for prey. All of these will affect the structure of the food web and overall dynamics of the ecosystem related to the flow of energy and materials throughout the ecosystem. This difference in flow of energy and biomass can lead to some ecosystems being more stable then others and it is this concept of concept of trophic levels of energy, the development of food chains and food webs from the food chains that we will examine in this modeling exercise. Where you will be able to see how stable various ecosystems are based on the flow of energy and the relationship to the biomass in that ecosystem.