Relationships in an Ecosystem Instructions: View this powerpoint on concepts and terms that will be useful to you in understanding relationships within an ecosystem. As you view each slide, follow the instructions on the viewing guide handout. Definitions Ecology: The study of the interactions among organisms and between organisms and their environment Biotic: The living parts of an environment Abiotic: The non-living parts of an environment Overview: There are 5 Levels of Ecological Study. Individual Organisms Populations Communities Ecosystems Biosphere Populations A group of individual organisms of the same species Communities The populations of all the species that inhabit a particular area Ecosystems Includes the abiotic factors and biotic factors in an area Biosphere The sum of all the Earth’s ecosystems Within an ecosystem, there are various feeding relationships… Food Chain A pathway of food transfer in an ecosystem from one trophic (feeding) level to another is called a food chain. There are many different food chains in every ecosystem. This diagram shows two food chains, one on land and one in the sea. Notice the direction of the arrows in the diagram. Since food provides energy for living things, the arrows show the direction of energy flow through the chain. Producers Producers use the sun’s energy to create chemical energy for themselves. (Through the food chain, this energy is transferred to consumers.) Consumers Primary Consumers: Organisms that eat producers (herbivores or omnivores) Secondary Consumers: Eat primary consumers (carnivores or omnivores) Tertiary Consumers: Eat secondary consumers (carnivores or omnivores) Decomposers Decomposers are consumers that obtain energy by feeding on and breaking down wastes and remains of dead organisms. Major decomposers are bacteria, fungi and worms. Decomposers are responsible for recycling chemicals in the ecosystem. Food Webs In every ecosystem, there are many food chains that are interconnected to make food webs. The next slide shows the interconnected pattern of feeding in a food web. Notice: some organisms have several sources of food they can eat and some organisms are eaten by several different kinds of consumers.