Energy in Ecosystems

Movement of Energy through Ecosystems Producers use the energy captured in photosynthesis to make energy-storing molecules. Primary productivity, or the rate at which organic material is produced by photosynthetic organisms in an ecosystem, determines the amount of energy available in an ecosystem. Consumers consume organisms to obtain the energy necessary to build their molecules.

Trophic Levels Trophic Levels—The level assigned to an organism to help see how energy moves through an ecosystem. The path of energy flowing through the trophic levels is called a food chain Food chain example on pg. 69 of your textbook

Trophic Levels First Level: Producers such as plants, algae and bacteria Use the energy of the sun to produce energy-rich carbohydrates Second Level: Herbivores such as cows, horses, caterpillars, etc. These are considered to be primary consumers, because they eat the producers and break down their molecules into usable compounds.

Trophic Levels Third Level: Carnivores and omnivores such as tigers, snakes, bears, etc. These are considered secondary consumers because they not only eat the plants, but they eat other animals that have eaten the plants. Detritivores are organisms that obtain their energy from organic wastes and dead bodies produced at every level. These include organisms like bacteria and fungi which are decomposers.

Energy Pyramids A pyramid containing the different trophic levels The width/size of each level is determined by the amount of energy stored in the organisms at that trophic level. (draw example)

Food Chains and Food Webs Food chains show the flow of energy through an ecosystem, but only show one option of what an organism might eat. Food webs are an interconnected group of food chains (see pg. 71)

Biome/Food Web/Energy Activity You were given a card with a number upon entering the classroom. The number on your card determines your job for this assignment. #1—Food Web Construct a food web for your biome. It must include at least 10 organisms. You must include pictures and color. #2—Common Biotic Factors Provide that common biotic factors for your biome, including common predators, prey, and vegetation. #3—Energy Pyramid/Trophic Levels Draw an energy pyramid for your biome. On the pyramid, you must include examples of organisms and proper labeling of the trophic levels. #4—Biome Information (Location, Abiotic Factors, etc.) Provide general information about your biome including common locations, climate, and other characteristics. You must include a colored map of the biome location(s).