Energy Flow in Ecosystems Mrs. Sandy Gómez
Energy Flow in Ecosystems • Are the feeding relationships between organisms. • A Food Chain is: • transfer of food energy from its source (plants and other autotrophs) • through herbivores (primary consumers) • to carnivores (secondary and tertiary consumers)
Energy Flow in Ecosystems • Energy flows through an ecosystem in one direction (sun → producers → consumers) • Food chain – a series of steps in which organisms transfer energy by eating and being eaten
Energy Flow in Ecosystems Food chains are never isolated, they hook together to make food webs.
Energy Flow in Ecosystems • Food web – a network of complex feeding interactions • Trophic levels – each step in a food chain or food web • 1st – producers • 2nd – primary consumers • 3rd – secondary consumers • 4th – tertiary consumers
Energy Flow in Ecosystems • What transforms a food chain into a food web? • A species appears into the web in more than one trophic level • Most consumers are not exclusive • May appear as carnivores, omnivores, etc
Energy Flow in Ecosystems Trophic Levels in Food Chains
Energy Flow in Ecosystems Trophic levels are the levels in a food chain. Food chains are limited to 4-5 trophic levels.
Energy Flow in Ecosystems • Types of ecological pyramids: • Energy Pyramid – shows the amount of energy available at each trophic level • Only about 10% of the energy is transferred to the next level • Biomass Pyramid – shows the amount of living tissue within each trophic level • Pyramid of numbers – shows the number of organisms at each trophic level
Energy Flow in Ecosystems • EnergyPyramid: • Shows thelost of energyfromoneleveltothenext. • Trophiclevels are stacked in blocks.
BiomassPyramid • Shows the total dryweight of allorganisms in a trophiclevel • Most of thisnarrowsharplyfrom base to top • In someaquaticecosystemspyramids are inverted Energy Flow in Ecosystems
Energy Flow in Ecosystems • Number Pyramid • Shows the exact amount of organisms at each trophic level in the ecosystem
CLASSWORK Make a diagram showing the main trophic levels Give 2 examples of terrestrial food chains