Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Teacher Information! • Necessary materials: • PowerPoint Guide • Teacher may wish to hand out these note guides: • Carbon Cycle Guided Discussion • Phosphorous Cycle Guided Discussion • Nitrogen Cycle Guided Discussion
Food Chains and Webs Principles of Ecology
Students will be able to… • Describe food chains and webs
The flow of energy “Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass.” —G. Tyler Miller, Jr., American Chemist (1971)
Ecosystems • Definition reviewed: • Community + abiotic factors interact to form stable system • Depends on: • One-way flow of energy • Energy input from sun • Cycling of materials • Nutrient inputs
“Biogeochemical” cycles • Recycles chemicals • Carbon cycle • Phosphorous cycle • Nitrogen cycle • Life on earth depends on these cycles & photosynthesis
Producers • The base of ecosystems • Convert sunlight energy to chemical energy • Construct organic compounds from inorganic raw materials
Producers • Photosynthesis a very fundamental process !! • Chlorophyll • Producer = autotroph = plants & algae (green organisms)
Consumers • Organisms that eat other living plants, animals or microbes • Get energy from preformed organic molecules heterotrophs • Primary consumers eat producers • Secondary eat primary consumers • Tertiary eat secondary consumers
Detrivores • Organisms that eat detritus • Detritus Dead plants, animals, & microbes & fecal wastes of animals • Get energy from preformed organic molecules • Decomposers Live on detritus in such a way that it decays • Subgroup of detrivores
Food chains & webs • Foodchain pathways of feeding relationships • Producer-consumer relationships • Parasite-host relationships • Foodweb Complex pattern of interconnected food chains
A food chain Nutrients
A food web Nutrients
Review • Describe food chains and webs • What can happen with a disruption in a food web?