Food Chains and Food Webs - ScienceGeek.net

Energy in Ecosystem s Food Chains, Food Webs and Energy Pyramids Courtesy: www.lab-initio.com Producers (Autotrophs) Photosynthetic organisms

Capture energy from sunlight, CO2 and H2O Most producers are photosynthetic Chemosynthetic organisms Capture energy from chemical compounds in the surroundings Consumers (Heterotrophs) Herbivores

Eat only plants and fungi Omnivores Eat both plants/fungi and animals Carnivores Eat only animals Detrivores Eat dead organic matter Decomposers Break down organic matter into simpler

compounds Movement of Energy Trophic Structures Manner in which energy moves through an ecosystem Each ecosystem has its own unique trophic structure Biotic Energy Movement Producers Autotrophs (Photosynthesizers, Chemosynthetic organisms)

Primary consumers Herbivores and omnivores that eat producers Secondary consumers Carnivores and omnivores that eat herbivores Tertiary consumers Carnivore eats another carnivore Decomposers and Detrivores Consume decaying producers and consumers

Food Chain Energy is lost in each step up a food chain Only 10 percent of the energy from one level on the food chain is available to the next level Food Webs Many consumers and

decomposers have more than one food source Movement of energy occurs in complex webs rather than in simple chains Arctic Marine Food Web A Simplified Food Web? Energy Pyramids

Energy pyramids show the reduction of available energy at each higher trophic level Biomass Distribution Why a Pyramid? Producers Producers must must comprise comprise most

most of of the the mass mass of of the the biotic biotic part part of of an an ecosystem ecosystem

This This is is the the ONLY ONLY place place where where energy energy (solar) (solar) enters enters the the ecosystem ecosystem

Energy Energy is is always always lost lost in in the the form form of of heat, heat, so so energy

energy transfers transfers are are no no more more than than 10% 10% efficient efficient Each Each trophic trophic level level must

must be be supported supported by by aa 10/1 10/1 energy energy ratio ratio below below it it The 10% Rule