Food Webs

Community All organisms inhabiting a particular area

Autotrophs Producers – self feeding Produce their own organic material Green plants Called primary producers

Heterotrophs Consumers Organisms which must consumer organic material to obtain energy

Consumers Primary Consumers Secondary Consumers

Primary Producers Control the rate at which producers convert sunlight to chemical energy in organic matter, or biomass Determines the energy budget for ecosystems

Decomposers Also called detritivores Acquire energy from all trophic levels waste products and dead material

Food Chain Pathway of food within a community Links energy and nutrients between producers, consumers and decomposers Divided into trophic levels

Trophic Structure Every community has a trophic structure Trophic levels increase as you go up the food chain

Energy levels decrease as you go up the food chain

Only approximately 10% of the energy stored at each trophic level is available at to the next level

Food Web A series of interconnected food chains

Biomass A measure of the dry weight of an organism is a rough measure of the energy it contains A measure of the population multiplied by the weight of an average individual in it