Food Webs

1. Food Webs

2. Community • All organisms inhabiting a particular area

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

4. Heterotrophs • Consumers • Organisms which must consumer organic material to obtain energy

5. Consumers • Primary Consumers • Secondary Consumers

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

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

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

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

10. Energy levels decrease as you go up the food chain

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

12. Food Web • A series of interconnected food chains

13. 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