EcologyEcologyThe study of interactions among
organisms (biotic factors) and their environment (abiotic factors)
Energy CyclingAll organisms need energy in order to survive.
This energy (`10%) passes from one organism to another in a FOOD CHAIN.
Each organism in a food chain represents a feeding step or TROPHIC LEVEL.
Example of a
Food Chain
10% Rule: Only 10% of energy is passed on. The
remaining energy is used for
metabolism, movement, lost as heat or lost during
incomplete digestion1st trophic level
2nd trophic level
3rd trophic level
4th trophic level
5th
trophic level
Producers (autotrophs)
Organisms use the sun’s energy to make their own food through photosynthesis.
Form the base of the food chain.
Ex: Cypress Trees Algae
Consumers (heterotrophs)
These organisms must feed on other organisms to get nourishment.
Ex: Wading birds feed on bottom-dwelling organisms.
Types of HeterotrophsCarnivores – Eat only other animals
Omnivores – Eat other animals and plants
Herbivores – Eat only plants
Scavengers – Feed on dead animals
Decomposers – Aide in the breakdown of dead organisms
Detritivores– Feed on dead or decaying matter
Food Web
Arrows show direction of ENERGY movement