ECOSYSTEMS FOOD CHAINS AND WEBS

ENERGY FLOW IN ECOSYSTEMS The greatest amount of energy is in the bottom level- or the producers Producers are photosynthetic

Biomass Total mass of organisms in a given area Producers make up the most biomass of any trophic level Ex. Plants, phytoplankton, seaweed

PRODUCERS Photosynthetic Contain most of the energy in a food web Autotrophic-make their own food

PRIMARY CONSUMERS Eat producers Herbivores-eat plants only Heterotrophic-get energy from food source Often prey animals-hunted by predators

SECONDARY CONSUMER Often eats primary consumer and producer Omnivore- eats meat (insects are meat) and plants Heterotrophic Could also be a small carnivore

TERTIARY CONSUMER Can be top of the food chain Carnivore- eats meat only Predator- hunts prey Has no natural predators

SCAVENGERS Eat animals that are already dead. Do not usually hunt prey.

DECOMPOSERS Eat dead and decaying plant and animal matter and waste. Examples: Bacteria and Fungi

DETRITIVORE Eats only dead matter, particularly dead plant matter Ex.: Earthworms

PREDATOR Organism that actively hunts prey. In the animal Kingdom, predators often have eyes on the front of their heads for better visual acuity.

PREY Organisms that are hunted by predators. In the animal kingdom, prey animals often have eyes on the sides of their heads for better peripheral vision.

SYMBIOTIC RELATIONSHIPS Long-standing relationships between organisms in an ecosystem

MUTUALISM Relationship where both organisms benefit

COMMENSALISM Relationship where one organism benefits, and the other is unaffected.

PARASITISM Relationship where one organism benefits and the other is harmed. Examples: mosquitoes, ticks, tapeworms

FOOD CHAIN Interconnection of organisms where the transfer of energy is shown by arrows

FOOD WEBS Interconnected organisms in an ecosystem. The arrow is always pointing to the thing doing the eating!

Energy Transfer and Energy Loss Only 10% of available energy is transferred to the next trophic level 90% lost as heat Most biomass is in producer level Any ecosystem can only support a small number of predators

VOCABULARY Producer Mutualism Primary consumer Commensalism Secondary consumer Parasitism Tertiary consumer Predator Herbivore Prey Carnivore Scavenger Omnivore Decomposer Autotroph Biomass Heterotroph Food chain Symbiosis Food web Trophic level Detritivore