Energy in Ecosystems Food Chains and Webs Note: Organisms interact in order to obtain energy and resources necessary to stay alive.

Energy Flow Energy flows thru an ecosystem in one direction: sun autotroph heterotroph

Autotrophs Organisms that use solar energy to make their own food. Auto = self Also called Producers

Heterotrophs Organisms that depend on other organisms for food and energy. Hetero = other Also called consumers

5 Types of Heterotrophs

Herbivores Eat only plants

Carnivores Eat other heterotrophs or eat meat

Scavengers Eat organisms that are already dead

Omnivores Eat both animals and plants omni = all

Decomposers Absorb nutrients from dead organisms Fungi, Bacteria

Quick Review

What do you call an organism that can make its own food? What direction does energy flow thru an ecosystem? What do you call an organism that eats both animals and plants? What do you call an organism that absorbs nutrients from dead organisms? autotroph Producer  consumer omnivore detrivore

Food Chain A model that shows how matter and energy move through an ecosystem. It has arrows that show the direction that energy is being transferred.

FOOD CHAIN

Trophic Level A feeding step in a food chain that represents each organism.

Can you name the trophic levels below?? Tertiary consumer Primary consumer Producer Secondary consumer

Food Web Shows all the possible feeding relationships at each trophic level in a community.

Energy pyramids Diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web. 3 types

Pyramid of energy Pyramid of Energy Heat 0.1% Consumers 1% Consumers 10% Consumers 100% Producers Parasites, scavengers, and decomposers feed at each level. Only about 10% of energy available within one trophic level is transferred to organisms at the next trophic level

Pyramid of numbers Pyramid of Numbers Fox (1) Birds (10) Grasshoppers (100) Grasses (1000) Based on the number of individual organisms at each trophic level

Pyramid of Biomass The total amount of living tissue within a given trophic level is called biomass. A pyramid of biomass represents the amount of potential food available for each trophic level in an ecosystem.