Trophic Levels, Energy transfer and Pyramids

Producers Sunlight is the main energy source for life on earth Also called autotrophs Use light or chemical energy to make food 1. Plants 2. plant-like protists (algae) 3. Bacteria

Consumers Organisms that rely on other organisms for their energy and food supply Also called heterotrophs

Trophic Levels – is the position an organism occupies in a food chain Trophic Levels – is the position an organism occupies in a food chain. It refers to food or feeding.

Trophic Levels (feeding levels) 3 2 1

Food Chain

Food webs are multiple food chains.

Food Webs Food webs show ALTERNATIVE PATHWAYS other possible pathways through which an organism can obtain energy

Food webs

1st 2nd producer Grass Mouse Primary consumer Grasshopper Frog Owl Energy Level Producer, primary consumer, secondary consumer, tertiary consumer? Grass Mouse Grasshopper Frog Owl Hawk 1st producer 2nd Primary consumer

Secondary and tertiary consumer Energy Level Producer, primary consumer, secondary consumer, tertiary consumer Grass 1st Producer Mouse 2nd Primary consumer Grasshopper Frog 3rd Secondary consumer Owl 3rd and 4th Secondary and tertiary consumer Hawk

Transfer of Energy Energy lost from chain “link” to “link” is significant! Each level above only gets 10% of the energy from below

Energy lost from one trophic level (energy level) to the next level can be represented by a pyramid 4⁰ CONSUMERS 3 CONSUMERS 2 CONSUMERS 1 CONSUMERS PRODUCERS

ENERGY PYRAMID 1 J 10 J 100 J 1,000 J 10,000 J

Ecological Pyramid Which level has the most energy? Which level has the most organisms? Which level has the least organisms? Which level has the least energy?