- Slides: 19
Trophic Levels, Energy transfer and Pyramids
Trophic Levels – is the position an organism occupies in a food chain. It refers to food or feeding.
Food Chains The energy flow from one trophic level to the other is know as a food chain Producers are at the first ENERGY LEVEL Primary Consumers are the SECOND ENERGY LEVEL Secondary consumers are at the THIRD ENERGY LEVEL
Trophic Levels (feeding levels) 3 2 1
Food Web Food webs are multiple food chains.
Food Webs Food webs show ALTERNATIVE PATHWAYS other possible pathways through which an organism can obtain energy
Energy Level Grass Mouse Grasshopper Frog Owl Hawk Producer, primary consumer, secondary consumer, tertiary consumer? 1 st producer 2 nd Primary consumer
Energy Level Producer, primary consumer, secondary consumer, tertiary consumer Producer Grass 1 st Mouse 2 nd Primary consumer Grasshopper 2 nd Primary consumer Frog 3 rd Secondary consumer Owl 3 rd and 4 th Hawk 3 rd Secondary and tertiary consumer Secondary consumer
Transfer of Energy lost from chain “link” to “link” is significant!
qfrom grass to sheep, loss is about 90%! HEAT 90% 100% Energy Available 10% Original Energy! 1% Original Energy!
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
¨Each level above only gets 10% of the energy from below - Ex: 10, 000 J of producers (plants) only give 10% of energy to primary consumers > 1, 000 J to primary consumers (snails, minnows, dragonflies) > 100 J to secondary consumers (small fish) > 10 J to tertiary consumers (big fish) > 1 J to quaternary consumers (fish hawk)
ENERGY PYRAMID 1 J 100 J 1, 000 J 10, 000 J
Usually no more than 5 trophic levels since 6 th level would have very little energy to keep it alive
Ecological Pyramid • • Which level has has the the most energy? most organisms? least energy?