Energy Flow in EcosystemsEnergy Flow in Ecosystems

I. ThermodynamicsI. Thermodynamics

A.A. = the study of energy transfer that = the study of energy transfer that occurs in occurs in mattermatter

matter = anything that has mass matter = anything that has mass &&takes up spacetakes up space

B. The Laws of B. The Laws of ThermodynamicsThermodynamics

1. 1. First Law of thermodynamicsFirst Law of thermodynamics

Energy can neither be Energy can neither be createdcreated nor nor destroyeddestroyed..

However:However:It can It can changechange form…….. form……..

Light ->->HeatLight ->->Heat

The Laws of The Laws of ThermodynamicsThermodynamics

2. 2. Second Law of thermodynamicsSecond Law of thermodynamics

Energy transformations lead to an Energy transformations lead to an increase in increase in ENTROPYENTROPY in a system. in a system.

Entropy = disorder (chaos)Entropy = disorder (chaos) Order ->->-> DisorderOrder ->->-> Disorder Entropy always increasesEntropy always increases..

II. Energy transformations in an II. Energy transformations in an ecosystemecosystem

A.A. Producers Producers (primary energy sources) (primary energy sources)Plants are Plants are producersproducers..

1. E travels via 1. E travels via Ultra-violetUltra-violet lightlight from Sun to plants from Sun to plants

2. 2. PlantsPlants (by photosynthesis) (by photosynthesis) make own foodmake own foodto store E to store E as glucose (sugar)as glucose (sugar)

(E = energy)(E = energy)

II. Energy transformations in an II. Energy transformations in an ecosystemecosystem

B. B. ConsumeConsumerr== organism organism that eats that eats plants or plants or other other organismorganisms to get Es to get E

Energy transformations in an Energy transformations in an ecosystemecosystem

C. C. DetrivoreDetrivore = breaks dead matter into = breaks dead matter into

smaller smaller pieces to help pieces to help recycle itrecycle it

E.g. worms, maggots, crabs, E.g. worms, maggots, crabs, millipedesmillipedes

Energy transformations in an Energy transformations in an ecosystemecosystem

D. D. DecomposerDecomposer = agent of decay= agent of decayRecycles the nutrients in dead bodies Recycles the nutrients in dead bodies to return them to the to return them to the ecosystemecosystem E.g. bacteria, E.g. bacteria, fungifungi

Energy transformations in an Energy transformations in an ecosystemecosystem

Energy Flow in an Ecosystem

III. Trophic levelsIII. Trophic levels

(-troph= feeder)(-troph= feeder)

Trophic levelTrophic level = = feedingfeeding level; level; levels of an levels of an ecosystem that ecosystem that E flows throughE flows through

Energy pyramid

IV. Energy Loss IV. Energy Loss Between Trophic LevelsBetween Trophic Levels

Only Only 10%10% 0f E moves from one trophic 0f E moves from one trophic level to the nextlevel to the next

∴∴(therefore) (therefore) 90%90% of E is of E is lost to lost to heatheat for each trophic level we go for each trophic level we go

upup

¿Why does it take so many mice to feed one hawk?

90% E lost each trophic level we go up

V. Food ChainsV. Food ChainsFood chainFood chain = =

the path that E takes the path that E takes through the through the trophic levelstrophic levels

Food Chain Examples

VI. Feeding patternsVI. Feeding patternspatternpattern definitiondefinition exampleexample

VI. Feeding patternsVI. Feeding patternspatternpattern definitiondefinition exampleexample

herbovoreherbovore

carnivorecarnivore

omnivoreomnivore

VI. Feeding patternsVI. Feeding patternspatternpattern definitiondefinition exampleexample

herbivoreherbivore Plant eaterPlant eater Deer, mouseDeer, mouse

carnivorecarnivore Meat eaterMeat eater Lion, dogLion, dog

omnivoreomnivore Eater of Eater of plants & plants & animalsanimals

Bear, pig, Bear, pig, humanhuman

VI. Feeding patternsVI. Feeding patternspatpat

VI. Feeding patternsVI. Feeding patternspatternpattern definitiondefinition exampleexampleFilter feederFilter feeder Filters food Filters food

from waterfrom waterBaleen Baleen whales,whales,flamingoesflamingoes

DetrivoreDetrivore Eater of dead Eater of dead organic organic mattermatter

Maggots, Maggots, crabs, worms, crabs, worms, millipedesmillipedes

DecomposerDecomposer Breaks dead matter Breaks dead matter to the molecular to the molecular level, returns level, returns nutrients to the nutrients to the envt.envt.

Bacteria, Bacteria, fungifungi