Energy Flow in an Ecosystem

Energy Flow Energy in an ecosystem originally comes from the sun Energy flows through Ecosystems from producers to consumers Producers (make food) Consumers (use food by eating producers or other consumers)

Producers Sunlight is the main source of energy for most life on earth. Producers contain chlorophyll & can use energy directly from the sun

Autotrophs An Autotroph is any organism that can produce its own food supply! Autotrophs are also called Producers Plants, algae, some protists, & some bacteria are examples

Niche of a Producer Captures energy and transforms it into organic, stored energy for the use of living organisms. May be photo-autotrophs using light energy (e.g. plants) May be chemo-autotrophs using chemical energy (e.g. cyanobacteria)

Photoautotroph Producer That Captures Energy from the sun by: Photosynthesis Adds Oxygen to the atmosphere Removes Carbon Dioxide from the Atmosphere Algae

Photosynthesis 6CO2 + 6H2O + chlorophyll  C6H12O6 + 6O2

6O2 + C6H12O6 ---> 6H2O + 6CO2 + energy CELLULAR RESPIRATION is the chemical reaction that releases the energy (ATP) in glucose.

Cellular respiration reactions

Habitat of Photoautotrophs On Land Plants In The Sea Algae Tidal Flats & Salt Marshes Cyanobacteria

Called a Black smoker (thermal vent) Chemoautotrophs Capture energy from the bonds of inorganic molecules such as Hydrogen Sulfide Process is called Chemosynthesis Often occurs in deep sea vents or gut of animals Called a Black smoker (thermal vent)

Tube Worms living in Black Smoker

Some energy in the primary consumer is STORED & not lost to the atmosphere or used by the consumer itself. This energy is available for another consumer (predator).

Heterotrophs eat other organisms to obtain energy. (e.g. animals) Consumers Heterotrophs eat other organisms to obtain energy. (e.g. animals) Herbivores Eat Only Plants Carnivores Eat Only Other Animals

Consumers Heterotrophs eat other organismsto obtain energy. Omnivores (Humans) Eat Plants & Animals Detritivores (Scavengers) Feed On Dead Plant & Animal Remains (buzzards) Decomposers Fungi & Bacteria

Trophic Levels, Energy Transfer and Pyramids

Feeding Relationships Energy flows through an ecosystem in one direction from producers to various levels of consumers

The transfer of energy from the sun to producer to primary consumer then to higher order consumers can be shown in a FOOD CHAIN.

Vocabulary Trophic Levels – is the position an organism occupies in a food chain. It refers to food or feeding. Apex predator – top level predators with few or no predators of their own.

Food Chain

Food Chains The energy flow from one trophic level to the other is know as a food chain Producers are at the first TROPHIC LEVEL Primary Consumers are the SECOND TROPHIC LEVEL Secondary consumers are at the THIRD TROPHIC LEVEL

Trophic Levels (feeding levels) 3 2 1

Food Web Most organisms eat more than JUST one organism When more organisms are involved it is know as a FOOD WEB Food webs are more complex and involve lots of organisms

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

Food webs

Grass Mouse Grasshopper Frog Owl Hawk Trophic Level Producer, primary consumer, secondary consumer, tertiary consumer? Grass Mouse Grasshopper Frog Owl Hawk

Secondary and tertiary consumer Trophic 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 When a lion eats a zebra, it does not get all of the energy from the zebra. Energy lost is usually in form of heat Energy lost from chain “link” to “link” is significant!

from grass to sheep, loss is about 90%! HEAT 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 10 J 100 J 1,000 J 10,000 J

Energy Pyramid

Three hundred trout are needed to support one man for a year Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass. -- G. Tyler Miller, Jr., American Chemist (1971)

Usually no more than 5 trophic levels since 6th level would have very little energy to keep it alive

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?

Pyramid of Numbers Shows the numbers of individual organisms at each trophic level in an ecosystem. tertiary consumers secondary primary producers 5 5000 500,000 5,000,000 A vast number of producers are required to support even a few top level consumers.

Biomass pyramid Biomass is a measure of the total dry mass of organisms in a given area. tertiary consumers secondary primary producers 75 g/m2 150g/m2 675g/m2 2000g/m2

Name the Producer, Consumers & Decomposers in this food chain:

Food Web