Energy Flow Through an Ecosystem Food Chains, Food Webs, Energy Pyramids

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2 Begins with the SUN Photosynthesis 6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

Photosynthesis Chemical reaction where green plants use water & carbon dioxide to store the sun’s energy in glucose ENERGY is stored in glucose Glucose is stored as starch in plants

Organisms that can make glucose during photosynthesis are called PRODUCERS or AUTOTROPHS.

Producers use most of the energy they make for themselves.

Producers use cellular respiration to supply the energy they need to live.

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

The energy that is not used by producers can be passed on to organisms that cannot make their own energy.

Organisms that cannot make their own energy are called CONSUMERS or HETEROTROPHS.

Consumers that eat producers to get energy: Are first (1st) order heterotrophs or primary consumers Are herbivores (plant-eaters)

Most of the energy the primary consumer gets from the producer is used by the consumer.

Some of the energy moves into the atmosphere as heat.

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).

A Consumer that Eats Another Consumer for Energy: Is called a secondary consumer or 2nd order (heterotroph). May be a carnivore or a omnivore May be a predator May be a scavenger

Most of the energy the secondary consumer gets from the primary consumer is used by the secondary consumer.

Some of the energy is lost as heat, but some energy is stored and can passed on to another consumer.

A consumer that eats a consumer that already ate a consumer: Is called a 3rd order heterotroph or tertiary consumer. May be a carnivore or a omnivore May be a predator May be a scavenger

Consumers that eat producers & other consumers Are called omnivores Omnivores eat plants and animals

Consumers that hunt & kill other consumers are called predators Consumers that hunt & kill other consumers are called predators. The animals that are hunted & killed are called prey.

Consumers that eat other dead consumers are called scavengers

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

Food Chains Show Available Energy

More Food Chains

Another way of showing the transfer of energy in an ecosystem is the ENERGY PYRAMID

Energy Pyramids Show Amount of available energy decreases for higher consumers Amount of available energy decreases down the food chain It takes a large number of producers to support a small number of primary consumers It takes a large number of primary consumers to support a small number of secondary consumers

Food Webs: Are interconnected food chains They show the feeding relationships in an ecosystem

How Many Chains are in this web?

Identify the Producers, Consumers, & Decomposers: Count the Food Chains!

Trophic Levels Trophic levels are feeding steps in a food chain or food pyramid. The base of the pyramid is the first trophic level. Many different species can occupy each trophic level. A single species may feed on many trophic levels. Ex. A bear may eat a mouse, but it also eats berries.

Trophic Levels 1st Trophic Level: Primary Producers 2nd Trophic Level: Primary Consumers or 1st Order Heterotrophs. 3rd Trophic Level: Secondary Consumers or 2nd Order Heterotrophs. 4th Trophic Level: Tertiary Consumers or 3rd Order Heterotrophs. Only 10% of the energy is available for the next trophic level.

Trophic Levels 10, 000 energy units at 1st trophic level. 1000 energy units would be available at 2nd trophic level. 100 energy units would be available at 3rd trophic level. Only 10 units are available at the 4th trophic level.