Ecosystems

An ecosystem includes all of the organisms as well as the nonliving things in a given area.

A community is a group of different species that live together in one area.

An ecosystem includes both biotic and abiotic factors. Biotic factors are living things.PlantsAnimalsBacteria

Abiotic factors are nonliving things. moisturetemperaturewindsunlight soil

What is the primary source of energy for an ecosystem?

ProducersMakes food by changing light energy of the sun into chemical energy, or foodAlso called AutotrophsEx. Plants, algae, some bacteria

ConsumersOrganisms that do not make their own food

Also known as HETEROTROPHS

Ex. Rabbits, Deer, Mushrooms

Heterotrophs

HeterotrophsConsumersA. Herbivores eat ONLY plantsEx. Cows, Elephants, Giraffes

HeterotrophsConsumersB. Omnivores eat BOTH plants and animals Ex. Bears and Humans

HeterotrophsConsumersC. Carnivores eat ONLY other animalsEx. Lions, Tigers, Hawks

HeterotrophsConsumersD. Scavengers/Detritivores feed on the tissue of dead organisms (both plants and animals)Ex. Vultures, Crows, and Shrimp

HeterotrophsConsumersE. Decomposers absorb any dead material and break it down into simple nutrients or fertilizersEx. Bacteria and Mushrooms

Food Chain

Food ChainsThe energy flow from one trophic level to the other is know as a food chainProducers are at the first TROPHIC LEVELPrimary Consumers are the SECOND TROPHIC LEVELSecondary consumers are at the THIRD TROPHIC LEVEL

Trophic Levels (feeding levels)3

2

1

Food WebMost 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

Transfer of EnergyWhen a lion eats a zebra, it does not get all of the energy from the zebra (much of it is lost as heat)

Only 10% of the energy from one trophic level is transferred to the next this is called the 10% rule

Ecological Pyramid

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)

Ecological PyramidWhich 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 NumbersShows the numbers of individual organisms at each trophic level in an ecosystem.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.

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