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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