Life AboundsAbiotic/Biotic Factors

& Energy Flow through Ecosystems

http://quest.arc.nasa.gov/projects/astrobiology/astroventure/index.html

Today’s ObjectivesBy the end of class today, you will be able to:distinguish the difference between biotic and

abiotic factors and the role they play in environmental communities

to identify the 4 mains parts of energy flow through an ecosystem

Changing Gears—Abiotic vs. Biotic Factors

Abiotic FactorsThe growth and survival of organisms depends on the physical conditions and chemical factors in the environment on which life depends—they themselves are not living.

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Changing Gears—Abiotic vs. Biotic Factors

Biotic FactorsIncludes all the living components of the

environment that affects the ecological community either directly or indirectly, and helps to limit the species that inhabit that area

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Abiotic FactorsLight intensity for photosynthesisTemperature rangeAmount of moisture availableTypes of rock under the soilMineral availabilityPresence of atmospheric gasespH of the system

Abiotic FactorsSubject to the physical laws of nature

Sunlight—affected by filtering of the atmosphere protecting us from harmful radiation

Water—expands and becomes less dense when freezes

Biotic FactorsPopulation levels of a particular speciesFood requirements for a particular speciesInteractions one species has with anotherWaste produced by the species

Biotic FactorsAbide by natural biological laws that govern

ALL life formsAll living things composed of cells (organism’s

functional unit)Living things MUST carry out their life

functions to surviveLiving things depend on the activities of other

living things to provide them with nutrients and essential components.