Download Bio Limiting Factors and Succession

Limiting Factors and Succession
Limiting factor
• Any biotic or abiotic factor that restricts the
existence, numbers, reproduction or
distributing of an organism is considered a
limiting factor.
• These factors will both directly and indirectly
affect populations.
• What are some limiting factors?
• Common limiting factors:
– Sunlight
– Climate
– Temperature
– Water
– Nutrients/food
– Fire
– Soil chemistry
– Space
– Other organisms
Tolerance
• The ability of an organism to withstand
fluctuations in biotic and abiotic
environmental factors is known as tolerance.
The limits of an organism's
tolerance are reached when
the organism receives too much
or too little of some
environmental factor. When
this happens populations
shrink.
Succession
• Ecologists refer to the orderly, natural changes
and species replacements that take place in
the communities of an ecosystem as
succession.
• It occurs in stages, and during each stage
different species of pants and animals may be
present due to changing conditions.
• Usually takes decades or even centuries for
one community to succeed another.
• There are two types of succession: primary
and secondary
Primary Succession
• The colonization of barren land is called primary
succession.
– Ex Lava flow creating new rocks
• Pioneer species are the first organism to inhabit an
area. They can withstand harsh environments. They
turn the new rock into soil.
– Ex lichen, moss
• Climax community occur after the pioneer species have
faded and given rise to new organism. There is little to
no change in a climax community
• Stability does not mean changes stops, however in a
climax community the changes are balanced (deaths =
births)
Secondary Succession
• Takes place after a disruption of some type
(natural or manmade) occurs to a preestablished climax community.
• This means that the pioneer species are going
to be things more complex such a wild flowers
instead of things like moss and lichen.
• Because soil is already present it usually takes
place much faster than primary sucession