Download Biotic and Abiotic Influences on Limiting Factor - snc1p

How do biotic and abiotic factors interact to help keep
terrestrial and aquatic ecosystems balanced and healthy?
limiting factors place upper limits on the size of a population
can be biotic or abiotic
o abiotic factors determine where a species can live and
biotic factors determine how successful it will be
o biotic factors involve interaction among individuals and
different species groups
Abiotic Factors
o every species is able to survive within a range of abiotic
factors
o population will be high within the optimum range
o population will be low outside of the optimum range but
within the tolerance range
o the species will not exist outside of the tolerance range
Ex.
Precipitation and Population
o species with broader tolerance ranges are able to adapt
to a larger variety of conditions and are better suited to
acting as an invasive species
 terrestrial abiotic factors include temperature,
precipitation, nutrient availability and light
 aquatic abiotic factors include salinity,
temperature, acidity, light penetration and
availability of oxygen and nutrients
Biotic Factors
Relationship
Competition
Definition
two species vie for the
same resource
Example
foxes and coyotes both
eat field mice
Predation
one species eats
another
lynx eat snowshoe hares
Mutualism
both species benefit
nitrogen-fixing bacteria in
the roots of plants provide
nitrogen and take sugar
tapeworms in the
intestines of cats and
dogs
barnacles on a whale
Parasitism
one species lives in or
on a host organism
(causing harm)
Commensalism one species lives in or
on a host species
(doesn’t cause harm)
Carrying Capactiy
o as a population’s size increases so does their demand for
available resources
o limits to growth result in the population reaching a stable
upper limit that the ecosystem can support
 this is the carrying capacity
o can be altered by humans or other species
Ex.