Download 5.1 Habitats and Niches

5.1 Habitats and Niches
Ecosystems
*Large systems
*Cover many miles
*Contain many different species
* The environment within an ecosystem is different
depending on where you are.
*The area where a trout lives is different than where
a bear lives, but is still the same ecosystem.
Habitat
The place within an
ecosystem where an organism
lives.
Niche
The role of an organism in
the ecosystem and what an
organism does within its
habitat
*Every organism is adapted to life
in its habitat
*Each organism has its own way
of gathering food, reproducing
and avoiding predators
*Includes biotic factors (living
parts) which include food
sources and predators and
abiotic factors (non-living
parts) which include sunlight,
water, and temperature.
*All members of a species are
adapted to a niche
*No two different species can
share the same niche but can
have similar niches. This is
because of competition for
resources like food. If 2
different species ate the same
food and 1 species was better
at getting the food than the
other species, the one species
not so good at getting the food
would die off.
Competitive Exclusion

The extinction of a population due
to direct competition with another
species for a resource. This could
also cause one species to be
evicted from the niche which
would allow survival of both
species.
Niches
Fundamental niche
* The niche that an
organism could
theoretically occupy.
 Realized niche
* The niche that an
organism actually
occupies which could be
less extensive (smaller)
than the fundamental
niche.
Read p.74 about barnacles

Niche Diversity
 The number of different niches in an ecosystem.
 Determined by abiotic factors which could make more
niches.
 Predators (organisms that actively hunt other organisms
known as prey) increase niche diversity by decreasing the
population size of their prey species which allows more
resources for other species in that niche.
*Keystone predator is a predator that promotes a great
niche diversity in its habitat
*Abiotic factors contribute to niche diversity. These
include temperature changes and moisture