Download Interactions among species

Interactions among species
Tolerance
Every species has its own range of tolerance.
Tolerance = the ability to survive and reproduce
under a range of environmental circumstances.
Stress
Stress
Stress
When an environmental condition extends
beyond an organism’s optimum range = stress.
The organism expends more energy trying to
maintain homeostasis and less energy on
growth and reproduction.
Habitat
Habitat = the general
place an organism lives
(Home)
Niche = what an
organisms does and
how it interacts with
the environment
(Job)
Niche
Niche = the range of physical and biological
conditions in which a species lives and the way
the species obtains what it needs to survive and
reproduce.
Resource
Resource = any necessity of life. Ex. Water,
nutrients, light, food, space, shelter
Organisms compete for these resources.
Competition
Direct competition between species almost
always produces a winner and a loser…
Competitive Exclusion Principle
No two species can occupy exactly the same
niche in exactly the same habitat at exactly the
same time.
If there are two species, one will be better at
competing for limited resources and will
eventually exclude the other species.
Resource Sharing
Predator-Prey Relationships
Predation = one animal (predator) captures and
feeds on another animal (prey)
Predators can affect the size of prey populations
in a community and determine the places they
can live.
Herbivore-Plant Relationships
Herbivores can affect the size and distribution of
plant populations in a community.
Keystone Species
Changes in a single species can cause dramatic
changes in the structure of a community.
Ex. Sea otter
keystone species
Symbioses
Any relationship in which two species live
closely together is called symbiosis.
- Mutualism
- Parasitism
- Commensalism
Symbiosis
Mutualism
Both species benefit.
Ex. Clown fish and sea anemone
Parasitism
One species feeds on or lives in another species
and harms it.
A parasite will usually weaken the host, but not
kill it.
Commensalism
One species benefits, the other is neither helped
nor harmed.
Ex. Barnacles on whale
• Human parasites
• Mind Control Parasites