Ecology: Interactions with the Environment

 

Ecology focuses on interactions between organisms and their environment. 

 

The millions of species on Earth can interact in many different ways.  These interactions can be classified in many different ways, but the three most common kinds of interactions are as follows: mutualism, exploitation, and competition.

 

v  Mutualism:

o   Symbiosis:

 

 

o   Many different types of mutualisms exist.

 

§  Gut inhabitant mutualisms

 

 

§  Seed dispersal mutualisms

 

 

§  Behavioral mutualisms

 

 

§  Pollinator mutualisms

 

 

o   Mutualists are in it for themselves.

 

 

o   Mutualisms are everywhere.

 

 

o   Mutualisms can determine the distribution and abundance of species.

 

 

v  Exploitation:

o   3 main groups:

§  Herbivores

 

§  Predators

 

§  Parasites

 

o   Consumers and their food organisms can exert strong selection pressure on each other.

 

 

o   Consumers can alter the behavior of the organisms they eat.

 

 

o   Consumers can restrict the distribution and abundance of their food organisms.

 

 

o   Consumers can drive their food organisms to extinction.

 

 

v  Competition

o   2 main types:

§  Interference

 

 

§  Exploitative

 

 

o   Competition can limit the distribution and abundance of species.

 

 

o   Competition can increase the differences between species.

 

 

Interactions among organisms shape communities and ecosystems.

v  Ex: moth and cactus in Australia, grasslands and grazing