-+Niches+and+Community+Interactions

toc =- niche=

=- habitat=

=- resource=

-EX: water, nutrients, light, food, space
 * Resource ** = any necessity to life.

= =

=- competition=

-When two different organisms attempt to use the same resource at the same time. -The strength and life span of one individual is lowered by another.
 * Competition: **

=- competitive exclusion principle=


 * Competitive Exclusion Principle: **

-No two species can share the same niche in the same habitat at the same time. -Different species can occupy niches that are very similar. -It is a theory that proclaims that two species which are competing for the same resources cannot coexist if other ecological factors are constant.

http://www.youtube.com/watch?v=lvsqc1fqAFg

=- predation=
 * Predation** is the act of one organism preying, meaning capturing and eating another organism. A **predator** is the organism that does the capturing and eating on the other organism. The **prey** is the organism that gets eaten by the predator. Predators are usually carnivores but in some cases omnivores. Prey is always a herbivore.

This is an example of predation. Here is a predator. Here is an example of prey.

http://www.youtube.com/watch?v=WdGnIH9GJbM

=- predator/prey relationship=

A **predator-prey relationship** is important to an ecosystem and organisms involved. In a predator-prey relationship the population levels of the predators and the prey are important. If there is a high death rate and low birthrate for the predators there will be a missive increase in the population of the prey, meaning a low death rate, and presumably a high birthrate. If the population of prey decreases the population of the predators will also decrease. The prey are the food supply for the predators, and with a loss in that food supply they will die. However this is not the case for the prey, since the prey do not eat the predators.



This is an example of how the predator-prey relationship works. WIth increases in hare population comes increases in lynx population. With that increase in the lynx population there is a decrease in hare population. When the hare population drops drastically so does the lynx population, but with a drop in the lynx population comes an increase in the hare population, and the cycle repeats.

http://www.youtube.com/watch?v=LEx-R6-_XF4

=- mutualism=
 * one of the three main types of __symbiosis__
 * **__Mutualism__** - a relationship between two species where the relationship is beneficial for both species
 * Example: Clownfish and Sea Anemone -- The Sea Anemone protect the clownfish from predators while the clownfish chase away potential attackers of the Sea Anemone

=- commensalism=
 * second of the three main types of __symbiosis__
 * __**Commensalism**__ - a relationship in which one species is benefitted by the relationship and the other isn't helped but not harmed
 * Example: Barnacles and Whales -- The Barnacles are benefitted because the whale provides them food while the whale isn't harmed in the process

=- parasitism=
 * the third main type of __symbiosis__
 * __**Parasitism**__: a relationship where one organism is benefitted by the relationship and the other is harmed or isn't helped during the process
 * Example: Tick and Dogs -- The tick takes blood from the dog while the dog doesn't receive anything in return from the tick and is hurt by the process[[image:images-2.jpeg width="211" height="153"]](Image of a Tick)