E5 - Biotic Interactions

Interactions between organisms in a community

Competition Predation Symbiosis

Interaction between 2 or more organisms competing for the same resource in a given habitat

interspecific competition

intraspecific competition

Different niches allow for similar species to exist in the same community without competition.

One organism eats another to obtain food Prey are usually adapted to avoid being eaten (camouflage, speed) Predators are usually adapted to catch prey (eyesight, speed)

Some prey animals defend themselves by mimicking (looking like) other animals that are not hunted. The monarch butterfly tastes terrible to birds and is usually avoided. The viceroy butterfly looks similar to the monarch, so birds avoid eating it (even though it is “tastier”)

An interaction between two species One species lives in, on or near members of the other species

Three main types: Mutualism – both species benefit Commensalism – one species benefits, other is unaffected Parasitism – one species benefits, other is harmed

both their biotic and abiotic interactions with the environment in order to be sustainable. As populations grow, each individual gets a smaller share of resources. When this happens, the affected organisms become stressed. Some may die, others may not be able to reproduce.

When # births = # deaths,

is the maximum number of individuals that can ecosystem can support without reducing its ability to support future generations of the same species. Exceeding carrying capacity for a long time results in environmental harm.