L3 - Interactions in Communities

Flashcards covering key vocabulary terms related to interactions within communities.

Community

All populations of different species that interact in a given ecosystem.

Interspecific interactions

Interactions between different species in a community.

Competition

An interaction in which 2 or more populations compete for resources

Intraspecific competition

Members of the same species rely on the same resources for survival. Individuals of the same population compete for resources in their habitat

Interspecific competition

Interactions between individuals of different species for an essential common resource that is in limited supply.

Interference Competition

An organism directly alter the ability of another organism to obtain resources; often involves aggression.

Exploitative competition

An indirect competition for resources where one organism may have superior ability over another to gather the same resource.

Competitive Exclusion Principle (Gause’s Principle)

Two species with identical niches cannot coexist; the better competitor excludes the other, so species must have slightly different niches to coexist.

Ecological Niche

An organism’s biological characteristics, including interactions with abiotic and biotic resources.

Resource Partitioning

Competitive exclusion is avoided when a species evolves to use different resources, occupy a different area, or feed at a different time. Results in two similar species using largely non-overlapping resources.

Fundamental Niche

Biological characteristics of an organism and the resources it is theoretically capable of using in ideal conditions.

Realized Niche

Biological characteristics of an organism and the resources it actually uses under prevailing environmental conditions.

Predation

The predator eats part or all of the living body of another organism, the prey. It is beneficial for the predator and harmful for the prey.

Camouflage

Cryptic coloration that allows organisms to blend with their surroundings.

Mimicry

A type of protective coloration where organisms resemble another. Includes Batesian and Mullerian mimicry.

Batesian mimicry

A palatable or harmless species mimics an unpalatable or harmful organism

Mullerian Mimicry

Species that resemble one another and are all poisonous or dangerous

Chemical Defense

An organism releases noxious odors or poisons in its body to make itself chemically unattractive.

Behavioural Defense

Hiding, freezing, playing dead (passive) or fleeing, herding, mobbing, distraction (active)

Structural Defense

External armor that is hard or thorny.

Symbiosis

Individuals of two different species live in close, usually physical contact and at least one of the two species benefits

Mutualism

Both organisms benefit from the interaction.

Obligatory Mutualism

Symbiotic relationship where neither species could survive without the other.

Commensalism

Difficult to ascertain whether an individual of the unaffected species is being harmed or benefited

Parasitism

Parasites cannot complete their life cycle in absence of their hosts

Microparasites

Microscopic parasites with a rapid reproduction rate.

Macroparasites

Larger parasites like tapeworms, fleas, ticks, and lice.

Endoparasites

Organisms that live inside the body of their hosts.

Ectoparasites

Organisms that live and feed on the outside surface of their host.