COMMUNITY

ECOLOGY

CHAPTER 3

SPECIES INTERACTIONS

Community: all the interacting organisms in one area

Symbiosis: the relationship between different species living in one area

5 Major Types:1) Predation 4) Mutualism2) Parasitism 5) Commensalism3) Competition

1) PREDATION

Predator: captures, kills, and consumes another organism (the Prey)

Adaptations include: venom, fangs, claws, speed, camouflage

Prey: organism being consumedAdaptations include: speed, camouflage, poisons, thorns, mimicryMimicry: a defense in which one organism resembles another that is dangerous or poisonous

2) PARASITISM

Parasitism: an interaction in which one individual is harmed and the other benefits

Parasite: feeds on another individual (the “Host”)

3) COMPETITION

Competition results from limited resources in a community

Competitive Exclusion: when one species is eliminated due to competition

Character Displacement: evolution of anatomical differences to reduce competition

i.e.: Darwin’s finches evolved specialized beaks

4) MUTUALISM

Mutualism: a cooperative relationship in which both species benefit

Pollination is an important mutualistic relationship

Flowers can reproduce and spreadAnimals receive food from plants

5) COMMENSALISM

Commensalism: a relationship in which one species benefits and the other is not affected

i.e.: Clown fish and sea anenome

PROPERTIES OF COMMUNITIES

Species Richness: the # of species in a community

Species Diversity: abundance of each species type

SUCCESSIONSuccession: the gradual regrowth of species in an area

2 Types: 1) Primary Succession: in an area that has not previously

supported life 2) Secondary Succession: follows a disruption of an

existing community i.e. flood, fire, etc.

Pioneer Species: the first species to colonize a new habitat

Climax Community: the end result of succession which remains constant over time