Ecosystem Interactions

Interactions

• The organisms in a community are capable of interacting with each other in some very complex ways.– They can:• Hurt Each other• Help each other• Live indifferently

Competition• Competition occurs when 2 or more organisms

(same or different species) attempt to us the same resource at the same time and place.

• Resource: any necessity of life – Ex. Water, nutrients, light, food, space, etc…

• Two types:– Intraspecific: members of the same species

compete for a resource– Interspecific: members of different species compete

Intraspecific Competition

Interspecific Competition

Predation• An interaction in

which one organism captures and feeds on another

• Predator- organism that does the killing and eating

• Prey- organism that is the food

• This relationship can have a drastic effect on the community (more on this later)

Symbiosis

• The relationship in which there is a close and permanent association between organisms of different species

• Three kinds of symbiosis are: – Mutualism

– Commensalism

– parasitism.

commensalism

predation

Symbiosismutualism

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mutualism• Relationship in which

both species benefit from the interaction

e.g., intestinal bacteria, lichens, pollinators

commensalism

• Relationship in which two organisms live together …one benefits and the other is unaffected

e.g., barnacles on whales, orchids

parasitism• a member of one species

derives benefit at the expense of another species: usually harm but don’t kill host

• Parasite- organim that obtains benefit

• Host- organism that the parasite feeds from– e.g., ticks, mistletoe,

disease-causing bacteria