Post on 17-Jan-2016
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