interspecific competition pt 1 (species interactions->encounter)

when species occupy the same physical area, what interactions can happen between individuals of the same/different species?

1) interspecific competition

2) predation

3) host/parasite

4) mutualism

interspecific interactions play a central role in population dynamics by affecting _____ and _____

birth + death

interspecific interactions can function as agents of _______ ______ because they influence what two qualitites?

natural selection

→ 1) survival 2) reproduction

darwin’s theory of natural selection was prompted by what?

struggle for existence (competition)

why is competition regarded as a major force in natural selection?

it forces species to diverge from one another and to become specialists in certain areas

competition

individuals seeking a common resource in short supply

interspecific competition

relationship that affects the populations of two or more species adversely

intraspecific competition

a relationship that affects individuals among the same species adversely

what are the two forms of interspecific competition?

1) exploitation

2) interference

exploitation

competition occurs when species indirectly interact with one another but affect the availability of shared resources

interference

competition occurs when species directly interact and prevent others from occupying a habitat or accessing resources within it

what is an example of exploitation?

tree taking up water + cows grazing

what is an example of interference?

animals defending their territory

what are the six types of interspecific competitive interactions?

1) consumption

2) preemption

3) overgrowth

4) chemical interaction

5) territorial

6) encounter

consumption

one species inhibits another by consuming a shared resource

→ a cow grazes a patch of grass before another cow could, meaning there is no more grass for the other to graze on

preemption

occupation by one individual precludes establishment by others

→ polyp is stationary and will not move from a spot, meaning nothing else can take that spot because the polyp is already there

overgrowth

one organism grows over another + inhibits access to an essential resource

→ kudzu overgrows on any other organism, blocking light from penetrating

chemical interaction

production of chemical growth inhibitors or toxins released by an individual

→ plants releasing toxins across their roots to affect other plants to poison their competitiors

territorial

the behavioral exclusion of others from a defended territory

→ a lion chasing away tiger from its territory

encounter

results during nonterritorial meetings

→ scavengers fighting over a carcass—this is not due to territory, but due to the snowball effect of species constantly trying to out-compete one another