Module 6 Population size and competition

what is limiting factor

environmental resource or constraint that limits pop growth

what are abiotic factors

temp, light, pH, water/oxygen availability, humidity

what are biotic factors

predators, disease, competition, food

what is carrying capacity

max pop size an env can support (earth capacity is 2-40bn

what are the two types of migration

immigration, emmigration

what is immigration

movement of individual organisms into a particular area, increases pop size

what is emigration

movement of individual organisms away from a particular area, decreases pop size

what does this growth show

pop growth with no limiting factors

what are density independent factors

factors that affect whole pop regardless of its size, can change pop size and remove pop e.g. earthquakes, fires, volcanic eruptions, storms

what is competitive exclusion principle

1 specie better adapted so out compete other causing pop decline of weaker specie

what is interspecific competition

competition between different species for same resources

what is intraspecific competition

competition between members of same species

what is an example of intraspecific competition

red vs grey squirrel, grey squirrel has more varied diet and are larger so less resources for red squirrels

what happens when members of the same species compete for same resources

the availability of the resources determines the pop size so fluctuations of pop number

what does this graph show

number of organisms fluctuating due to availability of resources

how are predators evolved to be efficient at capturing prey

bursts of speed, stealth, fast reactions

how are prey evolved to avoid capture

camouflage, mimicry, defence mechanisms

how are predator and prey interlinked

as pop size of one changes it causes change in the other

what does the graph show

lag time for predators to respond to increase in prey and reproduce