19.3 Competition Flashcards
What is Intraspecific competition
What is interspecific competition
Competition between members of the same species
Competition between members of different species
In Intraspecific competition, what are some examples of what limit the size of the population
. Individuals of the same species are competing for food, water, breeding sites etc
So the more resources that are available, the larger the population will grow
The lower the availability, the smaller the population will be
An example of intraspecific competition: oak trees
If there are lots of oak trees in one area, there will be less minerals, water and light available
So some will grow larger than others and restrict these resources to other trees which will die
So population will reduce
What is interspecific competition
Occurs when individuals of different species are competing for resources
Eg food, light, water
When populations of two species are competing, one will usually have a competitive advantage over the other
So the population size of one species will increase whilst that of the other will decrease
If conditions remain the same, this will completely diminish one of the species
COMPETITIVE EXCLUSION PRINCIPAL
In interspecific competition
When two species are competing for the same limited resources, the one that uses the resources more effectively will eventually eliminate the other
So no two species occupy the same niche when resources are limiting
How do you show how a factor influences population size
You have to link it to birth rate and death rate
Eg an increase in food supply might not make more individuals, it may actually make bigger individuals
A decrease in food supply could lead to people dying of starvation, which will directly reduce population size
Whilst an increase will take long to make a bigger population size because more individuals will survive so reproduce to give more offspring , so it takes longer to influence population size
