Download Population and Carrying Capacity

Population and Carrying Capacity
Your family has decided that you are going to bring a dog into your household. What limiting factors will determine whether your new family addition will live a happy and healthy life? List them.
Pull
• Population: all the members of one species that occupy a certain area during a certain time.
• Ex. The population of bass in Lake Ontario
Four factors affect the size of a population:
1. Natality ­ the number of offspring of a species born in one year
2. Immigration ­ the number of individuals of a species moving into an existing population
* These __________________ the size of the population
3. Mortality ­ the number of individuals of a species that die in one year
4. Emigration ­ the number of individuals of a species moving out of an existing population
*These __________________ the size if the population
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Carrying Capacity
'Carrying capacity' refers to the size of a population that can be supported indefinitely by the resources and services of a given ecosystem.
Beyond this carrying capacity, no additional individuals can be supported, at least not for long.
When a population is maintained at its carrying capacity, the size of the population is at an equilibrium.
Which of the following curve﴾s﴿ shows the existence
of a carrying capacity?
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Pull
Population Density
Here are some h
Time
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Limiting Factors
Carrying Capacity can be affected by limiting factors such as:
1. Amount of available water and energy
­ If the population grows too large it will eventually crash when resources run out.
­ ex. The availability of frogs limits the population of garter snakes.
2. Predation
­ If the population grows too large, predation will increase, reducing the size of the population of prey.
­ ex. As the number of moose increases, the number of wolves increases. When the number of moose decreases, the population of wolves also decrease.
Pull
3. Competition
­ If resources become scarce, members of a population must fight for resources and their survival. The more energy an organism spends on competing, the less energy it has for growth and reproduction.
­ This limits the size of a population.
4. Space
­ If a population grows too large, space will run out. Competition for space will reduce the population.
­ ex. Moose need lots of room to forage.
Homework: Elk and Wolf Population Case Study
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