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Changes to Populations. 4 factors that effect the size of a population . Increase Population 1) Birth 2) Immigration (entering a population) Decrease Population 3) Death 4) Emigration (leaving a population)

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4 factors that effect the size of a population
4 factors that effect the size of a population

  • Increase Population

    • 1) Birth

    • 2) Immigration (entering a population)

  • Decrease Population

    • 3) Death

    • 4) Emigration (leaving a population)

  • See if you can create an equation using these 4 terms for Population Growth, Population Decrease, Population Stability


Is the population increasing or decreasing
Is the population increasing or decreasing?

  • Populations Increase:

    • When Immigration + Births > Death + Emigration

  • Population Remains Stable:

    • When Immigration + Births = Death + Emigration:

  • Populations Decrease:

    • When Immigration + Births < Death + Emigration


What are limiting factors
What are Limiting Factors?

  • Anything that prevents the growth of a population

  • What would happen without limiting factors?


Carrying capacity k
Carrying Capacity (k)

  • The maximum population a species can maintain in a certain area without damaging the ecosystem.



Limiting factor 1 space loss of habitat
Limiting Factor #1: Space/Loss of Habitat

  • Territorial Animals need a large amount of space.

  • Loss of Habitat causes the decline of many species.

Who took my towel?


Loss of space habitat example bluebirds
Loss of Space/Habitat Example: Bluebirds

  • Loss of trees/wooden posts caused a huge decline

  • Between 1935-1985 numbers declined by 90%


Limiting factor 2 food and water
Limiting Factor #2Food and Water

  • Leads to death via dehydration, starvation

  • Some animals will emigrate

  • Organisms that rely on one type of food are severely affected


Food and water example snowshoe hare and lynx
Food and Water Example: Snowshoe Hare and Lynx


Limiting factor 3 climate and weather
Limiting Factor #3: Climate and Weather

  • Temperature changes can affect plants and animals

  • Floods and storms can cause death & destruction of habitat


Climate changes example mosquito populations
Climate Changes Example:Mosquito Populations

  • Mosquitoes breed in standing water

  • Rainfall creates puddles of standing water


Temperature changes coffee habitat
Temperature Changes: Coffee Habitat

Impact of Temperature

Rise on Robusta Coffee

in Uganda.

*Developing countries,

whose economies often

rely heavily on one or two

agricultural products, are

especially vulnerable to

climate change.

*This graphic shows that

With an increase of only

2 degrees Celsius, there

would be a dramatic

decrease in the amount

of land suitable for

growing Robusta coffee

in Uganda.


Limiting factor 4 cover
Limiting Factor #4:Cover

  • Protection from predators

  • Protection from weather


Cover example ruffed grouse
Cover Example:Ruffed Grouse

  • Ruffed Grouse- Requires brushy forests for cover and food. Most of Pa’s forest were logged (cut down) 80 to 100 years ago. They grew into brushy forest allowing grouse populations to increase. Forests are now maturing reducing cover and food causing populations to decline. Land development has also reduced populations


Limiting factor 5 increase predation
Limiting Factor #5:Increase Predation

  • An increase in the number of predators to an area will impact prey species.


Predation example house cats
Predation Example: House Cats!

  • Predicted that in one year house cats kill 1 billion songbirds!


Limiting factor 6 disease
Limiting Factor #6:Disease

  • Spread quickly through high density populations

  • Can devastate populations with low genetic diversity


Disease west nile virus
Disease: West Nile Virus

  • Mosquito born disease

  • 5,697 crows reported dead in NYS in 1999


White nose syndrome
White Nose Syndrome

  • Fungus that has killed over one million bats

  • 90-100% of some species of hibernating bats are in danger of being killed.


Limiting factor 7 light
Limiting Factor #7:Light

  • Plants that cannot tolerate too much or too little light can be affected


Light example tree growth and shade
Light Example:Tree Growth and Shade

  • Aspen Pine Poplar = intolerant, will dominate young forests

  • Beech, Fir, Hemlock, Maple = tolerant will dominate older forests


Limiting factor 8 human presence
Limiting Factor #8:Human Presence

  • Close proximity to humans causes some species to emigrate

  • Other species thrive



Competition
Competition

  • Limiting factors lead to competition among organisms for available resources

  • A loss in a limiting factor can contribute to a decline in populations

  • Increased due to exotic species


Exotic Species- Introduced species not native or endemic to the area in question.OTHER NAMES: non-native & invasive


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