Take your Population Lab out for me to check

Take a seat, Get out your PENCIL!

Changes to Populations

Ecological CommunityGroups of interacting organisms

Pond Community (lilly pads, frogs, fish, snakes, elodea, etc)Forest Community (trees, shrubs, squirrels, birds, deer, etc)Coral Reef Community (coral, sponges, sharks, fish, algae,

etc)

HabitatArea where community of organisms live.Requires 4 components:

Food, water, cover, space

EcosystemInteractions of communities of organisms with each

other and their habitat.

What are some terms used in Ecology to study organisms?

Increase Population1) Birth2) Immigration (entering a population)

Decrease Population3) Death 4) Emigration (leaving a population)

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

4 factors that effect the size of a population…

Populations Increase: When Immigration + Births > Death + Emigration

Population Remains Stable:When Immigration + Births = Death + Emigration:

Populations Decrease: When Immigration + Births < Death + Emigration

Is the population increasing or decreasing?

Anything that prevents the growth of a population

What would happen without limiting factors?

What are Limiting Factors?

What is Carrying Capacity (k)?

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

Population can stabilize at K…

What happens when a population goes above carrying capacity?

29 introduced in 1944

More than 6,000 by 1963

Down to 42 by 1966

Populations also can crash if #s go above K…

How overpopulation and decrease (k)

Season Fluxuations

Seasonal Fluctuations

What will happen with World Population?

Territorial Animals need a large amount of space.

Loss of Habitat causes the decline of many species.

Limiting Factor #1: Space

Who took my towel?

Loss of trees/wooden posts caused a huge declineBetween 1935-1985 numbers declined by 90%

Loss of Space/Habitat Example: Bluebirds

Q. What are the major needs of an organism’s habitat? Answer- Food, water, cover, and space.

Leads to death via dehydration, starvation

Some animals will emigrate

Organisms that rely on one type of food are severely affected

Limiting Factor #2: Food and Water

Food and Water Example: Snowshoe Hare and Lynx

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

Mosquitoes breed in standing water

Rainfall creates puddles of standing water

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.

Protection from predatorsProtection from weather

Limiting Factor #4: Cover

What is Edge?

Positives and Negatives of Edge…

Some organisms prefer edge, because they need the cover and specific species of plants that grow there to feed on…

Other species have their habitats Fragmented by roads, fields, farms, etc.

Habitat Fragmentation

Cover Example: Ruffed GrouseRuffed 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

White-tailed Deer

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

Limiting Factor #5: Increase Predation

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

Predation Example: House Cats!

Spread quickly through high density populationsCan devastate populations with low genetic diversity

Limiting Factor #6:Disease

Mosquito born disease

5,697 crows reported dead in NYS in 1999

Disease: West Nile Virus

Fungus that has killed over one million bats90-100% of some species of hibernating bats are in

danger of being killed.

White Nose Syndrome

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

Limiting Factor #7:Light

Light Example: Tree Growth and ShadeAspen Pine Poplar = intolerant,

will dominate young forestsBeech, Fir, Hemlock, Maple =

tolerant will dominate older forests

Close proximity to humans causes some species to emigrate

Other species thrive

Limiting Factor #8: Human Presence

Think of an example where an organism does not have enough limiting factors.

What is the organism, how does this affect the habitat around that organism?

Reflection

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

Competition

~Introduced species not native or endemic to the area in question. ~Can cause competition for resources.

Exotic Species

Changes in Population

Watch this… http://www.youtube.com/watch?v=b98JmQ0Cc3k&feature=related

What is the solution? Is there one? Use the debate form I give you with directions to come up with solutions…if there are any…if we need them.

What do you believe about world population?