Carrying CapacityHomework (Carbon worksheet, Study guide) on your desk.Catalyst: Humans cut down 2.4 acres of rainforest (about the size of two football fields) EVERY SECOND. It is estimated that 137 species go extinct every day as a result.

1. How does deforestation affect biodiversity?

2. Are rainforest ecosystems more or less stable due to deforestation?

3. Describe how the biodiversity in these rainforests might benefit humans.

4. How can deforestation affect the amount of carbon in our atmosphere? Support your answer.

Write in complete sentences!Don’t talk during the Catalyst!

Objectives

By the end of today, all SWBAT…

Dominate the quizPredict if population size will increase or decrease based upon limiting factors and carrying capacity

Wazzam

AGENDA Catalyst review QUIZ! How many in a population?

CC graphs THIS IS JEOPARDY? EQs

HOMEWORK Take Home Quiz (Carrying Capacity worksheet) – Due Wednesday

Extra Credit: Ecological Footprint – On website

QUIZ!20 minutes!YES, YOU CAN!

How Many?

We’ve been talking about populations of organisms increasing or decreasing in size… When new predators come When organisms leave the food web

But what controls how many organisms exist in a population in the first place?

What determines population? Why can’t we have 1,000,000 students here at Helen Cox? Space Teachers Supplies Student Behavior These

resources are our limiting

factors

Carrying Capacity Key Point #1: An environment can only support as many organisms as there is available food, water, and free space Carrying capacity = maximum number of organisms that can live somewhere, based on the food, water, and free space there

Every species has a different carrying capacity.

Food, water, and free space are the LIMITING FACTORS that determine carrying capacity

Your fridge is like all of the resources (food, water, free space) in an ecosystem.

What if we want to throw a party?

Imagine Your Fridge

We can keep inviting people, as long as there’s enough food in the fridge.But with each new guest, there’s less to go around.

Imagine Your Fridge

Imagine Your Fridge

The fridge won’t replenish magically, and I don’t have the money to keep putting food in the fridge forever.

So too many guests means that…So too many animals means that…

Someone goes hungry… Not enough food/water/free space…

And leaves the party. And organisms die.

Carrying Capacity Key Point #2: We can read a carrying capacity graph to predict changes in population size

Time

Population size

Graph line = Population size at a

specific time

Dotted line = Carrying Capacity

Carrying Capacity

When a population is BELOW its carrying capacity, it will INCREASE in size

Birth rate exceeds death rates

Time

Population size

Carrying Capacity

But if it increases too much and rises ABOVE its carrying capacity, it will DECREASE in size

Death rate exceeds birth rate

Time

Population size

Carrying Capacity

When a population is BELOW its carrying capacity, it will INCREASE in size

Birth rate exceeds death rates

Time

Population size

Carrying Capacity

This happens over and over… but the increases and decreases get smaller and smaller…

Time

Population size

Carrying Capacity

Until eventually, the population size BECOMES STABLE AT THE CARRYING CAPACITY

Birth rate = death rate

Time

Population size

determined by

such asabove it

WORD BANK: water, carrying capacity, pop. size increases, limiting factors, food, pop. size decreases, space

below it

Carrying Capacity

Limiting Factors

Space

WaterFoodPopulation decreases

Population increases

What are threefactors that limitdeer populationsize?

Why doespopulation sizedecrease in the highlighted portion of the graph?

At which point does birth rate exceed death rate the most?

What is the carrying capacity of deer on WallaWalla Island?

At which point do deer exceed their carrying capacity?

In what threeyears doespopulation sizemost exceedcarrying capacity?

Why does the populationdecrease after 1850?

Why does population size rise again after each big drop?

Identify three periods of time where birth rate exceeds death rate

What is the relationship between population size and carrying capacity between 1800-1840?

Write, write, now write it out

CHOOSE ONE, PART A: Lions hunt and eat wildebeest. If a hunter enters the grassland and kills all the lions there, what will happen to wildebeest population size? Explain why.

Bald eagles eat vertebrate fish. If humans pollute the water and many fish die, what will happen to bald eagle population size? Explain why.

CHOOSE ONE, PART B: Bears eat salmon. If a disease causes massive amounts of salmon to die, what will likely happen to the bears? Explain why.

If a population has exceeded its carrying capacity, what will happen to it? Explain why.

Jeopardy!

Rules:1. Groups will be pulled at random to

select questions from Jeopardy board

2. All groups will answer all questions

3. All groups will get 50 points for a correct answer, and the group that selected the answer will get ALL points

Closing An environment can only support as many organisms as there is available food, water, and free space Carrying capacity = maximum number of organisms that can live somewhere based on these limiting factors

We can read a carrying capacity graph to predict changes in population size Below carrying capacity = increase Above carrying capacity = decease Over time, population stabilizes at carrying capacity

Exit Questions

What is the carrying capacity of rabbits in this ecosystem?

When is the carrying capacity for rabbits first reached?

Why does rabbit population size increase in the highlighted section of the graph?