carrying capacity
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Write in complete sentences! Don’t talk during the Catalyst!. Carrying Capacity. Homework (Carbon worksheet, Study guide) on your desk. - PowerPoint PPT PresentationTRANSCRIPT
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?