Terms
Density dependent limiting factors
parasitism
disease
competition for food
what else?
What could indicate that a population is decreasing in size?`
- the birth rate is decreasing
- the death rate is increasing
- the emigration rate is increasingWhat happens to populations when they reach carrying capacity?
The positive factors equal the negative factors:
BIRTHS + IMMIGRATION= DEATHS + EMIGRATION
using resources at a rate that does not deplete them
sustainability
grass, weeds, beetles, other insects, earthworms, and grubs
What are examples of populations?
A resource that cannot be replenished in a reasonable time frame for continued use
nonrenewable resource
What processes increase a given population
-births
-immigration
Draw a logistic population growth curve
your graph should have population # on the y-axis and time on x-axis and an S Curve
Age Structure Diagrams or Population Pyramids show
percentage of males and females for each population age group
EX: 0-4 years old represents the babies/young children (bottom of graph)
80+ represents the elderly (at the top of the graph)
Disadvantages of renewable resources
Expensive to put in place
Can harm wildlife (windmills-birds and bats, etc.)
What is an example of a density independent factor?
-weather events
-natural disasters (earthquake, volcano, tsunami, etc.)
Draw an graph for a population that is increasing exponentially.
your graph should have population # on the y-axis and time on x-axis and an J Curve
Populations move from exponential growth to logistic growth (two different graphs!!) due to what factors?
limiting factors: limited resources
deforestation
removal entire forests of all the trees
How does the natural increase in the human population affect the environment?
-exponential growth of the human population can result in resources being used faster than they can be replaced
Why does a population's exponential growth change to logistic growth?
Ecosystems that have more consumers that producers are not ______________
sustainable
The total variety of organisms in the biosphere
Biodiversity
How does adding nonnative or invasive species like the python in South Florida, affect the environment?
nonnative or invasive species often prey on native organisms and cause native populations to decrease.
At what part of an exponential growth curve does a population show the greatest rate of growth?
Where the line is the most steep, almost vertical
What are the negative effects of burning fossil fuels (nonrenewable resources)
- they will run out eventually
- the pollute, adding extra carbon dioxide to the atmosphere faster than can be removed in the carbon cycle.