1. Population Growth & Nutrient cycles

2. $10,779,362.27…that’s almost 11 MILLION dollars
If you were smart you picked option 2…after the 30 days you would have made…
$10,779,362.27…that’s almost 11 MILLION dollars

3. Exponential Growth
When a population has UNLIMITED resources (food, space, protection from predators, etc.) they will reproduce and grow EXPONENTIALLY
Known as a J-curve

4. Carrying Capacity No population can grow exponentially forever!!
They will eventually run out of and/or reach the maximum on their resources (space, food, etc.)
This limit is known as the CARRYING CAPACITY of the environment

5. Logistic Growth
As a population approaches its carrying capacity the growth rate will SLOW DOWN.
This is known as LOGISTIC growth
Also known as an S-curve

6. Carrying Capacity
Carrying capacity is defined as the number of individuals an environment can support.
Limiting factors in the environment help to maintain ecosystem stability by allowing populations to fluctuate around the carrying capacity.
This is called dynamic equilibrium.

7. What happens when the population EXCEEDS the carrying capacity?
DEATH
What happens when the population is UNDER the carrying capacity?
GROWTH
Carrying Capacity

8. Limiting Factors
Limiting Factor – anything that limits population growth
Two types:
Density-dependent
Density-independent

9. Density-Dependent
Density dependent factors have a greater effect on a population when there is a higher population
When the population is higher…it is more dense!
The higher the population, the MORE you will feel these limiting factors
Ex. Disease, predation, competition
The more mice there are, the easier they will be to catch…therefore, more of them will die!

10. Spreading of Disease
The higher the population, the faster diseases spread because individuals are closer together (DENSE) so its easier for germs to go from one individual to the next!
Density-DEPENDENT!!

11. Density-Independent
Density-Independent factors will effect all populations the same…no matter how big or small they are.
Abiotic factors
Ex. Natural disasters (drought, storms, forest fires, etc.)
It doesn’t matter if 5 rabbits live in this forest, or if 5000 rabbits do. This fire will not be stronger because more rabbits live here.

12. Predator-Prey Curve
Both the predator and the prey are limiting factors for the other.
If there are LOT of wolves, there will not be a lot of rabbits because they are being eaten.
BUT when the rabbit population gets too low, the wolves will start to die because there now isn’t enough food.

14. Biogeochemical Cycles
Biogeochemical Cycles – the pathway through which a substance is recycled.

15. Water Cycle
Returns to ecosystem by precipitation; soaked into ground by infiltration; or run-off into surface water.
Returns to atmosphere by evaporation or transpiration (the loss of water by plants)

16. Carbon Cycle Powered by 2 main processes: Other processes:
Photosynthesis – plants and algae capture CO2 from the atmosphere and convert it into sugars
Respiration - all living things break down sugars for energy, which returns CO2 to the atmosphere during exhalation
Other processes:
Decomposition returns carbon to ground and atmosphere
Burning of fossil fuels (coal, oil, gas, etc.) adds CO2 to the atmosphere

17. Carbon Cycle Practice
Using the Carbon Cycle diagram on page 77 of textbook:
What are 4 sources/processes that ADD carbon to the atmosphere?
What are 2 sources/processes that REMOVE carbon from the atmosphere?
What process do animals carry out that adds CO2 to the atmosphere?
What process do plants carry out that removes CO2 from the atmosphere?

18. Carbon Cycle Practice
The combustion of ___________________ by humans can add CO2 to the atmosphere.
____________________ of dead organisms may return carbon to the soil.
How is carbon stored in plants transferred to animals?

19. Carbon Dioxide – Oxygen Cycle
OXYGEN is converted into CARBON DIOXIDE by Respiration
CARBON
DIOXIDE
is converted
into
OXYGEN
by PHOTOSYNTHESIS

20. Nitrogen Cycle
Nitrogen is essential for living organisms so that they can build proteins; nitrogen is plentiful in the atmosphere, but is not usable in this form.
Nitrogen fixation – bacteria living in the roots of plants convert nitrogen from the air into a more usable form.