1. Next Review Session is: Wednesday 5/17 @ 7:15 AM
Date: May 15th, period 5
Aim # 77: How have humans negatively affected diversity in the environment
HW:
RRB pages 9-18 due Friday
Castle Learning (QUIZ #3) due next MONDAY
Human Impact Test next Wednesday
Do Now:
What are renewable resources? Give an example.
What are nonrenewable resources? Give an example.
How can we prevent depletion of our resources? (Hint: 3R’s)
Next Review Session is: Wednesday 7:15 AM

2. Next Review Session is: Tuesday 5/16 @ 3:15 PM
Date: May 15th, period 1
Aim # 77: How have humans negatively affected diversity in the environment?
HW:
RRB pages 9-18 due Friday
Castle Learning (QUIZ #3) due next MONDAY
Human Impact Test next Wednesday
Do Now:
What are renewable resources? Give an example.
What are nonrenewable resources? Give an example.
How can we prevent depletion of our resources? (Hint: 3R’s)
Next Review Session is: Tuesday 3:15 PM

3. Aim #77: How have humans negatively affected diversity in the environment?

4. Review: What is an ecosystem?
Consists of all the living
and nonliving things that
interact in a specific area

5. Review: Relationships in an Ecosystem:
Predator vs. Prey
The stability of an Ecosystem is
dependent on the balance of these
relationships/cycles.
Water Cycle
Photosynthesis

6. 1) Human Impact
Although not the most numerous organisms on earth, humans have the greatest effect on the environment.

7. 2) How do humans usually impact the balance in ecosystems?

8. 3) Why are humans disrupting the balance in ecosystems?
The sheer number of people on this planet are
putting a tremendous strain on the Earth’s
environmental resources.

9. 4) How did this rapid growth occur?
Increased Food Supply
Improved Health Care
Improved Sanitation and
Hygiene

10. 5) Carrying Capacity & Limiting Factors
Carrying Capacity- is the number
of organisms the environment
can support.
Limiting Factors- are factors in the
environment that limit the size of
populations.
a) What are some of our limiting factors?
Food, Water, Oxygen, Space

11. Carrying Capacity
Time

12. 6) Have we reached earth’s carrying capacity?
No, because we continuously come up with new technologies to produce more
________
food.

13. 7) What are some of the detrimental effects of overpopulation?
Over Consumption
Technology
Waste Disposal

14. 7) What are some of the detrimental effects of overpopulation?
Overcrowding
Habitat Destruction
Industrialization

15. 8a) Human Activities & the Loss Of Diversity: Deforestation
Why?
1) Provide land for farming
2) Provide people places to live
Provide resources to use in
building or manufacturing
Effects:
Deforestation leads to habitat
destruction.
2) Organisms have no place to live.
Organisms can become endangered
or extinct.
4) Biodiversity decreases.

16. 8b) Human Activities & the Loss of Diversity: Direct Harvesting
Organisms (plants and animals) are removed from the environment and NOT replaced.
Organisms are usually obtained through hunting or poaching (illegal hunting).
Often results in the loss or elimination of a species & a decrease in diversity.
Examples:
Ivory, Shark Fins, Exotic Birds

17. 8c) Human Activities & the Loss of Diversity: Imported Species
Non-native (not belonging to) animal and vegetation species often become invasive when introduced into environments lacking natural predators or other mechanisms to keep the dominating species in check. These species become pests & disrupt the current ecosystem by reducing diversity.

18. Australia’s Biggest Pest (26 in 1800s to billions)
Highly adaptable animal. Not a picky eater and breeds very fast.
Destroyed massive amounts of vegetation & reduced diversity.
In Australia, it spread like wildfire because its natural predators from back home, the weasel and fox, were not originally present.
The dingo and Tasmanian wolf, Australia's native carnivores(and potential rabbit consumers), were themselves being kept in check by local sheep and cattle ranchers.
The European Rabbit

19. New York’s Biggest Pest: Gypsy Moth
The Gypsy Moth originally
evolved in Asia & was
introduced here accidentally
in 1868.
9) What can happen when non-native species are added to a new environment?
They often have no natural enemies.
Rapidly overpopulate.
They then crowd out, feed on, or otherwise eliminate
native species.
4) Diversity decreases.

20. 10) How do ecologists solve these pest problems?
A virus was promptly released into the wild in Australia and effectively spread like wildfire through mosquito and rabbit flea bites, and killed all but 0.2% of the rabbits. This small percentage had built a resistance to the virus, bred like rabbits, and passed on the resistance to the virus.
Disease Organism
Specific for the Pest:

21. 10) How do ecologists solve these pest problems?
Use of Pesticides or Insecticides:
These chemicals/poisons can kill the pest, but also
other organisms native to the ecosystem.

22. 10) How do ecologists solve these pest problems?
The release of native predators of a pest species is
a safe way to control pest problems without reducing
diversity.
If a non-native predator is imported to control the
pest, it may choose to feed on other native organisms
reducing diversity.

23. What are the effects of farming?
What happened to biodiversity?
What happened to ecosystem stability?
What would happen if an insect came along?
What do farmers use to get rid of insects?

24. Biological Magnification
The concentration of toxic substances (DDT) as you move through the food chain increases.

25. Let’s Review!