Homework 9, due Wed Dec 2, 2009
			ENVR 30: Fall 2009 

1. Is saving the spotted owl important?  Why or why not?

2. Name two or three invasive species that have had severe ecological impacts.

3. What is extirpation?  Give an example.

4. What is the extinction vortex?  Name a species that is now in this vortex.

5. One valid estimate of the land species number on the Earth is 
A. 1 million to 4 million 
B. 4 million to 100 million 
C. 100 million to 500 million 
D. 500 million to 1 billion 

6. Ecological extinction means that the species is 
A. completely extinct 
B. rare but still having an ecological impact 
C. rare to the point it has no ecological impact 
D. recovering its numbers in an area 

7. The rainforests contain about what percentage of the species of the world.
A. 10 
B. 30 
C. 50 
D. 90 

8. Most analysts agree that the MVP of a population must be at least a few _______ to ensure long-term survival.
A. dozen 
B. hundred 
C. thousand 
D. million 

9. The sea otter and the spotted owl are respectively:
a. Indicator and Keystone species
b. Keystone and Indicator species
c. Keystone and Predictor species
d. Predictor and Indicator species
e. Both Indicator species
f. Both Keystone species

10. Select the geographic region of the U.S. which has the most remaining natural vegetation.
A. Central
B. South-western Coastline
C. Desert-like regions in the Western U.S.
D. North Eastern U.S.


11. According to the United Nations, the recommended daily amount of Calories 
per person is: 
A. 1500 
B. 2350 
C. 2950 
D. 3400 

12. The largest average consumption of meat per year occurs among persons in 
A. Egypt 
B. India 
C. Japan 
D. the United States 

13. Currently about 1.5 Billion hectares are used for croplands and 3.3 billion 
hectares are used for grazing animals.  
The total amount of cultivable land in the world could be as high as 
A. 4 Billion hectares
B. 6 Billion hectares
C. 12 Billion hectares
D. 24 Billion hectares

14. The peak of grain production per person worldwide was reached in 
A. 1972 
B. 1984 
C. 1990 
D. 1994 
E. 2008

15. Which of the following will not reduce desertification?
A. planting trees
B. increasing soil coverage
C. decreasing grazing
D. increasing irrigation

16. The bacterium Bacillus thuringiensis (Bt) produces a toxin against 
A. birds 
B. caterpillars 
C. humans 
D. plants 

17. Commerical extinction means what?