Human Impact on the Biosphere/Conservation Biology
A. Acid Rain
1. What is acid rain?
2. What causes acid rain?
a) rain is normally acid because of CO2
CO2 + H2O --> H2CO3 (carbonic acid)
b) oxides of nitrogen and sulfur get into the atmosphere and react with water to form acids
SO3 + H2O --> H2SO4 (sulfuric acid)
NO2 + H2O --> HNO3 (nitric acid)
c) the sources of nitrogen and sulfur are both natural and man-made
3. What is the distribution of acid rain?
-testing station -water testing
4. What is the impact of acid rain on natural ecosystems?
-lakes and rivers particularly vulnerable
B. Rising Atmospheric CO2 Levels and Global Warming
1. Are global temperatures rising?
2. Are global CO2 levels rising?
3. Is there a causal connection between CO2 and temperatures?
a. CO2 is a greenhouse gas
-greenhouse effect
c. Impact of Industrial Activity
d. Use of Computer Modeling
C. Conservation Biology/Loss of Biodiversity
1. How many species are there?
-~1.4 million-up to 100 million?
1982 Terry Erwin National Museum of Natural History
Luehea seemanii: 163 x 50,000 = 8,150,000/ 0.4 = 20,375,000 arthropods
2. What is the rate of loss of biodiversity?
-habitat destruction......................................75%
-displacment by introduced species..............68%
-alteration of habitat by chemical pollutants...38%
-hybridization with other species..................38%
-over-harvesting..........................................15%
example: cichlid fishes of Lake Victoria
1959 Nile perch
example: Mussel Shoals Alabama
1924 Wilson Dam
3. Why care about the loss of biodiversity?
a. Biophilia
E.O. Wilson "The Diversity of Life"
b. Sources of Natural Resources
-food crops
-genetic material (pest resistance, stress resistance) Germplasm storage: Colorado, Arctic
example: wheat stem rust
-medicinal compounds (anti-microbial, anti-viral, anti-tumor)
c. Ecosystem Services
-purification of air and water
-CO2 sink
-nutrient cycling
-pollination of crop plants
-!!!!!
