Transcript Has reduced Biodiversity!

World
6,785,186,332
12:15 GMT (EST+5) Jun 08, 2009
U.S. 306,617,138
JUNE 2008
One birth every.................................. 7 seconds
One death every.................................. 13 seconds
One international migrant (net) every............ 29 seconds
Net gain of one person every..................... 10 seconds
Human population growth is the root of
many environmental issues.
•Overuse of non-renewable resources
•Destruction of habitats
•Deforestation
•Pollution
•Atmospheric changes
Industrialization
Increased industrialization demands more resources and energy
use.
This has positive and negative effects on humans and ecosystems
Eutrophication is caused by enrichment of the aquatic biomes from
fertilizers and wastes. (too much of a good thing)
Eutrophic Lake
•reduces the content of water in
the soil and groundwater as well as
atmospheric moisture
•reduces soil cohesion, so that
erosion, flooding and landslides
often ensue.
•reduces biodiversity
•reduces possible medicinal
advances
•Adds to global warming
Soil, Thermal, Noise, Light
Acid Precipitation is caused mainly by combustion of fossil fuels.
Acid rain cause the rapid erosion of statues and
destruction of lakes
Average pH profiles in U.S. in 1999
Why is the eastern U.S. so high in acid rain?
Air Pollution
PART II
DO NOW:
Which animal has modified
ecosystems more than any other
animal and has had the greatest
negative impact on world ecosystems?
1.
2.
3.
4.
gypsy moth
zebra mussel
human
shark
A major reason that humans have
negatively affected the environment in
the past is that humans have
1. frequently lacked an understanding of how
their activities affect the environment
2. passed laws to protect certain wetlands
3. attempted to control their population
growth
4. discontinued the use of certain chemicals
used to control insects
Green House Effect: Climatic change
caused by increasing Greenhouse Gases
(carbon dioxide)
Which factor is a major cause of
global warming?
1.
2.
3.
4.
increased burning of fuels
increased number of green plants
decreased mineral availability
decreased carbon dioxide in the atmosphere
Introduced Species: species from another
ecosystem is a problem because there usually
aren’t natural checks
May
reduce
Biodiversity!
Nile perch (Lake Victoria)
Brown tree snake (Guam)
Argentine ants
Caulerpa (seaweed)
Zebra Mussels in the Great Lakes
Has reduced Biodiversity!
Imported animal species often disrupt
an ecosystem because in their new
environment, they will most likely
1. eliminate the genetic variation of the
autotrophs
2. increase the number of mutations in the
herbivores
3. have no natural enemies
4. be unable to produce offspring
The importation of organisms such as
the Japanese beetle and gypsy moth to
areas where they have no natural
enemies best illustrates
1. the use of abiotic factors to reduce pest
species
2. the selection of species to mate with each
other to produce a new variety
3. attempts by humans to protect extinct
species
4. a human activity that disrupts existing
ecosystems
African elephant tusks consist of highquality ivory. In recent years, the
elephant population in certain African
wildlife preserves has decreased. This
decrease is most likely due to
1.
2.
3.
4.
air pollution
human exploitation
biocide use
importation of Japanese beetles
Trade-offs:
solving environmental issues
involves trade-offs. There are
always costs associated with social
decisions.
Solar Energy reduces dependence on fossil fuel
but it is expensive.
Nuclear Power provides electricity without
fossil fuel but generates nuclear wastes.
Societies must decide on proposals and assess risks,
costs, benefits and trade-offs.
SUMMARY
Which situation has had the most negative
effect on the ecosystems of Earth?
1. use of air pollution controls
2. use of natural predators to control insect
pests
3. recycling glass, plastic, and metals
4. increasing human population