Goal 2.7.3 Ecology and Human Interaction Human Impact on the Environment
Humans and the Biosphere – Negative Aspects Loss of Biodiversity Extinction Endangered Species Threatened Species
Threats to Biodiversity Habitat Loss Overhunting Deforestation
Figure 55.0 Deforestation of tropical forests
Figure 55.00x Deforestation in the United States
Deforestation
Habitat Fragmentation Separation of habitats due to development, farming, etc.
Habitat corridors – protected parts of habitats that allow migration of organisms from one area to another
Figure 55.5 Fragmentation of a forest ecosystem
Habitat Degradation Damage due to pollution Acid Rain Water Land Air
Think-Pair-Share
Answers 22. fragmentation or loss 23. loss 24. fragmentation 25. degradation 26. degradation 27. loss 28. degradation
ACID RAIN!!!!
How have pH levels changed?? And in 2003??
Acid Rain
Figure 3.10x2 Acid rain damage to statuary, 1908 & 1968
Water Pollution
Biomagnification - Higher concentrations of toxins accumulate at higher trophic levels This is also called bioaccumulation!
Biological Magnification The concentration effect occurs because DDT and other toxins are metabolized and excreted much more slowly than the nutrients that are passed from one trophic level to the next. So DDT accumulates in the bodies (especially in fat).
Figure 54.25 Biological magnification of DDT in a food chain
Air Pollution
Land Pollution
Exotic Species (introduced or nonnative species) Organisms are not native to the particular area In 2005, 95 pythons were captured in the Everglades. In 2006, more than 154 have been picked up.
13 foot python, 6 foot gator Python Python Gator http://www.cbsnews.com/video/watch/?id=930769n Python Python Gator
Nonnative species video
Purple Loosestrife
Purple Loosestrife Predators Biological control – using natural predators to rid of pests.
Defoliated Purple Loosestrife
Figure 55.7x Zebra mussels
Zebra Mussels Get Around!!
Predators of Zebra Mussels: Redhorse Suckers & Common Carp
Figure 55.7 Disastrous species introductions: Nile perch (top left), brown tree snake (top right), Argentine ants (bottom left), seaweed Caulerpa (bottom right)
What is a very common exotic species here in NC?
Exploitation of Wildlife
Positive Aspects Population Control Conservation of Resources Pollution Control Species Preservation Biological Control – using a natural predator to control a population instead of pesticides
Ozone Depletion Ozone protects us from the sun’s harmful UV rays Consequences – skin cancer, mutations in algae
Figure 54.27a Erosion of Earth’s ozone shield: The ozone hole over the Antarctic
Greenhouse Effect – the sun’s heat gets trapped inside the CO2 layer, so Earth’s temperature is increasing