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Explore how human activities impact biological diversity, leading to habitat loss, pollution, and threats to ecosystems. Learn about conservation efforts, sustainable development, and the importance of preserving biodiversity.
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Human Activities… • …affect the biosphere • Hunting and gathering • Have caused extinctions • Agriculture • Provides dependable food supply • Pollution source • Industry and Urban development • Big pollution producer • Loss of farmland • Loss of habitats
Poor management leads to… -Soil Erosion (loss of fertile soil) -Desertification (productive landdesert) -Deforestation (loss of forests) -Overfishing -Overgrazing -General loss of resources
Resources • Renewable resources - can regenerate if alive (trees, plants) or can be replenished by biochemical cycles if abiotic (water) • Nonrenewable resources - cannot be replenished by natural processes (fossil fuels) • Sustainable development - using natural resources without depleting them
Biodiversity • Biodiversity refers to the genetically based variety of all organisms in the biosphere • Importance: • Stability • Because living things are interdependent • Humans are part of food webs & energy cycles
Loss of Biodiversity endangered threatened extinct
Threats to Biodiversity • Invasive species – no predators • Habitat • loss & fragmentation • degradation • acid precipitation • global warming • water pollution • land pollution
Non-native species • Pythons in FL • CLICK ME • Snakehead MUTE
Habitat Loss • Biggest reason for decline in biodiversity • Results in loss of habitat – makes a species more vulnerable to extinction
Acid Precipitation • sulfur dioxide – from coal-burning • nitrogen oxides – from automobile exhaust • damages plants and plant growth
Ozone Problems • UV radiation damages living tissues • CFC’s (from aerosols) are a big problem • Results in ozone depletion • Greenhouse effect – adding to ozone – traps heat
Water Pollution • excess nitrogen-based fertilizers and animal waste are carried by rain into lakes and streams • excess nutrients cause algal blooms – depletes oxygen from other organisms
Land Pollution • Most trash becomes part of billions of tons of solid waste buried in land fills • Pesticides degrade habitat • DDT was a major threat • spreads throughout the food chain • “Silent Spring” by Rachel Carson • banned in U.S. in 1972 DDT accumulated at higher trophic levels!
Conservation…past and future steps • Efforts to preserve habitats and the species within • “Hot Spots” are identified • Areas where species are in danger of extinction • 1933 – Civilian Conservation Corp. • “Tree Army” • 1966 – Endangered Species Preservation Act • 1970 – 1st celebration of Earth Day
Google Earth Timelapse (1984-2016) • Click ME!