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Alligator. Bacteria. Snake. Bunny. Weasel. Grass. Biomagnification through trophic chains. Biomagnification is not limited to mercury. DDT and other pesticides. UC Santa Cruz. Current. Endocrine disrupters. Nutrients. Why not twinkies?. Alligator. Bacteria. Snake. Bunny. Weasel.
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Alligator Bacteria Snake Bunny Weasel Grass
Biomagnification is not limited to mercury DDT and other pesticides UC Santa Cruz Current Endocrine disrupters
Nutrients Why not twinkies?
Alligator Bacteria Snake Bunny Weasel Grass
Nutrients are cycled • Carbon • Nitrogen • Phosphorous • Water*
Biogeochemical Cycles • Nutrients cycle through: • Atmosphere • Hydrosphere • Terrasphere • Biosphere • Reservoirs are major storage sites
Carbon Cycle Summary • CO2 is small proportion of atmospheric gas • Far more CO2 is stored in oceans
Carbon Cycle Summary • Photosynthesizers store carbon through photosynthesis • Living things store carbon in living tissue and release small amounts of CO2 through respiration into ocean and atmosphere
Carbon Cycle Summary • Fossil fuels are the bodies of ancient buried plants and animals • Heat and pressure converted the bodies to fuel
The Carbon cycle disrupted The Greenhouse Effect Global Climate Change Global climate change refers to humans unnaturally elevating the rate at which greenhouse gasses are added to the atmosphere • Greenhouse gasses (like CO2) trap sunlight heat energy near Earth’s surface • The Greenhouse Effect is a natural process
Carbon cycling processes Natural processes Human generated Burning fossil fuels Slash and burn deforestation Certain types of Agriculture Stockyards Rice paddies • Volcanoes • Hot springs & geysers • Ocean out-gassing • Respiration encarta
Impacts of Carbon cycle disruption Uh Oh! • Melting glaciers and ice caps • Extremes in weather • Increasing disease • Ocean acidification Hooray! Eek!
Nitrogen Cycle Summary • Major reservoir is atmosphere (N2) • Nitrogen fixing bacteria convert N2 to nitrate (NO3-) or ammonia (NH3) for use by plants
Nitrogen Cycle Summary • Nutrients move through the food web • Denitrifying bacteria convert nitrate and ammonia back to N2 for release to atmosphere
Overwhelming the Nitrogen Cycle • Excess chemical production by humans of nitrogen oxides and sulfur dioxides • Chemically combine with rainwater to form nitric acid and sulfuric acid
Overwhelming the Nitrogen Cycle • Acid rain damages plant life and acidifies ponds and lakes rendering them unlivable • Acid rain eats away at rocks and buildings
Phosphorous Cycle Summary • No atmospheric component • Rocks are major reservoir • Phosphate stored in rocks can be eroded & dissolved by rainwater • Phosphate is easily absorbed by plants and other photosynthesizers and passed through food webs • Phosphate is reincorporated into rock from soil or water
Eutrophication follows disruptions to Nitrogen and Phosphorous cycles • Fertilizers and excess nutrients runoff into streams and rivers • Stimulate rapid growth of algae and bacteria
Fertilizers & Dead Zones • Nutrients stimulate algal growth • Rapid growth leads to anoxic conditions Science Daily NASA • Anoxia leads to suffocation US Army
Hydrologic (Water) Cycle Summarized • Water remains chemically unchanged • Ocean is primary reservoir • Solar energy evaporates water to atmosphere • Water returns from atmosphere as precipitation • A small amount may enter reservoirs • Plants absorb water for use in photosynthesis, but most evaporates through leaves • Consumers drink water