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Nutrient Cycles. Water, Carbon, Phosphorus, Nitrogen and Sulfur. Water Cycle. Collects, purifies and distributes earth’s supply of water Driven by evaporation (from oceans, lakes, rivers and soil), precipitation (rain, snow, sleet, dew), and transpiration (from surfaces of plants and soil)
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Nutrient Cycles Water, Carbon, Phosphorus, Nitrogen and Sulfur
Water Cycle • Collects, purifies and distributes earth’s supply of water • Driven by evaporation (from oceans, lakes, rivers and soil), precipitation (rain, snow, sleet, dew), and transpiration (from surfaces of plants and soil) • Reservoirs (sinks): groundwater/aquifers, ocean, ice and snow (glaciers), lakes and reservoirs • Humans influence cycle by: • Increased surface runoff • Taking too much groundwater out • Water pollution
Carbon Cylce • Building block for organic compounds necessary for life • Key component in atmosphere—greenhouse gases and temperature regulation • Driven by photosynthesis and cell respiration • Reservoirs (sinks): atmosphere, plants, animals, fossil fuels, dissolved in ocean, limestone and ocean sediments • Human Impacts (releasing CO2 into atmosphere): • Driving cars • Deforestation • Burning fossil fuels • Burning forests
Nitrogen Cycle • Component of proteins, vitamins and nucleic acids • Cannot be absorbed directly by plants and animals (N2)—rely on nitrogen fixing bacteria • Reservoirs (sinks): atmosphere, ocean sediments, soil (ammonia and nitrates), plants and animals • Human Impacts: • Runoff from fertilizers and decomposition (water, soil) • Burning fuel and fertilizers (atmosphere) • Remove from soils with agriculture and irrigation
Phosphorus Cycle • Circulates through water and soil, does not include the atmosphere • Very slow cycle. Component of nucleic acids and ATP/ADP, bones and teeth • Reservoirs (sinks): phosphate salts in rock and ocean sediments; plants and animals • Human Impacts: • Runoff from mining waste, sewage and fertilizer • Erosion of rock
Sulfur Cycle • Used to produce proteins • Stored in underground rocks and minerals, and sulfate salts in ocean sediments • Hydrogen sulfide gas released to atmosphere through volcanoes and decomposers • Reservoirs (sinks): atmosphere, plants, animals, rock and soils, ocean sediments • Human Impacts: • release sulfur dioxide through burning of fossil fuels and refining coal • Mining • Acid rain from fossil fuel burning