Hydrological Cycle Precipitation to land Runoff Percolation Groundwater movement Ocean storage Evaporation from ocean Precipitation to ocean Surface runoff (rapid) Transpiration from plants Evaporation from land
Hydrological Cycle Hydrological Cycle (water cycle) 1. Reservoir – oceans, air (as water vapor), groundwater, lakes and glaciers; evaporation, wind and precipitation (rain) move water from oceans to land 2. Release – plants transpire, animals breathe and expel liquid wastes
Burning fossil fuels Atmosphere Carbon Dioxide Excahnge Ocean surface Deep circulation Deep ocean Sinking sediment phytoplankton Rock formation Weathering and Runoff Sediments and sedimentary rock Coal, oil, gas Soil and Organic matter vegetation decay respiration burning photosynthesis
Carbon Cycle 1.Reservoir – atmosphere (as CO 2 ), fossil fuels (oil, coal), 2. Assimilation – plants use CO 2 in photosynthesis; animals consume plants. 3. Release – plants and animals release CO 2 through respiration and decomposition; CO 2 is released; wood and fossil fuels are burned.
Nitrogen Cycle Nitrogen Cycle (Nitrogen is required for the manufacture of amino acids and nucleic acids) 1. Reservoir – atmosphere (as N 2 ); soil (as NH 4 + or ammonium, NH 3 or ammonia, N0 2 - or nitrite, N0 3 - or nitrate
2. Assimilation – plants absorb nitrogen as either NH 4 + or as N0 3 -, animals obtain nitrogen by eating plants and other animals. The stages in the assimilation of nitrogen are as follows: Nitrogen Fixation: N 2 to NH 4 + by nitrogen-fixing bacteria (prokaryotes in the soil and root nodules), N 2 to N0 3 - by lightning. Nitrification: NH 4 + to N0 2 - and N0 2 - to N0 3 - by various nitrifying bacteria. Nitrogen Cycle
3. Release – Denitrifying bacteria convert N0 3 - back to N 2 (denitrification); detrivorous bacteria convert organic compounds back to NH 4 + (ammonification); animals excrete NH 4 + (or NH 3 ) urea, or uric acid. Nitrogen Cycle
Phosphorus Cycle Phosphorus Cycle (Phosphorus is required for the manufacture of ATP and all nucleic acids) 1. Reservoir – erosion transfers phosphorus to water and soil; sediments and rocks that accumulate on ocean floors return to the surface as a result of uplifting by geological processes 2. Assimilation – plants absorb inorganic PO 4 3- (phosphate) from soils; animals obtain organic phosphorus from plants and other animals 3. Release – plants and animals release phosphorus when they decompose; animals excrete phosphorus in their waste products