Biogeochemical Cycles

Transcription

1 Biogeochemical Cycles SB4b. Explain the flow of matter and energy through ecosystems by explaining the need for cycling of major nutrients (C, O, H, N, P).

2 Biogeochemical Cycles describe the flow of essential elements from the environment through living organisms and back into the environment.

3 Key Terms Reservoir where nutrient is stored Assimilation how nutrient is used Release how nutrient leaves living things

4 Hydrological Cycle 1. Reservoir oceans, air (as water vapor), groundwater, lakes and glaciers; 2. Assimilation plants absorb water from the ground, animals drink water or eat other organisms which are composed mostly of water. 3. Release plants transpire, animals breathe and expel liquid wastes.

5 Phases of Hydrological Cycle Evaporation process by which water changes from a liquid into an atmospheric gas Transpiration loss of water from a plant through its leaves Condensation process by which water changes from an atmospheric gas into a liquid Precipitation - rain, sleet, hail, snow and other forms of water falling from the sky

6 Hydrological Cycle

7 Carbon Cycle (carbon is required for building organic compounds) 1. Reservoir main: ocean, atmosphere (as CO 2 ), fossil fuels (oil, coal natural gas), 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 as wood and fossil fuels are burned.

8 Carbon-Oxygen Cycle Photosynthesis and respiration cycle Carbon and Oxygen atoms through an ecosystem Consumers die decomposers give off CO 2 Consumers die heat, pressure, time become fossil fuel (coal, oil and natural gas)

9 Carbon Cycle

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11 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, NO 2- or nitrite, NO 3- or nitrate) 2. Assimilation plants absorb nitrogen as either NH 4+ or as NO 3-, animals obtain nitrogen by eating plants and other animals. 3. Release Denitrifying bacteria convert NO 3- back to N 2 ; detrivorous bacteria convert organic compounds back to NH 4+ ; animals excrete NH 4+, urea, or uric acid.

12 Nitrogen Cycle N 2 in air ( 80% of the atmosphere) organisms cannot use Nitrogen fixing bacteria convert N 2 into a usable form plants use to grow LEGUMES (beans, alfalfa) nodules contain bacteria that can take atmospheric N 2 and convert it to usable nitrogen Animals obtain nitrogen from the plants they eat and return it to the soil in their stool.

13 Nitrogen Cycle

14 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 when they plants and other animals 3.Release plants and animals release phosphorus when they decompose; animals excrete phosphorus in their waste products *This is the only cycle that does NOT have an atmospheric component.

15 Phosphorus Cycle Erosion releases phosphorus from rocks into the surrounding soil Phosphate in soil can either: 1) Be used by plants 2) Leach (drain away from soil) into the water Animals receive nutrients by eating the plants Decomposers return phosphorus to the soil Phosphorus in water will be used by aquatic plant or settle in sediment that forms new rocks

16 Phosphorus Cycle

17 ATP Cycle ATP (Adenosine Triphosphate) = The only usable energy form. To release energy one of the bond between one of phosphate atoms is broken Phosphate is released Produces ADP (Adenosine Diphosphate) = the uncharged form A phosphate must be added back to the ADP molecule to recharge it and make a new ATP molecule

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