biogeochemical cycles. elements describe the flow of elements from the environment through living...
TRANSCRIPT
describe the flow of elementselements from the
environment through living things and back to the
environment.
Biogeochemical Cycles
Reservoirsplaces (called reservoirs) where the elements are accumulated or held
AssimilationTransfer of elements from the abiotic into the biotic
ReleaseTransfer of elements from the biotic back into the abiotic
Biogeochemical Cycles
Hydrological CycleHydrological Cycle(water cycle)
Reservoirs
Open water - oceans, lakes, rivers……
Water vapor -clouds, fog
Groundwater
Glaciers, snow and ice
Hydrological CycleHydrological Cycle(water cycle)
Assimilationplants
– absorb water from the ground
animals – drink water– eat other organisms which are composed mostly
of water
Hydrological CycleHydrological Cycle(water cycle)
Release plants
– Transpiration from leaves of plants
animals – Breathing releases water vapor– Expel liquid wastes– Evaporation off the surface of the body
Carbon CycleCarbon Cycle(carbon is required for building organic compounds)
Reservoir
The atmosphere (as CO2)
Fossil fuels (oil, coal,…)
Organic materials (tissues of plants and animals).
Carbon CycleCarbon Cycle(carbon is required for building organic compounds)
Assimilation
plants
use CO2 in photosynthesis
animals consume plants or other animals made up of carbon compounds
Carbon CycleCarbon Cycle(carbon is required for building organic compounds)
Release
plants release CO2 during breathing and decomposition
animals release CO2 during breathing and decomposition
CO2 is released during combustion of fossil fuels and other materials
Nitrogen CycleNitrogen Cycle(Nitrogen is required for the manufacture of
amino acids and nucleic acids)
Reservoirs
In the atmosphere (as N2)
In the soil as
NH4+ or ammonium
NH3 or ammonia
N02- or nitrite
N03- or nitrate
Assimilation
plants can absorb either NH4+ or N03
-
animals obtain nitrogen by eating plants and other animals
Nitrogen CycleNitrogen Cycle(Nitrogen is required for the manufacture of
amino acids and nucleic acids)
The stages in the assimilation of nitrogen:
Nitrogen Fixation: Some bacteria turn N2 to NH4
+
Lightning and radiation turn N2 to N03-
Nitrification: Some bacteria turn NH4
+ to N02- then to N03
-
Nitrogen CycleNitrogen Cycle(Nitrogen is required for the manufacture of
amino acids and nucleic acids)
Release
Denitrifying bacteria change N03- back to N2
Animals excrete NH4+
or NH3 in their urine
Nitrogen CycleNitrogen Cycle(Nitrogen is required for the manufacture of
amino acids and nucleic acids)
Phosphorus CyclePhosphorus Cycle(Phosphorus is required for the manufacture
of ATP and all nucleic acids)
Reservoir sediment and rocks contain phosphorus. When
they erode, they transfer phosphorus into the water and soil
Phosphorus CyclePhosphorus Cycle(Phosphorus is required for the manufacture
of ATP and all nucleic acids)
Assimilation
plants absorb inorganic phosphate from the soil
animals obtain organic phosphorus when they eat plants or other animals
Phosphorus CyclePhosphorus Cycle(Phosphorus is required for the manufacture
of ATP and all nucleic acids)
Release plants release phosphorus when they decompose
animals release phosphorus when they decompose animals excrete phosphorus in their waste products