biogeochemical cycles

importance of carbon

• found in all organic molecules which make up living organisms

• essential for photosynthesis and cell respiration

carbon reservoirs

• sedimentary rock

• atmosphere

• fossil fuels

• soil

• plants / animals

  • old trees are big sinks

carbon sources

• photosynthesis

• cell respiration

• ocean-atmosphere exchange

• decomposition

carbon short cycles

cycle #1

1. plants take in carbon dioxide and water and convert it into glucose and oxygen

2. some form of cellular respiration takes place, which converts the glucose and oxygen back into carbon dioxide and water

3. the carbon dioxide is returned to the atmosphere

cycle #2

1. carbon dioxide gets absorbed by waves in ocean water

2. the gas is trapped in air bubbles

3. carbon dioxide is dissolved into water

4. the water evaporates and returns to the atmosphere as carbon dioxide

carbon long cycle

carbon is stored in sedimentary rock, fossil fuels, soil, etc and held for thousands to millions of years

• humans burning fossil fuels = releases carbon that has been buried for an extremely long period of time

carbon anthropogenic disruptions

1. deforestation increases carbon dioxide levels and decreases photosynthesis rate

2. burning biomass increases carbon dioxide levels

3. burning fossil fuels increases carbon dioxide levels

nitrogen importance

• essential factor in DNA, RNA, and proteins

• chemically inert due to its triple bond and cannot be used by plants + cannot leave atmosphere without assistance

• limiting factor

nitrogen reservoirs

• atmosphere

• plants + animals

nitrogen sources

1. fixation - lightning / microbes in soil break the triple bond of N2 (atmospheric nitrogen) and convert it into NH3

2. ammonification - soil bacteria converts NH3 into NH4+

   1. some NH3 also enters soil by decay of organic matter (animal waste)

3. nitrification - soil bacteria converts NH4 to NO2 (nitrite) then NO3 (nitrate)

4. assimilation - NO3 is absorbed by plants through roots, then delivered to animals through plant consumption

5. denitrification - NO3 is converted back to N2 (atmospheric nitrogen)

nitrogen anthropogenic disruptions

• eutrophication - nitrogen-rich fertilizer and livestock waste runs into the ocean, causing the ocean to be overly enriched w/ nitrogen

• burning gasoline releases NOX, an ingredient for a pollutant called ozone

phosphorus importance

• essential factor in cell membranes, DNA, RNA, and proteins

• limiting factor

• no atmospheric form!!!!!!!

phosphorus reservoirs

• rocks

• soil / sediments

• animals

• plants

• shells / ocean sediments

phosphorus sources

• weathering + erosion

• plants absorbing phosphorus from underground

• animals eating plants

phosphorus anthropogenic disruptions

• eutrophication - synthetic fertilizer with phosphorus and nitrogen (both limiting factors) and livestock waste runs off into ocean; stimulates algae growth and ends up taking oxygen out of water which suffocates fish

• ex: gulf of america dead zones

water importance

necessary for life

water reservoirs

• oceans

• groundwater reserves

• atmosphere

• ice caps, snow, and glaciers

water sources

• precipitation

• evaporation

• infiltration - precipitation seeping into the ground

• transpiration - plants absorb water from soil and release it as water vapor

• fog drip - water vapor lands on foliage and drips to the ground

water anthropogenic disruptions

• rise in ocean levels due to higher temps

• intensified rain downfall

• increased evaporation due to higher temps

sulfur importance

determines the 3D folding patterns of proteins

sulfur reservoirs

• rocks

• soil

• atmosphere

• plants + animals

sulfur sources

• rock weathering

• volcanic activity

• geothermal vents

• decomposition of dead organisms

sulfur anthropogenic disruptions

burning of fossil fuels increases atmospheric sulfide and causes acid rain

nitrogen sources - fixation

1. fixation - lightning / microbes in soil break the triple bond of N2 (atmospheric nitrogen) and convert it into NH3

nitrogen sources - ammonification

1. ammonification - soil bacteria converts NH3 into NH4+

   1. some NH3 also enters soil by decay of organic matter (animal waste)

nitrogen sources - nitrification

1. nitrification - soil bacteria converts NH4 to NO2 (nitrite) then NO3 (nitrate)

nitrogen sources - assimilation

1. assimilation - NO3 is absorbed by plants through roots, then delivered to animals through plant consumption

nitrogen sources - denitrification

1. denitrification - NO3 is converted back to N2 (atmospheric nitrogen)