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Biogeochemical Cycles. APES Fall 2013. Inorganic and Organic Chemical Cycles: Key ideas: Cycles are driven by the sun’s energy The importance of “storage”. Simplified Carbon Cycle Key ideas: Carbon sinks, photosynthesis, cellular respiration, global climate change. Carbon Sources:.
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Biogeochemical Cycles APES Fall 2013
Inorganic and Organic Chemical Cycles: Key ideas: Cycles are driven by the sun’s energy The importance of “storage”
Simplified Carbon CycleKey ideas:Carbon sinks, photosynthesis, cellular respiration, global climate change
Carbon Sources: Burning Tropical Forests Rising Atmospheric CO2, 1970-1996
The Nitrogen CycleKey ideas:Bacteria….Forms and Availability of Nitrogen: NO3 vs NO2 vs NH3
Nitrogen Fixing Bacteria • Soy beans • Peas • String beans • Clover • Alfalfa
Global change in reactive nitrogen from burning fossil fuels, agriculture and other human activities Human based sources of nitrogen Change in agricultural fertilizer use, 1973-2000
The Phosphorous Cycle Key ideas: rocks and birds…
Micro-nutrients:Cycles for trace minerals and micro-nutrients (Between 0.2 and 1% of organic mass) • Sulfur • Magnesium • Cesium • Aluminum • Others?
Key concept: Limiting Nutrients Example: a farmers field in New York State The least available factor (e.g. potassium) limits the overall productivity of the field
Limiting nutrients, cont.Changes in N and P levels in runoff to streams due to the clearing of Amazonian rainforestSource: http://ecosystems.mbl.edu/staffweb/ldeegan/brazil.html