The Cycling of Matter in Ecosystems
Everest University Online
Summarize man’s impact on the carbon, phosphorus, and nitrogen.
* Discuss how humans impact each cycle.
* Give specific examples of each cycle and how humans impact these cycles.
The Carbon Cycle:
Reservoir of carbon dioxide (CO2 molecules present in the air). Using photosynthesis and further metabolism, carbon atoms, from CO2 these carbon atoms of the organic molecules make up the plant’s body. The carbon atoms are then eaten and become part of the issues of all other organisms in the ecosystem. Half is respired by plants and animals (60 Gt/yr), and the other half is deposited to the soil (a large reservoir) in the form of detritus (dead plant animal matter – conversion organic deposits to coal, oil, gas and tar sands (Fossil fuel 4,130 Gt) (2,500 Gt). The organisms in the soil eat dead matter and return more carbon to the atmosphere as CO2.
In the oceans the cycle changes CO2, (Ocean absorption of Co2 92.3 Gt/yr) (Ocean release of CO2 60 Gt/yr) it is removed by photosynthesis by phytoplankton and macroalgae from huge pool of inorganic carbonates in seawater. Feeding moves the organic carbon through marine food webs through means of physical and chemical processes the biota returns the CO2 to the inorganic carbon compounds in solutions (2500 Gt).
Two other processes other than the transfer of carbon among producers, consumers, and organisms eating dead material are also significant factors. The diffusion exchange between the atmosphere (765Gt (+3.3 Gt/yr) and the ocean (2500 Gt) and the combustion (6.6 Gt/yr) are part of adding carbon atoms back into the atmosphere.
The carbon atom cycles from the atmosphere through one or more living things and back to the atmosphere about every six years because the total carbon dioxide in the atmosphere is about 76.5 Gt and the photosynthesis in terrestrial ecosystems remove 120 Gt/year.