BIOSPHERE CYCLE - HYDROLOGIC or WATER CYCLE

HYDROLOGIC OR WATERCYCLE 1.     The Hydrologic or Water cycle is probably the most important of all the natural cycles in the biosphere. 2.     More than 97% of water in the biosphere is found in the oceans, the remaining 3% is found on the continents and in the atmosphere. 3.     But more than 70% of this latter portion is locked in glaciers and icecaps. 4.  ...

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NUTRIENT CYCLE - SULPHUR CYCLE or S CYCLE

SULPHUR CYCLE 1.     Sulphur, like nitrogen, is a basic constituent of proteins in plants and animals. 2.   It is found in the biosphere in a wide variety of forms. Sulphur dioxide (SO2) and Hydrogen Sulphide (H2S) are the important gaseous forms, and the sulphate ion (SO42-) is the common form found in water and soil. The distribution of sulphur in the environment ia as shown in figure. 3.  Sulphate...

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NUTRIENT CYCLE - NITROGEN CYCLE OR N CYCLE

NITROGEN CYCLE 1.  Nitrogen in its gaseous form constitutes 79 percent of the atmosphere. However, it cannot be used directly by most forms of life.  2.    It must be first “ fixed ” before it can be utilised by plants and animals. By fixation, nitrogen is converted into it’s chemical compounds, largely nitrates (NO3) and ammonia (NH3).  3.  The fixation of nitrogen takes...

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NUTRIENT CYCLE - CARBON CYCLE or C CYCLE

CARBON CYCLE 1.     The Biosphere contains a complex mixture of carbon compounds in a dynamic equilibrium of Formation, Transformation And Decomposition.  2.     The producers, through the process of Photosynthesis, reduce the carbon dioxide from the atmosphere to organic carbon. 3.     This then passes through consumers and decomposers, then usually re-enters...

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