Mineral cycles (Biogeochemical cycles)

Look at the above Figure before examining some individual cycle!!!
Most nutrients accumulate in 4 reservoirs, each of which is defined by two characteristics:
- Whether the nutrients contain organics or inorganics
- Whether or not the nutrients are directly available for use by organisms
The first compartment of organic materials is composed of living organisms themselves and detritus (readily available nutrients)
The second one is fossilized deposit of once living organisms (coal, oil, peat that cannot be assimilated directly)
Nutrients also occur in two inorganic compartments (one are available for use and the other are not)


Introduction
– As discussed previously that most of the chemical energy disappear/lost at each trophic level
– However, the energy stored as biomass at each trophic level is not lost
– This biomass actually consists of elements that will undergo cycles in the ecosystem
– Life on earth therefore depend on recycling of essential chemical elements
– This cycle also occurs even while an individual organism alive.
– Example: nutrients are absorbed and the wastes are released, after the nutrients are processed in their body
– All materials including living organisms are composed by the smallest unit of elements called atom
– Especially for living organisms, when they die, all of these element will return as simpler compound to atmosphere, water, or soil through the action of decomposers
– The products of decomposition (inorganic nutrients) can be used by plants or other autotroph to build new organic matters.
– Because this nutrient cycles involves complex biotic and abiotic components in the ecosystem, they then are called Biogeochemical cycles
– Look at the above Figure before examining some individual cycle!!!
Most nutrients accumulate in 4 reservoirs, each of which is defined by two characteristics:
Whether the nutrients contain organics or inorganics
Whether or not the nutrients are directly available for use by organisms
The first compartment of organic materials is composed of living organisms themselves and detritus (readily available nutrients)
The second one is fossilized deposit of once living organisms (coal, oil, peat that cannot be assimilated directly)
Nutrients also occur in two inorganic compartments (one are available for use and the other are not)
In this lesson we will study the water cycle and three important element cycles (Carbon, Nitrogen, and phosphorous cycles)
Bear in mind that chemical cycle in the ecosystem depends on both biological and geological processes