Biological | Chemical | Geological

Biogeochemical Cycles are ecological limiting factors

biosphere ATP, molecule that holds energy for life in the phosphate bonds

"some of the bacterial fermenters also developed the ability to absorb nitrogen gas from the air and convert it into various organic compounds. To 'fix' nitrogen–in other words to capture nitrogen directly form the air–takes large amounts of energy and is a feat that even today can be performed only by a few special bacteria. Since nitrogen is an ingredient of the proteins in all cells, all living organisms today depend on NITROGEN-FIXING BACTERIA for their survival."

Fritjof Capra, The Web of Life, pp. 236-237.

Water enables life.



Slow, variable, & fast cycles.

H for HydrogenPotassiumCarbon Phosphate Sulfur Cobalt Manganese Magnesium Oxygen NitrogenSodium Calcium H for Hydrogen Radium Krypton Barium

Periodic Table of the Atomic Elements

The roles of recurrent nutrient-cycles in the ecological dynamics sustaining life: nitrogen, sulfur, and carbon.

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The transport and removal or deposition of vital atomic elements needed to understand the dynamic qualities of ecological systems is embodies in a study of nutrient cycles.

Biogeochemical cycles account for the characteristics, robustness and resilience of ecosystems to withstand stress, rapid change, or population explosions. Justus Liebig over 150 years ago defined a "law of the minimum," by which he understood that the material element, or nutrient, needed in only trace amounts – but necessary to the viability of production is the most serious limiting factor.
Carbon atoms arranged in a ball.

For example, plants cannot photosynthesize without magnesium in their chloroplasts. Magnesium is not needed in large amounts but is a significant limiting factor because of its functional necessity. For plant-life magnesium is an excellent example of the law of the minimum. This is particularly true in tropical climates where water and temperature conspire to increase the rate of evaporation and transpiration in plants.

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Combining parts of the terrain, ecology systematically examines biogeochemical functions sustaining life.
Air biosphere  
    The three terms rearranged spell L A W










Biogeochemical means that the biology of living creatures, the geological terrain and essential chemical elements are moved from the air, water, landscape and seas into and out of living parts of the world on a constant and recycling basis.


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Biological means produced by living things.

So many living beings thrive together that symbiosis is an important factor in life.
Fuel, food, fiber and forage material are all produced by bacteria, fungi, plants or animals.

Virus and an associated bacteria.


Bacteria sustains all other forms of life.


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Chemical refers to those compounds of an elemental character, referring to the trace matter, or nutrients that a living creature, or creatures sharing and ecosystem need to function properly.

Glucose molecule; sugar is made by plants and is food for other forms of life.

animationProteins are essential for all forms of life and are made of chains of amino acids.

nuclear Deoxyribonucleic acid or DNA – often shown as a double helix cartoon– is the heritable material of life.

nuclearCarbon atom cartoon; carbon is the elemental basis of life on Earth.


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means both the time and the property of belonging to the earth's processes even in the absence of living things, elements predate life on earth. These elements are iron, silica,or magnesium and compounds such as methane and ammonia.
 anim pool
group land
The study of rock layers is called stratigraphy. For billions of years the Earth was home to bacteria.

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Different conditions or states of matter on Earth:










"Water is the driver of life"
said Leonardo da Vinci.

Water is also the principle mover, together with the Earth's tectonic forces, of trace elements and nutrients through the air, onto the land, into rivers, and oceans and into the rocks of the planet. As the nutrients pass from one state and one place to another they are made available for living organisms. This availability is largely, but not always, the work of bacteria.


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Places on Earth globe

Air (atmospheric component) wind dispersal, precipitation and temperature transport.

Water (marine and aqueous component) current dispersal and removal by currents and evaporation.

Land (terrestrial component) evapotranspiration through vegetation, animal and bacteria transport.

Underground (subsurface component) animal and anaerobic bacteria transport.

Rocks (lithic component) tectonic (slow) and biological (less slow) transport.

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Slow, variable, and fast cycles are moved by radiation heating water and carrying these nutrients throughout ecosystems.


states of matter

The state of matter in which nutrients are moved by inorganic forces has an important influence on the availability of trace elements. Reservoirs or the total mass of these compounds on earth are characterized by either readily soluble and thus moving compounds as opposed to mostly insoluble and sluggish compounds. Slow cycles can also occur due to the number of states of matter that the compound element moves before it becomes available to bacteria.

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gases are most readily distributed from place to place.

Any atomic elements and compounds of hydrogen, oxygen, nitrogen, sulfur and carbon all have a gas phase.

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liquids are readily moved by gravity from sources to sinks.

The hydrogen and oxygen compound of water exists in each of these states on earth and the changes occur in its condition or arrangement of molecules due to changes in temperature. Normally a s gas at high (evaporation point: 162° F) temperatures, water will freeze into a solid at 32° F, or will remain liquid in the middle range of these temperatures, like other elements and compounds.

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solids are hard to transport from sinks where they accumulate.

Ice is a solid, but so are metals, minerals and crystals, the heaviest and often most massive of compounds and elements on earth. At high temperatures, such as in the core of the Earth, iron, normally a solid exists as a liquid. The viscous magma from volcanic explosions is an example of a super heated iron, nickel and mercury compound that is, at surface temperatures, a solid.

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C. Hopkins Cafe

Carbon dioxide compound.


Nutrients are those compounds or elements called trace elements, because they are so scarce and they are needed only in the least amount, for necessary functions of life in ecological systems to sustain itself and other forms of life.

states of matter

"…Carbon, the chemical backbone of life, combined rapidly with hydrogen, oxygen, nitrogen, sulfur, and phosphorus to generate an enormous variety of chemical compounds. Those six elements–C, H, O, N, S, P–are now the main chemical ingredients in al living organisms."

Fritjof Capra, The Web of Life, p. 235.


qualities versus quantities

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They come in two quantities based on how much of the compound is needed for living things to function in a healthy condition:

1. Major trace elements are: calcium, potassium, magnesium, phosphorus, sulfur, carbon, oxygen, sodium, and nitrogen

2. Minor trace elements are: copper, cobalt, manganese, molybdenum, boron, zinc, iodine, and iron.

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Nutrients exist with several qualities related to the frequency of their availability for living creatures as they cycle quickly, slowly and with volatility.


Fast cycling and readily available: oxygen, sodium and nitrogen,
nitrogen nitrogen cycle
Atomic element Roles of nitrogen in the land, air, and water. animated N, nitrogen cycle














Slow cycling and scarcely available: sulfur, calcium, potassium, magnesium, phosphorus, copper, cobalt, manganese, molybdenum, boron, zinc, iodine, and iron.


sulfur cycle
These are compounds often needed in the least amount and are examples of the law of the minimum.

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Variable cycling: carbon.  
carbon carbon dioxide

atomic structure

compound molecule

the biogeochemical cycle

Atoms Compounds Cycles

Carbon cycling in a forest

In the temperate rainforests of the Pacific rim carbon moves from the air into the ground an into cellulose due to photosynthesis.


A miraculous transformation, or as Oliver Sacks has suggested:

"It is impossible to imagine a world without photosynthesis . . . this most important life process."

The Earth's Green Mantle

More on life sciences

More on nutrients

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