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ecological dictionary

N

National park

A territory protected for the preservation of its resources, plant and animal life, land, air, water and historical and cultural artifacts.

Natural equilibrium

The theory of ecological balance. A natural system in equilibrium will return to its stable state after it has been disturbed. Natural equilibrium therefore usually contains self-correcting and self-repairing mechanisms.

Natural resources

All environmental components, renewable or otherwise, that can be useful for humans.

Niche

A unique set of environmental conditions (physical, chemical and biological) under which a particular organism can exist.

Nicotine poisoning

Chronic intoxication produced by too much tobacco use, damaging the respiratory system and possibly contributing to the development of cancer.

Nitrate

A salt of nitric acid essential for the growth of plants. Large quantities of nitrate are added to crops to increase the output of harvests, in the form of animal manure and more commonly artificial fertilizers. Nitrate runoff from fertilized fields may cause exaggerated plant growth (eutrophication), and subsequent oxygen depletion in waterways.

Nitrite

A salt of nitrous acid, found naturally in the earth and also formed in the human intestine from nitrates by the action of bacteria. In nature it is part of the nitrogen cycle and is quickly transformed into nitrate, which is absorbed by plants. As nitrites react with hemoglobin (the red pigment of blood cells that carries oxygen) they can be detrimental to humans.

Non-renewable natural resources

Natural resources that take thousands or millions of years to reproduce, and are therefore depleted after consumption, e.g. petroleum and emeralds.

Nutrients

Chemical elements that are essential for life. Examples include carbon, oxygen, nitrogen, sulfur, phosphorous, magnesium and potassium. 

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