Glossary of Environmental Science - N

N

• National Packaging Covenant - a self-regulatory agreement between packaging industries and government.
• natural- the existing air, water, land and energy resources from which all resources derive. Main functions include resource production (such as fish, timber or cereals), waste assimilation (such as CO₂ absorption, sewage decomposition), and life support services (UV protection, biodiversity, water cleansing, climate stability). The environmental services that must be maintained so that human development can be sustainable.
• natural capital - natural resources and ecological processes that are equivalent to financial capital.
• natural resources - naturally occurring substances that are considered valuable in their relatively unmodified (natural) form.
• natural selection - the process by which favorable heritable traits become more common in successive generations of a population of reproducing organisms, and unfavorable heritable traits become less common.
• neighbourhood environment improvement plan - plans developed by a local community including residents, special interest groups, local government, local industry and government agencies.
• nematocide – a chemical that kills nematodes.
• net primary production - the energy or biomass content of plant material that has accumulated in an ecosystem over a period of time through photosynthesis. It is the amount of energy left after subtracting the respiration of primary producers (mostly plants) from the total amount of solar energy that is fixed biologically; gross primary productivity minus respiratory losses (this is the carbon gain).
• nickel cadmium batteries - batteries typically used in appliances such as power tools and mobile phones. Cadmium is a heavy metal that poses risk to human and ecosystem health.
• noise pollution (environmental noise) - displeasing human or machine created sound that disrupts the activity or happiness of human or animal life.
• nonpoint source pollution - water pollution affecting a water body from diffuse sources, rather than a point source which discharges to a water body at a single location.
• no-till farming - considered a kind of conservation tillage system and is sometimes called zero tillage.
• non-ferrous metals - those metals that contain little or no iron, e.g. copper, brass and bronze.
• Non Government Organisation (NGO) - A not-for-profit or community based organization.
• nutrients – chemicals required for the growth of organisms. Phosphorus, nitrogen and potassium are major plant nutrients but there are also many trace elements, elements that are needed in small quantities for the growing and developing of animal and plant life.