The harvesting of animals or cash crops for commercial reasons.

The means by which energy is cycled through the biosphere

Reduced by a degree or intensity, elimination of pollution.

Non-living thing. Usually refers to the physical and chemical components of an organism's environment. Also called inorganic

An environmental factor which is nonliving such as water, soil, temperature, sunlight

The process of absorbing or of being absorbed -- to incorporate or take up -- to take in.

Rain (and snow, fog, dust particles, etc.) containing acids that form in the atmosphere when sulfur dioxides and nitrogen oxides from industrial emissions and automobile exhaust combine with water.

Having the properties of an acid, or containing acid; having a pH below 7.0

Acute is a short, one time exposure while chronic is a continuous, low-level exposure.

To be accustomed to the natural factors that are in a given area and to be able to survive these factors, being either positive or negative.