Range Condition

• Range condition describes the current state of the vegetation compared with that of the climax or original vegetation for the range site. Range condition is used to measure deterioration or improvement in the plant community.
• Four classes of range condition are used to express how much the composition of the present plant community has changed from that of the climax community. The four condition classes, based on the percentage of climax vegetation are:

Condition Class Percent of Climax Vegetation

Excellent	76-100%
Good	51-75%
Fair	26-50%
Poor	0-25%

• Changes in range condition occur mainly through prolonged, heavy grazing. A series of wet or dry years may also cause changes in range condition.

• Range condition classes are relative. If a range site is described as being in good condition, the description is relative to the kind and amount of native vegetation that particular site is capable of producing.

• To assist in determining range condition, plant species are grouped as decreasers, increasers, or invaders, based on their response to grazing pressure by cattle. Decreasers are species that decrease in relative abundance under continued heavy use. They are palatable and are dominant plant species in the climax community. Increasers are species that normally increase in relative abundance as the decreasers decline. They are commonly shorter, less productive species that are present in the climax community. These species initially increase under heavy use, but may later decrease if grazing pressure continues. Invaders are species that are not present in the climax community. They invade the site as grazing or disturbance reduces decreasers and increasers.

• Range condition classes indicate how far the vegetation has changed from the climax or original cover. Range condition rating is based on weight of vegetation, so knowledge of the vegetation and its reaction to grazing is essential.