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1 U.S, DEPARTMENT OF AGRICULTURE ~ • PAGE 2 OF 2 NATURALrRESUURCES CONSERVATION SERVICE 01/27/98 Endnote -- RANGELAND PRODUCTIVITY AND CNRACTERISTIC PLRNT COMMUNITIES In areas that have sieilar clieate and topography, differences in the kind and mount of vegetation produced on rangeland are closely related to the kind of soil. Effective eanageeent is based on the relationship between the soils and vegetation and water. This report shows, for each soil, the range site; the total annual production of vegetation in favorable, noreal, and unfavorable years; the characteristic vegetation; and the average percentage of each species. Only those sails that are used as rangeland or are suited to use as rangeland are listed. An explanation of the coluen headings in this report follows. RRRGE SITE is a distinctive kind of rangeland that produces a characteristic natural plant coeeunity that differs froe natural plant coeeunities on other range sites in kind, aeount and proportion of range plants. The relationship betweeen soils and vegetation was ascertained during this survey; thus, range sites generally can be detereined directly froe the soil ea p. Soil properties that affect eaisture supply and plant nutrients have the greatest influence on the productivity of range plants. Sail reaction, salt content, and a seasonal high water table are also ieportant. TOTAL PRODUCTION is the aeount of vegetation that can be expected to grow annually on well eanaged rangeland that is supporting the potential natural plant coeeunity. It includes all vegetation, whether or not it is palatable to grazing anieals. It includes the current year's growth of leaves, twigs, and fruits of woody plants. It does not include the increase in stew diaeeter of trees and shrubs. It is expressed in pounds Der acre of air-dry vegetation for favorable, noreal, and unfavorable years. In a favorable year, the aeount and distribution of precipitation and the teeperatures wake growing conditions substantially better than average. In a noreal year, growing conditions are about average. In an unfavorable year, growing conditions are well below average, generally because of low available soil eoisture. Dry weight is the total annual yield Der acre of air-dry vegetation. Yields are adjusted to a coeeon percent of air-dry eeisture content. the relationship of green weight to air-dry weight varies according to such factors as exposure, aeount of shade, recent rains, and unseasonable dry periods. CHARACTERISTIC VEGETATION The grasses, (orbs, and shrubs that wake up cost of the potential natural plant coeeunity on each soil is listed by coeeon nave. Under COMPOSITION the expected percentage of the total annual production is given for each species caking up the characteristic vegetation. The aeount that can be used as forage depends on the kinds of grazing anieals and on the grating season. Range eanageeent requires a knowledge of the kinds of soil and of the potential natural plant coeeunity. It also requires an evaluation of the present range condition. Range condition is detereined by coeparing the present plant coeeunity with the potential natural plant coeeunity on a particular range site. The core closely the existing coeeunity reseebles the potential coeeunity, the better the range condition. Range condition is an ecological rating only. The objective in range eanageeent is to control grazing so that the Dlants growing on a site are about the save fn kind and aeount as the potential natural plant coeeunity for that site. Such eanageeent generally results in the optieue production of vegetation, control of undesirable brush species, conservation of water, and control of erasion. Soeetiees, however, a range condition soeewhat below the potential Beets grating needs, Drovides wildlife habitat, and protects soil and water resources. C ,X b1-1 A rr E-'