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S. DEF.4RTMENT OF AGRIi'ULTOF.E iUIL L'VNSERVATION SERVICE .r, ? uF 1 OI/)/96 Endnote -- RANGELAND PRODUCTIVITY AND CNRACTERISTIC PLANT COMNUNITfES In areas that have similar climate and topography, differencesl,in the kind and amount of vegetation produced on rangeland are closely related to the kind of soil. Effective lanmgement 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, normal, and unfavorable years; the characteristic uegelstion; and the average percentage of each species. Only those sails that are used es rangeland or are suited to use as rangeland ere listed• An explanation of the column headings im this report tollows• MANGE SITE is a distinctive kind of rangeland that produces a characteristic natural plan) community that differs from natural Plant communities on other range sites in kind, anounl end proportion of range plants. 1'he relationship betveeen soils and vegetation was ascertained during this survey; thus, range sites generally ran be determined directly from the soil map. Soil properties that affect moisture supply and plant nutrients leave the greatest influence on the productivity of range plants. Sail reaction, salt content, and a seasonal high water table are also important. TOTAL PRODUCTION is the amount of vegetation that can be expected to grow annually on well managed rangeland Ihat is supporting the potential natural plant community. It includes ell vegetation, whether or not it is palatable to grazing animals. II includes the current year's growth mf leaves, twigs, and fruits of woody plants. It does not include the increase in stem diameter of trees end shrubs. It is expressed in pounds per acre of air-dry vegetation for favorable, normal, and unfavorable years. In a favorable year, the amount end distribution of precipitation and the temperatures make growing conditions substantially better than average. In n normal year, growing conditions ere about average. In en unfavorable year, growing conditions are well below average, generally because of lov available soil moisture. Ory weight is the total annual yield per acre of air-dry vegetation. Yields are adjusted to a cosmos percent of air-dry moisture content. The relationship mi green weight to air-dry night varies according to such factors es Exposure, amount of shade, recent rains, and unseasonable dry periods. CHARACTERISTIC VEGETATION The grasses, (orbs, and shrubs that Hake up post of the potential natural plant community on each soil is listed by common name. Under COMPOSITION the expected percentage mf the total annual production is given for each species asking up the characteristic vegetation. The amount that can be used as forage depends on the kinds of gracing animals and on the grazing season. Range management requires a knowledge of the kinds of soil end of the potential natural plant community. Il also requires en evaluation of the present range condition. Range condition is determined by cmmparing the present plant community with [he potential natural plant community on a particular range site. The more closely the existing community resembles the potential community, the better the range cmndilimn. Range condition is an ecological rating only. The objective in range management is to control grazing so that the plants growing an a site ere about the same in kind and amount es the potential natural plant community for that site. Such management generally results in the optimum production of uegelstion, control of undesirable brush species, conservation of water, and control of erosion. Sometimes, however, a range condition somewhat below the potential meets grazing needs, provides wildlife habitat, and protects soil and water resources.