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precursors being big sage, and then serviceberry (Amelanchier alnifolia)and <br />chokecherry (Prunus virginiana). During the 35 year life of the Trapper mine, <br />• areas presently dominated by serviceberry and chokecherry can be expected to <br />give way to Gambel oak unless management controls are applied or the natural <br />vegetation potential shifts. Vegetation potential may also change over the <br />long term in response to climatic changes or the influence of grazing. This <br />may be represented by shifts in species composition and adjustments in cover, <br />production, and density - the same parameters to be used to evaluate <br />revegetation success. Such changes have, in fact, been documented by various <br />researchers (Hastings and Turner, 1966; Dury, 1966). <br />The obvious question is, how does one establish a revegetation standard <br />that remains valid for any given year regardless of annual variations and long <br />term trends of vegetation? The reference area concept, i.e. measuring and•then <br />Comparing vegetation on undisturbed sites to vegetation on reclaimed sites, <br />intuitively appears to offer the sort of self-adjusting standard that is <br />needed. This self-adjusting ability is an advantage not offered by the use of <br />an historical data base. <br />(• However, several problems occur with the application of the reference area <br />concept. First, no hard evidence has been presented that the vegetation on <br />reference areas will truly reflect the vegetation potential- of sites affected <br />by mining, had the mining not occurred. It is presumptious at this point to <br />assume in regulation that the relationship between the vegetation of any two <br />separate areas will remain constant and linear over extended or even short per- <br />iods of time. Further, reference areas are often hard to locate and manage. <br />To work, the concept requires that all vegetation types to be affected by min- <br />ing also occur outside but adjacent to the area to be disturbed. This is <br />necessary so that reference areas can be located outside the effects of mining <br />but on sites similar to those to be affected by mining. An operator must also <br />have or gain surface control of not only the reference areas, but the entire <br />management unit each reference area is a part of to ensure proper grazing <br />management and to protect the site from other kinds of disturbances. <br />-3- <br />m '1J 21982 <br />r <br />