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lab le 9.- :.1 nea ~dels and co rte lotion toefftcle n[s for • annual p raduc[1 on item three pre tine pion[ cor_•s uni [!es (y) and roan annual produc tton for each of three se izcced co¢?erlson areas (x). Comps rison area Pcemi ne plan[ Linear Corte Lecion (x) eo¢uni ty (y) model toeftlcSznt (y-a+bx) (r) Sage-grass No. 3 Sage-grass y - 7.63 + 0.63x 1.00 Mountain shrub A y ~ 53.14 + 1.36x 0.97 Houn Lela shrub 8 y - 35.75 + 0.99x 0.98 Hountain shrub No. 2 Sage-grass y - -75.75 + O.SBx 1.00 Hountain shrub A y - -31.90 + 1.26x 0.98 Hountain shrub B y ~ -25.96 + 0.91x 0.98 Hountain shrub No. 3 Sage-grass y - -1.64 + 0.46x 0.99 Hountain shrub A y - 40.88 + 1.0Ix 0.99 Nountaln shrub B y ~ 26.92 + 0.73x 0.99 11980, 1981 and 1982 production data from a coal su rf ate mine in n orthwest Colorado. [tying to reduce of eliminate [hem. An operator may also be prevented from developing seasonal pasta relands on reclaimed rangelands because [he change would no[ represent pre mine conditions, even though the utility may be enhanced. The comparl son area concept of setting revege[a[!on success s[a nda rds is ~Y de ly used but etf 11 unproven. flit hin [he cons[ tai acs of current sampling technology and based on three yenta of data from a coal surface mine Sn northwest Colorado, both [he reference area and eon[iol area approaches of a con pa rison area ton rapt appear invalid. I[ Ss possible another approach, [he correlation a: ca approach, is usable. It is premature, however, to conclude this new approach is valid over time or for other s1[ea. Beteuse re vegetation success standards may be used 40-50 years, and because ve ge[a[ion potential may change over such a time pe rl od, the his[o tie record [ante pt may also be Snva lid. It in possible, ho~~eve r, [het an hi s[o rte record standard could be adjusted [o reflect changes that may influence ve GCta[ion poten[1a1. Use of Chia concept needs further study. An t<l stork record program will usually require spending pore money in [he early years of a prof ec[ than a cov- perison area program. This can na ke i[ a more coat ly program to Implement. The use of technical guf da nee doe ume n[s for setting re ve getat ion success standards has been limited because [eu such docu vz n[s axis[. More are needed in order [o se[ s[anda rda chat are not always based on imi toting [he premining tondi- C1ons. Several al to me tf ve concepts exist for set- [1ng revege[a[1on succ ass standards that may be appropriate in ce r[ain instances. Use of these or other al[e rnatives should be alloyed by regu- latory agencl es. eeca use of the unce mainly of the validity of the concepts used for setting re ve ge tattoo success s[an da rds, mine operators should preserve ae many options as pro c[Sca ble. Adequate da [:t for en historic record approach should be obtained even iE comparison areas are estab- lished. Rav da [a should hz preserved and should be in a form to allow estimates of ca trying capacity vhe re rangelands are involved. Records of pre d pi[a[1 on, [e ¢pe rotate and possibly soli moisture shou Ld be kept [o provide a ba sSs for adjusting an historic record s[anda rd. Preserv- ing options cY 11 be more costly Sn the sho r[ term, but nay be very important if [here is e future dis pu [? over a mul tl-million dollar bond release. IC Le critical that [he existing concepts for se [t ing re ve ge[a tl on success standards be thoroughly evaluated [o date rmine [heft va 11 d3[y owe rtlme and for dlffere n[ geographical loca- tions. Note owe r, modtffed or addl[f anal concepts arc needed to accovodatc land use and ve gcta[Son changes.. -i _ ~..