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L ble 3.-~•:a fur ion of [he cons is eenev In the :Lang h.t ps between control areas and affee red areas ovar [nree wears ue Lng cF.u ._m La¢ Depa::xevc ox Z~avLronnen[a1 Oua LLCv (1981) hvpucnescs res to nz proredura far shruh la ads.` She data are .rom a coal v:rf ace nine is norc rwesc Colu rado ^nd ref lee produc[ior. of he r6aceaus planes. Year used 'tear Flanc co~unicy - for used lase line for test Sa_e-crass Moun[atn-shrub 1980 1981 x2 x z.8,fs_ + e-' VV ~2 x 16.13 - 18.41 + 0.85 • 1.37 + 10.19 1982 1981 - 1.72 <0 Conclusion: Failed [o meet standard 1 i - x + z 8 sx2 + sX ) 0 Lndi rates success The use of the his [orlc record concept dl sp enses with [he problem of findinc suitable comparison areas an operator can control and chat von'[ interfere :+i th einin¢. I[ necessitates, however, obtaining adeq uace information from each plan[ coc~u ni[y bet ore [he ccm_nunity is disturbed by mining. In some instances, this cuy no[ be possible to do, pa r[icularly if seven or more years of base line'da to are needed as !s re qut red Sn New Me xito. Further, if the range condition ie no[ accep to b'_e, the baseline data will not reflect the fu 11 land capa bi li[y. there Ss also a question of how [o conpare a reclaimed area agai nsc the standard in any gi van year. Values obtained froe a re claf ned area in a poor or drou thy year .:ay 6e vary diffe re n[ from [he historical va'_ce. A Simi lac sit ua [ion is likely Sf success is [e sted dart aG a very favor- able year. where the standard is escabLished from years when the effective prec ipi cation is near or greater Chan the ann uaL and nunchLy aver- age as in Utah, it is likely [ha[ =any years will be unsul[a ble for tesctr.g re c=_•~e to Lion suc- eess. A possible solu[i on [u t~^is is [o pro- bThe Ocah guide lines ~ree ulra us!ng data [o Be[ [he h1s[orl tai re to rd standard [rom a wear when [he eifec cl :e annual p: =_tLpitation ? ?OR of [he 10 year awe rare. "cffectLvr_ pro ci pi ration" Ss that occurrlny, iron Octc Err 1 01 chc pavlous year [o the end of [he aor.th prior co sacpling. The last moo;h bcf ore sa r:p LlnG mnsr also re ce i•:e 90Y of [he f0 yea: avc ra re for that none h. (L4 ah Dlvl slon of 011, Cas anJ Nin inh, 1931) z2 - x + z 8 s% + s2 2 x 55.53 - 62.97 + 0.84 23.93 + 54.15 - 0.02 <0 Conclusion: Failed to meet standard vide for an adjus[re nt in the standard Gised on the pre cipicact on received prior to data collec- tion for testing success. 41ghr and flanks (1981), For exanp le, developed a model from stud- ies in Hon Lana and 7o rch Ca kola chat pa[lsfac- torily predicted nac Lve grassland production from field measured soil wale r. A similar approach might be used a[ a mine site co adjust an historic record standard to more area ra [ely represent current year conditions. A disad van[a ge to the historic record con- cept is [hat i[ requires all the ve zetaeion data [o be colic c. ed using the same sampling mechodol- ogy. The procedures used ii the iirsc year of baseline data tot le ct ion teed [o ba used consls- [ently [h rouohout [.`.e .espo ns ibi Li [y period. More eff tricot or i.pnved methods of data col- lection prot~a bly ccu ld no[ be adopted. Cost Ccm pa rlsons.--`.: ~~ conga red [hc life of pro- jecc cos [s for usi ^,; :he historic record con cep[ against these Eor usC~r the con p., rf son area con- cept. These cos[ rr.r. r.:[tsor.s are based on actual 1980 ba self ne :'e Beta :or. su: ve ys in sa u[h ce n[ral Uteh. For [he pa r: ct•:'.ar project ••va lua red, the area Co be distu rb,••! ."•uals 10,50^ acres. The mine has a protc rte' 3i-year life M;;inn ing fn 1985 and end Ln,; in ::: ?. 8Lx diffc rent vcye[a- [lon cocruni ties _.lL hr affected by alning ac[lvi ties and ago rer.!ra to ly JUO at res wi L1 bu reve ge[aced each year :ocaencl ng Sn 193+. The actual sa-n'.:n- aas Jone for a,reEe rence area prop ra m. Cusv ve re rato rded for each vege[a[lon communtt^ far sampl Lug the preminc - 5- - - g--..