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traduced sµt'cies on reclaimed mined land. produced beef gams and ummal perf~r- mance equal tour erecter than cool-season introduced pastures nr native pastures nn nonmined land grazed early in the season. These reclaimed postures appeared to be adoptable to a complementary' grazing sys- tem m which hi¢h-prnducin¢, cool-season introduced species are grazed early in spnn¢ followed by native species that pro- vide better summer and fall grazing. This practice is recommended for nonmined grazing land and reportedly has potential Eor mined land 11). Vc¢etatfce rompasrtinn. Lou'-growing blue grama nr sedges (Cares sp.) com- prised 58 percent of the native pastures. classified in good range condition (Table 3). Reseeded_ mine land seas composed of fall-growing species, including 63 to 68 `percent smooth 'bromegrass and alfalfa. Differences in crazing intensitc over the ,precedm¢ 4 years produced some differ- ences in composition, but four seeded spe- cies persisted on the reclaimed land. Sweetcloser. because of its biennial growth habit, depends upon favorable climatic conditions in spring to produce new seed- ings. it therefore caries widely in abun- dancefrom year to year on mined and non- mined cress. Principal tall-growing species on the range sites were green needlegrass (Slips ciridu/nl, needle-and-thread (Slips com- atal, and western svheat¢rass (Agropgron snot/iii). They made up 29 percent and l9 percent of the composition on sites 1 and li, respectively'. Site l contained 3 percent and site 11 6 percent of fringed sa¢e (Artenri.sia frid;;ido). generally considered an undesir- able range species. The remainder of the native community included Id other spe- cies. These represented 11 percent and 17 percent of the live plant composition on sites I and lI. respectively. ' Dicersin~ in species compostion is often suggested as a criterion Eur determining iE a site has been successfully reclaimed. \Ve ' identified at least _'0 different plant species on the nauce range sites but Dole eight on the reclaimed area. The yytere much more di raPn wecies ~~os>y,.m~,,,; - however. only jyytryiyfylNaiG'{'ylt".~~, percent of the lire plant composition on curl `n -- '~~~rr~+„n sue 11 This situa- ~~ hon a true on aunt native ranges. In this light, perhaps sve should critically question whether diyersnc aught to remain a major criterion for determining successful recla- mation. Cnuuulrocer. Groundcover is impor- tant in precentinq sod losses from both u d[er and wind tin reclwmed as well os nonmined land. Properly managed native Table 4. Percentages of live plants. litter, and bare soil on reclaimed mined land and native rangeland sites, September 1979. Pasture and Grazrng Lrve + Intensrly Lrve Lifter Bare Litter Percent basal hits Reclaimed Heavy t0 b' S2 a 38 a 62 c Moderate 1Z b 69 be t9 b 81 b Light 16 b 77 ab 7 c 93 a Ungrazed t3 b 85 a 2 c 90 a Native Sitel 30a 63cd 7c 93a Site II 36 a 55 de 9 c 91 a Reclaimed - Percent foliage hits - Heavy a0 c 34 be 26 a 74 b Moderate 4a c 46 ab 10 b 90 a Light 48 c 50 a 2 b 98 a Ungrazed 50 be 49 a 1 b 99 a Native Site I 72 a 26 c 2 b 98 a Site II 66 ab 30 c 4 b 96 a 'Values In columns followed by same letter are not significantly different at .OS level accortlung to 0uncan's multiple range test. Table 6. Soil loss in tons per acre as predicted by tha universal soil loss egos. lion, RKLS' equals 58 tons per acre per year and cover factor computed by point Irame estimates of cover on reclaimed and native pastures. Soil Loss (f/a/ Pasture and Basal Hits Foliage Hits Grazrng Live+ Live+ Intensrly Live Lrtfer Live Litter Reclaimed Heavy 16.8 4.2 5.8 1.6 Moderate 15.7 1.3 4.8 0.4 Light 13.6 0.2 4.3 0.1 Ungrazetl 15.7 0.1 4.1 0.1 Native Site I 8.2 0.2 1.6 0.1 Site II 6.7 0.2 2.2 0.2 •RKLS are those factors of the universal sod loss equation that estimate the loss occurring under continuous tallow; R is rainfall and runoff; K is soil erodibility; L:5 slope length; antl S is slope steepness. rangeland should have adequate ground- cocer to protect the soil. Groundcover on a reclaimed site then, if it equals or exceeds that tin native rangeland, should be a good guideline fur evaluating land reclaimed as part of a managed grazing system in the Northern Plains. However, mismana¢ed native range may have inadequate cover or vegetation containin¢ a hi¢h percentage of low-growing, low-producing species. In this situation, use of native range as a ref- erence is a poor guideline. in our shidc. lice plant cover svgs signif- icantly greater on native sites. and litter cover seas significantly greater tin Un- grazed ur lightk grazed reclaimed pastures jTable dl. \lore bare soil was exposed nn moderately and heacilc grazed reclaimed pastures. The universal soil Ims equation IGSLE'; i.1 can help determine the adequacs of sus er on reclaimed land. The percentage of canopy cover is defined us the percent- age uF the field area that could not be tut bs' vertically falling raindrops because of cunopc interception (~. The first contact a point frame makes with live tissue or litter best simulates a vertically falling raindrop. Leases and branches that do not directly contact the soil nonetheless reduce rainfall energy by intercepting falling raindrops. Residue mulches and stems from close- &rowing vegetation are also effective coyer (~. Both the live plant and the litter thus should be considered in cover estimates. ,One study (3) of runoff and erosion on mined sites in North Dakota produced fac- tors fur adjusting values used in the USLE. Using these adjusted values, sve predicted, with the USLE. that an absence of cover on our reclaimed site svnuld result in an annual soil loss.of 53 tons per acre. Table 5 presents our soil loss predictions for re- claimed and native sites with cover as esti- mated by point frames. Acceptable soil losses range from ° to 5 tons per acre per year (7. Our measure- ments of live plant cover measured by basal hits produced an unacceptable soil loss on all sites. in contzast, our cover mea- surements based nn foliage hits resulted in tolerable soil loss predictions tin the native sites and on ail reclaimed pastures except those heavih' grazed. Our foliage-hit esti- mates of live tissue plus litter cover indi- cated adequate cover on aB sites. Adequate cover can be defined in differ- ent sva}'s, dependin¢ upon the scoop}. measurements and characteristics consid- ered. Low-growing, dense, and low-pro- ducinq blue grama or sedges comprised the highest percentage of live plant cover tin the native sites. The xdvanra¢e of losc- growing species is their ability to svi[h- stand heavy grazing and protect against erosion. Tall-growing species. yvhich dom- inated the reclaimed site, produced more forage but had less lice basal area. H~w- ever. without grazing or with light graz- ing, the canopy of living and residual ma- terial on reclaimed sites was appxrenth• equal to that u[ the native sites. Even un- der the heave grazing regime tested, pre- dicted soil loss using the coyer factor c~m- puted from foliage hits of live plants plus litter was L8 tons per acre per }'ear. This is within published limits from the stand- point of maintaining soil pmducticiq•. If proper grazing management provides greater forage production Ernm taller growing species and soil fusses remain tol- erable, are nut tall-growing plant species as acceptable as low-growing species even January-February 1981 43