most often found as small stands extending from the 

 brow of the slope (where it grades to STICOM - 

 BOUGRA- CARFIL of benches) to mid-slope and is 

 occasionally weakly represented fiirther downslope. 

 Total vegetation cover is low, seldom exceeding 25-40 

 % and concomitantly the amount of base soil and rock 

 often exceeds 85 %. We speculate that these sites differ 

 from other associations strongly associated with sandy 

 sites (e.g. GALLON - GARFIL) by having more 

 exposed rock and gravel. Fragrant sumac (Rhus 

 aromatica) shares dominance of the shrub layer with 

 yucca (Yucca glauca) , and their relative proportions 

 shifting with no obvious environmental correlates. The 

 graminoid component is usually dominated by low 

 coverages (not exceeding 25 %) of bluebunch 

 wheatgrass (Pseudoroegneria spicata) and cotisiderably 

 lesser amounts of grasses associated with sandy soils like 

 indian ricegrass (Oryzopsis hymenoides) , little bluestem 

 (Schizachyrium scoparium) , and prairie sandreed 

 (Calamovilfa longifolia). Along with the widespread 

 rangeland forbs such as scarlet gaura (Gaura cocdrda) 

 and scarlet globemallow (Sphaeralcea cocdnea), occur 

 species that are restricted to sandy sites like green 

 milkweed (Asclepias viridiflora) , prairie spiderwort 

 (Tradescantia occidemalis) and nodding wild buckwheat 

 (Eriogonum cemuum). [Plot NHMTGR97SG00041 



Juruperus scopubrum I ?seudiyroegneria spicata Woodland 



UUNSGO/PSESPI] 



Rocky Mountain juniper / bluebunch wheatgrass 



woodland 



This woodland occurs in small patches on moderate to 

 steep northwest- to northeast-facing slopes from the 

 bottom of ravine slopes to midslope, with soils derived 

 from sandstone or interbeddings of sandstone and 

 shale/mudstone. Some outcrops test positive for 

 calcium carbonate. Generally more than 70% of the 

 surface is exposed as soil and rock. These slopes are 

 moderately to highly erosive. Short-statured (less than 

 8-9 ft.) Rocky Mountain juniper (Junipems scopuhmm) 

 dominates the tree layer and generally its cover exceeds 

 50 %, making it difficult to traverse stands. Though 

 representing some of the more mesic habitat in the 

 RNA, these are still stressful sites with depauperate 

 undergrowth. Bluebunch wheatgrass (Pseudoroegneria 

 spicata) and field milkvetch (Astragalus agrestis) are the 

 only forbs occurring in greater than trace amounts. 

 This association is singular for the occurrence of certain 

 forbs, including false starry Solomon's seal (Smiladna 

 stellata), Missouri goldenrod (Solidago missouriensis) , 

 and harebell (Campanula rotundifolia) . 



There is not a discrete pine woodland type present in 

 the RNA, though pine trees are scattered across the 

 juniper woodland. Ponderosa pine (Pinus ponderosa) is 

 widespread, but there are no areas where it is common 

 or dominant, as evaluated in studying aerial photos and 

 visiting areas of highest tree density on foot. All 

 probable locations were considered, such as north- 

 facing slopes that might have calcareous outcrops, 

 attempting to locate the limber pine (Pinus flexilis). We 

 found only P. ponderosa, though the search was not 

 exhaustive. Finding P. flexilis is plausible in light of its 

 presence in the Hell Greek State Park to the west on 

 Fort Peck Reservoir, and the Terry Badlands to the 

 southeast. Its presence here would signify an 

 intermediate location between other outlying stands; 

 however, failure to find it here does not diminish the 

 status of this RNA. [Plot NHMTEGGR97SG0003J 



C/irysot/iamnus ruiuseosm I Eriogonum pauciflorum 



Sparse Vegetation 



[GHRNAU/ERIPAU] 



common rabbitbnish / few-flowered wild buckwheat 



barrens 



This small and localized community occurs on steep, 

 south-facing outcrop slopes at the bottom of the ravine, 

 representing a stressful and unique envirormient. Soils 

 exhibit salt efflorescence. Slopes show signs of sheet 

 and gullying erosion, with over 90% of the surface 

 made up of exposed soil. A similar vegetation 

 association has been described by Branson et al. (1970) 

 in Valley County and by Vanderhorst et al. (1998) for 

 Garter Gounty; both of their studies indicated acid 

 shales as the determinant of the unusual and 

 depauperate vegetation. The examples from the 

 literature occurred on gently rolling terrain whereas 

 this type was only represented on steep slopes on the 

 RNA. Sites are species poor (<20 species) and total 

 vegetation canopy cover does not exceed 30% with 

 dominance shared by common rabbitbrush 

 (Chrysothamnus nauseosus), few-flowered wild 

 buckwheat (Eriogonum pauciflorum), and bluebunch 

 wheatgrass (Pseudoroegneria spicata). 

 [PlotNHMTEGGR97BH0001] [Plot 

 NHMTEGGR97BH0002] 



]ur\^rus horizontalis I Pseudoroegneria spicata Shrubland 



QUNHOR/PSESPI] 



creeping juniper / bluebunch wheatgrass shrubland 



This plant association has been reported in the Little 

 Missouri River badlands Gensen et al. 1992) and 

 previously noted in the county in the course of baseline 

 botanical work (Heidel 1994), but it has not previously 



20 



