Sarcobatus vermiculatus / Elymus lanceolatus Plant Association 



Syn. Sarcobatus vermiculatus / Agropyron dasystachyum 



SARVER / ELYLAN; black greasewood / thick-spiked wheatgrass 



MTNHP rank: G3/S3 



Environment: Relatively large acreages of SARVER / ELYLAN are found on Carter County BLM 

 tracts. It is a typical saline lowland range site on alluvial bottoms, but is also found on upland shale 

 slopes. Upland examples occur in highly dissected drainage headwaters (e.g. North Cottonwood 

 Creek) in patchy mosaics with ELYLAN grassland communities occupying drainage bottoms with 

 alluvial soils and SARVER/ELYLAN occupying the residuum of the eroding shale substrate. 

 Sarcobatus vermiculatus was also observed in badlands where it has an even more patchy 

 distribution and reduced cover with obscured community structure and delimitation; other lifeforms 

 have extremely sparse coverage on these badland sites. In bottomland settings (alluvial terraces and 

 fans) SARVER/ELYLAN forms more extensive, uninterrupted communities, which are often 

 bordered by and grade to sagebrush steppe (ARTTSW / ELYLAN) on better-drained soils, and 

 riparian wetland stringers with Populus deltoides on wetter positions along creeks. In these 

 bottomland settings black greasewood communities grade between jurisdictional wetlands and true 

 upland environments (DeVelice et al. 1995, Hansen et al. 1995); regardless of where it occurs S. 

 vermiculatus indicates the presence of unique soil properties indicating the plant associations present 

 are edaphically conditioned. 



Vegetation: SARVER/ELYLAN was sampled in five plots. Sarcobatus vermiculatus is the 

 dominant shrub with cover ranging from about 10 to 38%. The shrubs Artemisia tridentata ssp. 

 wyomingensis and Gutierrezia sarothrae have high constancy (75%) in the plots, the former sharing 

 dominance with Sarcobatus vermiculatus in one plot (each with 1 0% cover), and the latter being 

 well represented (10-20% cover) in two plots. The rhizomatous grass Elymus lanceolatus (syn. 

 Agropyron dasystachyum) was identified as the lower layer dominant in all plots with cover ranging 

 from about 20 to 70%. The morphologically and ecologically similar Pascopyrum smithii (syn. 

 Agropyron smithii) was also identified in trace amounts in two plots. Other grasses with high 

 constancy (>50%) include the natives Koeleria macrantha and Poajuncifolia and the exotic annual 

 Bromusjaponicus. The latter and the exotic perennial grass Poa pratensis are common increasers in 

 this association and may be persistent; Poa pratensis is well represented in one plot even though the 

 habitat was ungrazed for twelve years (C. Fruit, pers. commun.). Cover and diversity of forbs is 

 relatively low; the natives Achillea millefolium and Astragalus agrestis and exotics Taraxacum 

 officinale (or T. laevigatum) and Tragopogon dubius are the only species with greater than 50% 

 constancy. The BLM watch species Astragalus racemosus was found in small numbers in two 

 stands of SARVER / ELYLAN. 



Soils: All the sites sampled had non-saline soils (conductivity of the saturation extract < 4 

 mmhos/cm). The soil of at least one site (97A^0048, see inset below) with a pH in excess of 8.5 is 

 classed as a "black alkali"; soils of this type typically occur in semiarid regions in small irregular 

 polygons known as "slick spots". Though data regarding exchangeable sodium percentage was not 

 run on any samples, the pH values less than 8.5 (single exception noted above) point to non-alkali 

 soils. Hansen and Hoffman (1988) described a S. vermiculatus I Pascopyrum smithii type occurring 

 on terraces and fans within Powder River Co. which closely matches our SARVER / ELYLAN 



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