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4 Vegetation A Sea of Sagebrush or Landscape of Great Variety 26 What was Nevada’s cold desert vegetation like at the time Europeans entered the Great Basin? The answer is steeped in controversy. George Stewart’s analysis of ecological data and historical records in northwestern Utah showed a predominance of perennial grass.1 On the other hand, analysis of immigrants’ journals and government surveys, although documenting the presence of grass in the mountains, led Thomas Vale to conclude that shrubs visually dominated the pristine vegetation of Nevada.2 These divergent assessments could be explained by differences in the ecological potential of sites described in early records. The Utah study involved elevated valleys, foothills, and benchlands where favorable precipitation and soil provided potential for growth of grass. Vale’s Nevada review is largely confined to primary travel routes in semiarid valleys. semiarid valleys Government surveys commissioned during the westward movement indicate that shrubs predominated in Nevada’s semiarid valleys.An 1854 Corps of Geographical Engineers report concludes:“The greater part of the surface of these valleys is merely sprinkled by several varieties of sombre artemisia [wild sage], presenting the aspect of a dreary waste. Though there are spots more thickly covered with this vegetation, yet the soil is seldom half covered with it, even for a few acres.”3 Captain J. H. Simpson came to the same conclusion: “The most abundant plant in the Great Basin is the artemisia, or wild sage, and it is seen almost everywhere in the valleys and on the mountains.”4 Botanist Sereno Watson, a member of Clarence King’s 1867–68 geological survey of the new territories, found sagebrush to be “by far the most prevalent of all species covering valleys and foothills in broad stretches farther than the eye can reach, the growth never so dense as to seriously obstruct the way but very uniform over large surfaces.”5 Vegetation | 27 There are a variety of Artemisia species (see appendix 2), each with different habitat requirements.Wyoming big sagebrush, which is adapted to moderately deep soils in drier environments, is likely the principal sagebrush referred to in the valley areas covered by Watson and others, although failure to recognize different taxa of sagebrush may be part of a larger failure to recognize that not all gray shrubs are sagebrush of any kind. Forty-four species and subspecies of rabbitbrush grace the Intermountain West along with various chenopods and other low-desert shrubs. Several observers recorded variation in the growth habits of sagebrush. During his 1854 survey Lieutenant Beckwith crossed an area in DiamondValley “covered with rank sagebrush from three to five feet high.”6 Likewise, Captain Simpson found sagebrush to be “quite rank in growth” in upper Huntington Valley. South of the Roberts Mountains in Kobeh Valley, he reported that “the sage we have daily to break through with our wagons [basin big sagebrush] ranges from 3 to 8 inches at butt.”7 Basin big sagebrush commonly reaches heights of eight or more feet but rarely lives longer than sixty years. It grows on very deep soils and often indicated good cropland to settlers. Less productive sites produced black sagebrush or low sagebrush. These species occupy thin soils atop clay layers or shallow bedrock that restricts water percolation. Black sagebrush grows on soils derived from limestone. In upper Big Smoky Valley Simpson reported that the soil was “very thinly covered by Artemisia.” In the Goshute Valley of eastern Nevada Beckwith found that “the road was dry and hard, and the Artemisia, which covered the whole face of the country, small.” Bryant, also in the Goshute Valley, found only “wild sage, greasewood, and a few shrubs of small size, for the most part leafless.”The latter were likely shadscale and other salt desert shrubs. Crossing lower Grass Valley, south of Winnemucca, Beckwith found “the soil of the valley  . . . friable and dry, supporting only a small variety of artemisia.”8 Recognizing site potential differences,Watson recorded the presence of salt desert shrubs on the somewhat less alkaline and drier portions of valleys where the potential for grass and forbs was low. Noting the presence of clay soils on the west side of lower Steptoe Valley near Schellbourne, Simpson concluded that it was a poor, arid valley and surmised it would be boggy in wet weather. Saltgrass bordered the stream, and greasewood 2–4 feet tall was growing where the party crossed. Lower Newark Valley typifies areas occupied by playa lakes where heavy salt concentrations precluded...

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