Wyoming Big Sagebrush and Herbaceous Cover Relationships
&lt;p class="emsd"&gt;&lt;span lang="EN-GB"&gt;We measured 328 sites in northern, central, and southern Montana and northern Wyoming during 2003 to test the competitive relationship of herbaceous cover in the interspaces to Wyoming big sagebrush (&lt;em&gt;Artemisia tridentata wyomingensis)&lt;/em&gt; cover. Long term annual precipitation at all sites was approximately 31 cm. Sagebrush and total herbaceous cover varied from 5 to 45 percent and 3.5 to 55 percent, respectively. Simple linear regression was the best fit model for predicting herbaceous cover from sagebrush cover using the highest R&lt;sub&gt;&lt;span&gt;a&lt;/span&gt;&lt;/sub&gt;&lt;sup&gt;&lt;span&gt;2&lt;/span&gt;&lt;/sup&gt; values as the model selection criteria. In northern Montana, herbaceous vegetation was predicted by sagebrush cover with the following model: Y = 37.4 – 0.61X (&lt;a name="OLE_LINK2"&gt;&lt;/a&gt;&lt;a name="OLE_LINK1"&gt;&lt;/a&gt;R&lt;sub&gt;&lt;span&gt;a&lt;/span&gt;&lt;/sub&gt;&lt;sup&gt;&lt;span&gt;2&lt;/span&gt;&lt;/sup&gt; = 0.16, P &amp;lt; 0.001, n = 87). In central Montana, the model was Y = 14.0 – 0.00X (R&lt;sub&gt;&lt;span&gt;a&lt;/span&gt;&lt;/sub&gt;&lt;sup&gt;&lt;span&gt;2&lt;/span&gt;&lt;/sup&gt; = 0.00, P = 1.0, n = 155). In southern Montana, the model was Y = 35.9 – 0.39X (R&lt;sub&gt;&lt;span&gt;a&lt;/span&gt;&lt;/sub&gt;&lt;sup&gt;&lt;span&gt;2&lt;/span&gt;&lt;/sup&gt; = 0.14, P &amp;lt; 0.001, n = 86). When all sites were combined, the best fit model was Y = 23.7 – 0.15X (R&lt;sub&gt;&lt;span&gt;a&lt;/span&gt;&lt;/sub&gt;&lt;sup&gt;&lt;span&gt;2&lt;/span&gt; &lt;/sup&gt;= 0.01, P &amp;lt; 0.061, n = 328). This analysis determined that only 1 percent of the variation in herbaceous vegetation cover was associated with Wyoming big sagebrush cover. Management suggestions to reduce Wyoming big sagebrush in order to increase long-term herbaceous production for greater sage-grouse (&lt;em&gt;Centrocercus urophasianus&lt;/em&gt;) would not be recommended.&lt;/span&gt;&lt;/p&gt;