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i <br />4.1.2 Herbaceous Production <br />' <br /> Herbaceous production sampling for 1993 is summarized in Table 36 for the Test Plots, <br /> North and South Areas, and the Shadscale Shrubland Reference Area. Relatively high <br />' herbaceous production may be accounted for by cool and relatively moist spring <br /> weather (Reschke, 1993). Total herbaceous production on the Test Plots showed a <br />' general increase with increasing soil depth. The only exception was the 48" soil depth <br />on Test Plot 1, which showed a 59.7% decrease in production compared with the 24" <br /> soil depth treatment on Test Plot 1. Unlike cover values, Test Plot 1 herbaceous <br /> production values for all soil depth treatments were not significantly lower than <br />' herbaceous production values for all soil depth treatments on Test Plots 2 and 3, and <br /> the North and South Areas. <br /> i <br />h <br />i <br />d <br /> w <br />th cover) was note <br />t <br />The same general trend in herbaceous production (as w <br /> respect to slope and aspect of the Test Plots (Figure 19). Herbaceous production is <br />' consistently lower on the flat aspect of Test Plot 1 compared to either the west facing <br /> aspect of Test Plot 2 or the north-northwest facing aspect of Test Plot 3 when <br /> comparing the same treatment depths. The lowest herbaceous production value of all <br /> Test Plots occurred in the 6" treatment of Test Plot 1 (29.36 g/ sq m) and the highest <br /> herbaceous production was present in the 24" treatment of Test Plot 3 (265.20 g/ sq <br />,~ m). Test Plot 2 herbaceous production values were intermediate between Test Plot 1 <br />and 3 when comparing individual soil depth treatments. Test Plot 2 and 3 herbaceous <br /> production values for 12" and 24" treatment plots were also statistically equal to or <br /> greater than those of the Reference Area, which has a predominantly west-facing <br />' aspect. These observations indicate that the predominant aspect (even on the slopes of <br /> the RDA) affects the prevailing moisture regime, providing a more mesic condition <br />' favorable to plant growth on the slopes, especially the north-northwest aspect. <br /> Twelve and twenty four inch individual treatments on Test Plots 2 and 3, and the North <br />' Area had herbaceous production values exceeding the mean herbaceous production of <br /> the Shadscale Shrubland Reference Area at 98.22 g/ sq m (Figure 19). The 24" <br /> treatment in Test Plot 1 was equal to or exceeded the Reference Area revegetation <br />' success herbaceous production standard (90% of the herbaceous production value with <br /> 90% confidence) when tested using a Students t test (Zar, 1974, CDMG, 1988). All <br /> other treatments (Test Plot 1 6", 12"; Test Plot 2 6"; and Test Plot 3 6", South Area) <br />' had mean herbaceous production values statistically less than the Reference Area <br /> herbaceous production standard. <br />' In all cases, perennial graminoids in the Test Plots and North and South Areas provided <br />higher relative production than perennial graminoids in the Shadscale Shrubland <br />' Reference Area. In all areas sampled, Bromus japonicus/tectorum remained the <br />dominant in terms of relative herbaceous production. Perennial forts did not constitute <br />significant contributors to herbaceous production, though in all fairness, the sampling <br />' time was not optimum for either annual or perennial native forts (Weber, 1993). <br />' S1 <br />