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• <br />herbaceous production is attributable to perennials, with grasses contributing 494 lbs./acre, forbs <br />providing 87 lbs./acre, and sub-shrubs adding 160 lbs./acre. Eighteen percent (167 pounds per acre) of <br />the total production is attributable to annuals, with grasses contributing 130 lbs./acre and forbs providing <br />37 lbs./acre. Noxious weeds were not found in any of the sampling quadrats in this community. <br />Perusal of Tables V12 and Chart V4 indicates that the estimated woody plant density in this area <br />was 3,275 woody plants per acre with the shrub lifeform accounting for 100% of the total. Mountain big <br />sagebrush was the dominant woody species with 1,679 plants per acre followed by low rabbitbrush at <br />1,541 plants per acre. <br />3.6.3 Study Area - Reference Area Comparability <br />Review of Table V2 indicates that the total vegetation ground cover and production for the <br />ip <br />Sagebrush baseline study area is comparable to the values obtained from the Sagebrush reference area. <br />These comparisons of the "tabular" versus "calculated" t-statistics on Table V2 also indicate success <br />given the Students t-test indicated by the guidelines. A two-sided t-test for two independent samples <br />was considered appropriate and the decision rules for this test were: <br />If t* >_ t(o.95,n1+n2-2) , conclude that the two areas are unequal, and <br />If t* < t(o.95,n1+n2-2), conclude that the two areas are equal (for a = 0.05). <br />The tabular t values for an a = 0.05 and n-2 degrees of freedom (d.f.) and calculation of the <br />comparison t* statistic for comparison are as follows: <br />Variable tabular t value t* statistic <br />Vegetation Cover 1.9855 1.6206 <br />Production 1.9810 1.8912 <br />Comparison of the calculated t-statistic (t*) for the two areas with the respective tabular tvalues <br />indicates that in each case t* is less than t. This results in the conclusion that the total vegetation <br />ground cover and production for the Sagebrush baseline study area is comparable (equal) to the values <br />obtained from the Sagebrush reference area. <br />3.7 Minor Vegetation Communities and Other Designations <br />3.7.1 Improved Pasture and Reference Area <br />0 CIEDA,R CREEK Ada [AT ES, INC. <br /> <br />Page 31 <br />2005 Collom Vegetation Survey