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2000 Thistle Density Summary <br /> Beltline Reference Area #3 <br /> Transect Thistles per square meter <br /> 1 0.3 <br /> 2 0 <br /> 3 0.1 <br /> 4 1.1 <br /> 5 1.4 <br /> 6 0.1 <br /> 7 0.8 <br /> 8 0.7 <br /> 9 0.4 <br /> 10 0.7 <br /> Sample Mean= 0.6 plants per square meter <br /> 1998/1999/2000 Thistle Density Comparison <br /> 1998 Sample Mean . . . . . . 10.7 plants per square meter <br /> 1999 Sample Mean . . . . . . 7.3 plants per square meter <br /> True Mean . . . . . . . . . . . . . 4.0<u<10.6; 99% C.I. <br /> 2000 sample Mean . . . . . . . 0.6 plants per square meter <br /> True Mean . . . . . . . . . . . . . 0.1<u<1.1; 99% C.I. <br /> There was no statistically significant difference between 1998 and 1999, but there was a highly <br /> significant decrease from 1999 to 2000 (alpha= .01; 2 tail, 9 df). Both Canada thistle and <br /> plumeless thistle were present. Oxeye daisy was also present. Oxeye density was estimated in <br /> 1999 but not 2000. <br /> A total count census of thistle plants was performed in 2000, within the 500 meter reference area. <br /> Total thistle count was 188 plants. The sample mean of 0.6 per square meter corresponds to a <br /> reference area total of 300 plants, with upper and lower bounds on a 95% confidence interval of <br /> 500 and 100, respectively. <br />