Changes in the Heavy Metal Levels in Highway Landscaping and Protective Effect of Vegetative Materials

Table 5

Dunn’s test results of Cu and Ni contents.

Sample 1-sample 2	Cu				Ni
	Test statistic	Std. err.	Std. test statistic		Test statistic	Std. err.	Std. test statistic
RS-NL	4.20	6.37	.660	0.51	5.63	6.37	.88	0.38
RS-RA	11.37	5.29	2.15	0.03	8.33	5.29	1.57	0.12
RS-UA	−16.87	6.93	−2.43	0.02	−10.17	6.93	−1.47	0.14
RS-AA	26.70	7.94	3.36	0.01	28.00	7.94	3.53	0.00
NL-RA	7.17	5.70	1.26	0.21	2.71	5.70	.48	0.64
NL-UA	−12.67	7.25	−1.75	0.08	−4.54	7.25	−.63	0.53
NL-AA	−22.50	8.22	−2.74	0.00	−22.38	8.22	−2.72	0.01
RA-UA	−5.50	6.32	−.87	0.39	−1.83	6.33	−.29	0.77
RA-AA	−15.33	7.42	−2.07	0.04	−19.67	7.42	−2.65	0.01
UA-AA	9.83	8.66	1.14	0.26	17.83	8.66	2.06	0.04

 < .05 (95%).