Spatial patterns and temporal trends of trace elements in mosses from 1990 to 2020 in Germany

Environmental Sciences Europe

Table 4 Percentile and U test statistics for the total sample 2015 (n = 397 to 400) and the sub-sample 2020 with concentration values of the year 2015 (n = 25)

Element	n (2015) [μg/g]	P₂₀ (2015) [μg/g]	P₅₀ (2015) [μg/g]	P₉₀ (2015) [μg/g]	n (2020) [μg/g]	P₂₀ (2020) [μg/g]	P₅₀ (2020) [μg/g]	P₉₀ (2020) [μg/g]	p-value (U test)
Al	400	138.88	196.9	460.84	25	173.1	270.1	493.04	0.06*
As	398	0.07	0.11	0.22	25	0.08	0.13	0.22	0.49
Cd	398	0.09	0.14	0.26	25	0.1	0.13	0.27	0.92
Cr	399	0.4	0.57	1.24	25	0.47	0.76	1.41	0.07*
Cu	400	3.55	4.65	7.77	25	3.26	4.81	6.98	0.50
Fe	400	152.12	206.15	433.02	25	181.04	250.4	534.46	0.04**
Hg	397	0.02	0.03	0.05	25	0.02	0.03	0.07	0.26
Ni	400	0.44	0.68	1.46	25	0.42	0.67	1.63	0.93
Pb	400	1.23	1.83	4.33	25	1.03	2.09	5.71	0.56
Sb	397	0.06	0.09	0.16	25	0.05	0.1	0.15	0.74
V	400	0.37	0.52	1.08	25	0.48	0.72	1.4	0.01***
Zn	400	22.68	30.69	48.21	25	27.45	35.43	51.09	0.08*

n number of values above the limit of quantification (BG); values < BG were not considered for the characteristic value calculations, P20 20th percentile, P50 50th percentile, P90 90th percentile
***p ≤ 0.01 (very significant)
**p ≤ 0.05 (significant)
*p ≤ 0.1 (weakly significant)