. 2017 Mar 10;7:44049. doi: 10.1038/srep44049

Table 2. Kruskal-Wallis H test for the effect of urbanization on the potential microbial activities and gene abundances.

	Chi square	Significance	Significant level
Potential N₂O emission	13.35	0.001	***
PDA	15.35	<0.001	***
N₂O/(N₂O + N₂)	3.98	0.137	NS
PNR	12.50	0.002	**
Bacterial 16 S abun.	16.17	<0.001	***
Archaeal 16 S abun.	15.07	0.001	***
AOA amoA abun.	28.74	<0.001	***
AOB amoA abun.	19.60	<0.001	***
AOA/AOB	23.73	<0.001	***
nirK abun.	13.35	<0.001	***
nirS abun.	25.57	<0.001	***
nirK/nirS	20.42	<0.001	***
nosZ I abun.	20.39	<0.001	***
nosZ II abun.	10.86	0.004	**
nosZ I/nosZ II	6.23	0.044	*
nir/nos	13.54	0.001	***
AOA amoA R.abun.	25.73	<0.001	***
AOB amoA R.abun.	10.45	<0.001	***
nirK R.abun.	4.05	0.132	NS
nirS R.abun.	17.83	<0.001	***
nosZ I R.abun.	16.88	<0.001	***
nosZ II R.abun.	0.48	0.788	NS

Urbanization refers to three categories (urban, suburban, and rural) defined by population densities. NS, not significant. abun., abundance. R. abun., relative abundance. *, significance level at 0.05; **, significance level at 0.01; ***, significance level at 0.001.