Table 2.

Results of the multi-response permutation procedure (MRPP) testing of the null hypothesis of no significant difference in denitrifier nosZ community composition between land-use and time (Date).

Land-use	Date	Average distance	N	MRPP statistics
Cultivated wetlands	Jun 01	0.9560	3	Observed delta = 0.1367
	Sep 12	0.1740	3	Expected delta = 0.7009
Uncultivated wetlands	Jun 01	0.1884	3	T = −7.2334, A = 0.8050
	Sep 12	0.8877	3

Average distance is the mean Euclidean distance between each pair-wise combination of land-use and sampling date: N is the number of replicate wetlands sampled. The observed delta is calculated from the data while the expected delta is derived from a null distribution: T is the MRPP test statistic, and A is the chance corrected within-group agreement. The MRPP was significant (P (0.01).