TABLE 2.

Copy numbers of the 16S rRNA and the narG, nirK, nirS, and nosZ genes from different successional stages

Sampling mo	Successional age (yr)	No. of gene copies (g−1 of soil)a
		16S rRNA	narG	nirK	nirS	nosZ
August	25	3.4 × 109 A	1.6 × 108 A	7.7 × 106 A	1.9 × 107 A	1.3 × 107 A
	40	7.0 × 109 A	1.7 × 108 A	1.1 × 107 A	2.2 × 107 A	3.7 × 107 A
	44	1.9 × 1010 A	1.4 × 108 A	2.2 × 107 AB	1.1 × 108 A	5.1 × 107 A
	72	1.6 × 1010 A	7.7 × 107 A	2.9 × 107 B	4.9 × 106 A	1.2 × 108 A
	129	4.2 × 1010 B	1.1 × 108 A	5.7 × 107 C	3.1 × 107 A	2.8 × 108 B
September	25	4.0 × 109 A	1.9 × 108 A	8.9 × 106 A	5.6 × 107 A	1.4 × 107 A
	40	6.2 × 109 A	1.9 × 108 A	1.0 × 107 A	2.4 × 107 A	5.3 × 107 A
	44	9.8 × 109 A	1.2 × 108 A	1.4 × 107 A	3.8 × 107 A	2.3 × 107 A
	72	1.1 × 1010 A	1.2 × 108 A	2.4 × 107 AB	1.8 × 107 A	7.1 × 107 A
	129	2.1 × 1010 B	1.1 × 108 A	3.2 × 107 B	7.6 × 107 A	1.3 × 108 B

^aSuffix letters (A to C) indicate significant differences between successional stages.