Distribution of organic carbon fractions in soil aggregates in Chinese fir plantations with different stand ages

Ecological Processes

Table 4 Effects of aggregate sizes (> 2, 2–1, 1–0.25, and < 0.25 mm) and stand ages (0, 9, 17, and 26 years old) on the soil readily oxidizable carbon concentration in a chronosequence of Chinese fir plantations

Stand age (years)	Soil readily oxidizable carbon concentration (g kg⁻¹)				Effects
	> 2 mm	2–1 mm	1–0.25 mm	< 0.25 mm	Aggregate size (A), df = 3		Stand age (S), df = 3		A × S, df = 9
	> 2 mm	2–1 mm	1–0.25 mm	< 0.25 mm	F	P	F	P	F	P
0	2.02 ± 0.01 a	2.57 ± 0.29 b	2.74 ± 0.45 a	3.25 ± 0.32 a	7.093	0.009	0.554	0.511	0.150	0.997
9	2.48 ± 0.29 a	3.28 ± 0.06 a	3.25 ± 0.39 a	3.35 ± 0.11 a
17	2.60 ± 0.65 a	3.31 ± 0.72 a	3.40 ± 0.02 a	3.77 ± 0.25 a
26	2.07 ± 0.01 a	2.44 ± 0.08 b	2.59 ± 0.17 a	3.03 ± 0.11 a
Mean	2.29 ± 0.11 B	2.90 ± 0.14 AB	3.00 ± 0.23 AB	3.34 ± 0.18 A

Data represent the average of 3 replicates ± standard errors. Different lowercase letters indicate significant differences among the different stand ages. Different capital letters indicate significant differences among the different aggregate sizes