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

Ecological Processes

Table 7 Effects of aggregate sizes (> 2, 2–1, 1–0.25, and < 0.25 mm) and stand ages (0 years, 9, 17, and 26 years) on the soil water-soluble organic carbon concentration in a chronosequence of Chinese fir plantations

Stand age (years)	Soil water-soluble organic carbon concentration (mg 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	61.12 ± 1.97 c	65.33 ± 1.29 b	88.14 ± 4.53 b	98.99 ± 2.96 b	86.733	< 0.0001	45.693	< 0.0001	4.271	0.001
9	83.18 ± 2.24 a	94.09 ± 6.89 a	103.54 ± 1.11 a	99.28 ± 2.50 b
17	71.54 ± 2.70 b	77.72 ± 4.53 b	89.95 ± 3.24 b	110.25 ± 2.67 a
26	49.76 ± 1.77 d	66.85 ± 1.96 b	74.96 ± 3.25 c	90.24 ± 1.87 c
Mean	66.40 ± 3.85 C	76.00 ± 3.92 C	89.15 ± 3.36 B	99.69 ± 2.40 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