Nitrogen and Carbon Cycling in a Grassland Community Ecosystem as Affected by Elevated Atmospheric CO₂

Table 3

Effect of atmospheric CO₂ concentration on soil C turnover during a 60-day soil incubation at three soil depth increments^†.

CO2 level	0–20 days			20–40 days			40–60 days
	Depth
	0–20 cm	20–50 cm	50–80 cm	0–20 cm	20–50 cm	50–80 cm	0–20 cm	20–50 cm	50–80 cm
(μmol mol^−1)	(mg kg^−1)
385	1.01 a	1.12 a	0.65 a	0.85 a	1.18 a	1.04 a	3.70 a	4.62 a	4.02 a
690	1.63 a	0.74 a	1.17 a	1.75 b	0.98 a	1.27 a	3.49 b	3.81 a	4.32 a
980	1.54 a	1.23 a	5.34 a	2.19 c	0.75 a	1.22 a	2.19 c	2.97 a	4.51 a

^†Values represent means of three replications. Means within a column for each sampling date followed by the same letter do not differ significantly (𝛼=0.1).