Figure 3.

Mean soil carbon stocks (tC/ha) at experimental sites. Error bars indicate standard error of the mean (X error = control values, Y error = treated values). (a) Lightly thinned, heavily thinned, and unthinned control plots, 0-20 cm depth. (b) Lightly thinned, heavily thinned, and unthinned control plots, 0-5 cm depth. (c) Clearcut and uncut control plots, 0-20 cm depth; year of cut is listed by each point. (d) Clearcut and uncut control plots, 0-5 cm depth; year of cut is listed by each point. Note that scales differ.