Carbon accumulation outcomes in restored forests
Restoration management significantly affected biomass accumulation
(F1,21 = 7.9, P < 0.001): tree plantations
accumulated approximately 50% more above-ground carbon than
second-growth forests throughout the chronosequence (Fig. 1A). Soil
carbon stocks at 0-20 cm depth were not affected by forest age for any
of the restoration management type (F1,11 = 0.25, P =
0.62 and F1,10 = 1.6, P = 0.22 for plantations and
second-growth forests, respectively; Fig. 1B). Similar results were
observed when soil layers 0-10 and 10-20 cm were analyzed separately
(Fig. S2). Soil carbon stocks were strongly correlated with clay content
(Fig. 2), which positively influenced soil carbon stocks in restored
forests (F1,11 = 26.2, P < 0.001 and
F1,10 = 22.6, P < 0.001 for plantations and
second-growth forests, respectively; Fig. 2). When controlling for the
effect of clay content, soil carbon stocks were higher for reference
than for restored forests (F1,27 = 23.9, P =
<0.001), but were similar between plantations and
second-growth forests (F1,22 = 2.18, P = 0.15). Stem
density had no significant effect on any of the explored dependent
variables.