Change in soil organic carbon
In this experiment, the organic carbon content (units: g 100 g−1) and the SOC stock (units: Mg ha−1) of the pasture was greater than
that of the tree planted treatments in the surface soil layer (0–10 cm).
The mean SOC stocks in the surface layer of the silvopastoral trees and
the woodland were 0.90 and 0.78 of that in the pasture respectively.
Our findings agreewith those of Shi et al. (2013) who report that the response
ratio (defined as the new SOC stock divided by the SOC stock of
the control at each depth) in studies of tree planting on grasslands
tended to be below 1.00 but not significantly different from 1.00.