The SOC stock measurements from the mature silvopastoral system at Helen's Wood were not included in statistical analyses because the level of replication was low (n = 3 per depth). However the SOC has been included in Fig. 7 as a point of reference with 95% confidence intervals. Whilst the confidence intervals are large for the deeper depth increments, the sample mean SOC stock in the mature grazed woodland was larger than the other treatments at 0–10 cm and 10–20 cm.
3.4. Carbon fractionation
Results from carbon fractionation were highly variable (Table 5) and there was no (p < 0.05) treatment, depth, or interaction effect. The level of organic carbon in the rSOC fraction below the silvopastoral trees and the woodland was occasionally below the detection limit of the elemental analyser.