Pearson correlation coefficients were computed to determine relationships between soil characterization data and SOCD. Analyses were conducted using SPSS 10.0 statistical package and Origin 6.0 software package.
Mean SOCD was 8.23 [+ or -] 1.40 kg C [m.sup.-2] in the upper 100 cm (39.38 in) of EBFZ, higher by about 41% than that of FLWP (table 3), which means that the open wetland had larger C storage than the closed wetland.
SOCD generally decreased with depth in soil profiles in both FLWP and EBFZ, with the highest values 2.64 kg C [m.sup.-2] and 2.14 kg C [m.sup.-2] in top soils, respectively (figure 2).
In addition, there was also a significantly negative correlation between SOCD and soil pH, which supported the conclusion that the closed wetland had lower C storage, since there was higher alkalinity in the closed wetland than in the open wetland due to drought in recent years (Bai et al.
SOCD were positively significantly correlated with SOM, TN, TP and clay contents (p < 0.001) and negatively significantly correlated with sand contents (p < 0.001).