## 3 Results
### Environmental Effects on Enzyme Activity  
Principal Component Analysis (PCA) of environmental variables (Eh, pH, total root biomass and soil water content) and enzyme activity showed different drivers of enzyme rates between the two sites and how enzyme rates were normalized, although there were some similarities (Figures 4 and 5). For enzyme activity normalized by soil weight, soil water (r = 0.37-0.86) and total root biomass (r = 0.50-0.73) showed a significant, positive correlation with all enzymes (except soil water and PER) in the natural wetland (Figures 4a and 5a). In the drained wetland, all enzymes normalized by soil weight were highly correlated with soil water content (r = 0.54-0.92), but only PER and total root biomass were significantly correlated (r = 0.30) (Figures 4b and 5b). Enzyme activity normalized per unit mass of soil was uncorrelated with pH across all enzymes in the natural wetland, while AG (r = \(-\)0.38), XYL (r = \(-\)0.48), POX (r = \(-\)0.31) and PER (r = \(-\)0.49) showed significant negative correlation in the drained wetland. Finally, POX, PER and NAG all exhibited negative correlations with Eh in the natural wetland, and all but PER in the drained wetland. For AG, BG, CBH and NAG activity normalized by SOC, soil water (r = 0.32-0.62) and total roots (r = 0.33-0.70) had a positive correlation in the natural wetland (Figures 4c and 5c). No significant correlations were found for total root biomass and enzyme activity normalized by SOC in the drained wetland, but BG, CBH and NAG did show a positive correlation with soil water content (Figures 4d and 5d). XYL, POX, and PER activity normalized by SOC all exhibited positive correlations with pH at both sites, as well as AG in the drained wetland. Similarly, enzyme activity normalized by SOC was negatively correlated with Eh in the natural (all except AG and XYL) and drained (only BG, CBH, and NAG) wetland (Figures 4 and 5). For enzyme activity normalized by MBC, significant correlations with environmental variables were minimal compared to other methods of normalization (Figure 4e,f and Figure 5e,f). AG, BG, CBH, and NAG exhibited a positive correlation with soil water content in the natural wetland (r = 0.35-0.67). In the drained wetland, BG (r = 0.41) and CBH (r = 0.45) were positively correlated with soil water content while POX (r = \(-\)0.27) and PER (r = \(-\)0.39) were negatively correlated with soil water content. For enzymes normalized by MBC, only BG (r = 0.32) and NAG (r = 0.44) were positively correlated with total root biomass in the natural wetland, and XYL (r = 0.20), POX (r = 0.28), and PER (r = 0.35) in the drained wetland. Enzyme activity normalized by MBC was uncorrelated with pH and Eh in the natural wetland. In the drained wetland, AG (r = 0.45), XYL (r = 0.31), POX (r = 0.42) and PER (r = 0.53) were positively correlated with pH and CBH (r = \(-\)0.31) was negatively correlated with Eh. Figure 4: Principal Component Analysis (PCA) showing the relationship between environmental variables (pH, total root biomass, Eh, and soil water content) and extracellular enzyme activity in natural (**a**,**c**,**e**) and drained (**b**,**d**,**f**) forested wetlands in eastern North Carolina estimated using three different normalization methods (**a**,**b**): normalized by soil weight; (**c**,**d**): normalized by soil organic C content; and (**e**,**f**): normalized by microbial biomass C content. Activity of seven enzymes were measured: \(\alpha\)-glucosidase (AG), \(\beta\)-glucosidase (BG), cellobiohydrolase (CBH), xylosidase (XYL), phenol oxidase (POX), peroxidase (PER) and N-acetyl glucosamide (NAG). Data are averaged over soil horizons. Figure 5: Plot showing correlation coefficients (r) between environmental variables and enzyme activity calculated three ways for natural (**a**,**c**,**e**) and drained (**b**,**d**,**f**) forested wetland sites in eastern North Carolina.