McLatchey and Reddy, 1998; White, 1999; Venterlink et al., 2002). Enhanced LEU

activity was observed in the WCA-3A 0 to -10 cm layer dry treatments over the

incubation period in the CES, CEA, and individual enzyme activities. However, this

difference was only exhibited by the ENP-TS cores at 12 weeks. The relegation of this

increase largely to the 0 to -10 cm layer is analogous to larger increases in N

mineralization rates in this layer in aerobic versus methanogenic conditions (White,

1999). Therefore it appears that 02 availability is limiting N mineralization in the WCA-

3A cores with the ENP-TS cores responding slower to a decrease in water levels. The

difference between the two sites may be due to the greater abundance of organic matter

for C mineralization in the WCA-3A cores which would energetically lead to greater N

mineralization.

EICQ

 The Enzyme Index of Carbon Quality (EICQ) was expected to increase during a

simulated drought as conditions became more favorable for microbial production. The

largest predicted effect on the EICQ was exhibited by both layers in the WCA-3A cores

where values were significantly higher in the dry treatments across the incubation period.

However, the ENP-TS dry treatment in the 0 to -10 layer was only significantly higher at

the 12 week collection. Thus drought duration appears to play a significant role in the

cumulative effects on potential decomposition. Higher EICQ values in the dry

treatments, which have been correlated to microbial biomass and productivity

(Sinsabaugh and Findlay, 1995), are supported by greater C flux and soil respiration

(DeBusk, 1996) as a result of drainage as well as increased microbial biomass and C flux

(Blodau et al., 2004).