Reddy, 1998) and to increase after the drying of wet soils (Cabrera 1993; Bridgham et al.,

1998). N ammonification rates were specifically found to be 2-3 times greater in drained

wetland soils (White and Reddy, 2001; Venterlink et al., 2002). Benthic ammonification

rates have also been shown to be approximately 2 times greater in Everglades sediment

cores than the corresponding deeper layers (White and Reddy, 2001).

 The objectives of this study were to determine; (1) the response of enzyme

activities to a controlled water level decrease in soil cores extracted from a marl

dominated wetland (Taylor Slough in Everglades National Park (ENP-TS)) and a peat

dominated wetland (Water Conservation Area 3A (WCA-3A)); (2) the differences in

response to drained and flooded conditions between the two sites; and (3) any effects that

an extended laboratory incubation has on enzyme activities.

 Materials and Methods

Site Description

 The Florida Everglades is an oligotrophic system with reference surface water total

phosphorus (TP) levels averaging less than 10 pg L-1 throughout the interior of the marsh

(McCormick et al., 2003). Field study sites were located within the interior of WCA-3A

and ENP-TS.

 WCA-3A encompasses 2,012 km2 and is predominantly a vast peat sawgrass marsh

interspersed with sloughs, tree islands, and wet prairies. It is the only area not completely

enclosed by levees. The highest annual mean surface water TP levels in the inflow and

interior marsh were 67.3 and 20.3 pg L-1, respectively for 1978-2000 (Newman et al.,

2002). The vegetation at the sampling site is generally composed of water lilies,

spikerush, and periphyton assemblages.