Lower Ecell/En values at the reference sites may be attributed to shifts from

primarily macrophyte to algal inputs at the reference sites (Figure 4-2). This would be

manifested in higher LEU activity, in relation to BGL, since algae generally contain

a higher protein content than macrophytes (Boschkler and Cappenberg, 1998). This is

especially important since LEU may also function in C mineralization from protein

sources. One driving force behind higher Ecell/En values at the enriched sites may be the

generally elevated BGL activities, which has been correlated with microbial production

in nutrient enriched mesocosms (Chr6st and Rai, 1993). Overall, the increases in

Ecell/En at the enriched sites mimic a southerly pattern: LNWR<WCA-2A<WCA-

3A<ENP-TS, indicating that N pressures on the microbial community appear to become

less important in the southern regions. Compared to the northern Everglades,

significantly lower C/N ratios of the DOC/DON fraction of surface and shallow pore

water were found within the southern Everglades (Qualls and Richardson, 2003), which

mirrors the decreased apparent N control on C mineralization (Ecell/En). Several

hypotheses concerning the southerly trend of decreasing DOC/DON ratios are presented

by Qualls and Richardson (2003) and include increased rates of biodegradation, greater

plant production of soluble organic matter, and greater production of soluble organic

matter by-products where peat is being decomposed faster.

 Plots of log Ecell/En vs. log Ecell/Ep indicate higher perceived P, and to a lesser

extent, N in the enriched sites (Figure 4-3). Reference sites generally reside in the low N,

low P quadrant. The general lack of sites residing in low P, high N conditions indicates

that N loading may not be a substantial issue in the Everglades, which is consistent with

the view that the system is P, not N limited.