as microbial community shifts, vegetative changes, and differences in interactions

between the heterotrophic and algal communities may outweigh the singular dynamics of

the individual enzyme activity components of the EICQ model, especially in terms of

lignin degradation. Therefore it does not appear that the EICQ model is a powerful

predictor of microbial responses in this system among the different hydrologic units.

Additionally, the use of only 5 enzymes in this study may be restrictive on the validity of

the EICQ model.

ENP-TS

 Special consideration is attributed to the ENP-TS sites due to the large shift in

apparent N dynamics across the gradient, as compared to the relatively large shifts in P

dynamics in the other areas. As previously discussed, ENP-TS had the greatest shift in

apparent N influence and the smallest shift in apparent P influence on C mineralization.

The highest Ecell/En and lowest Ecell/Ep values at the ENP-TS enriched sites suggests

that P is the most limiting of the enriched sites, which is expected, and that N is the least

limiting of any site, which is not expected. Although this site has a higher LEU activity,

the relationship with the amount of C mineralization that appears to be occurring

indicates that, energetically, this community is expending a smaller proportion of its

resources on the acquisition of N from organic sources.

 The lowest overall Ecell/Eox at the ENP-TS enriched site points to increased lignin

control on C mineralization. This indicates that perceived lignin content is playing an

important part in the C mineralization process, with increased combined oxidative

enzyme activities, although % lignin content is lowest at this site. Interactions among

environmental and microbial parameters may play an important part in the elevation of

apparent lignin control. Elevated PHE activity may be partially due to the lack of