The most parsimonious Generalized Linear Models (GLMs) relating different environmental and macrofauna community variables with and without treatment as a factor (terms that were not significant were dropped from the final models).

The Akaike's Information Criterion (AIC) and the proportional increase in explained deviance (pseudo-R2) were used to evaluate each regression-based model fit and parsimony. NH4+: ammonium uptake; NO3−: nitrate uptake; DIN: dissolved inorganic nitrogen (Σ NH4++NO3−); NO3−light: nitrate flux during daylight. DRP: dissolved reactive phosphorus (HPO42−- P); DIClight: dissolved inorganic carbon flux during daylight. GPP: gross primary production; Chla: chlorophyll a concentration. Abundance: total macrofauna abundance; DF: deposit feeders abundance. pseudo-R2 = (null deviance-residual deviance)/null deviance; (sensu[46]). §There was no significant interaction between the response variable and treatment (NH4+*Tr). We dropped the interaction term from the analysis and ran the model again. Final Model 1b: GPP∼NH4++Tr (AIC = 683.4, pseudo-R2 = 0.593).