Appendix A. Scaled displacement (i.e., sensitivity) of food web and ecosystem properties in response to a nutrient pulse perturbation.

Scaled displacement (i.e., sensitivity) of food web and ecosystem properties in response to a nutrient pulse perturbation

Appendix A. Supplemental data set description, methods, and coefficient estimates for phytoplankton presence / absence and biovolume models.

Supplemental data set description, methods, and coefficient estimates for phytoplankton presence / absence and biovolume models

Appendix C. Table containing group-specific and total zooplankton production and terrestrial resource reliance estimates for each lake.

Table containing group-specific and total zooplankton production and terrestrial resource reliance estimates for each lake

Appendix A. Table containing end member stable isotope values for each lake.

Table containing end member stable isotope values for each lake

Super Hume effects on the aquatic light-environment.

<p>Comparison of color (A) and Secchi depth (B) as a function of DOC in natural lakes and experimental ponds. Variation in DOC concentration in the experimental ponds was achieved by manipulating the Super Hume supply rate. Regression lines represent predicted values and 95% prediction intervals.</p

Heat map of Super Hume chemistry.

<p>The heat map represents the excitation-emission matrix spectra (EEMs) from a 3D fluorescence scan of Super Hume that was used in parallel factor analysis (PARAFAC).</p

Effects of Super Hume on <i>Daphnia.</i>

<p>A) We observed the accumulation of humic substances in gravid individuals of <i>Daphnia pulex x pulicaria</i> collected from a pond that had been experimentally enriched with Super Hume. Subsequently, we measured the effects of Super Hume (1666 µmol L⁻¹) on the life history (B–D), algal ingestion rates (E), and algal assimilation efficiency (F) where <i>D. pulex x pulicaria</i> was fed algae in the presence (+SH) or absence (−SH) of Super Hume. Values represent means ± SEM.</p

Super Hume stoichiometry.

<p>Molar ratios of major cation and anions with respect to DOC. We express alkalinity as equivalents per mole DOC. Observations for natural ecosystems (stream, groundwater, lakes, wetlands, and soil water) come from a survey of sites distributed throughout southwestern Michigan. Super Hume values are represented by the horizontal dashed line.</p