DNA metabarcoding of bulk soil to characterize belowground arthropod communities.

Taxa tables, metadata, repse

Datasheet_covercrop_root_shoot_label_Austinetal2017_GCBB

Datasheet_covercrop_root_shoot_label_Austinetal2017_GCB

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

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

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

Heterotrophic bacteria grew on Super Hume.

<p>Phylogenetic relationship of bacteria cultivated on Super Hume as a sole carbon source (bold) along with reference sequences (non-bold). Trees were constructed from aligned 16S rRNA sequences using neighbor-joining methods. γ = γ-Proteobacteria and β = β-Proteobacteria. The scale bar represents the sequence dissimilarity. <i>Thermotoga</i> is an archaeon that was used as an outgroup.</p

Microbial metabolism along a Super Hume gradient.

<p>We created a DOC gradient in a set of experimental ponds by altering the supply rate of Super Hume. There was no relationship between bacterial productivity (BP) and DOC (A), but bacterial respiration (BR) significantly increased (B) and bacterial growth efficiency (BGE) significantly decreased (C) along the DOC gradient. Regression lines represent predicted values and 95% confidence intervals for significant (solid lines) and non-significant (dashed lines) models.</p

Multivariate ordination of Super Hume chemistry.

<p>We performed a Principal Coordinates Analysis (PCoA) based on the chemical characteristics of Super Hume and other reference organic materials as determined by pyrolysis-gas chromatography/mass spectrometry (py-GC/MS). Reference samples are represented by symbols, while vectors reflect correlations between chemical attributes and the samples.</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

Flocculation rates of Super Hume.

<p>We estimated flocculation rates in laboratory assays as the loss of dissolved organic carbon (DOC) at different Super Hume concentrations added to water from a reference pond. Regression lines represent predicted values and 95% confidence intervals.</p