Appendix

The weights (eigenvalues – “EV”) and loadings (correlation with a principal component – “PC”) of our environmental variables on the four retained principal components. The 39 variables encompassed five major sets of environmental features: 1) physical characteristics (water depth, pool area, canopy cover, hydroperiod, and soil organic matter); 2) water quality (dissolved oxygen (DO), temperature, conductivity, pH, dissolved organic carbon (DOC), nitrate (NO3-), ammonium (NH4+), total nitrogen (total N), phosphate (PO43-), total phosphorous (total P), and total phenolic compounds); 3) leaf litter measurements (litter depth, total litter mass, unidentified litter fragment mass, and the individual masses of the five most common species: Quercus palustris (pin oak), Acer saccharinum (silver maple), Populus deltoides (cottonwood), Acer rubrum (red maple), and Quercus alba (white oak); 4) producer and plankton communities (chlorophyll a (chla), vegetation richness and density, zoo- and phytoplankton density, and total algal genera); and 5) surrounding land cover classifications (deciduous forest, evergreen forest, cropland, open water, residential, commercial, bare/mines, herbaceous wetland, and woody wetland). Data transformations were applied before analysis to reduce heteroscedasticity: canopy cover and soil organic material were logit transformed; DOC, NO3-, NH4+, total N, PO43-, and total P were ln(X) transformed; total phenolic compounds was ln(X + 0.5) transformed; and total algal genera, algal density, zooplankton density were square root transformed. Loading scores marked in bold indicate strong correlations (> 0.60; sensu Quinn and Keough 2002) with corresponding principal component. Moderate loading scores (0.40 – 0.60) are underlined.

Variable / EV1 / EV2 / EV3 / EV4 / PC1 / PC2 / PC3 / PC4
Physical Characteristics / Depth / -0.216 / 0.074 / -0.129 / 0.126 / -0.669 / 0.21 / -0.265 / 0.237
Area / 0.057 / -0.159 / -0.059 / -0.08 / 0.177 / -0.45 / -0.121 / -0.151
Logit (Canopy / -0.009 / 0.313 / 0.000 / -0.166 / -0.027 / 0.888 / 0.001 / -0.312
Cover)
Hydroperiod / -0.229 / 0.066 / -0.127 / 0.18 / -0.71 / 0.186 / -0.263 / 0.338
Logit (Organic / 0.091 / -0.051 / 0.266 / 0.084 / 0.282 / -0.146 / 0.548 / 0.158
Matter)
Water Chemistry / DO / -0.074 / -0.26 / -0.105 / 0.065 / -0.229 / -0.737 / -0.215 / 0.122
Temperature / 0.073 / -0.236 / 0.043 / 0.175 / 0.226 / -0.67 / 0.089 / 0.33
Conductivity / -0.015 / 0.027 / 0.232 / -0.394 / -0.047 / 0.076 / 0.478 / -0.741
pH / -0.178 / -0.077 / 0.13 / -0.341 / -0.552 / -0.219 / 0.268 / -0.641
ln(DOC) / 0.275 / 0.117 / 0.043 / -0.126 / 0.851 / 0.333 / 0.088 / -0.237
ln(NO3-) / 0.235 / -0.007 / -0.051 / -0.082 / 0.729 / -0.021 / -0.104 / -0.154
ln(NH4+) / 0.284 / 0.097 / -0.051 / -0.072 / 0.881 / 0.275 / -0.106 / -0.135
ln(Total N) / 0.299 / 0.074 / -0.012 / -0.01 / 0.926 / 0.211 / -0.024 / -0.019
ln(PO43-) / 0.213 / 0.111 / -0.254 / 0.104 / 0.661 / 0.315 / -0.522 / 0.195
ln(Total P) / 0.244 / 0.103 / -0.207 / 0.087 / 0.756 / 0.292 / -0.427 / 0.164
ln(Phenolics) / 0.278 / 0.113 / -0.002 / -0.145 / 0.862 / 0.32 / -0.005 / -0.273
Leaf Litter / Litter depth / -0.151 / 0.195 / 0.089 / -0.016 / -0.468 / 0.552 / 0.184 / -0.03
Total litter mass / -0.027 / 0.167 / 0.248 / 0.256 / -0.084 / 0.475 / 0.511 / 0.482
Litter fragment / 0.049 / 0.111 / 0.053 / 0.207 / 0.153 / 0.315 / 0.109 / 0.389
mass
Q. palustris / -0.048 / 0.095 / 0.406 / 0.196 / -0.15 / 0.27 / 0.836 / 0.368
mass
A. saccharinum / 0.09 / 0.091 / -0.142 / -0.204 / 0.28 / 0.257 / -0.293 / -0.384
mass
P. deltoides / -0.162 / 0.106 / 0.281 / 0.204 / -0.502 / 0.299 / 0.578 / 0.383
mass
A. rubrum mass / -0.138 / 0.202 / -0.084 / 0.043 / -0.426 / 0.573 / -0.173 / 0.08
Q. alba mass / 0.167 / 0.02 / -0.118 / 0.265 / 0.517 / 0.057 / -0.243 / 0.497
Producers and Plankton / Chla / 0.241 / 0.053 / 0.091 / 0.226 / 0.746 / 0.151 / 0.188 / 0.425
Vegetation / 0.055 / -0.305 / 0.131 / 0.005 / 0.171 / -0.865 / 0.271 / 0.01
richness
Vegetation / -0.025 / -0.289 / -0.068 / 0.06 / -0.076 / -0.819 / -0.14 / 0.113
density
Zooplankton / 0.049 / -0.088 / -0.174 / 0.122 / 0.151 / -0.248 / -0.358 / 0.23
density
Phytoplankton / 0.073 / -0.086 / -0.178 / 0.125 / 0.227 / -0.244 / -0.366 / 0.236
density
Total algal / -0.103 / -0.301 / -0.099 / 0.073 / -0.318 / -0.853 / -0.203 / 0.138
genera
Land Cover / Deciduous forest / -0.188 / 0.199 / -0.143 / 0.049 / -0.582 / 0.563 / -0.294 / 0.093
Evergreen forest / -0.077 / 0.179 / -0.285 / -0.04 / -0.239 / 0.507 / -0.587 / -0.076
Cropland / 0.167 / -0.073 / 0.166 / -0.042 / 0.517 / -0.206 / 0.341 / -0.078
Open water / -0.084 / 0.229 / -0.092 / -0.033 / -0.261 / 0.65 / -0.189 / -0.062
Residential / -0.005 / 0.13 / 0.209 / 0.15 / -0.015 / 0.368 / 0.43 / 0.283
Commercial / 0.231 / 0.057 / 0.147 / -0.004 / 0.716 / 0.162 / 0.303 / -0.007
Bare/Mines / 0.199 / -0.01 / 0.103 / 0.228 / 0.617 / -0.029 / 0.213 / 0.429
Herbaceous / 0.055 / -0.063 / 0.148 / -0.248 / 0.172 / -0.178 / 0.306 / -0.467
wetland
Woody / 0.034 / -0.29 / -0.003 / -0.015 / 0.106 / -0.823 / -0.007 / -0.028
wetland