Table 2.
Summary statistics. Summary of repeated measures two-way PERMANOVA’s testing for the effects of pH treatment (Control (CTR), Treatment (TRE)), time (initial (INI), final (FIN)) and light regime (light (LIG), dark (DAR)) on sediment total O2 uptake (TOU), light/dark differences in TOU (∆TOU), and the flux of ammonium (NH4+) and nitrate/nitrite (NOX−). For each sediment type (estuarine sand (ES) or subtidal silt (SS)) the effects of two factors on a response variable were tested within the different levels of the third factor. The first column of the table indicates the response variable-sediment type-third factor combination followed by the pperm values for the two tested factors. Results of post-hoc tests (significant interaction term) (pperm < 0.05) are given where appropriate. NS = not significant (pperm > 0.2).
| Response | Pair-wise or Post-hoc test results | ||||
|---|---|---|---|---|---|
| (a) pH treatment and light regime within time | |||||
| pH | Light | Core(pH) | pH × Light | ||
| TOU-ES-INI | NS | NS | NS | NS | |
| TOU-ES-FIN | NS | <0.001 | 0.0011 | <0.0012 | LIG(CTR = TRE), DAR(CTR = TRE); CTR(DAR > LIG), TRE(DAR > LIG) |
| NH4+-ES-INI | NS | NS | 0.011 | NS | |
| NH4+-ES-FIN | 0.0394 | 0.0118 | NS | NS | TRE < CTR, DAR < LIG |
| NOx−-ES-INI | NS | NS | NS | NS | |
| NOx−-ES-FIN | 0.0081 | NS | 0.0017 | NS | CTR < TRE |
| TOU-SS-INI | NS | 0.0104 | NS | NS | DAR > LIG |
| TOU-SS-FIN | 0.103 | <0.001 | NS | 0.019 | LIG(CTR > TRE), DAR(CTR = TRE); CTR(DAR > LIG), TRE(DAR > LIG) |
| NH4+-SS-INI | NS | NS | NS | NS | |
| NH4+-SS-FIN | 0.015 | 0.0493 | NS | NS | CTR < TRE, DAR < LIG |
| NOx−-SS-INI | NS | 0.0014 | NS | NS | DAR < LIG |
| NOx−-SS-FIN | 0.0083 | 0.045 | NS | NS | CTR < TRE; DAR < LIG |
| (b) pH treatment and time within light regime | |||||
| pH | Time | Core(pH) | pH × Time | ||
| TOU-ES-DAR | NS | NS | NS | NS | |
| TOU-ES-LIG | NS | 0.006 | NS | NS | FIN < INI |
| ∆TOU-ES | 0.016 | 0.0073 | NS | NS | CTR < TRE, INI < FIN |
| NH4+-ES-DAR | NS | NS | NS | NS | |
| NH4+-ES-LIG | NS | NS | NS | NS | |
| NOx−-ES-DAR | 0.0287 | 0.0031 | NS | 0.0155 | INI(CTR = TRE), FIN(CTR < TRE); CTR(FIN < INI), TRE(INI = FIN) |
| NOx−-ES-LIG | 0.0069 | 0.0095 | NS | NS | CTR < TRE; FIN < INI |
| TOU-SS-DAR | NS | 0.0099 | NS | 0.059 | FIN > INI |
| TOU-SS-LIG | NS | 0.0053 | NS | 0.047 | CTR(INI = FIN), TRE(INI = FIN); INI(CTR = TRE), FIN(TRE < CTR) |
| ∆TOU-SS | NS | 0.0022 | NS | 0.019 | INI(CTR = TRE), FIN(CTR < TRE); CTR(INI = FIN), TRE(INI < FIN) |
| NH4+-SS-DAR | NS | NS | NS | NS | |
| NH4+-SS-LIG | NS | NS | NS | NS | |
| NOx−-SS-DAR | 0.0415 | 0.003 | NS | 0.0023 | INI(CTR = TRE), FIN(CTR < TRE); CTR(FIN = INI), TRE(INI < FIN) |
| NOx−-SS-LIG | 0.0258 | 0.0015 | NS | 0.0059 | INI(CTR = TRE), FIN(CTR < TRE); CTR(FIN = INI), TRE(INI < FIN) |
| (c) Light regime and Time within pH treatment | |||||
| Light | Time | Core(Light) | Light × Time | ||
| TOU-ES-CTR | NS | NS | NS | NS | |
| TOU-ES-TRE | 0.031 | NS | NS | 0.026 | DAR(INI = FIN), LIG(INI = FIN); INI(DAR = LIG), FIN(DAR > LIG) |
| NH4+-ES-CTR | NS | NS | NS | NS | |
| NH4+-ES-TRE | NS | NS | NS | NS | |
| NOx−-ES-CTR | NS | <0.001 | NS | NS | FIN < INI |
| NOx−-ES-TRE | NS | NS | NS | NS | |
| TOU-SS-CTR | 0.0094 | NS | NS | NS | |
| TOU-SS-TRE | 0.003 | NS | NS | 0.003 | DAR(INI < FIN), LIG(INI = FIN); INI(DAR = LIG), FIN(DAR > LIG) |
| NH4+-SS-CTR | NS | NS | NS | NS | |
| NH4+-SS-TRE | 0.0289 | NS | NS | NS | DAR < LIG |
| NOx−-SS-CTR | 0.0075 | 0.047 | NS | NS | DAR < LIG; INI < FIN |
| NOx−-SS-TRE | 0.009 | <0.001 | NS | 0.0376 | DAR(INI < FIN), LIG(INI < FIN); INI(DAR < LIG), FIN(DAR = LIG) |