Table 4.
Contributions of different factors to the variation in the community structure of AOA and AOB as revealed by canonical correspondence analysis or redundancy analyses
| Variables | AOA | AOB | ||
|---|---|---|---|---|
| Variance explained (%) | P value | Variance explained (%) | P value | |
| Climate | ||||
| MAT (°C) | 5.53 | 0.01 | 2.00 | 0.30 |
| MAP (mm) | 7.68 | 0.00 | 1.00 | 0.36 |
| Catchment land use | ||||
| Agriculture (%) | 2.00 | 0.50 | 22.00 | 0.00 |
| Built-up land (%) | 4.76 | 0.02 | 2.00 | 0.23 |
| Vegetation (%) | 3.68 | 0.15 | 0.00 | 0.63 |
| Water bodies (%) | 0.00 | 0.55 | 3.00 | 0.09 |
| Water quality | ||||
| pH | 3.38 | 0.13 | 1.00 | 0.54 |
| Depth (m) | 3.38 | 0.13 | 2.00 | 0.11 |
| DO (mg L‒1) | 3.53 | 0.13 | 3.00 | 0.11 |
| TOC (mg L‒1) | 2.15 | 0.51 | 1.00 | 0.36 |
| NH4 + (mg L‒1) | 7.06 | 0.00 | 1.00 | 0.31 |
| NO3 − (mg L‒1) | 4.14 | 0.06 | 3.00 | 0.06 |
| TP (mg L‒1) | 3.22 | 0.24 | 12.00 | 0.01 |
| Chl-a (mg m−3) | 3.07 | 0.20 | 22.00 | 0.00 |
| Sediment properties | ||||
| Moisture (%) | 3.07 | 0.16 | 2.00 | 0.37 |
| Density (g cm−3) | 1.84 | 0.55 | 1.00 | 0.19 |
| STC (mg g−1) | 2.92 | 0.24 | 1.00 | 0.38 |
| STN (mg g−1) | 2.30 | 0.38 | 2.00 | 0.15 |
| C/N | 7.06 | 0.00 | 0.00 | 0.58 |
| Vegetation characteristics | ||||
| Richness | 2.46 | 0.40 | 1.00 | 0.44 |
| Biomass (g m‒2) | 1.23 | 0.78 | 1.00 | 0.35 |
| PTN (mg g−1) | 3.99 | 0.04 | 1.00 | 0.41 |
| PTP (mg g−1) | 2.76 | 0.24 | 0.00 | 0.63 |
| All variables | 81.21 | 84.30 | ||
Significance was determined by 499 permutations