Table 3. Submergence tolerance of R. nutans seeds within the winter impoundment of the Three Gorges Reservoir (mean±SE).
| Submergence depth (m) | Flooded by winter impoundment in the PR-DZ | Flooded by winter impoundment in the PU-DZ | ||
|---|---|---|---|---|
| Proportion of intact seeds | Cumulative germination rate | Rate of intact seeds | Cumulative germination rate | |
| 5 | 24.44±9.55 a | 53.34±13.68 A | 85.33±1.48 i | 90.38±4.05 I |
| 10 | 64.13±8.99 b | 87.52±3.05 B | 79.95±3.64 i | 86.75±7.14 I |
| 15 | 81.87±4.4 c | 95.37±0.8 C | 40.45±5.48 ii | 79.63±8.25 II |
| 17 | 15.36±3.05 a | 83.88±5.54 B | —— | —— |
| 20 | —— | —— | 39.87±6.49 ii | 76.06±2.15 II |
The lowercase letters a, b, c, d, i and ii indicate significant differences between the proportions of remaining intact R. nutans seeds subjected to winter impoundment in the PR-DZ and those subjected to full flooding by winter impoundment in the PU-DZ at different elevations. The uppercase letters A, B, C, D, I and II indicate significant differences between the cumulative germination rates of the remaining intact seeds under natural conditions (p<0.05). An em-dash indicates that the parameter was not determined in this research.