Table 1 Vegetation and water characteristics of the floating mat
Environmental components | PA (n = 54) | ZL (n = 7) | Total (n = 61) | ||||
|---|---|---|---|---|---|---|---|
I. laevigata under PA (n = 13) | M. trifoliata under PA (n = 6) | PA (n = 54) | |||||
Major components (mean ± SD) | PA | Shoot height (cm) | 160.9 ± 10.2 | 156.6 ± 12.6 | 158.5 ± 11.0 | 164.2 ± 15.4 | 159.2 ± 11.5 |
Shoot density (no./m2) | 23.2 ± 7.7 | 22.7 ± 6.3 | 23.0 ± 8.0b | 12.2 ± 4.7a | 21.9 ± 8.3 | ||
Coverage (%) | 66.0 ± 15.1 | 69.5 ± 13.1 | 66.8 ± 17.7 | 37.5 ± 10.1 | 63.8 ± 19.1 | ||
AGDW (g/m2) | 288.7 ± 116.9 | 263.8 ± 81.5 | 286.5 ± 123.3 | 141.6 ± 39.8 | 271.5 ± 124.3 | ||
ZL | Shoot height (cm) | 115.2 ± 15.7 | 121. ± 12.1 | 116.2 ± 13.8 | 103.4 ± 11.0 | 115.2 ± 14.1 | |
Shoot density (no./m2) | 20.9 ± 9.3 | 24.8 ± 9.6 | 20.1 ± 8.9 | 46.5 ± 9.8 | 23.0 ± 12.1 | ||
Coverage (%) | 23.9 ± 12.2 | 26.8 ± 12.9 | 21.6 ± 10.6 | 51.5 ± 6.4 | 25.0 ± 14.6 | ||
AGDW (g/m2) | 68.7 ± 34.9 | 101.5 ± 52.7 | 69.7 ± 29.1 | 100.8 ± 22.6 | 74.6 ± 32.8 | ||
Minor components (frequency, %) | P. thunbergii | 61.5 | 100 | 79.6 | 33.3 | 75.4 | |
C. heterolepis | 61.5 | 75.0 | 64.8 | 0 | 57.4 | ||
P. muricata | 15.4 | 0 | 20.0 | 33.3 | 24.6 | ||
B. frondosa | 0 | 16.7 | 12.9 | 16.7 | 13.1 | ||
S. fluviatilis | 0 | 0 | 0.04 | 66.7 | 0.08 | ||
S. tabernaemontani | 0.08 | 0 | 0.04 | 0 | 0.05 | ||
J. effusus | 15.4 | 0 | 0.04 | 0 | 0.03 | ||
I. globosa | 0.08 | 0 | 0.02 | 0 | 0.03 | ||
H. erectum | 0 | 0 | 0 | 16.7 | 0.02 | ||
Water environments (mean ± SD) | Water level (cm) | 6.1 ± 3.4 | 5.2 ± 2.5 | 4.3 ± 3.6 | 11.8 ± 7.2 | 5.1 ± 4.6 | |
pH | 6.6 ± 0.2 | 6.7 ± 0.1 | 6.7 ± 0.2 | 6.4 ± 0.3 | 6.6 ± 0.2 | ||
EC (μS/cm) | 160.4 ± 59.3 | 218.8 ± 49.0 | 167.2 ± 55.4 | 141.2 ± 59.3 | 165.0 ± 55.4 | ||
NO3–N (ppm) | 0.10 ± 0.04 | 0.09 ± 0.02 | 0.09 ± 0.03 | 0.12 ± 0.05 | 0.10 ± 0.03 | ||
NH4–N (ppm) | 1.01 ± 0.91 | 1.37 ± 0.88 | 0.90 ± 0.77 | 0.62 ± 0.48 | 0.87 ± 0.74 | ||
PO4–P (ppm) | 0.26 ± 0.39 | 0.12 ± 0.04 | 0.18 ± 0.23 | 0.28 ± 0.25 | 0.19 ± 0.23 | ||
K+ (ppm) | 9.95 ± 7.38 | 15.5 ± 8.7 | 11.2 ± 8.4 | 8.26 ± 4.43 | 10.9 ± 8.0 | ||
Ca2+ (ppm) | 4.71 ± 4.26 | 5.32 ± 1.84 | 5.16 ± 3.98 | 2.22 ± 1.53 | 4.9 ± 3.9 | ||
Na+ (ppm) | 14.2 ± 1.7 | 13.2 ± 0.9 | 13.6 ± 1.5 | 14.5 ± 4.6 | 13.7 ± 2.0 | ||
Mg2+ (ppm) | 5.25 ± 3.78 | 9.72 ± 1.86 | 5.77 ± 3.16 | 3.31 ± 2.44 | 5.6 ± 3.2 | ||