Table 3. Nitrogen pools in the mesocosms on day 21 and 42 for the four treatments.
| NO3 -/NO2 - | NH3/NH4 + | TDN | Seston N | Total N | Sediment N a | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (μmol L-1) | (μmol L-1) | (μmol L-1) | (μmol L-1) | (μmol L-1) | (mmol kg-1) | |||||||
| Treatment | D21 | D42 | D21 | D42 | D21 | D42 | D21 | D42 | D21 | D42 | D21 | D42 |
| U | 0.96 ab | 1.40 | 2.33 a | 16.33 | 183 a | 185 ab | 53.0 a | 49.8 a | 236 a | 235 a | 182 | 242 |
| (0.20) | (0.47) | (0.64) | (12.51) | (9.51) | (32.81) | (3.73) | (21.44) | (9.60) | (42.32) | (17) | ||
| P | 0.65 a | 1.15 | 0.16 b | 4.13 | 192 a | 184 a | 76.5 a | 76.3 ab | 269 a | 260 a | 212 | 243 |
| (0.24) | (0.77) | (0.15) | (3.75) | (17.88) | (20.81) | (14.05) | (12.77) | (31.49) | (32.81) | (74) | ||
| NP16 | 0.89 ab | 1.01 | 0.37 b | 3.41 * | 202 a | 192 ab | 110 b | 84.2 ab | 312 b | 276 ab | 186 | 257 |
| (0.18) | (0.39) | (0.10) | (2.44) | (12.11) | (16.08) | (23.78) | (20.07) | (34.04) | (33.67) | (27) | ||
| NP75 | 2.89 b | 1.38 | 1.21 ab | 3.59 | 226 b | 212 b | 117 b | 103 b | 340 b | 315 b | 247 | ND |
| (2.04) | (0.52) | (0.73) | (2.14) | (25.63) | (23.87) | (14.91) | (37.57) | (16.27) | (53.90) | |||
Each value represents the average and one standard deviation in parentheses. Different bolded letters indicate significant differences between the treatments within day, based on randomized block ANOVA. ND: Not determined.
* on day 42 denotes a significant change from day 21 based on Student’s t-test.
a No replication was made for this analysis due to insufficient sediment samples.