TABLE 1.
Environmental variables and biomasses of the most important groups in the plankton of the four lakes studieda
| Variable | Blankaart reserve
|
De Maten reserve
|
||
|---|---|---|---|---|
| Lake Blankaart | Lake Visvijver | Lake Maten 12 | Lake Maten 13 | |
| Nitrogen (μg liter −1) | 5170 ± 5430 | 457 ± 632 | 245 ± 604 | 70 ± 95 |
| Phosphorus (μg liter −1) | 427 ± 970 | 506 ± 332 | 53 ± 30 | 10 ± 12 |
| SPM (mg liter −1) | 49 ± 39 | 5.0 ± 2.1 | 23 ± 11 | 11.0 ± 14.6 |
| pH | 8.52 ± 0.70 | 8.15 ± 0.43 | 7.30 ± 0.24 | 6.94 ± 0.25 |
| Phytoplankton (μg of C liter −1) | 1587 ± 1490 | 140 ± 165 | 459 ± 340 | 228 ± 175 |
| % chlorophytes | 51 | 11 | 29 | 26 |
| % euglenophytes | 6 | 1 | 27 | 26 |
| % cyanobacteria | 7 | 6 | 4 | 1 |
| % cryptophytes | 15 | 53 | 17 | 31 |
| Bacteria (μg of C liter −1) | 187 ± 221 | 111 ± 95 | 134 ± 118 | 79 ± 49 |
| HNF (μg of C liter −1) | 21 | 1 | 7 | 2 |
| Ciliates (μg of C liter −1) | 180 | 37 | 301 | 84 |
| % oligotrich ciliates | 64 | 88 | 42 | 52 |
| Macrozooplankton (μg of C liter −1) | 967 ± 1100 | 547 ± 834 | 254 ± 259 | 134 ± 176 |
| % daphnids | 16 | 22 | 6 | 19 |
| Submerged macrophytes (% cover) | 0 | 55 | 0 | 43 |
a
Results are given as mean ± standard deviation for concentration data; no standard deviation is given for the percentage data. Since the percent cover by submerged macrophytes was determined only twice during the summer period, no standard deviation is given for these data.