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Table 1

General features and the mean values (with SD) of environmental variables of the reservoirs R1, R2 and R3. Codes of environmental variables used in CCAs and units are given in brackets.

Feature R1 R2 R3
General features of the reservoirs
Creation date 1971 1968 2000
Altitude (m asl) 149.4 158.6 171.0
Area (ha) 350 240 48
Depth (m) max. 2.5, mean 1.97 max. 3.0, mean 1.5 max. 2.5, mean 2.3
Degree of shoreline indentation (K) 0.02 0.03 0.08
Capacity (mln m3) 6.9 5.0 1.13
Water supply Wieprz-Krzna Canal Wieprz-Krzna Canal River Mogielnica
Original area fen meadows fen meadows fens in a river valley with peat excavations
Dominating surrounding type Wet meadows secondary turned into swamps, forests Alder and mixed forests, croplands, pastures Croplands and dried out meadows, mixed forests and fens
Purpose Agricultural usage, fisheries management Agricultural usage, fisheries management Fisheries management, recreation
Environmental variables
Physical and chemical parameters of water
Temperature (Temp, °C) 15.0 ± 9.0 20.8 ± 9.9 14.62 ± 8.5
pH 8.4 ± 0.33 8.0 ± 0.38 8.3 ± 0.38
Oxygen reduction potential (ORP, mV) −35.69 ± 27.9 73.21 ± 42 75.45 ± 44.22
Dissolved oxygen
(DO, ppm)
7.31 ± 1.4 7.41 ± 1.8 7.66 ± 0.6
Electrical conductivity
(EC, μS/cm)
367 ± 29 215 ± 59 298 ± 81
Total dissolved solids
(TDS, ppm)
191.28 ± 5.6 105.93 ± 3.8 181.44 ± 9.7
Salinity (Salin, PSU) 0.18 ± 0.005 0.1 ± 0.004 0.16 ± 0.006
Structural parameters of reservoirs
Water depth (Depth, m) 0.8 ± 0.4 0.9 ± 0.67 0.73 ± 0.23
Bottom type (Bottom) 1.37 ± 0.48 1.27 ± 0.45 1.8 ± 0.95
Elodeids (Elodeids) 2.54 ± 0.5 3.57 ± 0.83 1.15 ± 1.75
Helophytes (Heloph) 2.20 ± 0.4 2.51 ± 0.5 1.88 ± 1.52
Shade (Shade) 0 1 ± 0.5 0.8 ± 0.33
Landscape parameters in buffering zones of reservoirs (areas or distances)
Forests (Forests, m2) 579 ± 27 4547 ± 532 1581 ± 52
Wet meadows and fens (Meadows, m2) 26609 ± 2363 3905 ± 632 7677 ± 571
Water (Water, m2) 19829 ± 5122 13928 ± 1822 5590 ± 799
Tall emergent vegetation (TEV, m2) 8356 ± 1876 872 ± 40 309 ± 9
Distance to the nearest standing water body (SW_dista, m) 3240  ±  40 1270  ±  50 52  ±  10
Distance to the nearest running water (RW_dista, m) 20  ±  10 994  ±  30 130  ±  22