Appendix S3 Univariate zooplankton and phytoplankton species responses
Most zooplankton species showed a negative response to Nutrient addition in the PCA
biplot (Figure 2A, main article). In univariate analyses for each species separately (Table
1; Figure 1), we found a significant NUT x DISP interaction for Daphnia magna and
Cyclopoid copepods. Daphnia magna had significantly higher densities under high
nutrient additions in the presence of a high dispersal rate. Cyclopoid copepods on the
other hand reached the highest densities under a low dispersal rate under high nutrient
additions. Nutrient addition had a negative impact on Chydorus sp., Bosmina sp.,
Daphnia galeata, Scapoholeberis mucronata and Simocephalus vetulus densities. Only
Daphnia magna was positively influenced by dispersal.
The phytoplankton species showed a strong response to the Nutrient addition in the
PCA biplot (Figure 2B, main article). In the univariate ANOVA analyses (Table 2;
Figure 2) Chlorella cf. ellipsoidea (Chloe) and the spineless bi-, four- and eightcellular
Desmodesmus colonies (Des 2-, 4-, 8-) showed a strong association with a high nutrient
addition Peridinium sp. (Perid) was associated with a low nutrient content.
Monoraphidium circinale (Mcir) performed best under low levels of dispersal. Within the
high nutrient addition treatment spined four- and eightcellular Desmodesmus colonies
(Des 4-, 8-) where highly associated with the absence of dispersal, Pseudanabaena
catenata (Pscat) showed a association a low dispersal rate and the spineless solitary
Desmodesmus (Des 1-) showed a strong association with the high dispersal treatment.
The filamentous Chlorophyceae Mougeotia sp. (Moug) and Oedogonium sp. (Oedo)
reached the highest densities under low nutrient additions in the presence of a high
dispersal rate.
Figure 1: Zooplankton densities in the different treatment combinations. Error bars
denote twice the standard error.
Bosmina sp.
Chydorus
500
800
400
density (# / L)
density (# / L)
600
300
200
400
200
100
0
0
NDISP
LDISP
HDISP
NDISP
80
200
60
density (# / L)
density (# / L)
250
150
100
LDISP
HDISP
Daphnia galeata
Cyclopoid copepods
40
20
50
0
0
NDISP
LDISP
NDISP
HDISP
LDISP
HDISP
Scapoholeberis mucronata
Daphnia magna
14
800
600
density (# / L)
density (# / L)
12
400
10
8
6
4
200
2
0
0
NDISP
LDISP
HDISP
NDISP
Simocephalus vetulus
50
HNUT
LNUT
density (# / L)
40
30
20
10
0
-10
NDISP
LDISP
HDISP
LDISP
HDISP
Figure 2: Phytoplankton densities in the different treatment combinations. Error bars
denote twice the standard error.
Chlorella cf. ellipsoidea
Desmodesmus 1-
400
200
6
density (x10^6 ind / L)
600
density (x10^6 ind / L)
density (x10^6 ind / L)
Desmodesmus 2-
6
800
4
2
4
2
0
0
0
LDISP
NDISP
HDISP
Desmodesmus 4-
density (x10^6 ind / L)
density (x10^6 ind / L)
2
1
NDISP
HDISP
Desmodesmus 8-
4
3
LDISP
10
0.04
8
0.03
0.02
0.01
LDISP
HDISP
Desmodesmus 4+
0.05
density (x10^6 ind / L)
NDISP
6
4
2
0.00
0
0
-0.01
NDISP
LDISP
NDISP
HDISP
Desmodesmus 8+
LDISP
NDISP
HDISP
Monoraphidium circinale
HDISP
Mougeotia sp.
6
1.0
LDISP
0.006
0.6
0.4
0.2
4
density (x10^6 ind / L)
density (x10^6 ind / L)
density (x10^6 ind / L)
0.8
2
0
0.004
0.002
0.000
0.0
-2
NDISP
LDISP
NDISP
HDISP
Oedogonium
LDISP
HDISP
NDISP
LDISP
HDISP
Pseudanabaena catenata
Peridinium sp.
0.020
0.020
0.015
0.015
0.004
0.002
density (x10^6 ind / L)
density (x10^6 ind / L)
density (x10^6 ind / L)
0.006
0.010
0.005
HNUT
LNUT
0.010
0.005
0.000
0.000
0.000
-0.005
-0.005
NDISP
LDISP
HDISP
NDISP
LDISP
HDISP
NDISP
LDISP
HDISP
Table 1. ANOVA results for the response of the different zooplankton species to the
experimental treatments. Only the fixed effects are shown of the species that responded
significantly.
d.f.
Species
Bosmina sp.
NUT
1
DISP
2
NUT x DISP
2
Chydorus
NUT
1
DISP
2
NUT x DISP
2
Cyclopoid copepods
NUT
1
DISP
2
NUT x DISP
2
Daphnia galeata
NUT
1
DISP
2
NUT x DISP
2
Daphnia magna
NUT
1
DISP
2
NUT x DISP
2
Scapoholeberis mucronata
NUT
1
DISP
2
NUT x DISP
2
Simocephalus vetulus
NUT
1
DISP
2
NUT x DISP
2
MS
F
P-value
703227.71
29663.44
31645.41
10.53
0.77
0.82
0.0054
0.47
0.45
2709088.08
174452.07
159996.92
21.36
2.18
2.05
0.00033
0.13
0.15
14474.17
44687.82
19781.71
2.90
5.05
4.15
0.11
0.013
0.026
14261.94
297.52
373.61
8.45
0.22
0.27
0.011
0.80
0.76
1315883.23
847354.48
799024.19
32.44
13.31
12.60
0.000042
0.000073
0.00011
661.38
90.97
45.14
16.62
1.45
0.66
0.001
0.25
0.52
2784.66
414.12
426.22
4.92
0.69
0.71
0.042
0.51
0.50
Table 2. ANOVA results for the response of the different phytoplankton species to the
experimental treatments. Only the fixed effects are shown of the species that responded
significantly.
Chlorella cf. Ellipsoidea
NUT
DISP
NUT x DISP
Desmodesmus 1NUT
DISP
NUT x DISP
Desmodesmus 2NUT
DISP
NUT x DISP
Desmodesmus 4NUT
DISP
NUT x DISP
Desmodesmus 8NUT
DISP
NUT x DISP
Desmodesmus 4+
NUT
DISP
NUT x DISP
Desmodesmus 8+
NUT
DISP
NUT x DISP
Monoraphidium circinale
NUT
DISP
NUT x DISP
Mougeotia sp.
NUT
DISP
NUT x DISP
Oedogonium
NUT
DISP
NUT x DISP
Peridinium sp.
NUT
d.f.
MS
F
P-value
1
2
2
1380918.00
252922.00
255367.00
5.84
1.79
1.81
0.029
0.18
0.18
1
2
2
29.90
18.28
18.22
9.52
5.48
5.48
0.0075
0.0094
0.0094
1
2
2
47.45
4.59
4.60
9.082
0.73
0.74
0.0087
0.49
0.49
1
2
2
43.64
6.032
6.037
18.16
2.68
2.69
0.00068
0.085
0.084
1
2
2
0.0031
0.0011
0.0011
8.52
2.48
2.48
0.0106
0.1005
0.101
1
2
2
158.44
65.23
64.37
14.35
5.44
5.35
0.0018
0.0097
0.0103
1
2
2
0.45
0.44
0.46
3.82
3.79
3.96
0.069
0.034
0.03
1
2
2
1.41
40.053
6.33
0.094
3.37
0.48
0.76
0.048
0.62
1
2
2
0.000036
0.000022
0.000022
8.054
5.19
5.19
0.012
0.012
0.012
1
2
2
0.000026
0.000023
0.000023
4.8
4.36
4.36
0.045
0.022
0.022
1
0.00027
5.56
0.032
DISP
NUT x DISP
Pseudanabaena catenata
NUT
DISP
NUT x DISP
2
2
0.000071
0.00014
0.91
0.94
0.41
0.4
1
2
2
1014.85
728.10
730.28
7.41
5.079
5.11
0.016
0.013
0.012