Table 2 Mean (SD) values of environmental and macroinvertebrate variables at each study segment in each season, and the results of nested or nested repeated-measures analyses of variance (rm-ANOVA).

From: Effects of sediment replenishment on riverbed environments and macroinvertebrate assemblages downstream of a dam

Variables

Seasons

Studey segments and reaches

ANOVA

UD

DD

TR

Season

Segment

Season[Segment]

Mean

 

SD

n

Mean

 

SD

n

Mean

 

SD

n

F

P

F

P

F

P

Water temperature (°C)

March

6.3

 ± 

3.1

(8) b

7

 ± 

1.4

(8) b

6.7

 ± 

1.5

(8) b

815.2

< 0.001

2.0

0.590

0.2

3.273

August

21.7

 ± 

2

(8) a

23.6

 ± 

0.7

(8) a

21.9

 ± 

1.1

(8) a

      

DO (mg L-1)

March

12.1

 ± 

1.1

(8) a

12.2

 ± 

0.2

(8) a

12.3

 ± 

0.2

(8) a

844.7

< 0.001

0.2

3.437

0.1

3.671

August

7.8

 ± 

0.1

(8) b

7.6

 ± 

0.2

(8) b

7.8

 ± 

0.3

(8) b

      

Electrical Conductivity (mS m-1)

March

3.1

 ± 

0.4

(8) d

5.3

 ± 

0.1

(8) ab

5.7

 ± 

0.1

(8) a

131.5

< 0.001

548.0

< 0.001

3.4

0.175

August

2

 ± 

0.5

(8) e

5.4

 ± 

0.3

(8) ab

4.2

 ± 

0.2

(8) c

      

Turbidity (NTU)

March

0.9

 ± 

0.4

(8) b

0

 ± 

0

(8) c

1

 ± 

0

(8) b

40.3

< 0.001

17.3

< 0.001

0.4

3.205

August

2.1

 ± 

0.8

(8) a

1

 ± 

0

(8) b

1.5

 ± 

0.8

(8) b

      

Depth (cm) *

March

26.8

 ± 

7.8

(12) b

31.7

 ± 

6.7

(12) ab

25.2

 ± 

6.6

(12) b

7.8

0.168

11.5

0.004

6.6

0.077

August

29.5

 ± 

4.5

(12) b

36.8

 ± 

14.5

(12) a

28.9

 ± 

5.3

(12) b

      

Velocity (cm s-1)

March

58.2

 ± 

20.9

(12) a

37.5

 ± 

17.1

(12) b

57.4

 ± 

11.1

(12) ab

30.1

< 0.001

4.8

0.286

6.8

0.070

August

78.5

 ± 

22.6

(12) a

74

 ± 

21.5

(12) a

64.8

 ± 

21.5

(12) a

      

Bedload flux (mg m-1 s-1)

March

10.2

 ± 

10.6

(6) b

1.2

 ± 

1.9

(5) b

3.1

 ± 

2.6

(6) b

5.2

0.03

4.7

0.019

0.1

0.911

August

274.6

 ± 

285.5

(6) a

6.6

 ± 

3.6

(6) b

20.8

 ± 

14.5

(6) b

      

Drift

 Zooplankton (N m-3)

March

0.0

 ± 

0.1

(8) a

145.2

 ± 

197.3

(8) b

0.2

 ± 

0.5

(8) a

5.1

0.24

14.6

< 0.001

11.3

0.001

August

0.1

 ± 

0.1

(8) a

37.6

 ± 

46.0

(8) b

0.0

 ± 

0.0

(8) a

      

 Phytoplankton (N. cells mL-1)

March

77.9

 ± 

33.5

(8) a

420.6

 ± 

244.5

(8) b

23.1

 ± 

5.7

(8) a

13.5

0.01

74.6

< 0.001

8.5

0.008

August

6.3

 ± 

4.0

(8) a

1043.6

 ± 

423.3

(8) b

58.6

 ± 

59.1

(8) a

      

Substrate composition

 Sand (%)

March

7.2

 ± 

4.6

(12) a

1.5

 ± 

1.5

(12) c

6.5

 ± 

4.3

(12) ab

1.5

4.109

12.2

0.003

0.4

11.751

August

5.7

 ± 

3.8

(12) ab

2.6

 ± 

1

(12) bc

4.2

 ± 

3.1

(12) abc

      

 Gravel (%)

March

20.7

 ± 

10.9

(12) a

6

 ± 

3.5

(12) c

17.4

 ± 

6.3

(12) ab

2.8

1.852

25.3

< 0.001

1.5

4.154

August

21.5

 ± 

8.5

(12) a

9.9

 ± 

4.7

(12) bc

21.8

 ± 

7.1

(12) a

      

 Pebble (%)

March

25.7

 ± 

7.8

(12) a

15.7

 ± 

4.6

(12) c

25.7

 ± 

8.3

(12) a

1.6

3.853

12.1

0.003

4.2

0.433

August

19.6

 ± 

8.8

(12) abc

16.8

 ± 

7.2

(12) bc

23.6

 ± 

7.5

(12) ab

      

 Cobble (%)

March

32.7

 ± 

11.5

(12) cd

45.9

 ± 

9.1

(12) ab

37.2

 ± 

9.3

(12) bc

3.3

1.436

16.1

< 0.001

5.4

0.179

August

37.2

 ± 

11.1

(12) bc

48.6

 ± 

11.3

(12) a

40.1

 ± 

7.3

(12) abc

      

 Boulder (%)

March

13.6

 ± 

15.4

(12) b

30.9

 ± 

13.8

(12) a

13.1

 ± 

13.4

(12) b

1.2

4.931

8.5

0.023

3.8

0.596

August

16

 ± 

15.8

(12) ab

22.1

 ± 

15.1

(12) ab

10.3

 ± 

12.2

(12) b

      

Substrate coarseness

March

3.2

 ± 

0.4

(12) b

4

 ± 

0.3

(12) a

3.3

 ± 

0.3

(12) b

0.4

9.862

26.8

< 0.001

1.3

5.335

August

3.4

 ± 

0.4

(12) b

3.8

 ± 

0.2

(12) a

3.3

 ± 

0.3

(12) b

      

Chlorophyll a (mg m-2)

March

18.5

 ± 

9.1

(12) a

87

 ± 

87.7

(12) b

2.3

 ± 

1.4

(12) a

9.5

0.081

11.1

0.005

3.8

0.613

August

12.9

 ± 

5.2

(12) a

13.1

 ± 

8.8

(12) a

11

 ± 

7.6

(12) a

      

BCPOM (mg m-2)

March

9.3

 ± 

5.1

(12) b

9.2

 ± 

9.3

(12) b

17.2

 ± 

13.8

(12) a

27.5

< 0.001

3.9

0.550

4.0

0.535

August

5.3

 ± 

2

(12) b

2.4

 ± 

1.7

(12) b

4.7

 ± 

1.7

(12) b

      

BFPOM (mg m-2)

March

3.5

 ± 

1.6

(12) ab

3.6

 ± 

1.9

(12) ab

4.3

 ± 

3.6

(12) ab

38.9

< 0.001

1.8

3.312

2.1

2.578

August

2.4

 ± 

1.4

(12) bc

0.3

 ± 

0.2

(12) c

0.7

 ± 

0.7

(12) c

      
  1. n = total number of subsamples in each segment. The effects that were significant with corrected α are denoted in bold font. Values of a variable labeled with the same letters are not significantly different (Tukey’s multiple comparison test under one-way ANOVA design).
  2. UD upstream of dam and impoundment, DD downstream of dam, and TR in the tributary, DO dissolved O2, BCPOM benthic coarse particulate organic matter, BFPOM benthic fine POM.
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