Ecological Archives E089-078-A2

Timothy A. Nelson, Karalon Haberlin, Amorah V. Nelson, Heather Ribarich, Ruth Hotchkiss, Kathryn L. Van Alstyne, Lee Buckingham, Dejah J. Simunds, and Kerri Fredrickson. 2008. Ecological and physiological controls of species composition in green macroalgal blooms. Ecology 89:1287–1298.

Appendix B. Statistical tables.

Section I. Growth of Ulva and Ulvaria in Chambers at Different Depths

Table B1.1. ANOVA results for growth of Ulva and Ulvaria in monospecific chambers positioned at different depths.
Table B1.2. Post-hoc Tukey's HSD multiple comparisons for the nested ANOVA in Table B1.1.
Table B1.3. Multifactor blocked ANOVA results for growth of Ulva and Ulvaria in chambers at different depths when grown together.

Section II. Light Acclimation Experiments

Table B2.1. Nonlinear regression results for photosynthetic parameters of Ulva grown at the sea surface.
Table B2.2. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at the sea surface.
Table B2.3. Nonlinear regression results for photosynthetic parameters of Ulva grown at 2.5 m below the sea surface.
Table B2.4. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at 2.5 m below the sea surface.
Table B2.5. Nonlinear regression results for photosynthetic parameters of Ulva grown at 5 m below the sea surface.
Table B2.6. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at 5 m below the sea surface.
Table B2.7. Nonlinear regression results for photosynthetic parameters of Ulva grown at 7.5 m below the sea surface.
Table B2.8. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at 7.5 m below the sea surface.
Table B2.9. ANOVA results for dark respiration of Ulva and Ulvaria when acclimated to different light intensities.

Section III. Salinity effects on growth.

Table B3.1. ANOVA of salinity and species effects on growth.
Table B3.2. Post-hoc Tukey HSD test of salinity and species effects on growth.

Section IV. Nitrogen effects on growth and physiology.

Table B4.1. MANOVA tests of the effects of collection site and species on tissue C and N in Ulva and Ulvaria .
Table B4.2. MANOVA of media [N] and species effects on growth and tissue C and N in the laboratory manipulation.
Table B4.3. Post-hoc Tukey's HSD multiple comparisons test of species and media [N] effects on tissue N and CN ratio (See Table B4.2 for associated MANOVA).
Table B4.4. Homogenous subsets of supplemental N treatment concentration on growth in the second experiment based on Tukey's HSD test. (See Table B4.2 for associated MANOVA.)
Table B4.5. MANOVA of media [N] and species effects on tissue protein, chlorophyll and N uptake in Ulvaria and Ulva.

Section V. Grazing Experiments

Table B5.1. The t test data for grazer choice experiments comparing grazing rate on Ulva and Ulvaria. Both “choice” and “no-choice” experiments are described.
Table B5.2. The t test results for field grazing experiments comparing Ulva and Ulvaria growth and loss in different environments.

Section I. Growth of Ulva and Ulvaria in Chambers at Different Depths

TABLE B1.1. ANOVA results for growth of Ulva and Ulvaria in monospecific chambers positioned at different depths.

Source

Numerator df

Denominator df

F

P

DEPTH

1

35247.571

154.317

<0.001

SPECIES

1

2845.845

12.459

0.001

DEPTH × SPECIES

1

1977.105

8.656

0.005

ERROR

42

228.409

   

 

TABLE B1.2. Post-hoc Tukey's HSD multiple comparisons for the ANOVA in Table B1.1, above. 

Variable 1

Variable 2

Mean difference
(% Growth)

P

Ulva at 0 m

Ulvaria at 0 m

28.59

<0.001

Ulva at 0 m

Ulva at -2 m

68.21

<0.001

Ulva at 0 m

Ulvaria at -2 m

70.64

<0.001

Ulvaria at 0 m

Ulva at -2 m

39.63

<0.001

Ulvaria at 0 m

Ulvaria at -2 m

42.05

<0.001

Ulva at -2 m

Ulvaria at -2 m

2.42

0.977

 

TABLE B1.3. Multifactor blocked ANOVA results for growth of Ulva and Ulvaria in chambers at different depths when grown together.

Source

df

MS

F

P

Total

79

563.5

   

Chambers

39

1015

   

Depth

1

26100

73.511

<0.001

Chambers(depth)

38

355.1

   
         

Within-chambers

40

123.1

   

Species

1

199.6

1.64

0.208

Species × depth

1

109.2

0.899

0.349

Species × chambers(depth)

38

121.4

   

 

Section II. Light Acclimation Experiments

TABLE B2.1. Nonlinear regression results for photosynthetic parameters of Ulva grown at the sea surface.

Source

df

Mean Square F

F

P

Regression

3

0.661

278

<0.001

Residual

22

2.38E-03

   

R2 = 0.942

 

TABLE B2.2. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at the sea surface.

Source

df

Mean Square

F

P

Regression

3

0.332

40.4

<0.001

Residual

22

8.22E-03

   

R2 = 0.705

 

TABLE B2.3. Nonlinear regression results for photosynthetic parameters of Ulva grown at 2.5 m below the sea surface.

Source

df

Mean Square

F

P

Regression

3

0.574

175

<0.001

Residual

22

3.28E-03

   

R2 = 0.908

 

TABLE B2.4. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at 2.5 m below the sea surface.

Source

df

Mean Square

F

P

Regression

3

0.489

311

<0.001

Residual

22

1.57E-03

   

R2 = 0.946

 

TABLE B2.5. Nonlinear regression results for photosynthetic parameters of Ulva grown at 5 m below the sea surface.

Source

df

Mean Square

F

P

Regression

3

0.447

180

<0.001

Residual

22

2.48E-03

   

R2 = 0.913

 

TABLE B2.6. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at 5 m below the sea surface.

Source

df

Mean Square

F

P

Regression

3

0.314

129

<0.001

Residual

22

2.44E-03

   

R2 = 0.882

 

TABLE B2.7. Nonlinear regression results for photosynthetic parameters of Ulva grown at 7.5 m below the sea surface.

Source

df

Mean Square

F

P

Regression

3

0.513

267

<0.001

Residual

22

1.92E-03

   

R2 = 0.938

 

TABLE B2.8. Nonlinear regression results for photosynthetic parameters of Ulvaria grown at 7.5 m below the sea surface.

Source

df

Mean Square

F

P

Regression

3

0.330

183

<0.001

Residual

22

1.80E-03

   

R2 = 0.909

 

TABLE B2.9. ANOVA results for dark respiration of Ulva and Ulvaria when acclimated to different light intensities.

Source

df

Mean Square

F

P

Light Treatment

2

1.458E-03

78.022

<0.001

Species

1

3.719E-05

1.990

0.171

Interaction (Light by Species)

2

2.126E-05

1.138

0.337

Error

24

1.869E-05

   

 

Section III. Salinity effects on growth.

TABLE B3.1. ANOVA of salinity and species effects on growth.

Source

df

Mean Square

F

P

Species Effect

1

964.855

17.941

<0.001

Salinity Effect

3

422.453

7.855

<0.001

Interaction

(Species × Salinity)

3

329.691

6.130

0.002

Error

31

53.781

   

 

TABLE B3.2. Post-hoc Tukey HSD test of salinity and species effects on growth.

Variable 1

Variable 2

Mean Difference

P

Ulva at 5 PSU

Ulvaria at 5 PSU

19.80(*)

0.004

Ulva at 5 PSU

Ulva at 10 PSU

0.70

1.000

Ulva at 5 PSU

Ulvaria at 10 PSU

20.00(*)

0.003

Ulva at 5 PSU

Ulva at 20 PSU

9.60

0.455

Ulva at 5 PSU

Ulvaria at 20 PSU

5.60

0.924

Ulva at 5 PSU

Ulva at 30 PSU

-6.00

0.894

Ulva at 5 PSU

Ulvaria at 30 PSU

-1.20

1.000

Ulvaria at 5 PSU

Ulva at 10 PSU

-19.10(*)

0.010

Ulvaria at 5 PSU

Ulvaria at 10 PSU

0.20

1.000

Ulvaria at 5 PSU

Ulva at 20 PSU

-1.20

0.379

Ulvaria at 5 PSU

Ulvaria at 20 PSU

-14.20

0.076

Ulvaria at 5 PSU

Ulva at 30 PSU

-25.80(*)

<0.001

Ulvaria at 5 PSU

Ulvaria at 30 PSU

-21.00(*)

0.002

Ulva at 10 PSU

Ulvaria at 10 PSU

19.30(*)

0.009

Ulva at 10 PSU

Ulva at 20 PSU

8.90

0.619

Ulva at 10 PSU

Ulvaria at 20 PSU

4.90

0.972

Ulva at 10 PSU

Ulva at 30 PSU

-6.70

0.867

Ulva at 10 PSU

Ulvaria at 30 PSU

-1.90

1.000

Ulvaria at 10 PSU

Ulva at 20 PSU

-1.40

0.356

Ulvaria at 10 PSU

Ulvaria at 20 PSU

-14.40

0.069

Ulvaria at 10 PSU

Ulva at 30 PSU

-26.00(*)

<0.001

Ulvaria at 10 PSU

Ulvaria at 30 PSU

-21.20(*)

0.002

Ulva at 20 PSU

Ulvaria at 20 PSU

-4.00

0.987

Ulva at 20 PSU

Ulva at 30 PSU

-15.60(*)

0.038

Ulva at 20 PSU

Ulvaria at 30 PSU

-1.80

0.311

Ulvaria at 20 PSU

Ulva at 30 PSU

-11.60

0.232

Ulvaria at 20 PSU

Ulvaria at 30 PSU

-6.80

0.819

Ulva at 30 PSU

Ulvaria at 30 PSU

4.80

0.965

* The mean difference is significant at the .05 level.

 

Section IV. Nitrogen effects on growth and physiology.

TABLE B4.1. MANOVA tests of the effects of collection site and species on tissue C and N in Ulva and Ulvaria .

Source

Dependent variable

df

Mean Square

F

P

Species

Nitrogen

1

20.081

10.920

0.004

 

Carbon

1

20.495

0.438

0.516

 

N:C

1

0.001

19.526

<0.001

Site

Nitrogen

1

40.666

24.487

<0.001

 

Carbon

1

2030.734

35.811

<0.001

 

N:C

1

0.000

0.008

0.930

Species × Site

Nitrogen

1

0.005

0.028

0.869

 

Carbon

1

0.000

0.000

0.993

 

N:C

1

0.000

0.036

0.852

Error

Nitrogen

19

0.191

   
 

Carbon

19

50.689

   
 

N:C

19

0.000

   

 

TABLE B4.2. MANOVA of media [N] and species effects on growth and tissue C and N in the laboratory manipulation.

Source

Dependent variable

df

Mean Square

F

P

Species

C:N

1

63.599

189.087

<0.001

 

N

1

26.561

246.329

<0.001

 

C

1

372.329

65.245

<0.001

 

Growth

1

0.053

6.286

0.016

Media [N]

C:N

2

99.841

296.840

<0.001

 

N

2

19.024

176.435

<0.001

 

C

2

3.451

0.605

0.551

 

Growth

2

0.063

7.463

0.002

Interaction (media [N] × species)

C:N

2

1.372

4.080

0.024

 

N

2

0.976

9.049

0.001

 

C

2

1.224

0.215

0.808

 

Growth

2

0.001

0.165

0.848

Error

C:N

42

0.336

   
 

N

42

0.108

   
 

C

42

5.707

   
 

Growth

42

0.008

   

 

TABLE B4.3. Post-hoc Tukey's HSD multiple comparisons test of species and media [N] effects on tissue N and CN ratio (see Table B4.2 for associated MANOVA). 

Dependent Variable

Variable 1

Variable 2

Mean difference

P

N

Ulva grown in seawater

Ulvaria grown in seawater

-1.14605(*)

<0.001

 

Ulva grown in seawater

Ulva grown in +20 mM NH4NO3

-0.49575(*)

0.046

 

Ulva grown in seawater

Ulvaria grown in +20 mM NH4NO3

-1.75893(*)

<0.001

 

Ulva grown in seawater

Ulva grown in +80 mM NH4NO3

-1.64982(*)

<0.001

 

Ulva grown in seawater

Ulvaria grown in +80 mM NH4NO3

-3.70384(*)

<0.001

 

Ulvaria grown in seawater

Ulva grown in +20 mM NH4NO3

0.65030(*)

0.004

 

Ulvaria grown in seawater

Ulvaria grown in +20 mM NH4NO3

-0.61288(*)

0.007

 

Ulvaria grown in seawater

Ulva grown in +80 mM NH4NO3

-0.50377(*)

0.041

 

Ulvaria grown in seawater

Ulvaria grown in +80 mM NH4NO3

-2.55779(*)

<0.001

 

Ulva grown in +20 mM NH4NO3

Ulvaria grown in +20 mM NH4NO3

-1.26319(*)

<0.001

 

Ulva grown in +20 mM NH4NO3

Ulva grown in +80 mM NH4NO3

-1.15407(*)

<0.001

 

Ulva grown in +20 mM NH4NO3

Ulvaria grown in +80 mM NH4NO3

-3.20809(*)

<0.001

 

Ulvaria grown in +20 mM NH4NO3

Ulva grown in +80 mM NH4NO3

0.10911

0.985

 

Ulvaria grown in +20 mM NH4NO3

Ulvaria grown in +80 mM NH4NO3

-1.94490(*)

<0.001

 

Ulva grown in +80 mM NH4NO3

Ulvaria grown in +80 mM NH4NO3

-2.05402(*)

<0.001

C:N

Ulva grown in seawater

Ulvaria grown in seawater

2.92471(*)

<0.001

 

Ulva grown in seawater

Ulva grown in +20 mM NH4NO3

2.32368(*)

<0.001

 

Ulva grown in seawater

Ulvaria grown in +20 mM NH4NO3

4.54344(*)

<0.001

 

Ulva grown in seawater

Ulva grown in +80 mM NH4NO3

5.54264(*)

<0.001

 

Ulva grown in seawater

Ulvaria grown in +80 mM NH4NO3

7.30463(*)

<0.001

 

Ulvaria grown in seawater

Ulva grown in +20 mM NH4NO3

-0.60104

0.321

 

Ulvaria grown in seawater

Ulvaria grown in +20 mM NH4NO3

1.61873(*)

<0.001

 

Ulvaria grown in seawater

Ulva grown in +80 mM NH4NO3

2.61793(*)

<0.001

 

Ulvaria grown in seawater

Ulvaria grown in +80 mM NH4NO3

4.37992(*)

<0.001

 

Ulva grown in +20 mM NH4NO3

Ulvaria grown in +20 mM NH4NO3

2.21977(*)

<0.001

 

Ulva grown in +20 mM NH4NO3

Ulva grown in +80 mM NH4NO3

3.21897(*)

<0.001

 

Ulva grown in +20 mM NH4NO3

Ulvaria grown in +80 mM NH4NO3

4.98095(*)

<0.001

 

Ulvaria grown in +20 mM NH4NO3

Ulva grown in +80 mM NH4NO3

0.99920(*)

0.015

 

Ulvaria grown in +20 mM NH4NO3

Ulvaria grown in +80 mM NH4NO3

2.76119(*)

<0.001

 

Ulva grown in +80 mM NH4NO3

Ulvaria grown in +80 mM NH4NO3

1.76199(*)

<0.001

* The mean difference is significant at the .05 level.

 

TABLE B4.4. Homogenous subsets of supplemental N treatment concentration on growth in the second experiment based on Tukey's HSD test. (See Table B4.2 for associated MANOVA.)

Treatment

N

Subset

1

2

Seawater

16

0.3582

 

+20 mM NH4NO3

16

0.4202

0.4202

+80 mM NH4NO3

16

 

0.4840

P

 

0.150

0.135

 

TABLE B4.5. MANOVA of media [N] and species effects on tissue protein, chlorophyll and N uptake in Ulvaria and Ulva .

Source

Dependent variable

df

Mean Square

F

P

Media [N]

Protein

1

191.308

3.396

0.084

 

Chlorophyll a

1

59856.06

3.593

0.076

 

Chlorophyll b

1

35633.14

3.980

0.063

 

Chlorophylll b : a

1

0.002

0.885

0.361

Species

Protein

1

4029.145

71.524

<0.001

 

Chlorophyll a

1

1382421.9

82.984

<0.001

 

Chlorophyll b

1

870995.64

97.276

<0.001

 

Chlorophylll b : a

1

0.181

97.288

<0.001

Interaction (Media [N] × Species)

Protein

1

82.887

1.471

0.243

 

Chlorophyll a

1

18747.425

1.125

0.305

 

Chlorophyll b

1

16452.443

1.837

0.194

 

Chlorophylll b : a

1

0.000

0.234

0.635

Error

Protein

16

56.333

   
 

Chlorophyll a

16

16658.961

   
 

Chlorophyll b

16

8953.888

   
 

Chlorophylll b : a

16

0.002

   

 

Section V. Grazing Experiments

TABLE B5.1. The t test data for grazer choice experiments comparing grazing rate on Ulva and Ulvaria. Both “choice” and “no-choice” experiments are described.

Species

Choice?

Test type

N

df

t

P value

Littorina sitkana

Yes

Paired sample

23

22

7.74

<0.001

Lacuna variegata

Yes

Paired Sample

15

14

5.75

<0.001

Lacuna vincta

Yes

Paired Sample

16

15

6.27

<0.001

Strongylocentrotus droebachiensis

Yes

Paired Sample

15

14

9.82

<0.001

Idotea wosnesenskii

Yes

Paired Sample

15

14

5.64

<0.001

Lacuna vincta

No

Two Sample

11

9

0.43

0.679

Lacuna vincta, following conditioning

Yes

Two Sample

11

9

3.17

0.011

 

TABLE B5.2 The t test results for field grazing experiments comparing Ulva and Ulvaria growth and loss in different environments.

Location

Test Type

N

df

t stat

P value

Pinnacle Rock, tidepool

Two Sample

15

28

2.16

0.049

Cattle Point, tidepool

Two Sample

15

28

1.87

0.038

Pinnacle Rock, intertidal

Two Sample

10

18

2.34

0.031


[Back to E089-078]