Ecological Archives E088-041-A8

Donna Drury McCall and Chet F. Rakocinski. 2007. Grass shrimp (Palaemonetes spp.) play a pivotal trophic role in enhancing Ruppia maritima. Ecology 88:618–624.

Appendix H (Table H1). Orthogonal contrasts for response variables showing significant overall grass-shrimp effects within the split-plot ANOVA.

Experiment

Response

Contrast

Contrast t value

df

P

           

One

Ruppia Biomass

Encl

-0.168

44

0.868

 

(equal variance)

Addn

-3.163

44

0.003

   

Dens

-0.372

44

0.711

           
 

Shoot Number

Encl

-0.197

44

0.844

 

(equal variance)

Addn

-3.033

44

0.004

   

Dens

-0.099

44

0.921

           
 

Epiphyte chl [a]

Encl

1.269

43

0.069

 

(equal variance)

Addn

3.530

43

0.001

   

Dens

 2.148

14.212

0.037

           

Two

Ruppia Biomass

Encl

 1.412

21.230

 0.172

 

(unequal variance)

Addn

-5.041

19.060

<0.001

   

Dens

-3.248

13.338

  0.006

           
 

Shoot Number

Encl

1.353

20.802

 0.191

 

(unequal variance)

Addn

-5.743

20.113

<0.001

   

Dens

-3.331

12.216

 0.006

           

Three

Ruppia Biomass

Encl

-0.395

43

0.694

 

(equal variance)

Addn

-2.186

43

0.034

   

Dens

-0.415

43

0.680

   Note: Contrast Effects: Encl = Enclosure; Addn = Shimp Addition; Dens = Shrimp Density. Equal variance = equal variance assumed; unequal variance = unequal variance assumed.



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