Ecological Archives M080-021-A1

David M. Merritt, Christer Nilsson, and Roland Jansson. 2010. Consequences of propagule dispersal and river fragmentation for riparian plant community diversity and turnover. Ecology 80:609–626.

Appendix A. Results of repeated-measures generalized linear models and general linear models on the effects of river reach and treatment, and their interaction.

TABLE A1. Results of repeated measures generalized linear models (species richness and stem density) and general linear models on the effects of river reach (impounded, free-flowing tranquil, and free-flowing turbulent), and treatment (wind dispersed, water dispersed, or wind and water dispersed propagules), and their interaction. P contrast is the P value from contrasts comparing the pooled mean of the plots receiving water dispersed seeds to the wind dispersed treatment. χ2/df is a measure of dispersion and only applies to generalized linear models. Mean and SE of the repeated measure covariance estimates are presented. Significant effects (P ≤ 0.05) are in bold typeface.


Source of variation 

df

F

P

P contrast

χ2/df

Covariance parameter
(TIME) estimate


Stem density (m-2)

       

1.10

0.75 ± 0.02

Reach

 

2, 204

2.1

0.1

     

Treatment

2, 204

2.3

0.1

0.030

   

Reach × treatment

4, 204

1.1

0.4

     
               

Species richness

       

0.90

0.85 ± 0.02

Reach

 

2, 193

7.2

0.001

     

Treatment

2, 193

6.1

0.003

0.0006

   

Reach × treatment

4, 193

1.7

0.1

     
               

Shannon diversity (H')

       

0.99 ± 0.05

Reach

 

2, 282

15.2

<0.0001

     

Treatment

2, 282

3.5

0.03

0.009

   

Reach × treatment

4, 282

0.6

0.7

     
               

Evenness

       

0.92 ± 0.17

Reach

 

2, 208

5.7

0.004

     

Treatment

2, 208

1.0

0.4

0.15

   

Reach × treatment

4, 208

0.6

0.7

     
               

Vascular plant cover (%)

       

0.63 ± 0.03

Reach

 

2, 219

1.6

0.20

     

Treatment

2, 219

3.4

0.03

0.02

   

Reach × treatment

4, 219

1.2

0.3

     
               

Bryophyte cover (%)

       

0.72 ± 0.02

Reach

 

2, 220

1.8

0.2

     

Treatment

2, 220

1.0

0.4

0.90

   

Reach × treatment

4, 220

0.1

0.97

     
               

Jaccard similarity to control

plots

     

0.45 ± 0.04

Reach

 

2, 226

3.5

0.03

     

Treatment

2, 226

1.1

0.3

0.1

   

Reach × treatment

4, 226

1.0

0.4

     
               

Bray-Curtis similarity to control plots

   

0.57 ± 0.03

Reach

 

2, 216

7.0

0.001

     

Treatment

2, 216

0.1

0.9

0.69

   

Reach × treatment

4, 216

1.4

0.2

     
               

MacArthur and Wilson Turnover

   

0.11

0.95 ± 0.02

Reach

 

2, 187

12.60

<0.0001

     

Treatment

2, 187

1.40

0.26

     

Reach × treatment

4, 187

1.20

0.32

     
               

Baker Turnover

     

0.23

0.71 ± 0.04

Reach

 

2, 196

2.60

0.08

     

Treatment

2, 196

0.73

0.48

     

Reach × treatment

4, 196

0.08

0.99



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