Ecological Archives E089-018-A5

John N. Griffin, Kate L. de la Haye, Stephen J. Hawkins, Richard C. Thompson, and Stuart R. Jenkins. 2008. Predator diversity and ecosystem functioning: density modifies the effect of resource partitioning. Ecology 89:298–305.

Appendix E. Analysis of predator diversity and density effects.

TABLE E1. Analysis of predator diversity and density effects. Two-way ANOVA of effects of crab diversity and density on overall consumption rate and targeted asymmetrical contrasts of the effect of the average monoculture vs. the polyculture for data pooled across density levels and separately for low and high density.


Source

SS

df

MS

F

P


Density

0.0328

1

0.0328

1.48

0.23

Diversity

0.2223

3

0.074

3.33

0.03

     Monocultures alone

0.0026

2

0.0013

0.08

0.92

     Average monoculture vs. polyculture

0.2198

1

0.2198

9.88

0.003

Density × diversity

0.0164

3

0.0055

0.25

0.86

Residual

0.8895

40

0.0222

 

 

 

 

 

 

 

 

Low density

 

 

 

 

 

Diversity

0.0592

3

0.0197

0.71

0.56

     Monocultures alone

0.0003

2

0.0002

0.01

0.99

     Average monoculture vs. polyculture

0.0589

1

0.0589

2.11

0.16

Residual

0.5585

20

0.0279

 

 

 

 

 

 

 

 

High density

 

 

 

 

 

Diversity

0.1796

3

0.0599

3.62

0.03

     Monocultures alone

0.0029

2

0.0014

0.12

0.88

     Average monoculture vs. polyculture

0.1767

1

0.1767

10.64

0.004

Residual

0.3311

20

0.166

 

 



[Back to E089-018]