Redundancy Analysis on Ant Assemblage Data

Here are the preliminary results of the first redundancy analysis (RDA) for all the sites sampled over the summer of 2012. I performed a PCA with only environmental variables and one with only species data to look for an underlying pattern — which was confirmed. Then I ran an RDA with the full set of environmental variables and species data to determine the most significant quantitative environmental variables. Here are the results of the final RDA for this set of data which includes samples from 21 sites sampled monthly over the summer.

The Summary Table:

Axes

1

2

3

4

Total variance

Eigenvalues

0.358

0.129

0.060

0.020

1.000

Species-environment correlations 

0.977

0.956

0.923

0.720

Cumulative percentage variance of species data               

35.8

48.8

54.7

56.8

Cumulative percentage variance of species-environment relation

61.8

84.1

94.4

97.9

Sum of all eigenvalues     

1.000

Sum of all canonical eigenvalues     

0.580

Marginal effects of environmental variables:

Marginal Effects

Variable Var. N Lambda1
LiC 2 0.32
BG 4 0.27
LA 6 0.21
ToC 3 0.17
SP 5 0.07

Conditional effects of environmental variables:

Conditional Effects

Variable

Var. N

Lambda A

P

F

LiC 2 0.32 0.002 25.00
LA 6 0.13 0.002 12.20
BG 4 0.07 0.002 7.90
ToC 3 0.04 0.002 4.68
SP 5 0.02 0.028 1.81
LiC 2 0.32 0.002 25.00

Ordination Plots:

Species and environmental variables:

Species and Sites: