Table 3 Detailed results of dbRDA significance tests for the global dbRDA analysis (after removing non-significant terms) and the marginal test, considering 32 source populations of C. mauritiana

From: Genetic diversity and population divergences of an indigenous tree (Coffea mauritiana) in Reunion Island: role of climatic and geographical factors

 

dbRDA

Partial dbRDA

 

% of variance explained

d.f.

P-value

% of variance explained

d.f.

P-value

Global analysis

85.03

7

<0.001

   

Residuals

14.97

24

–

 

–

–

Marginal test

Geography

47.56

  

21.37

  

geo1

22.30

1

<0.001

10.54

1

<0.001

geo2

15.24

1

<0.001

7.01

1

<0.001

geo3

6.21

1

0.006

2.51

1

0.002

geo4

3.81

1

0.048

1.31

1

0.013

 Environment

23.66

  

7.20a

  

CDD

9.75

1

<0.001

4.27

1

<0.001

Tmean

6.06

1

0.008

2.43

1

0.014

PET

7.85

1

0.002

3.32

1

0.004

Residual

28.76

24

–

28.76

24

–

  1. CDD mean number of consecutive dry days, Tmean mean average daily temperature, PET average monthly potential evapotranspiration.
  2. In the dbRDA analysis, the marginal effects of each constraining factor were tested through 10,000 permutation tests, by removing each term one by one from the model containing all other terms. In partial dbRDA, the pure contribution of each factor was obtained after removing the confounding effects from the other constraining factors. geo1, geo2, geo3, geo4 are uncorrelated geographic factors
  3. aDue to remnant correlations between environmental variables, the estimated contribution of environmental factors in partial dbRDA (7.20%) does not correspond to the sum of individual contributions of each environmental factor (10.02%).
Back to article page