Table 10 Results of successive steps of double constrained correspondence analysis (dc-CA)
Variation explained by explanatory variables | Eigenvalues of axes | Explained variation of axis | Monte-Carlo permutation test of the first axis | Monte-Carlo permutation test of all axes | |
|---|---|---|---|---|---|
Step 1: CCA constraining species composition by environmental variables | R2 = 14.92% | Axis 1=0.4234 | Axis 1=7.56 | F=1.9 | F=4.1 |
adjR2=11.29% | Axis 2=0.1226 | Axis 2=2.19 | p=0.002 | p=0.002 | |
Step 2: RDA explaining constrained species scores by functional traits | R2 = 48.16% | Axis 1=0.332 | Axis 1=33.2 | F=1.5 | F=2.8 |
adjR2= 30.88% | Axis 2=0.0712 | Axis 2=7.12 | p=0.004 | p=0.004 | |
Step 3: CCA constraining transposed species composition table by functional traits | R2= 28.73% | Axis 1=0.4528 | Axis 1=8.39 | F=0.3 | F=1.2 |
adjR2= 4.97% | Axis 2=0.3039 | Axis 2=5.63 | p=0.076 | p=0.034 | |
Step 4: RDA explaining constrained sample scores by environmental variables | R2= 24.86% | Axis 1=0.1669 | Axis 1=16.69 | F=4.7 | F=7.8 |
adjR2= 21.65% | Axis 2=0.0398 | Axis 2=3.99 | p=0.002 | p=0.002 | |
Step 5: CA | Axis 1=0.6939 | Axis 1=12.4 | – | – | |
Axis 2=0.5721 | Axis 2=10.21 | ||||
Step 6: calculation of dc-CA scores | R2= 6.744% | Axis 1=0.2536 | Axis 1=4.7 | – | – |
adjR2=5.781% | Axis 2=0.0605 | Axis 2=1.12 |