Appendix C. Generalized linear models of mean plot-scale species richness as a function of treatment, and environmental covariables.
TABLE C1. Generalized linear models of mean plot-scale species richness as a function of treatment (plots receiving wind dispersed seeds, water dispersed seeds, and a plots receiving a combination), and environmental covariables. Principal coordinates axis (PCoA) 1 represents soil moisture and PCoA 2 represents light and exposure to fluvial disturbance. Significant effects (P ≤ 0.05) are in bold typeface.
Sources of variation |
Impounded reaches |
Free-flowing tranquil and turbulent reaches |
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|
df |
F |
P |
χ2/df |
Pcontrast |
df |
F |
P |
χ2/df |
Pcontrast |
2000 |
||||||||||
Treatment |
2, 67 |
13.8 |
<0.0001 |
0.98 |
<0.0001 |
2/127 |
4.3 |
0.02 |
0.94 |
0.004 |
PCoA 1 |
1, 67 |
5.6 |
0.02 |
1, 127 |
0.3 |
0.6 |
||||
PCoA 2 |
1, 67 |
0.5 |
0.5 |
1, 127 |
0.5 |
0.5 |
||||
2001 |
||||||||||
Treatment |
2, 67 |
6.2 |
0.003 |
0.96 |
0.0008 |
2, 127 |
0.8 |
0.4 |
0.97 |
0.2 |
PCoA 1 |
1, 67 |
6.2 |
0.02 |
1, 127 |
0.8 |
0.4 |
||||
PCoA 2 |
1, 67 |
0.8 |
0.37 |
1, 127 |
0.8 |
0.4 |
||||
2002 |
||||||||||
Treatment |
2, 67 |
2.7 |
0.07 |
0.88 |
0.03 |
2, 127 |
1.4 |
0.3 |
0.97 |
0.1 |
PCoA 1 |
1, 67 |
5.9 |
0.02 |
1, 127 |
2.8 |
0.1 |
||||
PCoA 2 |
1, 67 |
0.22 |
0.6 |
1, 127 |
1.6 |
0.2 |
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2003 |
||||||||||
Treatment |
2, 67 |
2.1 |
0.1 |
0.99 |
0.07 |
2, 127 |
0.06 |
0.9 |
0.92 |
0.96 |
PCoA 1 |
1, 67 |
4.4 |
0.04 |
1, 127 |
2.6 |
0.1 |
||||
PCoA 2 |
1, 67 |
0 |
0.97 |
1, 127 |
5.6 |
0.02 |
||||
2004 |
||||||||||
Treatment |
2, 67 |
1.7 |
0.2 |
1.1 |
0.07 |
2, 127 |
0.6 |
0.6 |
0.9 |
0.6 |
PCoA 1 |
1, 67 |
13.8 |
0.0004 |
1, 127 |
3.7 |
0.06 |
||||
PCoA 2 |
1, 67 |
1.5 |
0.2 |
|
|
1, 127 |
3.8 |
0.05 |
|
|
Notes: χ2/df is Pearson χ2 divided by degrees of freedom is a measure of dispersion; χ2/df near 1 indicates good model fit. Pcontrast is the P value from a linear contrast comparing mean species richness in the wind dispersed plots to mean richness of water and wind and water dispersed plots.